1. Introduction

Since the emergence of the first digital computer, people are set free from heavy computing works. Computers can process a large amount of data with high precision and speed. However, compared to the brain, the computer still cannot approach a comparable performance considering cognitive functions such as perception, recognition and memory. For example, it is easy for human to recognize the face of a person, read papers and communicate with others, but hard for computers. Mechanisms that utilized by the brain for such powerful cognitive functions still remain unclear. Neural networks are developed for providing a brain-like information processing and cognitive computing. Theoretical analysis on neural networks could offer a key approach to revealing the secret of the brain. The subsequent sections provide detailed background information, as well as the objectives of this book.