0引言计算机网络因广域分布性、开放性及动态性的特点,使得其非常容易受到来自各方面的入侵攻击威胁。近年来,国内外许多学者纷纷围绕着提升网络的安全性、可靠性,开展了大量的系统而深入的研究工作。其中,基于人工神经网络的入侵检测模型,就是当前网络安全领域中研究的热点课题,它对于有效预防网络入侵事件的发生,以及保障网络系统的安全都具有着非常重要的意义。目前,基于人工神经网络的入侵检测系统,通常采用的是 0 Introduction Computer network due to the wide area distribution, openness and dynamic characteristics, making it very vulnerable to invaders from all aspects of the threat of intrusion. In recent years, many scholars at home and abroad have carried out a large number of systematic and in-depth research around the issue of improving the security and reliability of the network. Among them, the intrusion detection model based on artificial neural network is the hot topic in the field of network security. It is very important for effectively preventing the occurrence of network intrusion and ensuring the security of network system. At present, based on artificial neural network intrusion detection system, is usually used