975 resultados para Interconexão em rede (Telecomunicações)


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The scarcity of natural resources and the search for alternative energy sources promote a rapid change in the energy world. Among the renewable energy sources, solar energy is the most promising, presenting technology of greatest growth rate nowadays. Researchers around the world are seeking ways to facilitate their progress, developing technologies with higher efficiency and lower cost. As a contribution to global progress, this master thesis proposes the development of a strategy of maximum power tracking based on perturbation and observation method for photovoltaic systems. The proposed control strategy is based on active power balance of the system, with a reduced number of sensors. It also allows the PV system to act as a regulator of the power quality at the point of commom coupling (PCC), compensating the harmonic distortion and power factor of the current netw

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This work holds the purpose of presenting an auxiliary way of bone density measurement through the attenuation of electromagnetic waves. In order to do so, an arrangement of two microstrip antennas with rectangular configuration has been used, operating in a frequency of 2,49 GHz, and fed by a microstrip line on a substrate of fiberglass with permissiveness of 4.4 and height of 0,9 cm. Simulations were done with silica, bone meal, silica and gypsum blocks samples to prove the variation on the attenuation level of different combinations. Because of their good reproduction of the human beings anomaly aspects, samples of bovine bone were used. They were subjected to weighing, measurement and microwave radiation. The samples had their masses altered after mischaracterization and the process was repeated. The obtained data were inserted in a neural network and its training was proceeded with the best results gathered by correct classification on 100% of the samples. It comes to the conclusion that through only one non-ionizing wave in the 2,49 GHz zone it is possible to evaluate the attenuation level in the bone tissue, and that with the appliance of neural network fed with obtained characteristics in the experiment it is possible to classify a sample as having low or high bone density

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The control of industrial processes has become increasingly complex due to variety of factory devices, quality requirement and market competition. Such complexity requires a large amount of data to be treated by the three levels of process control: field devices, control systems and management softwares. To use data effectively in each one of these levels is extremely important to industry. Many of today s industrial computer systems consist of distributed software systems written in a wide variety of programming languages and developed for specific platforms, so, even more companies apply a significant investment to maintain or even re-write their systems for different platforms. Furthermore, it is rare that a software system works in complete isolation. In industrial automation is common that, software had to interact with other systems on different machines and even written in different languages. Thus, interoperability is not just a long-term challenge, but also a current context requirement of industrial software production. This work aims to propose a middleware solution for communication over web service and presents an user case applying the solution developed to an integrated system for industrial data capture , allowing such data to be available simplified and platformindependent across the network

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Wireless sensor networks are reality nowadays. The growing necessity of connectivity between existing industrial plant equipments pushes the research and development of several technologies. The IEEE 802.15.4 LR-WPAN comes as a low-cost and powersaving viable solution, which are important concerns while making decisions on remote sensoring projects. This study intends to propose a wireless communication system which makes possible the monitoring of analogic and/or digital variables (i. e., the pressure studied) involved on the artificial methods for oil and gas lifting. The main issues are: To develop a software based on SMAC Standard in order to create a wireless network to monitoring analogic and/or digital variables; To evaluate the communication link based on the number of lost packets tested in different environments (indoor and outdoor) and To propose an instrumentation system consisting of wireless devices

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This work considers the development of a filtering system composed of an intelligent algorithm, that separates information and noise coming from sensors interconnected by Foundation Fieldbus (FF) network. The algorithm implementation will be made through FF standard function blocks, with on-line training through OPC (OLE for Process Control), and embedded technology in a DSP (Digital Signal Processor) that interacts with the fieldbus devices. The technique ICA (Independent Component Analysis), that explores the possibility of separating mixed signals based on the fact that they are statistically independent, was chosen to this Blind Source Separation (BSS) process. The algorithm and its implementations will be Presented, as well as the results

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Oil spill on the sea, accidental or not, generates enormous negative consequences for the affected area. The damages are ambient and economic, mainly with the proximity of these spots of preservation areas and/or coastal zones. The development of automatic techniques for identification of oil spots on the sea surface, captured through Radar images, assist in a complete monitoring of the oceans and seas. However spots of different origins can be visualized in this type of imaging, which is a very difficult task. The system proposed in this work, based on techniques of digital image processing and artificial neural network, has the objective to identify the analyzed spot and to discern between oil and other generating phenomena of spot. Tests in functional blocks that compose the proposed system allow the implementation of different algorithms, as well as its detailed and prompt analysis. The algorithms of digital image processing (speckle filtering and gradient), as well as classifier algorithms (Multilayer Perceptron, Radial Basis Function, Support Vector Machine and Committe Machine) are presented and commented.The final performance of the system, with different kind of classifiers, is presented by ROC curve. The true positive rates are considered agreed with the literature about oil slick detection through SAR images presents

Relevância:

20.00% 20.00%

Publicador:

Resumo:

There has been an increasing tendency on the use of selective image compression, since several applications make use of digital images and the loss of information in certain regions is not allowed in some cases. However, there are applications in which these images are captured and stored automatically making it impossible to the user to select the regions of interest to be compressed in a lossless manner. A possible solution for this matter would be the automatic selection of these regions, a very difficult problem to solve in general cases. Nevertheless, it is possible to use intelligent techniques to detect these regions in specific cases. This work proposes a selective color image compression method in which regions of interest, previously chosen, are compressed in a lossless manner. This method uses the wavelet transform to decorrelate the pixels of the image, competitive neural network to make a vectorial quantization, mathematical morphology, and Huffman adaptive coding. There are two options for automatic detection in addition to the manual one: a method of texture segmentation, in which the highest frequency texture is selected to be the region of interest, and a new face detection method where the region of the face will be lossless compressed. The results show that both can be successfully used with the compression method, giving the map of the region of interest as an input

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Hard metals are the composite developed in 1923 by Karl Schröter, with wide application because high hardness, wear resistance and toughness. It is compound by a brittle phase WC and a ductile phase Co. Mechanical properties of hardmetals are strongly dependent on the microstructure of the WC Co, and additionally affected by the microstructure of WC powders before sintering. An important feature is that the toughness and the hardness increase simultaneously with the refining of WC. Therefore, development of nanostructured WC Co hardmetal has been extensively studied. There are many methods to manufacture WC-Co hard metals, including spraying conversion process, co-precipitation, displacement reaction process, mechanochemical synthesis and high energy ball milling. High energy ball milling is a simple and efficient way of manufacturing the fine powder with nanostructure. In this process, the continuous impacts on the powders promote pronounced changes and the brittle phase is refined until nanometric scale, bring into ductile matrix, and this ductile phase is deformed, re-welded and hardened. The goal of this work was investigate the effects of highenergy milling time in the micro structural changes in the WC-Co particulate composite, particularly in the refinement of the crystallite size and lattice strain. The starting powders were WC (average particle size D50 0.87 μm) supplied by Wolfram, Berglau-u. Hutten - GMBH and Co (average particle size D50 0.93 μm) supplied by H.C.Starck. Mixing 90% WC and 10% Co in planetary ball milling at 2, 10, 20, 50, 70, 100 and 150 hours, BPR 15:1, 400 rpm. The starting powders and the milled particulate composite samples were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) to identify phases and morphology. The crystallite size and lattice strain were measured by Rietveld s method. This procedure allowed obtaining more precise information about the influence of each one in the microstructure. The results show that high energy milling is efficient manufacturing process of WC-Co composite, and the milling time have great influence in the microstructure of the final particles, crushing and dispersing the finely WC nanometric order in the Co particles

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Este estudo se propõe a analisar os mandatos das subsidiárias de empresas transnacionais (ETNs) no estrangeiro por intermédio dos mecanismos de alocação das atividades de pesquisa e desenvolvimento (P&D) entre os centros descentralizados de pesquisa. Iniciamos o trabalho com a apresentação de uma síntese das diferentes perspectivas encontradas na literatura econômica sobre a subordinação (ou condicionamentos) da autonomia administrativa e tecnológica das filiais. Tal síntese permite estabelecer uma hierarquia entre as subsidiárias e uma tipologia para evolução (retrocesso) de mandatos construída, principalmente, para as ETNs estruturadas em forma de rede corporativa. A seguir, a partir de pesquisas realizadas sobre as atividades dos laboratórios de P&D da indústria de equipamentos de telecomunicações no Brasil, procuramos mostrar que: a) a descentralização das atividades tecnológicas é um fato que não está restrito apenas aos países centrais; b) as tecnologias de informação permitiram que as subsidiárias no país se integrassem aos laboratórios centrais das ETNs, dando-lhes condições de desenvolver e participar de outras atividades tecnológicas, além das tradicionais funções de adaptação de processo e de produtos.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Este artigo trata da configuração de uma rede intelectual de dimensão internacional que uniu a América Latina e a Península Ibérica, a partir de meados do século XIX. Objetivamos analisar o papel dos intelectuais e órgãos de imprensa na formação dessa rede e discutir suas idéias e projetos, à luz do contexto político e do debate cultural. Consideramos que a ação dos intelectuais e da imprensa contribuiu para a configuração de um espaço singular de circulação de idéias e de formação de uma opinião pública ibero-americana.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

According to the studies in Applied Linguistics, this thesis is based on an interdisciplinary perspective (Critical Discourse Analysis, Sociology towards Social Change, Cultural Studies and Systemic-Functional Linguistics). The overall objective of the research was to analyze the discourses of Elementary School teachers in the state of Sergipe, by means of the discursive representations of the social actors, the processes of subjectivity and their fragmented identities in the context of standardized evaluations before the requirements of globalized pedagogical practices, based on the result-based management. The critical analysis of such discourses was motivated by the rapid pace with which the demands of innovation become part of the classroom, aiming at reaching the target in what concerns the indexes of the rankings which characterize the globalized discourse of the national education management, like Ideb (Basic Education Development Index), which makes teachers change their discourses, become silent or keep resistant. The work was initially endorsed by the theoretical lines of the Critical Discourse Analysis (FAIRCLOUGH, 2001, 2006), and poses a proposal for such purpose: the ASCD Discourse Sociological and Communicative Approach (PEDROSA, 2012, 2013). This is an interpretative-qualitative study of the Critical Discourse Analysis (FAIRCLOUGH, 2001, 2003; RAMALHO ; RESENDE, 2011) and to carry it out, semi-structured interviews were used as instruments of data generation (BAUER; GASKELL, 2011; GILL, 2011). Its corpus is composed of thirteen accounts of teachers from the Elementary school who teach Portuguese and work in the fifteen schools which were chosen to be the universe of the research at the Regional Board of Education (02) in the state of Sergipe. Such narratives are related to their impressions, expectations and actions which favor the management of results to which they have to submit themselves. The analytical overview of sociological and discursive line comes from the pan-semiotic categories (Inclusion and Exclusion) which appear in the theory of Representation of Social Actors (VAN LEEUWEN, 1997, 2008). To present the processes of subjectivity of these teachers, this work is based on the socio-analytical proposal of the classification of the subjects, which stems from the individual s work in the Gestão Relacional de Si , which comes from the Applied Sociology (towards) Social Change (BAJOIT, 2006, 2009). The discursive analyses were guided word for word, in their majority, by having the Systemic Functional Grammar as their theoretical basis, specifically by the processes of the Transitivity System postulated by Halliday, (1985); Halliday and Mathiessen, (2004); Eggins (2004); Cunha and Souza (2011). The work makes the field of Cultural Studies emerge towards the dialogue and the presentation of the fragmented identities of the teachers in the context of late modernity (GIDDENS, 2002; HALL, 2011). The thesis promoted a reflection over the teacher s condition, who is immerse in this context of knowledge construction of the present Brazilian educational system, the standardized evaluations, the indexes of development, the targets and the rankings. The considerations and outcomes of such a research dealt with the teachers emerging social practices and the need of planned initial and continuing teacher education towards the new moment which is foreseeable

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Esta investigación es un análisis del contexto actual que rodea a la publicidad brasileña, más concretamente, la publicidad discurso televisivo dirigido a los niños en Brasil. Análisis de los documentos se basa en la revisión retórica (Leach, 2004) (SODRE, 2006) A partir de la primera supuesta inadecuación de algunos de sus contenidos al público para que se comunican. También investiga las posibilidades de regulación y la educación del consumidor y el papel de los medios de comunicación en la sociedad mediante la movilización exigiendo el cumplimiento y la mejora de la legislación vigente, evitando los posibles abusos y distorsiones de las secciones generales de la ley. Hemos llevado a cabo por separado se analiza en los niños y sus conceptualizaciones y la función social, abordando también el juguete y el acto de jugar hoy y su sede histórica en un intento de crear una fundación que apoya el análisis de la relación entre la infancia y la publicidad y el consumo, basado en obras de Roger Silverstone, Kapferer, Leontiev y Walter Benjamin. También se hicieron inferencias basadas en estudios de Pablo Del Río, sobre las posibles consecuencias psicológicas del consumo de medios por los niños, sin embargo, en arvorarmos llevar a cabo investigaciones en el estudio de la recepción. Se enfrentarán, tanto en acciones a favor de la aprobación de la Ley 5.921/2001 N º Suplente sugiere que la prohibición de la publicidad infantil en todo el país, los enfoques ampliamente "integrado" y por lo tanto, favorables a la continuidad de la actividad publicitaria en el país bajo la acción de la CONAR de autorregulación, lo que demuestra sin embargo, la viabilidad de ambas propuestas. Tambien relativa a el CONAR se llevó a cabo un estudio sobre su Consejo Asesor, dando a entender su composición y características. Por último, se estudian las posibilidades y el concepto de la educación para el consumo de los medios de comunicación, a partir de la utilización de los recursos de los propios medios de comunicación, como una propuesta para un cambio de paradigma en el mercado de la publicidad en Brasil. En conclusión, vemos que a partir del análisis de la publicidad comercial de los niños atendidos por la Red Globo de Televisión, en una muestra de 170 inserciones, todavía existen graves lagunas, pero que los desequilibrios se pueden resolver con medidas relativamente sencillas que incluyan campañas de educación y la exigencia de adecuación de los pocos grandes anunciantes que violan la ley. Afortunadamente, una nueva entrega de los anunciantes mostró la responsabilidad social en sus acciones