“…Nowadays, the artificial neural networks have widely been applied in variety of fields, such as biology, mechanical engineering, electrical and computer engineering, computer science, and physics, etc. 1,3,5,17 The application problems have been occasionally converted into the problems of utilizing an underlying artificial neural network as an approximation function. 14,15,4,3,8,16,10 Although the approximation ability of artificial neural networks has been sufficiently discussed in some earlier articles, 3,8,16,10 the works of related quantitative analysis is recently gave rise to the strong attention of the people, especially on the topic of relationship between the converge rate of approximation and the structural topology of hidden layer.…”