La radio astronomie étudie les sources cosmiques au travers de leur rayonnement dans le domaine radio. Les astronomes, utilisateurs passifs du spectre électromagnétique, ont à faire face à une pollution radio de plus en plus importante. Cette thèse s’intéresse particulièrement aux interférences radio d’origine humaine (RFI), et comment les observations radio astronomiques peuvent être réalisées en bandes de fréquences non-protégées. Les approches classiques consistent à contrôler les paramètres statistiques d’une observation. Une fois détectées, les données polluées sont retirées avant post-traitement. En plus d’autres avantages techniques par rapport aux radiotélescopes paraboliques classiques, les réseaux d’antennes offrent une information spatiale lors d’une observation astronomique. La diversité spatiale entre source cosmique d’intérêt (SCOI) et RFI peut être exploitée pour développer des traitements spatiaux d’interférences. Après la formulation d’un module de données multidimensionnel, une technique de soustraction de sous espace RFI est introduite. Cette technique consiste à soustraire la contribution des RFI aux données d’une observation. La projection orthogonale a déjà été considérée auparavant. Cependant, l’orthogonalité requise entre CSOI et RFI pour retrouver une source d’intérêt non biaisée ne peut vraisemblablement pas être satisfaite. Une approche basée sur une projection oblique est introduite afin de pallier à cette condition. Les techniques de projections sont comparées aux techniques classiques de beamforming en termes de réjection de l’interférence et de récupération de la source d’intérêt. Le sous-espace RFI est inconnu de manière générale et se doit d’être estimé. Plusieurs techniques permettant cette estimation, basées sur des propriétés statistiques des RFI et sources cosmiques, sont également présentées et comparées. Les différentes techniques ont été appliquées à des données astronomiques délivrées par le radio télescope Européen LOFAR. Enfin, une implémentation d’un algorithme de traitement spatial d’interférences sur le démonstrateur EMBRACE est présenté. / Radio astronomy studies cosmic sources through their radio emissions. As passive users, astronomers have to deal with an increasingly corrupted radio spectrum. The research presented here focuses on man-made Radio Frequency Interference (RFI), and how astronomical observations can be performed in non-protected frequency bands. Traditional approaches consist in monitoring radio telescopes output data through statistical parameters. Once detected, the corrupted data is removed before further processing. Besides other technical advantages compared to single dish radio telescopes, antenna arrays provide spatial information about astronomical observations. The spatial diversity between cosmic sources-of-interest (CSOI) and RFI can be exploited to develop spatial RFI processing. After formulating a multidimensional radio astronomical data model, an interference subspace subtraction technique is introduced. This approach consists in subtracting RFI contributions from antenna array radio telescopes data. Orthogonal projection applied to astronomical observation vector spaces has already been considered by the past. The orthogonality between RFI and CSOI subspaces is required to recover the CSOI without bias. In order to avoid this latter requirement, an oblique projection approach is here proposed. The projection techniques are compared to classic beamforming techniques in term of interference rejection and CSOI recovering. Being usually unknown, the RFI subspace has to be estimated. Several techniques allowing this estimation, based on statistical properties of RFI and cosmic sources (whiteness and cyclostationarity), are also presented and compared. The different techniques have been applied to real astronomical data, provided by the European radio telescope LOFAR. A last section presents an RFI mitigation algorithm implemented on the demonstrator EMBRACE.

CRUZ, Tadeu Macryne Lima. Estratégia de monitoramento e automação em sistemas de irrigação utilizando dispositivos de comunicação em redes de sensores sem fio. 2009. 83 f. Dissertação (Mestrado em engenharia agrícola)- Universidade Federal do Ceará, Fortaleza-CE, 2009. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-06-28T19:11:40Z No. of bitstreams: 1 2009_dis_tmlcruz.pdf: 4718653 bytes, checksum: a034932d90f7e0a5ad3468c487ff63a7 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-06-30T22:50:20Z (GMT) No. of bitstreams: 1 2009_dis_tmlcruz.pdf: 4718653 bytes, checksum: a034932d90f7e0a5ad3468c487ff63a7 (MD5) / Made available in DSpace on 2016-06-30T22:50:20Z (GMT). No. of bitstreams: 1 2009_dis_tmlcruz.pdf: 4718653 bytes, checksum: a034932d90f7e0a5ad3468c487ff63a7 (MD5) Previous issue date: 2009 / The goal of this study was to develop strategies for monitoring and automated irrigation systems using FDR capacitance sensors to collect data of water content in the soil through Wireless Sensor Network (WSN). The FDR capacitance sensors were developed in the Department of Agricultural Engineering (DENA) pertain UFC. Were used 14 FDR capacitance sensors and one of them went through a calibration process in the laboratory, witch was superimposed a 100-watt bulb in the soil sample undeformed to accelerate the drying soil. At the end of the calibration we obtained an equation potential model. The WSN is formed sensors nodes can communicate with each other by radio frequency having a communication end point (base station). The WSN system consisted of 9 sensors modules and a master module connected to the PC. Each sensor module consists of the following elements: 2.4 GHz transceiver TRF of company Laipac (maximum range 150 m), memory, processor, 12-volt battery and two FDR capacitance sensors. The WSN was installed in a field of maize crop in an advanced stage of production (30 DAS). The FDR capacitance sensors were installed at two depths: 10 cm and 25 cm. The data from the sensor modules were transmitted to the master module through the 2 modules multihops. The responses of the FDR capacitance sensors were collected every day at the morning and afternoon, and the time of irrigation was determined based on the calibration equation. The responses of the FDR capacitance sensors obtained by WSN were collected before and after irrigation and the experiment lasted 15 days. We performed a validation of the field calibration relating the responses of the FDR capacitance sensors in real time with the water content by gravimetric method. The WSN enabled FDR capacitance sensors recorded the variation of water content during the events of rainfall and irrigation. The communications of sensors modules have been successful, despite the height of plants and occurrences of rainfall have impeded some transmissions. The equation obtained in laboratory underestimated the true values water content obtained by the direct method, due to the temperature that the light bulb emitted on the soil sample during the calibration process. The battery of the sensor modules was the most limiting factor and requires adjustment in the communication protocol of WSN to optimize consumption. The WSN was dynamic and accurate and may, in partnership with FDR capacitance sensors, help researchers and producers in decision-making irrigation. / O objetivo deste trabalho foi desenvolver estratégias de monitoramento e automação em sistemas de irrigação utilizando sensores capacitivos FDR para coletar dados do conteúdo de água no solo através de uma Rede de Sensores Sem Fio (RSSF). Os sensores capacitivos FDR foram desenvolvidos no Departamento de Engenharia Agrícola (DENA) da UFC. Foram utilizados neste trabalho 14 sensores capacitivos FDR e um deles passou por um processo de calibração em laboratório, onde foi sobreposta uma lâmpada de 100 watts na amostra de solo indeformada para acelerar o secamento do solo. Esta calibração derivou uma equação do tipo potencial. A RSSF utilizada é formada por módulos sensores capazes de comunicar-se entre si por rádio frequência, possuindo um ponto de comunicação final (estação base). O sistema de RSSF foi constituído de 7 módulos sensores, 2 módulos multihops e um módulo mestre conectado ao computador. Cada módulo sensor é constituído pelos seguintes elementos: transceptor TRF 2.4 GHz da Laipac (alcance máximo de 150 m), memória, processador, bateria de 12 volts e dois sensores capacitivos FDR. A RSSF foi instalada em um campo cultivado por milho em estádio avançado de produção (30 DAS). Os sensores capacitivos FDR foram instalados em duas profundidades: 10 cm e 25 cm. Os dados dos módulos sensores eram transmitidos ao módulo mestre através dos 2 módulos multihops. As respostas dos sensores capacitivos FDR foram coletadas pelos módulos sensores todos os dias, pelo período da manhã e da tarde, e o tempo de irrigação foi determinado com base na equação de calibração. As leituras foram coletadas antes e depois das irrigações e o experimento durou aproximadamente 15 dias. Foi realizada uma validação da calibração em campo relacionando as respostas dos sensores capacitivos FDR em tempo real com a umidade volumétrica pelo método padrão de estufa. A RSSF possibilitou que os sensores capacitivos FDR registrassem a variação do teor de água durante os eventos de chuva e irrigações. As comunicações dos módulos sensores foram bem sucedidas, apesar da altura das plantas e as ocorrências das chuvas terem impedido em alguns momentos as transmissões. A equação obtida em laboratório subestimou os valores de umidade volumétrica real, obtida pelo método direto, devido à temperatura que a lâmpada incidiu na amostra de solo durante o processo de calibração. A bateria dos módulos sensores foi o fator mais limitante e requer ajuste no protocolo de comunicação da RSSF par otimizar o consumo. A RSSF mostrou-se um sistema dinâmico e preciso e pode, em conjunto com os sensores capacitivos FDR, auxiliar pesquisadores e produtores na tomada de decisão de irrigação.

Radio Frequency Identification (RFID) is revolutionizing business practices across industries worldwide as means for its commercial application continue to be developed. It is surpassing barcoding as the preferred means of product identification due to its’ ability to identify goods at item-level as opposed to batch- or type identification, and with no line-of-sight requirements for item detection. Although many industries have successfully employed the technology and are reaping the rewards, RFID’s adoption in the truck tyre industry is still in its infant stage. A small number of documented cases discuss the limited roll-out and testing of RFID effectiveness in satisfying the demands and expectations associated with this specific application. This study is aimed at evaluating the viability of introducing RFID to the South African market. The market readiness is reflected in the perceptions of Continental Tyre South Africa’s (CTSA’s) customers regarding the perceived benefits of RFID. More importantly, it is revealed in how it affects customers’ buying behaviour and, by implication, the impact on CTSA’s sales. The results of the study also reveal critical aspects unique to the South African truck tyre market which could potentially be addressed through the introduction of RFID. These aspects form the basis of the conclusions and recommendations for future actions by CTSA.

Main goal of graduation theses is analysis possibilities to use logistic technologies in food company Fontea. This analysis is focused on material and informative flows in her logistic chain including analysis of key factors. These factors are important for implementation of chosen technologies. Subsequently were analyzed customer department, sales department, production department, purchasing department and shipping department. There were found several principal problems. Customer department staffs have a problem with finding actual quantity of manufactured finished goods, because up-dating of computer system is provided only once a day. Most of orders are inserted manually in computer system. Staffs are not able to find out charges of manufactured finished goods. Similar problems were discovered also in the next departments. To fix the problem were suggested implementation of Quick Response and automatic identification of barcodes and Radio Frequency Identification (RFID).

Made available in DSpace on 2015-04-09T12:28:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-12-09Bitstream added on 2015-04-09T12:47:59Z : No. of bitstreams: 1 000817267.pdf: 2036490 bytes, checksum: 2a66a1a45fbc89e11bd5d6f636e5887b (MD5) / A tecnologia de Radio Frequency Identification (RFID) tornou-se um tema importante desde 2006, quando vários autores começaram a avaliá-la. A aplicação de RFID para processos industriais tem uma abordagem estratégica, objetivando a melhoria da satisfação dos clientes e criar novas oportunidades de negócios, bem como uma abordagem operacional com foco na eficiência operacional e na flexibilidade dos processos. A tecnologia é aplicada na logística e nos demais processos da cadeia de suprimentos com o objetivo do rastreamento dos materiais, aumento de visibilidade, aumento da eficiência operacional, redução dos desvios do processo e aumento da acessibilidade do inventário. Neste cenário, a presente dissertação tem como objetivo a avaliação de projetos logísticos aplicados à indústria aeronáutica brasileira com o uso do AHP - Analytic Hierarchy Process com ratings - passando pela identificação e avaliação das características que motivam e restringem a utilização da tecnologia através de uma revisão da literatura e pesquisa de campo / Research on Radio Frequency Identification technology (RFID) has become an important issue since 2006 and several authors have begun to assess this technology. The application of RFID to industrial processes has a strategic approach, seeking to improve customer satisfaction and new business opportunities, and has an operational approach focusing on operational efficiency and flexibility of the processes. There is a great application of RFID in logistics, warehouse and supply chain processes seeking tracking materials, increase supply chain visibility, labor savings, shrinkage reduction and inventory visibility. In this scenario, this paper aims to evaluate logistics projects applied to the brazilian aircraft industry using the AHP - Analytic Hierarchy Process with ratings, in addition to the identification and evaluation of the characteristics that motivate and restrict the use of technology through a literature review and a survey

Les travaux présentés dans ce mémoire s’inscrivent dans le cadre de la détection d’évènements impulsionnels intermittents en provenance de pulsars. Ces objets astrophysiques sont des étoiles à neutrons hautement magnétisées en rotation rapide, qui émettent un faisceau radio balayant l’espace comme la lentille d’un phare. Ils sont détectables grâce à une instrumentation spécifique. Depuis quelques années, on a découvert de nouvelles catégories de ces pulsars, aux caractéristiques extrêmes, avec en particulier des impulsions individuelles plus intenses et irrégulières comparé à la moyenne. Il faut pouvoir les détecter en temps réel dans un environnement radio perturbé à cause des signaux de télécommunications. Cette étude propose des algorithmes de traitement d’interférences radio fréquence (RFI) adaptés à ce contexte. Plusieurs méthodes de traitement de RFI sont présentées et comparées. Parmi elles, deux ont été retenues et comparées au moyen de simulations Monte Carlo, avec un jeu de paramètres simulant le pulsar et un signal BPSK avec des puissances et des durées différentes. Pour la recherche de nouveaux pulsars, une méthode alternative est proposée (SIPSFAR), combinant capacité de recherche en temps réel et robustesse contre les RFI. Elle est basée sur la transformée de Fourier 2D et la transformée de Radon. Une étude comparative théorique a permis de confronter et comparer la sensibilité de cette nouvelle méthode avec celle communément utilisée par les radioastronomes. La méthode a été implantée sur un GPU GTX285 et testée sur un grand relevé du ciel effectué au radiotélescope de Nançay. Les résultats obtenus ont donné lieu à une comparaison statistique complémentaire à partir de données réelles. / The work presented in this thesis is in the context of the intermittent impulsive event detection at Nançay Observatory. The pulsars are highly magnetized neutron stars in rapid rotation, which emit a radio beam scanning the space like a lighthouse. They are detectable with a specific instrumentation. In recent years, new classes of such pulsars were discovered. These pulsars with extreme features, especially with individual pulses more intense and irregular compared to the average, must be detected in real time in a disrupted radio environment because of telecommunication signals. This study presents some radio frequency interference (RFI) mitigation algorithms adapted to this context. Several methods are presented and compared. Among them, two were selected and compared using Monte Carlo simulations with a set of parameters to simulate the pulsar and a BPSK signal with power and different durations. In the case of researching new pulsars, an alternative method is proposed (SIPSFAR), combining research capacity in real time and robustness against RFI. It is based on 2D Fourier transform and the Radon transform. A theoretical comparative study has confronted and compared the sensitivity of this new method and the commonly method used by radio astronomers. SIPSFAR was implemented on a GPU GTX285 and tested on a large survey of the sky made at Nançay radio telescope. The results have led to a further statistical comparison from the actual data.

Orientador: Barbara Stolte Bezerra / Banca: José Souza Rodrigues / Banca: André Luiz Barbosa Nunes da Cunha / Resumo: O objetivo desta pesquisa consiste em identificar e analisar as variáveis internas e/ou externas que se caracterizam como sendo fatores na adoção da tecnologia RFID no controle de estoques de materiais, especificamente nas áreas denominadas almoxarifados em usinas pertencentes ao setor sucroalcooleiro no atual cenário produtivo e econômico nacional. A escolha de usinas do setor sucroalcooleiro foi devido a relevância econômica que representou no ano de 2013, 2% do PIB nacional, montante este equivalente a US$ 43 bilhões, e tendo o valor bruto movimentado pela cadeia superior a US$ 100 bilhões. Para tanto foram empregados os métodos de revisão bibliográfica e survey. Como principais resultados foi possível observar que em um universo de 32 respondentes com cargos de liderança, 12,5% dos respondentes desconhecem a tecnologia RFID. De um total de 28 respondentes que demonstraram conhecer a tecnologia, 100% retornaram não ter a tecnologia implementada em suas operações, somente 28,6% entendem que a empresa já tenha avaliado em algum momento a possibilidade de implementação, e 60,7% acreditam que a implementação seja uma operação complexa, demonstrando que estes fatores contribuem negativamente para a adoção da tecnologia nas operações de almoxarifados em usinas. / Abstract: The objective of this research is to identify and analyze the internal and/or external variables that are characterized as being factors in the adoption of RFID technology in the control materials inventory, specifically in the areas called stockrooms in plants belonging to the sugarcane sector in the current production scenario and national economic. The choice of plants of this sector was due to the economic importance which represented in 2013, 2% of GDP, this amount equivalent to US $ 43 billion, taking the gross busy the upper chain to $ 100 billion. Therefore, we used the methods of literature review and survey. The main results we observed that in a universe of 32 respondents with leadership positions, 12.5% of respondents are unaware of the RFID technology. A total of 28 respondents who knew about the technology, 100% returned not have the technology implemented in its operations, only 28.6% believe that the company has been evaluated at some point the possibility of implementing, and 60.7% believe that implementation is a complex operation, demonstrating that these factors negatively contribute to the adoption of technology in warehouses operations in plants. / Mestre

Technologies for position sensing and identification are important to have in ubiquitous computing environments. These technologies can be used to track users, devices, and artefacts in the physical milieu, for example, locating the position of a cellular phone in av physical environment. The aim of this thesis was to survey and classify available technologies for location sensing and identification. We have made a literature study on both commercial and research-oriented systems and technologies for use in indoor and outdoor environments. We compared the characteristics of the underlying sensing technologies with respect to physical size, sensing method, cost, and accuracy. We conclude the thesis with a set of recommendations to developers and discuss the requirements on future sensing technologies and their use in mobile devices and environments.

Sintetizadores de Freqüências são circuitos que geram sinais em freqüências pré-determinadas, sendo estes sinais usados tanto na recepção como na transmissão de Rádio Freqüência. Os circuitos Sintetizadores possuem diversos blocos, dentre os quais podemos citar, osciladores controlados por tensão (VCO Voltage-Controlled Oscillator), divisores programáveis (Prescaler), comparadores de fase (DFF Detectores de Fase e Freqüência), bombas de carga (CP Charge Pump) e Filtros Passa Baixas (LPF Low Pass Filters). Em 2003 foi projetado por Angel M.G. Argüello [Ar04] um circuito Sintetizador de Freqüências com arquitetura tipo Integer-N. Este circuito, projetado para ter banda centrada em torno de 2,4 GHz e 16 canais de 4,78 MHz, foi implementado na tecnologia CMOS 0,35 µm da AMS (Austrian Micro Systems), que possui quatro níveis de metais e dois níveis de polisilício. Após testes do circuito as seguintes conclusões sobre seu funcionamento foram derivadas: o circuito funcionou qualitativamente como projetado, sintetizando 16 tons de freqüência; o ruído de fase medido ficou acima do valor desejado; a potência consumida esteve dentro dos valores previstos, porém elevada. No decorrer de 2004 foram feitas alterações no layout do circuito de Argüello com o objetivo de melhorar o ruído de fase. Estas alterações serviram como estudo preliminar para este trabalho. Dando continuidade ao desenvolvimento de Sintetizadores, em 2005 foram estudadas novas estruturas e layouts mais eficientes no tocante a ruído de fase, dando-se especial atenção às alimentações dos circuitos digitais e analógicos e ao isolamento entre os mesmos. Um novo circuito Sintetizador foi desenvolvido para aplicações em sistemas ZigBee, que operam na banda de freqüência entre 2,400 GHz a 2,485 GHz, com 16 canais de largura igual 2 à 5 MHz. Resultados de simulação sobre o circuito projetado apontaram o funcionamento adequado, com consumo de potência inferior a 32 mW para tensão de alimentação de 3,3 V. / Frequency Synthesizers are circuits that generate pre-determined frequencies, used in both radio frequency reception and transmission. The Synthesizer circuits are composed by several blocks, such as Voltage-Controlled Oscillator (VCO), Prescaler, PFD (Phase/Frequency Detector), Charge Pump (CP), and Low Pass Filters (LPF). In 2003, an Integer-N architecture Frequency Synthesizer circuit was developed by Angel M.G. Argüello [Ar04]. This circuit, designed to have a band centered around 2.4 GHz and 16 channels with a 4.78 MHz, were implemented with the 0.35 µm CMOS technology from AMS (Austrian Micro Systems), using four metal levels and two polisilicon levels. After the circuit tests, the following conclusions about its operation were derived: the designed circuit operated as expected, generating 16 tons of frequency; the phase noise stayed above of the desired value; the power consumption were within the expected values although high. During the year of 2004, several modifications in the Argüello circuit layout have been done in order to improve the phase noise. These modifications were a preliminary study to this work. Advancing in the development of Synthesizers, in 2005 new structures and more efficient layouts, in terms of noise, were studied, with special attention given to the digital and analog power supplies and their isolation. A new Synthesizer was developed for applications with the ZigBee, which operates with frequencies from 2.400 GHz to 2.485 GHz and 16 channels of 5 MHz. The simulation results pointed out the correct operation of the circuit, with power consumption lower than 32 mW for power supply of 3.3 V.

Orientador: Luiz Carlos Kretly / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-12T09:54:12Z (GMT). No. of bitstreams: 1 FonsecaJunior_PauloNazarenoLagoia.pdf: 5632530 bytes, checksum: ea9f82363483a872a3effe7dbd527b5f (MD5) Previous issue date: 2008 / Resumo: Este trabalho tem como finalidade a implementação de indutores integrados passivos baseados nas tecnologias de fabricação CMOS e BiCMOS. Os indutores são dispositivos fundamentais em aplicações de rádio freqüência e estão presentes na maioria dos circuitos de RF como amplificadores e osciladores. Os Indutores integrados passivos têm seus desempenhos degradados principalmente pelas perdas associadas ao metal e substrato. E apesar da existência de vários métodos de otimização, as foundries em geral, ainda oferecem um número reduzido de componentes, o que dificulta a escolha do melhor dispositivo para cada circuito. Sendo assim, a partir do projeto e implementação de indutores integrados o projetista é capaz de desenvolver novos dispositivos para cada aplicação. Este trabalho apresenta os resultados experimentais de indutores CMOS otimizados com a técnica de empilhamento para a redução de perdas ôhmicas e de PGS para a redução de perdas pelo substrato. Apresenta-se também indutores projetados na tecnologia BiCMOS com dupla camada de PGS; enterrada n+ e silício policristalino. / Abstract: This work aims the design and implementation of integrated passive inductors based on CMOS and BiCMOS processes. The inductors are essential devices in radio frequency applications and are used in many RF circuits such as amplifiers and oscillators. The inductors' performance is mainly limited by metal and substrate losses. Although various methods of improvement have been proposed, the foundries still offer a reduced number of components, making far more difficult to choose the best device for each circuit. In this way, from the design and implementation of integrated inductors, the designer is able to enhance and develop new devices for each application. This works presents the experimental results of inductors based on CMOS process. These inductors have been improved with two techniques; multilevel and PGS, the first one reduce the metal losses and the second to reduce the substrate losses. This work also shows inductors improved with double PGS based on BiCMOS process. The double PGS was designed with polysilicon and n+ buried layer. / Universidade Estadual de Campi / Telecomunicações e Telemática / Mestre em Engenharia Elétrica