Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Building Semantic Web Portals with WebML


Published on

Current conceptual models and methodologies for Web applications concentrate on content, navigation, and service modeling. Although some of them are meant to address semantic web applications too, they do not fully exploit the whole potential deriving from interaction with ontological data sources and and from Semantic annotations. This paper proposes an extension to Web application conceptual models toward Semantic Web. We devise an extension of the WebML modeling framework that fulfills most of the design requirements emerging for the new area of Semantic Web. We generalize the development process to cover Semantic Web and we devise a set of new primitives for ontology importing and querying. Finally, an implementation prototype of the proposed concepts is proposed within the commercial tool WebRatio.

Published in: Technology
  • Be the first to comment

Building Semantic Web Portals with WebML

  1. 1. Building Semantic Web Portals with WebML Marco Brambilla and Federico M. Facca ICWE 2007 Como, 20th July 2007
  2. 2. Agenda <ul><li>Introduction </li></ul><ul><ul><li>Requirements for metamodels of Semantic Web applications </li></ul></ul><ul><li>Extending WebML towards Semantic Web </li></ul><ul><ul><li>Evolving existing primitives </li></ul></ul><ul><ul><li>New Advanced units for ontology querying </li></ul></ul><ul><ul><li>Primitives for Ontology management </li></ul></ul><ul><ul><li>Example of Usage of Advanced Units </li></ul></ul><ul><li>Case Study Example </li></ul><ul><li>Implementation expirience </li></ul><ul><li>Conclusions & Future Works </li></ul>
  3. 3. Introduction <ul><li>Model-driven techniques aims to reduce the cost of design and implementation of software </li></ul><ul><li>The Semantic Web can benefit from Web Engineering field and viceversa </li></ul><ul><ul><li>there’s a lack of well engineered solution in SW </li></ul></ul><ul><ul><li>SW technologies provide more “flexibility” and allow complex reasoning task </li></ul></ul><ul><ul><li>Some effort have been already done: HERA, SHDM, … </li></ul></ul><ul><li>A Web Portal is a Web site providing personalization to to its visitors and designed to use distributed data sources </li></ul><ul><ul><li>One of the assumptions of Semantic Web is the use of distributed data sources and reuse of existing ones </li></ul></ul>
  4. 4. Introduction Requirements for metamodels of Semantic Web applications <ul><li>Support of semantic languages (OWL, RDF, WSML, …) </li></ul><ul><li>Models should be “semantic” </li></ul><ul><ul><li>i.e., grant self-annotation and explicit semantic annotation extraction </li></ul></ul><ul><li>Allow for flexible integration of heterogeneous sources and applications </li></ul><ul><li>Transformations towards a semantic query language </li></ul><ul><ul><li>allowing for inference, verification, query on schema and instances </li></ul></ul><ul><li>Allow for (semi-)automatic annotation of generated Web pages </li></ul><ul><li>Support the import and reference of remote ontologies </li></ul><ul><ul><li>reuse and sharing of the knowledge </li></ul></ul>
  5. 5. Extending WebML towards Semantic Web <ul><li>WebML methodology extended to support the new requirements </li></ul>+ Reuse of existing ontological data source + Specialized units for advanced queries over semantic data and annotation extraction
  6. 6. Extending WebML towards Semantic Web <ul><li>WebML methodology extended to support the new requirements </li></ul>
  7. 7. Extending WebML towards Semantic Web Evolving existing primitives <ul><li>Existing units can be adapted for direct access to ontology </li></ul><ul><ul><li>Changes in their “semantic” (query both on schemas and instances ) </li></ul></ul>instance uri class uri e.g. mf:Artist no input class uri e.g. vin:RedWine […] […] […] […]
  8. 8. Extending WebML towards Semantic Web New Advanced units for ontology querying Is x subproperty of y? Or: find subproperties/ find superproperties The list of URIs where property p has value v Or: find values/ find properties Is x property of y? Or: find the properties/ find the class Is x an instance of y? Or: find instances/ find classes Is x subclass of y? Or: find subclasses/ find superclasses
  9. 9. Extending WebML towards Semantic Web New Advanced units for ontology querying class uri instance uris instace uri classes uris instace & class uri boolean
  10. 10. Extending WebML towards Semantic Web Primitives for Ontology management <ul><li>Ontology composition: union, intersection, difference </li></ul><ul><li>Ontology importing: for direct query of existing ontologies </li></ul><ul><li>Semantic description extraction: for extracting semantic annotation of contents / pages </li></ul>
  11. 11. Extending WebML towards Semantic Web Example of Usage of Advanced Units The value submitted in the form is passed to the HasPropertyValue unit that extracts a set of URIs of instances (albums or artists) with mm:soundsLike property equal to Val. The InstanceOf unit that checks if they are instances of the class Artist. The URIs are then shown in a list of Artists.
  12. 12. Case Study Example
  13. 13. Implementation expirience <ul><li>Current extension is for RDF/OWL and uses SPARQL queries </li></ul><ul><li>New set of runtime components created to support semantic data sources based on Jena API and Pellet </li></ul><ul><li>Modeling environment extended for the use of the new units </li></ul>
  14. 14. Implementation expirience
  15. 15. Implementation expirience <ul><li>The automatic code generation phase is based on the generation of configuration files for the generic components </li></ul><ul><li>The transformation from design time descriptor to runtime descriptor is based on XSLT </li></ul>Design Time Descriptor Runtime Descriptor <SWINDEXUNIT class=&quot;mf:Track&quot; id=&quot;swinu1&quot; name=&quot;Tracks&quot; ontology=&quot;onto1&quot;> <DisplayedProperties property=&quot;mf:title&quot;/> <DisplayedProperties property=&quot;mf:descripion&quot;/> <SortProperties order=&quot;ascending&quot; property=&quot;mf:title&quot;/> <Filter boolean=&quot;or&quot;> <FilterCondition id=&quot;fselector1&quot; property=&quot;mf:playedBy&quot; predicate=&quot;eq&quot; name=&quot;Artist&quot;/> </Filter> </SWINDEXUNIT> <descriptor service=&quot;org.webml.onto. SWIndexUnitService&quot;> <onto>onto1</onto> ... <input-params> <input-param type=&quot;mm:Artist&quot; name=&quot;swdau2.rdf:ID&quot; /> </input-params> ... <query type=&quot;SELECT&quot;> SELECT DISTINCT ?instance ?p1 ?p2 WHERE {?instance rdf:type mm:Track . ?instance mm:title ?p1 . ?instance mm:descriptor ?p2 . ?instance mm:playedBy ?fs1 . FILTER (?fs1 = $swdau2.rdf:ID$)} ORDER BY DESC(?p1) </query> </descriptor>
  16. 16. Conclusions & Future Works <ul><li>Good abstractions are still valid even when new technologies become available </li></ul><ul><li>Schema querying become relevant in the context of Semantic Web and Models should provide support for it </li></ul><ul><li>Semantic Web introduces new query “types” and metamodels for Web applications should deal with this </li></ul><ul><li>Our solution is missing a real integration layer for better allowing seamless integration of the different datasources </li></ul><ul><li>Current implementations suffers performance issue when executed the first time </li></ul>
  17. 17. Thanks for the attention! <ul><li>For comments or questions: </li></ul><ul><ul><li>Marco Brambilla </li></ul></ul><ul><ul><li>Politecnico di Milano </li></ul></ul><ul><ul><li>Dipartimento di Elettronica e Informazione </li></ul></ul><ul><ul><li>[email_address] </li></ul></ul><ul><ul><li>Resources: </li></ul></ul><ul><ul><li> </li></ul></ul><ul><ul><li> </li></ul></ul><ul><ul><li> </li></ul></ul>