Driven by work needs or interests, many people who are not students become educators of distance education. They can learn their interested knowledge and skills in distance education, and enrich and improve their professional level.
1 Demand promotes the formation and development of modern distance education.
Since 1980s, computer multimedia technology has been gradually applied to education. Multimedia teaching integrates images, movies, sounds and animations into teaching through modern technical means, and the whole teaching process is more vivid and vivid. The amount of information contained in a class far exceeds the teaching content completed by a teacher with one mouth, a blackboard and a piece of chalk under the traditional education mode. Greatly improved the teaching efficiency. However, due to the limitation of time, space and region, multimedia teaching cannot be widely used in social education.
The demand of social education is the direct reason for the formation and development of modern distance education. Because the traditional pyramid-shaped higher education can't meet the knowledge needs of all members of society, as early as the middle and late19th century, the embryonic form of distance education appeared, that is, teachers and students exchanged answers and submitted homework by email. With the progress of science and technology and the development of information technology, more and more people need to receive all kinds of education and training in order to get sufficient job opportunities. Lifelong education is the inevitable trend of social development, and the new upsurge of distance education formed from it has contributed to the emergence of modern distance education. Although the information society has a strong potential demand for social education, the traditional face-to-face education has the limitations of centralized location and fixed time, which in turn seriously restricts the practical needs of social education. In order to fully meet the needs of scholars in all aspects, so that he can receive the education he needs at home and work at will, modern distance education has provided him with great convenience.
On the other hand, due to geographical constraints, some excellent teachers are relatively concentrated in a few colleges and universities. How to give full play to the limited educational resources, implement complementary advantages under the current educational form, make excellent educational resources and educational methods not limited by time and space, and avoid repeated investment in education. This is also a powerful driving force for modern distance education.
In addition, the traditional education model is unified, which can not provide the most effective teaching for learners at different levels. A new generation of educational model, which takes learners as the main body, fully embodies the initiative and enthusiasm of learners, and can be used for both personalized teaching and interactive teaching, came into being.
2 the technical realization of modern distance education
The demand of society is the driving force of the development of modern distance education, and the technology that depends on it is the guarantee of modern distance education. Modern distance education is the perfect combination of advanced computer network technology and multimedia technology. According to the different technical realization methods, it can be divided into distance education based on real-time conference TV system and distance education based on Internet network mode.
In the form of video conference system, teachers and students can connect in real time through audio and video technology, and information such as on-site information, interactive discussion on electronic whiteboard, computer multimedia files and charts can be shared. For those who are used to studying in the classroom, this can make students and teachers feel that the atmosphere is strong and the teaching is practical, but it needs to invest a lot of hardware. Conference TV system consists of conference TV terminal, multipoint control device (MCU) and transmission line. According to the different means of communication and transmission, conference TV system can be divided into large-scale private line conference TV system and desktop conference TV system based on IP video and transmitted through LAN or high-speed WAN.
Because of the dedicated data communication line, the data transmission bandwidth of the dedicated video conference system can be guaranteed, thus ensuring the consistent transmission quality of video signals. Special line conference TV is usually based on H.320, and the transmission channel can choose E 1, DDN and ISDN interfaces as required, and the networking can adopt special line mode or dial-up mode. According to the actual use effect, it can only be applied to modern distance education at a transmission rate of 2M. At this time, the resolution is 352X288, and the moving image reaches 25 to 30 frames, which can ensure the continuity of the image. There is no animation feeling of delayed flicker, and the resolution of the still image can reach 704X576.
In addition, while transmitting audio and video information to each other, the dedicated video conference system can usually reserve part of the bandwidth as a data channel for transmitting multimedia digital information based on computer files. It can also be used to * * * enjoy the electronic whiteboard for all parties concerned in distance education to exchange and discuss.