KMi Seminars
Scalable Query Answering over Linked Ontological Data
This event took place on Wednesday 15 July 2009 at 11:30

 
DR. Jeff Pan University of Aberdeen, UK

Scalable query answering over ontologies is one of the most useful and important services to support Semantic Web applications. For example, more and more ontological vocabulary used in linked data. Approximation has been identified as a potential way to reduce the complexity of query answering over OWL DL ontologies. Existing approaches are mainly based on syntactic approximation of ontological axioms and queries. In this talk, I will firstly give an overview of description logics in general, which are the underpinning of the OWL DL standard, and query answering over DL-based ontologies in particular. Then I propose to recast the idea of knowledge compilation into semantically approximating OWL DL ontologies with DL-Lite ontologies, against which query answering has only LogSpace data complexity. We identify a useful category of queries for which our approach guarantees also completeness. If time allows, I will also report on the implementation of our approach in the TrOWL system and preliminary, but encouraging, benchmark results which compare TrOWL's response times on queries in a well known ontology benchmark with those of existing ontology reasoning systems. I will conclude the talk with discussions on some future steps.

 
KMi Seminars Event | SSSW 2013, The 10th Summer School on Ontology Engineering and the Semantic Web Journal | 25 years of knowledge acquisition
 

Future Internet is...


Future Internet
With over a billion users, today's Internet is arguably the most successful human artifact ever created. The Internet's physical infrastructure, software, and content now play an integral part of the lives of everyone on the planet, whether they interact with it directly or not. Now nearing its fifth decade, the Internet has shown remarkable resilience and flexibility in the face of ever increasing numbers of users, data volume, and changing usage patterns, but faces growing challenges in meetings the needs of our knowledge society. Globally, many major initiatives are underway to address the need for more scientific research, physical infrastructure investment, better education, and better utilisation of the Internet. Within Japan, USA and Europe major new initiatives have begun in the area.

To succeed the Future Internet will need to address a number of cross-cutting challenges including:

  • Scalability in the face of peer-to-peer traffic, decentralisation, and increased openness

  • Trust when government, medical, financial, personal data are increasingly trusted to the cloud, and middleware will increasingly use dynamic service selection

  • Interoperability of semantic data and metadata, and of services which will be dynamically orchestrated

  • Pervasive usability for users of mobile devices, different languages, cultures and physical abilities

  • Mobility for users who expect a seamless experience across spaces, devices, and velocities