Single Frequency Networks
Mostrando 1-9 de 9 artigos, teses e dissertações.
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1. Frequency Domain Interleaving for Dense WDM Passive Optical Network
Abstract In this work, we introduce a new concept of frequency interleaving applied to passive optical networks based in Dense Wavelength Division Multiplexing (DWDM). In order to explore colorless ONUs approach, a single and centralized optical source is used to create the interleaved wavelengths for the downstream and upstream path. In this case, frequency
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 19/06/2019
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2. ANN model of RF MEMS Lateral SPDT switches for millimeter wave applications
This paper presents Artificial Neural Network (ANN) implementation for the Radio Frequency (RF) and Mechanical modeling of lateral RF Micro Electro Mechanical System (MEMS) series micro machined Single pole double through (SPDT) switch. We propose an efficient approach based on ANN for analyzing the losses in ON and OFF state of lateral RF MEMS series switch
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2012-06
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3. Redes de redistribuição de sinais a partir de redes de freqüência única (SFN)
This dissertation presents details of a structure needed to create a Single Frequency Network (SFN) using low-power transmitters, and a comparison with a network composed of a single transmitter with high power. Among the difficulties to implement networks which distribute signals in SFN, has prioritized the synchronization issue and equalization techniques
Publicado em: 2010
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4. New proposals for optmization of digital TV receivers based on OFDM in regional single frequency network environments / Novas propostas para otimização de receptores de TV digital baseados em OFDM em ambientes de redes de frequencia unica regionais
This thesis deals with the optimization of Digital TV receivers based on OFDM, with performance evaluation in regional single frequency networks (SFN). Such environment facilitates the channel distribution, however its characteristics degrade the receiver operation. Initially, projects of loop canceller filters in relay stations are treated, and they are nec
Publicado em: 2007
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5. AnÃlise e resultados experimentais de sistemas de distribuiÃÃo quÃntica de chaves usando fÃtons isolados e estados coerentes mesoscÃpicos. / Theorical analysis and experimental results of quantum key distribution systems using single-photons and mesoscopic coherent states
In this dissertation it is realized a study about quantum key distribution (QKD) in optical networks. Initially, a review of the theory of quantum key distribution and some of its implementations with strongly attenuated coherent states, as well a review of an optical system for physical encryptation using mesoscopic coherent states are realized. Following,
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 13/09/2006
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6. ARTIFICIAL NEURAL NETWORKS ON INFERENTIAL MODELLING OF PROPERTIES OF PETROLEUM PRODUCTS / REDES NEURAIS APLICADAS NA INFERÊNCIA DE PROPRIEDADES DE DERIVADOS DE PETRÓLEO
This work investigates the use of Artificial Neural Networks (ANN) on the inferential modelling of properties of petroleum products. Inferential modelling aims to provide a good estimation of chemical properties of petroleum products (i.e: final boiling point, vapour pressure). These properties can be determined by on-line process analysers or laboratory ana
Publicado em: 1996
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7. Emergent trade-offs and selection for outbreak frequency in spatial epidemics
Nonspatial theory on pathogen evolution generally predicts selection for maximal number of secondary infections, constrained only by supposed physiological trade-offs between pathogen infectiousness and virulence. Spread of diseases in human populations can, however, exhibit large scale patterns, underlining the need for spatially explicit approaches to path
National Academy of Sciences.
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8. Enhancement of long-term potentiation in the rat dentate gyrus by post-trial stimulation of the reticular formation.
The possibility that post-trial stimulation of the mesencephalic reticular formation (m.r.f.) may modulate long-term potentiation (l.t.p.) at the perforant path to dentate granule cell synapses was studied in freely moving rats. Extracellular potentials evoked in the dentate gyrus by test pulses to the perforant path were recorded before and at various delay
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9. Dynamic imaging of coherent sources: Studying neural interactions in the human brain
Functional connectivity between cortical areas may appear as correlated time behavior of neural activity. It has been suggested that merging of separate features into a single percept (“binding”) is associated with coherent gamma band activity across the cortical areas involved. Therefore, it would be of utmost interest to image cortico-cortical coh
The National Academy of Sciences.