Multilayer Structures
Mostrando 13-24 de 30 artigos, teses e dissertações.
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13. Geomagnetic DST index forecast using artificial neural networks and decision tree / Previsão do índice geomagnético dst utilizando redes neurais artificiais e árvore de decisão
The Earth suffers constant influence of the solar activity through the solar wind, which brings with it the resulting structures, mainly phenomena like solar flares and coronal mass ejection. The almost static interaction between the solar wind and the geomagnetic field forms a structure called magnetosphere, which acts as a shield that protects the planet f
Publicado em: 2009
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14. Production and characterization of chitosan and alginate multilayer membranes containing copper / Obtenção e caracterização de membranas multicamadas de quitosana e alginato contendo cobre
Study of membranes has attracted much interest in recent years due to their applicability in areas such as medicine, microelectronics, water treatment, etc. rather than in traditional separation processes. As the application range arises, the need for establishing more elaborated structures also increases. In this context, the present study adapts the layer-
Publicado em: 2009
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15. Filtros acústicos em cristais fonônicos
In this work, we have studied the acoustic phonon wave propagation within the periodic and quasiperiodic superlattices of Fibonacci type. These structures are formed by phononic crystals, whose periodicity allows the raise of regions known as stop bands, which prevent the phonon propagation throughout the structure for specific frequency values. This p
Publicado em: 2009
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16. Modeling of nano-structures for applications in generation - Plasmon Surface Polariton (SPP) / Modelagem de nano-estruturas para aplicações na geração de Plásmon-Poláritons de Superfície (SPP)
O incessante aumento do volume de informações produzido por uma sociedade cada vez mais informatizada tem elevado drasticamente os requisitos quanto ao desenvolvimento de dispositivos capazes de suportar velocidades de operação cada vez mais elevadas em tamanhos cada vez mais reduzidos. No entanto, a contínua redução do tamanho desses dispositivos, ce
Publicado em: 2009
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17. PROJETO, OTIMIZAÇÃO, SIMULAÇÃO E PREDIÇÃO DE PROPRIEDADES DE NANOESTRUTURAS ATRAVÉS DE TÉCNICAS DA INTELIGÊNCIA COMPUTACIONAL: NANOTECNOLOGIA COMPUTACIONAL INTELIGENTE / DESIGN, OPTIMIZATION, SIMULATION AND PREDICTION OF NANOSTRUCTURES PROPERTIES BY COMPUTATIONAL INTELLIGENCE TECHNIQUES: INTELLIGENT COMPUTATIONAL NANOTECHNOLOGY
This thesis investigates the Intelligent Computational Nanotechnology, that is, the support of Computational Intelligence (CI) techniques in the challenges faced by the Nanoscience and Nanotechnology. For example, Neural Networks are used for build Inference systems able to relate a set of input parameters with the final characteristics of the nanostructures
Publicado em: 2009
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18. Multilayer radar absorbing material processing by using polymeric nonwoven and conducting polymer
This study shows the processing of radar absorbing multilayer structures based on nonwoven substrates of polyacrylonitrile and poly (ethylene terephthalate) impregnated with a polyaniline and polyurethane mixture. Processed materials with different parameters - layer stacking and impregnated faces - were evaluated considering the incident radiation attenuati
Materials Research. Publicado em: 2008-09
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19. Análise neurocomputacional de Antenas de microfita multibanda para sistemas de comunicação sem fio
This work presents a study of implementation procedures for multiband microstrip patch antennas characterization, using on wireless communication systems. An artificial neural network multilayer perceptron is used to locate the bands of operational frequencies of the antenna for different geometrics configurations. The antenna is projected, simulated and tes
Publicado em: 2007
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20. Cristalização do germanio amorfo pelo aluminio : caracterização por espectroscopia Raman / Aluminium induced crystallization of the amorphous germanium : characterization for Raman spectroscopy
This research work studies the microscopic mechanisms leading to the low-temperature crystallization of amorphous germanium (a-Ge) films induced by aluminum. The crystallization process was studied in Al-doped samples and also in multi-layer structures possessing an Al layer sandwiched between the substrate and the a-Ge film. In the case of Al-doped samples,
Publicado em: 2007
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21. Bootstrap agregating : an investigation of performance in statistics and neural networks classifiers, numerical evaluation and application on breast cancer diagnostic support. / Agregação via bootstrap: uma investigação de desempenho em classificadores estatísticos e redes neurais, avaliação numérica e aplicação no suporte ao diagnóstico de câncer de mama .
In pattern recognition, the medical diagnosis has received great attention. In gene-ral, the emphasis has been to identify one best model for diagnostic forecast, measured according to generalization ability. In this context, ensembles methods have been eficients, can be considered on the improvement of performance in diagnostic tasks that demand greater pre
Publicado em: 2007
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22. EVOLUTIONARY SYNTHESIS IN NANOTECHNOLOGY / SÍNTESE EVOLUCIONÁRIA EM NANOTECNOLOGIA
The first Nanotechnology concepts were introduced by the American physicist Richard Feynman in 1959, in his famous lecture entitled There´s plenty of room at the bottom. Computational Intelligence has been successfully used in various areas in the academic and industrial worlds. This work investigates the potential of Genetic Algorithms in the optimization
Publicado em: 2006
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23. Aplicação do método LTT às estruturas retangulares e triangulares em multicamadas e empilhadas em substratos PBG para comunicações móveis
Recently the planar antennas have been studied due to their characteristics as well as the advantages that they offers when compared with another types of antennas. In the mobile communications area, the need for this kind of antennas have became each time bigger due to the intense increase of the mobile communications that needs of antennas which operate in
Publicado em: 2005
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24. Análise do espalhamento espectral em superfícies de estruturas complexas para comunicações móveis
In this work, the transmission line method is explored on the study of the propagation phenomenon in nonhomogeneous walls with finite thickness. It is evaluated the efficiency and applicability of the method, considering materials like gypsum, wood and brick, found in the composition of the structures of walls in question. The results obtained in this work a
Publicado em: 2005