Useful links for CNN:
http://wiki.fast.ai/index.php/Lesson_3_Notes#Activations
Formula calculate parameters of a CNN:
total_params = (filter_height * filter_width * input_image_channels + 1) * number_of_filters, 1 represent the bias term: https://stackoverflow.com/questions/42786717/how-to-calculate-the-number-of-parameters-for-convolutional-neural-network