网络技术

In this paper, the concept of network security and security structures of OSI and Internet is introduced, and various threats confronting the computer network are also discussed. Several kinds of network information security technologies, including firewall technology, virtual private network, intrusion detection system, data encryption technology, identity authentication and security protocol etc. are also examined. The security of internal network is the biggest problem in the construction of each network. The solution to this problem lies in setting up a firewall. The theory of a firewall and the approach to its actualization is studied. Intrusion detection system, an important part of the computer network security system, has gained extensive attention. IDS monitors the computer and network traffic for intrusion and suspicious activities. It not only detects the intrusion from the extranet hacker, but also the intranet users. The emergence of virtual private network paves the way for realizing secure connection of LAN quickly and at a relatively low cost. The concept, function, key techniques, including the tunnel technology, and the ways to realize VPN are expounded in this paper. Also introduced is the data encrypt network technology, which is called the soul of computer network security, such as digital digest, digital signature, digital certificate, digital encrypt arithmetic and so on. At the same time, the principle and the process of implementing network security by digital certificate and digital signature, the basic principle and characters of security protocols, and finally, three of the security protocols, concerning the security problems in network, IPsec, SLL and SET are analyzed in detail Computer network system should be a system of dynamic defence, both dynamic and static, passive as well as active, and even offensive, combined with management and technology.

本文系统地介绍了网络安全的概念、OSI及Internet的安全体系结构，并讨论了计算机网络面临的各种安全威胁；内部网络的安全问题是每个建网单位面临的最大问题，可以认为防火墙技术是解决网络安全的一个主要手段，本文研究了防火墙的原理及其实现手段；作为一种主动的防御措施，入侵检测系统作为网络系统安全的重要组成部分，得到了广泛的重视，TDS对计算机和网络资源上的恶意使用行为进行识别和响应，不仅检测来自外部的入侵行为，也监督内部用户的未授权活动；虚拟专用网技术的出现，为实现网络间的连接提供了快速安全但又相对便宜的手段，本文较深入的探讨了实现VPN的隧道技术，并对VPN的概念、功能、实现途径、基本构成、关键技术及发展前景等问题进行了全面论述；数据加密技术是网络安全核心技术之一，本文从数据加密算法、数字摘要、数字签名及数字证书等几方面简要介绍了数据加密技术，并分析用数字证书和数字签名实现网络安全的原理和过程；对安全协议的基本原理、主要特点进行了较为深入的研究，并就网络的安全性问题剖析了三种安全协议：IPsec协议、SLL协议和SET协议。

With the development of network technology, distance learning is playing an increasingly important role in education.

随着网络技术的发展，现代远程教育已经成为教学中越来越重要的组成部分。

At the first time, the artificial neural networks method is used in geothermal heat pump system identification

2首次利用神经网络技术对地热热泵系统进行了全面的系统辨识研究

There were two kinds of vehicular wireless networks: the centralized networks and the Adhoc networks.

车载无线网络技术包括集中式模式及自组织模式。

Currently, Peer-to-Peer technology is becoming more and more widely used in the design of systems and networks.

目前，基于对等网络技术的系统正得到越来越广泛的应用。

Emphasis is laid on the establishment of a registration and information system and a classified database of credit records of food producers and sellers, which collects information on food producers' and sellers' market access, food-safety control, and consumers' complaints and reports, to ensure an effective control based on adequate information.

近年来，采用最新网络技术，对食品质量安全实施电子监管网终端查询，及时、方便、快捷、有效地辨别食品真伪，维护了消费者利益，打击了假冒伪劣行为，促进了企业诚信建设。多年来，中国食品生产种类不断增加，数量不断扩大，质量不断提高，保障了人民日益增长的消费需求，提高了人民的生活水平，促进了国民经济的发展。

A network topology in which nodes are connected to a single cable with terminators at each end.

一种网络技术，节点连接到一根电缆中，端接器连接电缆的两头。

The baggage on 19 years old of backs leaves Shanxi in relief spring to arrive the Beijing University in the dream reads, 23 years old far cross the seas and oceans to go to American cloth city of law collect new York establishs computer of university main attack, 31 years old found China's oldest search index to prop up limited company of technology of company Baidu network, knowledge changed a destiny!

19岁背上行李离开山西阳泉到梦想中的北大读书，23岁远渡重洋赴美国布法罗纽约州立大学主攻计算机，31岁创建中国最大的搜索引擎公司百度网络技术有限公司，知识改变了命运！

Our team will be the network of technical experts and child psychology experts, marketing experts, etc..

我们的团队将由网络技术专家与儿童心理学专家、市场营销专家等构成。

The highway administrative system of Kweichow Province adopts the advanced computer and network technology, to the apparatus information of monitoring station, measure the information of recording to realize the resource-sharing of information, realize that offers the convenience to connection between each area, improves working efficiency to transporting and managing the automation of various operation, reduce resources to waste, strengthen the construction of the communication of our province.

问题补充：贵州省公路管理系统采用先进的计算机和网络技术，对监测站设备信息、检测记录信息实现信息资源共享，实现对运输管理各种操作的自动化，为各个地区之间联系提供方便、提高工作效率，减少资源浪费，加强我省交通事业的建设。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。