Nowadays, more and more digitalized spatial data are sold and transmitted on the Internet. Thus, there arises an important issue about copyright protection of the digital data. To solve this problem, this paper has designed and implemented a spatial data watermarking service (SDWS) system which can provide a secure framework for data transaction and transfer via the Internet and protect the rights of both copyright owners and consumers at the same time.
It can not provide dynamic view mechanism in previ-ous dataspace information system. In this paper,the dynamic ex-tendable view mechanism provided by object deputy model is proposed for personalized dataspace information system which can provide rich semantics and enough flexibility. The flexible inheritance avoids a lot of data redundancy. The cross class query mechanism allows users to find more related data based on com-plex relationships. The personalized dataspace service provides less storage space consumption and shorter query response time. The experiment result shows that our approach is more feasible and efficient than the traditional one.
LIU JunqiangPENG ZhiyongLI XuhuiZHENG CongyiFANG Chengxiang
