计算机网络黑客及网络攻防技术探析

本文首先介绍了网络黑客概念,然后介绍现有的各种网络攻击方法和防护方法,包括各种典型的攻击模式（如监听,密码破解,漏洞,扫描、恶意程序码,阻断服务和Social Engineering)和各种典型的防护模式（如数据加密,身份认证,存取控制,审计,监控和扫描）。     

Improved relevance ranking in WebGather

The amount of information on the web is growing rapidly,and search engines that rely on keyword matching usually return too many low quality matches.To improve search results,a challenging task for search engines is how to effecively calculate a relevance ranking for each web page,This paper discusses in what order a search engine should return the uRLs it has produced in response to a user‘s query,so at to show ore relevant pages first.Emphasis is given on the ranking functions adopted by WebGather that take link structure and user popularity factors into account.Experimental results are also presented to evaluate the proposed strategy.