随着互联网的蓬勃发展, Internet已成为世界上覆盖面最广、规模最大、信息 资源最丰富的计算机网络,网络应用日益普及。作为承载互联网应用的通信网,宏 观上可划分为接入网和核心网两大部分。接入网(AN: Access Network),或用户环 路,主要用来完成用户接入核心网的任务

1. Introduction This section discusses the legal protection of information and the security issues of computer data and electronic information systems and is organised into four parts: First, it focuses briefly on the basic conceptual distinction between information and data, providing a basis of understanding of the primary object of legal and technical means of protection. Second, access to Government information will be discussed

一、使用数据库的优越性 二、生成 ACCESS表 三、数据库管理系统的功用 四、查阅和编辑数据 五、排序、搜索、过滤 六、表的查询

《Excel与数据处理》课程教学资源（数据表）从Access学管理理数据库中发布的学生档案

Agenda SQL Server Overview SQL Server Architecture Storage and Access Methods Query Processing and Optimization Transaction Processing Other Topics

Carrier Sense Multiple Access(CSMA) In certain situations nodes can hear each other by listening to the channel “Carrier Sensing CSMA: Polite version of Aloha Nodes listen to the channel before they start transmission Channel idle=> Transmit Channel busy = Wait (join backlog) When do backlogged nodes transmit? When channel becomes idle backlogged nodes attempt transmission with probability q=1 Persistent protocol, q=1 Non-persistent protocol,< 1

October 22, 2001 Personal IdentityⅢ . Review soul criterion and body criterion Soul criterion: x is the same person as y iff and y have the same soul. Problems: i)There is no way to establish body-soul correlations; and no way to establish personality correlations. So soul criterion doesn't make sense of our practices of recognizing and identifying people ii)We have no special access to souls, so even in our own case we can't be sure it's the same soul \inside\ us whenever we are conscious. ii) The problem of identity is \pushed back\: what is it for person-stage x to have the same soul as person-stage y? What makes for sameness of souls? Body criterion: x is the same person as y iff x and y have the same living human body

20世纪70年代,数据库技术得到迅速发展 和推广使用。目前,流行的关系数据库系统 有:0 racle、 Sybase、 SQL Server、 Visual Foxpro、 Access等

第9章eb数据库安全性 本章内容: 一、数据库安全概述 二、Access数据库可能被下载的漏洞 三、SQL数据库安全 四、数据库的备份 五、IIS的安全性分析 六、ASP漏洞及解决方法 七、IIS、ASP的安全问题一点建议

a weakness of hashing Problem: For any hash function h, a set of keys exists that can cause the average access time of a hash table to skyrocket An adversary can pick all keys from tkeU: h(k)=i for some slot i IDEA Choose the hash function at random independently of the keys