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Foaf-O-matic and Okkam4P: two ENS-enabled applications for the Semantic Web

Foaf-O-matic and Okkam4P: two ENS-enabled applications for the Semantic Web. Paolo Bouquet° , Joint work with Heiko Stoermer ° , Stefano Bortoli°, Liu Xin* ° DISI, University of Trento, Italy * University of Jilin, China KnowDive Seminar Series January 14, 2008.

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Foaf-O-matic and Okkam4P: two ENS-enabled applications for the Semantic Web

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  1. Foaf-O-matic and Okkam4P: two ENS-enabled applications for the Semantic Web Paolo Bouquet°, Joint work with Heiko Stoermer°, Stefano Bortoli°, Liu Xin* ° DISI, University of Trento, Italy * University of Jilin, China KnowDive Seminar Series January 14, 2008

  2. Semantic Web: a long-term vision The Semantic Web is what we will get if we perform the same globalization process to knowledge representation that the Web initially did to hypertext. [Tim Berners-Lee, What the semantic Web isn't but can represent , 1998]

  3. In practice … Web of Meanings Sonia Knows Bouquet Is_involved_in Works-for UniTN Coordinates Works-for UniMORE Wisdom Web_page Web_page Web_page www.unitn.it www.trento.it www.ryanair.com href href href www.l3s.org href href www.paolobouquet.net href href href www.google.com ockham.org Web of Links

  4. The Semantic Web: a global K space • The Semantic Web way to information integration: • People will create and publish collections of RDF statements about any resources (documents, people, locations, events, topics, …). • [If information is contained in e.g. databases, they can be exported to RDF with some additional work]. • Any collection of RDF triples defines a graph, whose nodes are resources and arcs are relations between resources. • [The meaning of relations can be defined in vocabularies/ontologies] • Different RDF graphs can be merged by “collapsing” nodes and relations with identical identifier (URI). • The expected outcome is a smooth information integration across distributed information sources (a global distributed space of knowledge)‏

  5. An RDF scenario … hotel_pusan.org ISWC2007.org Lord Beach Hotel built_in located_in ISWC Pusan 2000 held_in attends part_of bouquet Busan South Korea placed_in rdf:type S.Korea country

  6. An example … Lord Beach Hotel ISWC built_in located_in held_in Busan 2000 attends part_of South Korea bouquet rdf:type country Query: find me an a hotel located where ISWC is held in 2007

  7. Key ideas: a summary • Names in natural language (like “Busan” and “Pusan”, “Paolo”, “Paolo Bouquet” and “Bouquet, P.”) can be ambiguous or not unique • Therefore, when we want to make a RDF statement about a resource, we must use its URI • When two nodes in two graphs have the same URI, they unambiguously refer to the same resource • The global knowledge space is achieved by applying the operation of merging local graphs into a single (virtual, decentralized) global graph • Now the virtual global graph can be queried as if it was a single knowledge base

  8. Knowlegde integration in the global space To implement this scenario, however, we need to address and solve two serious integration problems: • Schema-level heterogeneity: matching different vocabularies/ontologies so that equivalent (or related) classes and properties can be put in relation or collapsed • Instance-level mismatch: resolving identities between instances, so that all statements about it can be correctly integrated

  9. Issue #1: schema-level heterogeneity Lord Beach Hotel built_in located_in ISWC Pusan 2000 held_in attends part_of bouquet Busan South Korea placed_in rdf:type S.Korea ? country

  10. Issue #1: schema-level integration Lord Beach Hotel built_in located_in ISWC Pusan 2000 held_in attends part_of bouquet Busan South Korea placed_in rdf:type S.Korea Less general than country

  11. Isssue #2: entity-level mismatch Lord Beach Hotel built_in located_in ISWC Pusan 2000 held_in attends ? part_of bouquet Busan South Korea placed_in rdf:type ? S.Korea country

  12. Isssue #2: entity-level integration Lord Beach Hotel built_in located_in ISWC Pusan 2000 held_in attends = part_of bouquet Busan South Korea placed_in rdf:type = S.Korea country

  13. State-of-the-art • Schema-level integration is well-studied and supported (see ontology matching methods and tools)‏ • Entity-level integration is mostly neglected, perhaps because most people believe it is an easy (or at least easier) problem, mainly technological and not worth investigating for researchers. [May this be a partial explanation of why the Semantic Web is not taking off as fast as hoped??]

  14. And indeed … … the situation of instance-level integration is currently as follows: • The RDF metadata of some of the most important WWW and Semantic Web conference are poorly integrated at the instance level • FOAF profiles rely on ad hoc methods for identifying people (and don’t identify much else) • The most common available ontology editors (e.g. Protégé) or metadata management systems (e.g. in digital libraries) generate “local” URIs for any newly created instance • Some efforts exist to create reusable URIs (e.g. LSID, DOI), but are very vertical or commercial • URI retrieval and reuse in general is not well supported This way, the Semantic Web will never happen …

  15. What went wrong (personal view)‏ • The Semantic Web is not happening, at least not as the WWW happened in the 90’s • Enabling factors for the the WWW: • Any available information resource has a global URL, which allows Web clients to address it • The same identifier can be resolved to retrieve the resource through the HTTP protocol (running on top of TCP/IP)‏ • Creating href links is easy on top of this infrastructure • What about the Semantic Web? • Non information resources do not have an infrastructure for supporting the use of global identifiers (more about this)‏ • Non information resources cannot be retrieved • Creating global links between non information resources is problematic • Thesis: we lack an essential precondition for the Semantic Web to happen!

  16. Our solution: from DNS to ENS We need something like an Entity Naming System (ENS): • Building blocks: ENS servers (repository + “resolution” of names) • Basic idea: any description of an entity is “resolved” onto its global ID • An open, public service which can be invoked by any application in which entities are mentioned

  17. ENS-empowered applications Applications which can interact with the ENS for: • Creating new content (in any format) in which entities are annotated with global IDs • Offering smart services based on the availability of global IDs Examples: text processors, HTML/XML editors, RDF/OWL editors, filters for exporting relational DBs, metadata management tools, …

  18. And indeed … … the situation of instance-level integration is currently as follows: • The RDF metadata of some of the most important WWW and Semantic Web conference are poorly integrated at the instance level • FOAF profiles rely on ad hoc methods for identifying people (and don’t identify much else) • The most common available ontology editors (e.g. Protégé) or metadata management systems (e.g. in digital libraries) generate “local” URIs for any newly created instance • Some efforts exist to create reusable URIs (e.g. LSID, DOI), but are very vertical or commercial • URI retrieval and reuse in general is not well supported This way, the Semantic Web will never happen … Foaf-O-matic Okkam4P

  19. The OKKAM ENS Vision

  20. foaf-A-matic & Protégé • <http://www.w3.org/RDF/Validator/run/1198080996828#me> <http://xmlns.com/foaf/0.1/name> "Heiko Stoermer" • <http://www.w3.org/RDF/Validator/run/1198080996828#me> <http://xmlns.com/foaf/0.1/knows> _:jA64256 • _:jA64256 <http://xmlns.com/foaf/0.1/name> "Paolo Bouquet" • <http://www.owl-ontologies.com/Ontology1198072971.owl#Person_2> <http://www.owl-ontologies.com/Ontology1198072971.owl#Name> "Paolo Bouquet"^^<http://www.w3.org/2001/XMLSchema#string> • <http://www.owl-ontologies.com/Ontology1198072971.owl#Person_2> <http://www.owl-ontologies.com/Ontology1198072971.owl#attended> <http://www.owl-ontologies.com/Ontology1198072971.owl#Conference_1> • <http://www.owl-ontologies.com/Ontology1198072971.owl#Conference_1> <http://www.owl-ontologies.com/Ontology1198072971.owl#Name> "SWAP2007"^^<http://www.w3.org/2001/XMLSchema#string> .

  21. Okkam4P foaf-O-matic foaf-O-matic & Okkam4P

  22. VIDEO Protégé+Okkam4P & foaf-O-matic

  23. foaf-O-matic & Okkam4P • <http://www.okkam.org/entity/ok5f23a5cea6834c4dae73b78cdc17aec1> <http://xmlns.com/foaf/0.1/name> "Heiko Stoermer" • <http://www.okkam.org/entity/ok5f23a5cea6834c4dae73b78cdc17aec1> <http://xmlns.com/foaf/0.1/knows><http://www.okkam.org/entity/ok200706301185791252056> • <http://www.okkam.org/entity/ok200706301185791252056> <http://xmlns.com/foaf/0.1/name> "Paolo Bouquet" • <http://www.okkam.org/entity/ok200706301185791252056> <http://www.owl-ontologies.com/Ontology1198072971.owl#Name> "Paolo Bouquet"^^<http://www.w3.org/2001/XMLSchema#string> • <http://www.okkam.org/entity/ok200706301185791252056><http://www.owl-ontologies.com/Ontology1198072971.owl#attended> <http://www.okkam.org/entity/okasdf12191185791252056> • <http://www.okkam.org/entity/okasdf12191185791252056><http://www.owl-ontologies.com/Ontology1198072971.owl#Name>"SWAP2007"^^<http://www.w3.org/2001/XMLSchema#string>

  24. Okkam4P foaf-O-matic foaf-O-matic & Okkam4P

  25. OKKAM Architecture Prototype

  26. Your OKKAM-empowered Tool • OKKAM experimental service is online • OKKAM client libraries for Java available as Open Source: http://okkam-client.googlecode.com

  27. www. .org

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