TempoXML: Nested bitemporal relationship modeling and conversion tool for fuzzy XML

摘要

The importance of incorporating time in databases has been well realized by the research community. Accordingly, temporal databases have been extensively studied by researchers. The main idea is to add a time or temporal dimension to the model and then tag data elements with time in order to keep all values instead of only the last one, and hence allow for time driven queries. This way it becomes possible to retrieve various values of the same element. This leads for better knowledge discovery and trend analysis by looking back into the history to predict for the future. Unfortunately, one disadvantage of the temporal database management system is that it has not been commercialized. The work described in this paper reflects our effort to demonstrate the power and effectiveness of the temporal dimension once it is well integrated into databases. We decided on XML (eXtensible Markup Language) as the underlying data model. The motivation is twofold. First XML is a defacto standard for data exchange; we have already demonstrated the power of XML in our other work described in the literature. Second, nested bitemporal databases form one interesting type of temporal databases. Thus, our purpose is to suggest an automated system that converts a nested bitemporal database to a corresponding fuzzy XML database. Fuzzy query model has been implemented as part of the proposed framework in order to provide flexibility to a wide rang of end users willing to access the database. The implemented temporal operators are database content independent. Fuzzy elements are capable of having different membership functions and varying number of linguistic variables. We have proposed a scheme for determining membership function parameters.