searching semantic web objects based on class hierarchies
DESCRIPTION
Presentation given at LDOW2008. It describes Falcons Object Search, a keyword-based search engine for objects on the Semantic Web.TRANSCRIPT
Institute of Web Science
iws.seu.edu.cn
Searching Semantic Web ObjectsBased on Class Hierarchies
Gong Cheng, Weiyi Ge, Honghan Wu, Yuzhong QuInstitute of Web Science, School of Computer Science and Engineering
Southeast University, Nanjing, China
Presentation at the
WWW 2008 Workshop:
Linked Data on the Web (LDOW2008)
http://iws.seu.edu.cn/services/falcons/
Institute of Web Science
iws.seu.edu.cn
Gong Cheng [email protected]
Information Islands vs. Web of Data
Institute of Web Science
iws.seu.edu.cn
Gong Cheng [email protected]
Information Islands vs. Web of Data
Institute of Web Science
iws.seu.edu.cn
Gong Cheng [email protected]
Information Islands vs. Web of Data
Institute of Web Science
iws.seu.edu.cn
Gong Cheng [email protected]
Motivation
How to find URIs?
Linked Open Data brings …
Single-point retrieval system
Institute of Web Science
iws.seu.edu.cn
Gong Cheng [email protected]
Demo
http://iws.seu.edu.cn/services/falcons/
Institute of Web Science
iws.seu.edu.cn
Gong Cheng [email protected]
Navigating Class Hierarchies for Query Restriction
Filtering results
Recommending subclasses
Institute of Web Science
iws.seu.edu.cn
Gong Cheng [email protected]
Combined Inverted Index
Query: <terms, classes>
Institute of Web Science
iws.seu.edu.cn
Gong Cheng [email protected]
Provenance of Typing Information
HeuristicsDereference document
Namespace document
Documents on the same host
Other documents
Institute of Web Science
iws.seu.edu.cn
Gong Cheng [email protected]
Class-inclusion Reasoning (cont.)
Institute of Web Science
iws.seu.edu.cn
Gong Cheng [email protected]
Which axioms would be accepted by the reasoning engine?The authorized description of a vocabulary is allowed to reuse the classes from other vocabularies but CANNOT further constrain their meaning.
Class-inclusion Reasoning (cont.)
Institute of Web Science
iws.seu.edu.cn
Gong Cheng [email protected]
Recommending Subclasses
If a subclass covers more results, it will be more likely to be recommended.
AlgorithmIterate over the first 1,000 results to collect classes.
Rank classes.
Select top K classes, s.t.:Each selected class must be a strict subclass of a current class.
The class inclusion relation does NOT hold between any pair of the selected classes.
Institute of Web Science
iws.seu.edu.cn
Gong Cheng [email protected]
Example
K = 2
×
×
×
Current class
√
√
Institute of Web Science
iws.seu.edu.cn
Gong Cheng [email protected]
Expanding textual description of SW objects
Mapping Terms to SW Objects
Institute of Web Science
iws.seu.edu.cn
Gong Cheng [email protected]
Crawler
Seed document URLsPTSW, DBpedia …
Swoogle, Google …
Parse RDF documents and dereference all the mentioned URIs.
…