Table 4.

Neurons of two NN models.

	Input layer: 6 neurons, including six form elements of PDAs
NN-FE model	Hidden layer: 4 neurons, (6 + 1)/2 = 3.5 ≒ 4
	Output layer: 1 neuron for the S-C image value
	Input layer: 19 neurons, including 19 types of six form elements
NN-FT model	Hidden layer: 10 neurons, (19 + 1)/2 = 10
	Output layer: 1 neuron for the S-C image value