Design And Implementation Of Distance Education System Based On Layer Model

With the development of education and technology, the distance education needs urgently to be improved. A new-style distance education system is designed and implemented on the .NET platform, an improved version over the conventional distance education system. New solutions are proposed for the key problems in the distance education. This thesis mainly concentrates on the following aspects:1. Research and application of DES modelA five-layer distance education model (DES model) is built, which contains performance layer, management layer, transport layer, network layer and the physical layer. Two strategies on the design of the system are proposed: the down-to-up strategy and the up-to-down strategy.2. Implementation of security control technologyA method that combines the Forms authentication with the IIS authentication filter is proposed to ensure the role-based security on the network. This is a convenient tool to control the security of the roles that lie on different levels.3. Implementation of AJAX technologyConventional Web program needs to submit the forms to exchange the web pages, which often renders the fail of the transmission of the web pages. However, the AJAX technology presented in this paper can ensure the real-time refresh of web pages.4. Implementation of synchronous play of Courseware resourcesThe SMIL programming language is introduced in the programming code to implement the synchronous play of the courseware resources. By making use of the MPEG-4 compress technique and the streaming media transport technique, the software allows the users to watch a real-time play of the video images.5. Design and implementation of the distance education system Adopting ADO.NET, XML and security control technology, a distance education system is implemented on the .NET platform. After a full analysis of the requirement and the function, we outline the design principle, topology structure and the main modules of the system.