Optical Codes
Mostrando 13-23 de 23 artigos, teses e dissertações.
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13. Construction of optical orthogonal codes for use in cdma fiber-optics systems / Propostas de codigos ortogonais para sistemas OCDMA
This thesis presents a study of optical orthogonal codes (OOe) for application in communication systems using the technique of fiber-optics code division multiple access (OCDMA). The Prime Sequence codes and Quadratic codes are, for the first time in literature, characterized as Slepian group codes (spherical codes) and Quadratic Residues codes, respectively
Publicado em: 2005
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14. Alguns resultados em teoria de partições e teoria de codigos
This thesis consists of the publications done by the candidate. In these publications we have used many combinatorial to01s inc1uding: generating functions, q-calculus, various properties of sequences of integer numbers etc. were used in the theory of partitions and the coding theory. The thesis consists of six papers: three of them take into consideration c
Publicado em: 2004
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15. Analise experimental das aplicações de codigos corretores de erro em sistemas de comunicações opticas
This work presents an experimental analysis on the use of error correcting codes in optical communication systems, specifically by means of the Forward Error Correction (FEC) technique. Two electronic modules were designed and assembled during the experimental stages of the work - a coding and decoding module, which uses the Reed-Solomon RS (255,241) code, a
Publicado em: 2003
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16. Otimização de Tráfego: Roteamento e Critérios de Proteção em Redes Ópticas
Nowadays, many researchers of optical networks concentrate their studies on how to achieve the implementation of all links in the network, by using only the optical domain. This concept allows the transmission, switching and reception of all optical signals without eletronic conversion, and at the same time, increases the transmission speeds and the correspo
Publicado em: 2002
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17. Estudos de sequencias unipolares com aplicações em sistemas CDMA opticos
This work concerns optical fiber or infrared networks using code-division multiple access techniques. A theoretical basis for the behavior of the unipolar CDMA systems under strictly positive interference and binary signaling is developed, and their consequences are predicted. In addition, unipolar sequence properties and construction are studied, and the pe
Publicado em: 2001
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18. Codigos restritos para se reduzir o numero de fotons por bit em transmissão optica : Rony Mark da Silva
The present work aims at the study of line codes for Optical Transmission leading to an economy in the number of photons per bit required by this kind of communication. The codes chosen are those with (d,k) and RLL (Runlength-limited) constraints. A Photonic Efficiency Gain is generically defined, which takes place when a line coding is used. Next, the mathe
Publicado em: 1999
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19. Uma contribuição a minimização de jitter acustico em sistemas solitonicos
As the transmission rates of fiber optic systems increase, effects arising from fiber nonlinearities need to be taken into account in analises and simulations. For high rate systems (10-20 Gbps per channel) with large spacings between amplifiers, high intensity optical pulses, capable of exciting the nonlinearities, are required so that adequate signal to no
Publicado em: 1999
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20. Software para a geração de codigos RLL empregando o algoritmo dos blocos deslizantes
Sliding Block algorithm was developed in a branch of mathematics known as Symbolic Dynamics and it consists of a systematic and efficient procedure to fineI codes with desirable characteristics. This work will present a complete discussion of this algorithm, without emphasis on the rigorous mathematical details that are inherent in it. The techniques that co
Publicado em: 1994
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21. Codigos de linha para sistemas opticos de alta capacidade
Alternative coding techniques for high speed optical transmission systems, in wich the use of extensive tables in memory is a problem, have been discussed in recent literature. Two solutions for this problem are discussed in this work. The first is a modified version of the PFmB(m+ 1)B codes, with higher performance and no added complexity. The second coding
Publicado em: 1994
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22. Synthesis, bacterial expression, and mutagenesis of the gene coding for mammalian cytochrome b5.
We have totally synthesized a gene that codes for rat hepatic cytochrome b5. The 5' flanking region was designed for efficient expression of this gene in Escherichia coli by incorporating an optimum ribosome binding site and spacer region. Both a soluble form, analogous to the protease-treated microsomal protein, as well as the complete cytochrome with hydro
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23. Optical Imaging of Postsynaptic Odor Representation in the Glomerular Layer of the Mouse Olfactory Bulb
Olfactory glomeruli are the loci where the first odor-representation map emerges. The glomerular layer comprises exquisite local synaptic circuits for the processing of olfactory coding patterns immediately after their emergence. To understand how an odor map is transferred from afferent terminals to postsynaptic dendrites, it is essential to directly monito
American Physiological Society.