2014-08-222014-08-221999FERREIRA, Alexandre Beltrão. Detecção de refletores sísmicos por rede neural discreta. 1999. 93 f. Dissertação (Mestrado) - Universidade Federal do Pará, Centro de Geociências, Belém, 1999. Curso de Pós-Graduação em Geofísica.https://repositorio.ufpa.br/handle/2011/5470The artificial neural networks have proven to be a powerful technique in solving a wide variety of optimization problems. In this work, we develop a new recurrent network, with no self-feedback loops, and no hidden neurons, for seismic signal processing, where this neural network gives the true polarity, reflectors location and magnitude estimations. The main characteristic of this neural network is the use of a type of activation function which permits three possible states of neurons, to estimate the position of the seismic reflectors in such way to reproduce its true polarities. The basic idea of this new neural network type, denominated here by discrete neural network (DNN), is to relate a cost function, that describes the geophysical problem, with the Liapunov function, that describes the neural network dynamics. In this way, the dynamics of the network leads to a local minimization of the Liapunov function, and will consequently lead to a minimization of the cost function. Thus, with a convenient output signal codification of the neural network a geophysical problem solution is obtained. The operational evaluation of this neural network architecture is performed with synthetic data obtained through the simple convolutional model and seismic ray theory, and its behavior explained with additive noise in the data with minimum, maximum and mixed phase time source pulses.porAcesso AbertoMétodo de reflexão sísmicaProcessamento de dadosRedes neurais (Computação)DissertaçãoCNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOFISICA::GEOFISICA APLICADA