// if the activations are not supplied, we are using standard linear-sigmoid
// functions
if (conf.activationFunctions == null) {
this.activations = new ActivationFunction[layers.length];
this.activations[0] = new LinearActivationFunction();
for (int i = 1; i < layers.length; i++) {
this.activations[i] = new SigmoidActivationFunction();
}
} else {
this.activations = conf.activationFunctions;