Design And Implementation Of Network Classroom System Based On CSCW

Computer Supported Cooperative Work (CSCW) is a new area of research merging computer science, psychology, ergonomics and sociology. Its research contents can be divided into two levels: the upper level for the study of support for cooperative team-work; the lower level for the study of the techniques related to computerized cooperation between people.In the field of education, teaching and learning are process that a team interact and cooperate. This thesis is focused on the theory and technology of CSCW applied to the networked teaching and learning environment. Related theories involved in the networked classroom, including cooperation are introduced in this thesis, including cooperation, concurrent control, tele-education, network communication and data compression. Based on above, this thesis constructs a framework for the networked classroom, and implements some upper-level applications of the network classroom with Delphi.The main work done in this thesis is as follows:1. Built the framework for the network classroom, designed its topological structure, system architecture and the upper-level modules, and implemented screen control, screen broadcast, black screen, and etc.2. Designed and implmented the lower-level network communication. The multicasting and peer to peer data transimission are implemented in order to realize the real-time information sharing in the networked classroom. To meet the requirements for dependability and real-time ability, this thesis implements the lower-level data communication for the network classroom with connection-oriented and connectionless data transfer respectively.3. Data compression. The remote control of network classroom will involve image broadcast while implementing screen broadcast and screen control, and image broadcast and system control will produce a large amount of data, which will cause distortion and delay of the image under the limited bandwidth. This thesis chooses an effective data compression and decompression package named zlib that Delphi provided, through comparation, and implements the real-time image transmission under a limited bandwidth environment. The result indicates that the distorted degree of picture is small, and that the response is fast.