Access control and views in web data management

In the web data management area, several new research issues arise concerned with the access control and views, both of which are well-known notions in database systems. In conventional database systems, the data uni ts for access control are homogeneous (e.g. tuples or columns). On the other hand, the data units for access control in web data management are heterogenous since web data are complex and semi-structured, Next, image data or CG data contained in web pages have multiple representations, for which conventional all-or-nothing access control is not appropriate. Next, in the web data borwsing, when reading and navigating web data, it is desirable to prepare a facility to produce new access rights according to a user's reading and navigation history. Finally, more passive browsing interfaces are desired for beginners to read web data. Considering these requirements, we propose (1) as-much-as-allowed access control which rakes multiple representaion of web data components and several relationships (informative relationship, require relationship, and non-co-existence relationship) into consideration, (2) link activation and information complementation controlled by a user's link navigation history, and (3) the automatic transformation from a Web Page into a TV-program-like passive view.