【作者】 陈怡；

【导师】 耿国华；

【作者基本信息】 西北大学 ， 计算机应用技术， 2006， 硕士

【摘要】 现代远程教育是以计算机网络及卫星数字通讯技术为支撑,具有时空自由、资源共享、系统开放和便于协作等优点。以互联网为主要手段的现代远程教育的普及已成为一种不可阻挡的发展趋势。如何将传统的教学活动移植到网络平台上,利用现代信息技术手段实现人们终生教育的理想,成为亟待解决而又意义重大的实际问题。 为了实现构建扩展性、易用性和可靠性更强的远程教育平台,结合网上作业/考试/练习工具平台的需求,本文主要研究工作如下: 1) J2EE组件技术和设计模式的研究与应用 使用J2EE架构实现的系统具有较高的重用能力。结合在网上作业/考试/练习工具平台开发中的实际应用,分析研究了J2EE组件技术以及J2EE模式中的部分设计模式。 2) 基于J2EE多层架构的网上作业/考试/练习工具平台应用框架的设计 根据网上作业/考试/练习工具平台的具体应用,结合多种J2EE模式,提出了基于J2EE多层架构的系统框架,使用UML序列图对该框架进行了详细描述。 3) 基于Ajax的Web设计与实现 使用Ajax技术实现与服务器的异步通讯,提出基于Ajax的MVC架构设计方案。结合应用框架,通过实例给出方案的实现过程,最终在网页中实现丰富友好的用户界面,带给用户无刷新的视觉体验。 4) RBAC机制的研究与应用 通过对RBAC模型进行扩展和细化,实现了基于RBAC模型的动态访问控制机制,增强了RBAC模型的灵活性和安全性。 5) 组卷策略的研究与应用 探讨了网上作业/考试/练习工具平台中的关键问题——抽题组卷,通过对组卷参数和组卷步骤的分析,给出了机器智能组卷的算法和具体实现方案,实现了随机出题智能组卷。更多还原

【Abstract】 With the technology of Internet and digital satellite communication as the support, modern distance education boasts great freedom in time and space, rich shared resources, open system and convenient cooperation. Because of these advantages, the modern distance education with Internet as the major means becomes inevitable. Thereby, to turn the traditional teaching activities onto the network and to make lifetime education possible by using modern information technology are urgent and significant.In order to implement a more flexible, usable and robust distant education platform according to online assignment, quiz and practice requirements, this thesis has chiefly conducted the research of the following aspects:1) Research and application of J2EE component technology and design pattern. The system implemented by J2EE framework is more reusable. Combined withthe practical application in the development of the online assignment, quiz and practice platform, this thesis has studied and analyzed the J2EE component technology and several design patterns of J2EE.2) Design of online assignment, quiz and practice platform’s framework based on the multi-layer of J2EE architecture.According to the application of online assignment, quiz and practice platform, and after analyzing the design patterns of J2EE, this thesis puts forward one system framework which is based on the J2EE multi-layer architecture. The author uses UML’s sequence diagram to describe this framework clearly,.3) Web design and implementation based on AjaxUsing the asynchronous communication with Server implemented by Ajax, aMVC fabric design plan is proposed based on Ajax. Combined with the employing framework, this thesis provides the realization of this scheme through an embodiment, and realizes the most abundant and friendship user interface in the webpage, bringing to users no broken vision experience.4) Research and application of RBAC technologyThis thesis realizes dynamic access control module based on an extended and detailed RBAC model, to improve the flexibility and security of RBAC model.5) Research and application of strategy of organizing test paperThis thesis discusses the key point of organizing test paper automatically related to the online assignment, test and practice platform, and analyzes parameters of organizing test paper, particularly gives the concrete designs and realization steps, and realizes setting papers with problems chosen at random.更多还原