It follows from the plot in Figure 3a that the best validation performance of the ANN model for E′(T) occurred at the epoch 163 with the associated MSE value of 3.4304×10−6, for E′′(T) at the epoch 36 with MSE value of 7.4298×10−7 (Figure 3b) and for tan δ(T) at the epoch 274 with MSE value of 2.0137×10−7 (Figure 3c).