I. Introduction
Artificial neural networks (ANNs) have been successfully implemented on various design platforms, such as, analog, very large scale integrated circuits (VLSI), etc [1]. ANN is constructed from basic blocks called neuron, shown in Fig. 1 (a). The behavior of each neuron can be defined mathematically as and where n denotes the number of input signals, weights, and ϕ denotes the activation function on the summation. By connecting several cascaded neurons together we can form an ANN, shown in 1 (b), where each circle denotes a neuron.