Biometric Authentication: A Machine Learning Approach

5.3. Multi-Layer Neural Networks

Multi-layer networks are one of the most popular neural-network models. In a multi-layer network, the basis function of each neuron can be a linear basis function (LBF) with the activation function being either the step function or the sigmoidal function. Alternatively, RBF-type neurons can be adopted, which results in the RBF/EBF neural networks.

Multi-layer networks are typically trained by supervised learning, meaning that teacher information is used to train the network parameters. Depending on the nature of the teacher's information, there can be two approaches to supervised learning: One is based on the correctness of the decision and the other is based on the optimization of a training cost criterion. Of ...