【作者】 谢磊；

【导师】 付鹏斌；

【作者基本信息】 北京工业大学 ， 计算机应用技术， 2007， 硕士

【摘要】 近年来,随着计算机应用技术的迅速发展与普遍应用,以网络和多媒体技术为基础的网络教育逐渐改变着传统的教育模式。网络教育技术使得教育资源得到共享和优化,它扩大了教师的授课面,为求知者提供了丰富的获取知识的途径,极大地缓解了迅速增长的知识需求与匮乏的教学资源之间的矛盾,已经成为现代教育体系中不可缺少的重要部分。因此实现一个高效率、稳定、延时低、可交互的网络教学系统对于推动网络教育的发展具有十分重要的意义。校园网屏幕广播教学系统是一种具有视频会议特征的实时教学系统,实时性主要体现在教师机的电脑屏幕、教师视频和教师语音三种多媒体信息实时发布到学生端上。通过本系统教师能建立在线网络课堂,学生能够通过校园网络登录进入进来,使得课堂不必限制于传统意义上的物理教室范围,从而拓宽了教师的授课面。本文首先调查当前的网络教学系统的现状,阐述了网络教育系统的功能和特点,分析了现阶段网络教学系统的应用范围局限性,给出了以现阶段常见校园网络为基础的基于组播树的多媒体数据通信模型,并以此模型为基础设计实现了屏幕广播教学系统。在设计实现的过程中,综合对比了当前主流的多媒体技术,选择了目前先进、高效的解决方案对系统进行了实现。最后,本文对整个工作进行了总结,提出了系统的改进意见。更多还原

【Abstract】 During the last few years, with the rapid development of applying technology in computer science, network teaching based on network and multimedia technology is gradually changing the traditional teaching style. Network teaching technology enables sharing and optimizing of learning resources, it extends the number of students that teachers work on, it provides learners a way that helps them to obtain rich knowledge, it extremely alleviates the contradiction between rapid increasing knowledge requirement and lacking of teaching resources. Now network teaching is an important component in modern teaching hierarchy. So implementing an efficient, stable, low delaying and interactive network teaching system has a crucial important meaning.Campus network screen broadcast teaching system is a kind of video conference like system with real-time feature. Because multimedia information such as desktop screen, video and sound generated at teacher’s computer when a teacher is holding an active class sends to student’s computer in time. By using our system teacher can create network active class, students can join in the class created by their teacher via campus network, so traditional classes has no teaching location limitation any more, it extremely extends the number of taught students.In this paper we analyze functions and features of current popular teaching system at the beginning and point out their limitation. After that we propose a multimedia data transmission model based on application layer multicasting technology, and we design and implement a screen broadcast teaching system based on the transmission model. During the process of designing and implementing the system, we choose efficient solutions by comparing current common used multimedia technologies. Finally, we make a conclusion that look forward to future edition of the system.更多还原