Metadata can be used to precisely represent data semantics. It can also serve to improve data sharing and exchange. Because the various types of metadata are created in different ways, they can suffer from a problem of inconsistency. Recently, metadata gateway methods have been researched to solve this problem. However, the performance of the existing approaches based on metadata schemas is poor and their maintenance (adaptation of metadata changes) is time consuming. In this paper, a novel message conversion system is proposed, which functions by separating the heterogeneous mapping information from the mapping rules of the metadata, in order to overcome the drawbacks of the existing metadata gateway methods. The proposed system controls the standardized data elements dynamically based on the Metadata Registry (MDR), which is one of the most important elements of the ISO/IEC 11179 standard. The problems associated with adding supplementary metadata are resolved, since the standard provides for incorporating additional data elements created in the future. MSDL is defined as a protocol which can be used for exchanging messages between heterogeneous systems, and which ensures that all of the systems have their own independent metadata schemas.
D.-K. Baik , Trends of information communication and standard technology: data standardization and metadata registry , TTA Journal71 (2000) 120-127 .
2.
C. Blanchi and J. Petrone , Distributed interoperable metadata registry , D-Lib Magazine7(12) (2001). Available at: www.dlib.org (accessed 8 April 2005).
3.
G. Wiederhold , Intelligent integration of information . In: Proceedings of the 1993 ACM SIGMOD International Conference on Management of Data (Washington D.C., 1993) 434-437 .
4.
W. Kim and J. Seo , Classifying schematic and data heterogeneity in multi-database systems , IEEE Computer24(12) (1991) 12-18 .
5.
C. Parent and S. Spaccapietra , Issues and approaches of database integration , Communications of the ACM41(5) (1998) 166-178 .
6.
R.D. Holowczak and W.-S. Li , A survey on attribute correspondence and heterogeneity metadata representation , First IEEE Metadata Conference (IEEE, Silver Spring, 1996).
7.
ISO/IEC JTC 1/SC 32, ISO/IEC 11179: Information Technology - Metadata Registries (MDR) - Part 1-6 (2003). Available at: http://jtc1sc32.org/ (accessed 22 May 2005).
8.
DCMI (Dublin Core Metadata Initiative), Dublin Core Metadata Element Set, Version 1.1: Reference Description (2004). Available at: http://dublincore.org (accessed 8 April 2005).
9.
ONIX (ONline Information eXchange) International, ONIX for Books Product Information Message - Release 2.1 (2003). Available at: www.editeur.org (accessed 8 April 2005).
10.
W3C , eXtensible Markup Language (XML) 1.1 (2003). Available at: www.w3.org/XML/ (accessed 8 April 2005).
11.
D. Wang , Automated Semantic Correlation between Multiple Schema for Information Exchange (unpublished manuscript, MIT, Cambridge, MA , May 2000).
12.
The Library of Congress, MARC 21 Format (2004). Available at: www.loc.gov (accessed 8 April 2005).
13.
Microsoft , Microsoft BizTalk (2004). Available at: www.microsoft.com (accessed 8 April 2005).
14.
M.R. Genesereth , Knowledge Interchange Format (KIF) (1998). Available at: http://logic.stanford.edu/kif/ (accessed 8 April 2005).
