基于Delphi的计算机二级上机考试系统的设计与实现

我们采用Delphi作为开发工具,开发出计算机等级考试程序设计的上机网络考试系统,此系统能够充分挖掘现有资源,不增加新的投入,它能避免少数学生由于对软盘的操作命令出错或磁盘损坏,造成学生考试成绩发生错误,对学生的身心健康造成很大的伤害.此系统投入使用后,学校将不再投资给学生买软盘,可以为学校节约很大一笔教学开支.5年内全省可节约300万元的资金,具有一定的经济与社会效应.     

传感器非线性硬件校正技术

针对传感器的非线性问题,介绍了几种非线性硬件校正方法,如正反馈校正方法和四象限乘法器校正方法等方法. 并讨论了这些方法的局限、优点及应用技巧.     

智能水温控制系统实验设计

水温控制系统采用AT-89C51单片机为核心控制器件,实现对水温在40~90℃自动控制。温度信号由数字信号传感器DS18B20采集直接送入单片机进行处理,以控制固态继电器实现水的升温或降温,其精度为0.1℃。     

Ad Hoc网络多播协议研究

通过对当前的Ad Hoc网络多播协议进行研究,文章给出了当前Ad Hoc网络多播协议的三个重要特征:以按需路由发现为主要的路由确定方式,网格多播比树形多播更加实用,以及对路由之外的其他因素考虑很少.文章对当前Ad Hoc网络多播协议中尚未很好解决的问题也进行了总结和分析,并给出了部分问题的解决对策.     

无线局域网安全性研究

分析了无线局域网安全性方面的各种隐患,并对保障无线局域网安全所采取的各种技术,从其原理、结构方面作了安全性分析,同时制定相应的多重防范措施,使无线局域网更加安全地为我们提供服务。     

Modeling TCP performance with proxy and ARQ

INTRODUCTION The convenience of wireless communications has led to increasing use of wireless networks for civilian and critical applications. With the advent of Internet technology and the increasing popularity of wireless data devices, the wireless industry is evolv- ing its core networks toward IP-based networks. It will be necessary to integrate the wireless networks and the existing wired networks into the Internet. TCP has been the predominant transport protocol used in the wired …     

现代汽车电子控制技术

随着时代的进步和现代高科技技术在现代汽车上的应用,电子控制技术在汽车上的地位日益重要,本文主要从现代汽车电子控制技术的发展历史、应用现状和未来展望三个方面进行介绍和分析,为我们更好地使用和享受现代汽车拓宽了视野。     

无线宽带网络技术:WiMAX技术综述研究

随着全球通讯领域宽带业务的蓬勃发展,出现了具有4G象征的WiMAX宽带技术。介绍了WiMAx的概念、技术特点及支持的业务类型,并对其未来发展方向及应用进行了展望。     

嵌入式网络教学终端技术及其应用

嵌入式网络教学终端是利用嵌入式系统技术,根据教学实际需要研制的新一代网络教学产品,在网络教学、多媒体教学和远程教育中具有广阔的应用前景。文章在概述嵌入式系统结构和技术的基础上,对嵌入式网络教学终端的结构、性能和接口规范及其技术应用进行了详细的论述。     

Age of Uncontrolled Information Flow

We are heading into an era of uncontrolled and uncontrollable information flow. In the past, the tools of information flow required large investments, and the persons controlling them were easily identifiable. Now, effective long-range communication with large numbers of people can be done using tools that are easily affordable to the average citizen. Moreover, it can be done in ways that make monitoring and control virtually impossible. This is not a worrisome future change that can be averted by prompt action; it is a fait accompli and there is no reversing it. However, this is not necessarily clear to those interested in monitoring and control. Unfortunately, the bulk of electronic communication is still relatively exposed to monitoring and control, and is likely to remain so for a while. The danger is that the authorities, trying to retain a grip on a situation that is irretrievably slipping away, will react to the extremes of the problem in ways that leave ordinary users' privacy unprotected. The best approach is to adapt traditional solutions rather than inventing new ones. The safeguards built into the traditional solutions may not be precisely appropriate, but they are far better than nothing.