An on-line gradient descent trainer that radnomly splits the input trainingSet into a training and validation subsets. The trainier will keep selecting a random input/target pair from the training set and applying backpropagation until cross-entropy error on the validation set does not improve after MaxEpochsWithoutImprovement. The trainer will terminate after NumEpochs even if MaxEpochsWithoutImprovement condition has not been reached.