Alternant and BCH codes over certain rings

Alternant codes over arbitrary finite commutative local rings with identity are constructed in terms of parity-check matrices. The derivation is based on the factorization of x s - 1 over the unit group of an appropriate extension of the finite ring. An efficient decoding procedure which makes use of the modified Berlekamp-Massey algorithm to correct errors and erasures is presented. Furthermore, we address the construction of BCH codes over Zm under Lee metric.

A SYSTEMIC CONCEPT OF THE GENE

The univocal correspondence between one gene and one polypeptide has been challenged by many examples of ambiguities. A rapidly expanding list of one-to-many or many-to-one correspondences includes: genomic rearrangements, alternative processing of transcripts, overlapping translation frames, RNA editing, alternative translation modes, and polyprotein cleavage.The genomic message requires interpretation through decoding by a sophisticated information retrieval system which should also carry some kind of information. The full meaning of the whole cell, as a unit, is emphasized.The gene is a combination of (one or more) nucleic acid (DNA or RNA) sequences, defined by the system (the whole cell, interacting with the environment, or the environment alone, in subcellular or pre-cellular systems), that gives origin to a product (RNA or polypeptide).

Hamming and Reed-Solomon codes over certain rings

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

A CMOS/SOI single-input PWM discriminator for low-voltage body-implanted applications

A CMOS/SOI circuit to decode Pulse-Width Modulation (PWM) signals is presented as part of a body-implanted neurostimulator for visual prosthesis. Since encoded data is the sole input to the circuit, the decoding technique is based on a novel double-integration concept and does not require low-pass filtering. Non-overlapping control phases are internally derived from the incoming pulses and a fast-settling comparator ensures good discrimination accuracy in the megahertz range. The circuit was integrated on a 2 mum single-metal thin-film CMOS/SOI fabrication process and has an effective area of 2 mm(2). Measured resolution of encoding parameter a is better than 10% at 6 MHz and V-DD = 3.3 V. Idle-mode consumption is 340 LW. Pulses of frequencies up to 15 MHz and alpha = 10% can be discriminated for 2.3 V less than or equal to V-DD less than or equal to 3.3 V. Such an excellent immunity to V-DD deviations meets a design specification with respect to inherent coupling losses on transmitting data and power by means of a transcutaneous link.

Lattice constellations and codes from quadratic number fields

We propose new classes of linear codes over integer rings of quadratic extensions of Q, the field of rational numbers. The codes are considered with respect to a Mannheim metric, which is a Manhattan metric modulo a two-dimensional (2-D) grid. In particular, codes over Gaussian integers and Eisenstein-Jacobi integers are extensively studied. Decoding algorithms are proposed for these codes when up to two coordinates of a transmitted code vector are affected by errors of arbitrary Mannheim weight. Moreover, we show that the proposed codes are maximum-distance separable (MDS), with respect to the Hamming distance. The practical interest in such Mannheim-metric codes is their use in coded modulation schemes based on quadrature amplitude modulation (QAM)-type constellations, for which neither the Hamming nor the Lee metric is appropriate.

Instalação de uma rede mesh metropolitana utilizando o padrão IEEE 802.11a e implementação do serviço Voip (Wman-Voip)

Pós-graduação em Engenharia Elétrica - FEIS

A prática dos professores em relação à leitura e à escrita com alunos que ingressam aos seis anos de idade no ensino fundamental

Pós-graduação em Educação - IBRC

Desempenho de escolares do segundo ano do ensino fundamental em provas de compreensão de leitura: elaboração de procedimento avaliativo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caminhos para uma prática inclusiva de leitura e escrita na escola

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Eficácia do programa de remediação fonológica play on em escolares com dislexia de desenvolvimento

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desempenho de escolares de 1ª a 4ª séries do ensino fundamental em Provas de Habilidades Metalingüísticas e de Leitura (PROHMELE)

Pós-graduação em Educação - FFC

Leitura: algumas reflexões sobre teoria e prática no contexto escolar

Pós-graduação em Letras - FCLAS

A matemática dos códigos de barras

Pós-graduação em Matemática em Rede Nacional - IBILCE

Análise de desempenho do Criptossistema Fuzzy Vault em aplicações reais

Pós-graduação em Ciência da Computação - IBILCE

A educação escolar e a relação entre o desenvolvimento do pensamento e a apropriação da cultura: a psicologia de A. N. Leontiev como referência nuclear de análise

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)