Research On Several Key Issues Of Collaborative Awareness In Ubiquitous Environment

Computer supported collaborative editing systems allow a group of users to view and edit the same text/graphic/image/multimedia document simultaneously from geographically distributed sites connected by networks. They have many applications such as collaborative authorizing, collaborative product designing, collaborative pattern designing, video netmeeting and etc. Collaborative awareness, as an important technology for collaborative editing, will promote the collaborative capabilities and enhance the efficiency of group work.With the development of mobile computing and embedded computing, ubiquitous computing makes it possible for group to create the flexible and harmonious collaborative working environment. However, in ubiquitous environment the network connection and transmission are unstable and the resources of computing devices are quite different, which brings great challenges to the research of collaborative awareness. Therefore, it is important to research the related techniques.The investigation is combined with key issues in the research project of "Research on basic problems of collaborative editing in ubiquitous environment" and "Research on key technologies in the Internet-based collaborative pattern CAD/CAM system". Based on thories of cognition psychology, we research on collaborative awareness based on the characteristics of cognition. Related models, methods and algorithms are proposed and realized in our prototype system. Main research work is as follows:First, we analyze current research topics and key problems of collaborative awarenesss, the main characteristics of collaborative awareness in ubiquitous environment and challenges collaborative awareness meat. We present our research issues based on the characteristic of cognition.Second, we analyze the difference of the resources of collaborative sites and the limitation of cognition resources. We present the unsymmetrical awarenss mapping model, mechanism and related algorithm for maintaining the logical consistency of shared workspace. As attention is selective, based on the theory of attention resources in cognition psychology, we propose the algorithm of prediction for regions of interest. The prediction assures that the mapped awareness regions will be interested to users and the resoures that collaborative awareness needs is decreased. Third, network delay, packet loss and jitter brings halting and jumping presence of remote operating and it is necessary for people to gain better cognition based on integrated information. We present the algorithm of AFEC to solve the problem that brought by packet loss. And also, we propose Scale-Changeable Machine-Learning algorithm to predict the trace of the motion of remote control points in order to make the presence smooth.Finally, as appropriate ways of presenting awareness information will promote cognition ability and it is difficult to know user's editing intention in ubiquitous environment, we present the semantic awareness model based on various types of objects such as graphic and image. Related techniques like sematic maintenance, semantic conflict detection and solution are proposed to provide better awarenss.