Diss. no. 17094 sc. SFIT Zurich. / Im Buchh.: Zürich : Institut für Geodäsie und Photogrammetrie an der Eidgenössischen Technischen Hochschule Zürich. Literaturverz.

Chemnitz, Techn. Universiẗat, Habil.-Schr., 2005.

Orientador: Carlos Alberto dos Reis Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-21T12:27:23Z (GMT). No. of bitstreams: 1 Costa_AnaRavenaAlcantarada_M.pdf: 13775256 bytes, checksum: 0f5706077253c10b6bc23af8bef74253 (MD5) Previous issue date: 2012 / Resumo: O plantio e a colheita da cana-de-açúcar são atividades da agroindústria brasileira que ainda possuem uma série de desafios tecnológicos. Dentre esses desafios destaca se a busca de uma solução adequada para a redução das perdas associadas à separação da cana da palha durante a colheita. O trabalho que foi desenvolvido buscou solucionar este particular problema, avaliando a adequação de um sistema de placas condutoras paralelas ao monitoramento contínuo do fluxo da mistura entre elas. Considerando que a cana-de-açúcar possui alto teor de umidade, foram realizadas simulações com o software COMSOL para avaliar o impacto da adição de um material com constante dielétrica próxima à da água com diferentes orientações em um meio formado predominantemente por ar. Um circuito com excitação DC foi projetado e os resultados da medição comparados com os de um circuito AC. Os valores obtidos com cana e palha recém-colhidas mostraram que a palha seca não altera significativamente a capacitância medida, mas a palha verde e a cana influenciam de forma determinante. Apesar da interferência alta, que chegou ao patamar de 50 mV, a presença dos toletes de cana foi detectável dependendo da sua orientação e distribuição no interior do sistema de placas. A variação de capacitância encontrada para um único tolete com comprimento de 86 cm na direção longitudinal ao campo chegou a 61fF. Por outro lado, os testes e simulações também mostraram que a distribuição de material na direção do campo elétrico aplicado influencia de maneira mais importante que a diferença entre as constantes elétricas do meio e do material adicionado / Abstract: Plantation and harvesting of sugar cane are agricultural activities in Brazil that still have a number of technological challenges. Among them the search for a suitable solution to reduce losses in the separation of cane and dry or fresh leaves during harvesting shows up. The developed work searched for a solution to this specific problem and evaluated a system of parallel conducting plates to continuous monitoring the flux between them of a mixture of sugar cane and vegetable impurities. Considering a high moisture content for sugar cane, simulations with COMSOL software were conducted to evaluate the impacts of a material with a dielectric constant near to that of water in different orientations and distributions in a medium formed mainly by air. A circuit with DC excitation was developed and the measuring results were compared to those of an AC circuit. The values with cane and fresh leaves showed that when dried leaves are present capacitance variations are negligible, but cane and green leaves are determinants. Despite of strong interferences, which reached voltage oscillations up to 50mV the presence of cane billets was detectable depending on its orientation and distribution within the sensor arrangement. Capacitance variations due to a single cane billet with 86cm in length on a longitudinal orientation to the field reached 61fF. On the other hand, tests and simulations showed that material distribution in the direction of the electric field influences in a stronger way than the difference between dielectric constants of the medium and the added material / Mestrado / Eletrônica, Microeletrônica e Optoeletrônica / Mestra em Engenharia Elétrica

Techn. Univ., Diss.--Hamburg-Harburg, 1999. / Nebent.: Optoelektronische Sensoren in CMOS-ICs. Literaturverz. S. 146 - 152.

Tübingen, Univ., Diss., 2004.

München, Univ. der Bundeswehr, Diss., 2002. / Computerdatei im Fernzugriff.

München, Univ. der Bundeswehr, Diss., 2002. / Computerdatei im Fernzugriff.

München, Universiẗat der Bundeswehr, Diss., 2002.

The need to determine ones position is common and emerges in many different situations. Tracking soldiers or a robot moving in a building or aiding a tourist exploring a new city, all share the questions ”where is the unit?“ and ”where is the unit going?“. This is known as the localization problem.Particularly, the problem of determining ones position in a map while building the map at the same time, commonly known as the simultaneous localization and mapping problem (slam), has been widely studied. It has been performed in cities using different land bound vehicles, in rural environments using au- tonomous aerial vehicles and underwater for coral reef exploration. In this thesis it is studied how radar signals can be used to both position a naval surface ves- sel but also to simultaneously construct a map of the surrounding archipelago. The experimental data used was collected using a high speed naval patrol boat and covers roughly 32 km. A very accurate map was created using nothing but consecutive radar images.A second contribution covers an entirely different problem but it has a solution that is very similar to the first one. Underwater sensors sensitive to magnetic field disturbances can be used to track ships. In this thesis, the sensor positions them- selves are considered unknown and are estimated by tracking a friendly surface vessel with a known magnetic signature. Since each sensor can track the vessel, the sensor positions can be determined by relating them to the vessel trajectory. Simulations show that if the vessel is equipped with a global navigation satellite system, the sensor positions can be determined accurately.There is a desire to localize firefighters while they are searching through a burn- ing building. Knowing where they are would make their work more efficient and significantly safer. In this thesis a positioning system based on foot mounted in- ertial measurement units has been studied. When such a sensor is foot mounted, the available information increases dramatically since the foot stances can be de- tected and incorporated in the position estimate. The focus in this work has therefore been on the problem of stand still detection and a probabilistic frame- work for this has been developed. This system has been extensively investigated to determine its applicability during different movements and boot types. All in all, the stand still detection system works well but problems emerge when a very rigid boot is used or when the subject is crawling. The stand still detection frame- work was then included in a positioning framework that uses the detected stand stills to introduce zero velocity updates. The system was evaluated using local- ization experiments for which there was very accurate ground truth. It showed that the system provides good position estimates but that the estimated heading can be wrong, especially after quick sharp turns.

This thesis work is done for the department of Electronic System at The Institute of Technology at Linköping University (Linköpings Tekniska Högskolan). Study's focus is to design and implement a protocol for smart dust networks to improve the energy consumption algorithm for this kind of network. Smart dust networks are in category of distributed sensor networks and power consumption is one of the key concerns for this type of network. This work shows that by focusing on improving the algorithmic behavior of power consumption in every network element (so called as mote), we can save a considerable amount of power for the whole network. Suggested algorithm is examined using Erlang for one mote object and the whole idea has put into test for a small network using SystemC.