说明：  PNN又称为概率神经网络,它最初由数学家Specht于1990年提出,后经Master[1995]等不断发展和完善,已成功地应用于机器学习、人工智能、自动控制等众多领域.概率神经网络比多层前馈网络的数学原理简单,且易于实现
(PNN is also known as the probabilistic neural network, which was first introduced by the mathematician Specht in 1990, after the Master [1995], such as the continuous development and improvement has been successfully applied to machine learning, artificial intelligence, automatic control and many other fields. Probabilistic neural network than the multi-layer feedforward network of simple math, and are easy to achieve)