Leveraging Semantic Approximations in Heterogeneous XML Data Sharing Networks: The SUNRISE Approach.

In recent years, the huge amount of data available from Internet information sources has focused much attention on the sharing of distributed information through P2P and, in line with the Semantic Web vision, through Peer Data Management Systems (PDMSs).On the other hand, XML is with no doubt the most popular datarepresentation and exchange format on the Web and more and more Internet applications are conforming to this de facto standard for data sharing. In this chapter we present SUNRISE (System for Unified Network Routing, Indexing and Semantic Exploration) for XML data sharing. SUNRISE is a complete PDMS infrastructure aiming at semantic interoperability in heterogeneous networks. Decentralized data sharing is supported by a set of autonomous peers which model their local data through schemas and which are locally connected through semantic mappings. SUNRISE leverages the semantic approximations originating from schemas' heterogeneity for an effective and efficient organization and exploration of the network. For these purposes, SUNRISE implements soft computing techniques which cluster peers in Semantic Overlay Networks according to their own contents, and promote the routing of queries towards the semantically best directions in the network.