“…However, many applications of NNs are intended to model continuous response variables, and in this case a sigmoidal (s-shaped) transfer function is more useful. The transfer function illustrated in Figure 13.5 and Equation 13.9 is a bipolar sigmoidal function, with the bipolar meaning that Step 2 in the excitation of a network of nerve cells. Individual neurons are assembled in a configuration such as that illustrated in Figure 13.6, in which there are two process inputs, x 1 and x 2 , and one process response, y.…”