Stream Reasoning for Linked Data

Stream Reasoning introduction (30 min). The first session gives an overview of the Stream Reasoning research area, covering:

• Use cases and requirements
• Challenges
• How existing systems (DSMS/CEP, Semantic Web) address them
• Scope of Stream Reasoning research area
• Existing Systems (quick introduction and high-level comparison)

RDF stream processing models (45 min). This session covers:

• RDF and SPARQL extensions to manage streaming data
• overview of RDF model extensions (single timestamped RDF, double-timestamped RDF, etc.)
• quick recap on SPARQL and SPARQL continuous extensions (windows, S2R operators, followed-by operator, etc.)
• overview of existing systems w.r.t. models presented above

Naive reasoning on RDF streams (25 min). This session covers:

• the problem
• full goal drive approaches on each snapshot
• materialise each snapshot
• the DReD approach for incremental maintenance of materialisations

C-SPARQL: A Continuous Extension of SPARQL (20m). This session presents an overview of extensions of SPARQL for querying and naively reasoning on highly dynamic data streams using the Continuous-SPARQL (C-SPARQL) Engine. This session covers:

• Overview of the C-SPARQL language
• Overview of the C-SPARQL Engine
• Practical examples of continuous social media analysis using C-SPARQL and the C-SPARQL Engine

SPARQLstream: Ontology-based streaming data access (40m). This session presents an overview of extensions of SPARQLStream for querying existing data streams running on different types of Stream Processing Engines. This session covers:

• Overview of query rewriting and ontology-based access to streams.
• Semantic processing data streams delegating to stream processing engines and using R2RML mappings.
• Practical examples of semantic sensor network querying using SPARQLstream

Hands-on session (45m)

Approximate Reasoning and Approximate Stream Reasoning for OWL2-DL (70m). This session presents our recent work on faithful approximate reasoning for OWL2-DL, as well as its extensions for ontological stream reasoning in OLW2-DL. This session covers:

• Approximate reasoning for OWL2-DL
• Approximate stream reasoning for OWL2-DL

Hands-on session (20m)

IMaRS: Incremental Materialization for RDF Streams (30m). This session presents IMaRS, a variation of DRed for the incremental maintenance of the window materializations. This session covers:

• Optimization techniques for incrementally maintaining materializations when changes are caused by streaming data
• Practical examples of continuous social media analysis

Other Stream Reasoning approaches (30 min). This session covers:

• Complex Event Detection and Stream Reasoning in EP-SPARQL
• Sparkwave: Continuous Schema-Enhanced Pattern Matching over RDF Data Streams

Wrap-up and conclusions (30 min). This session covers:

• Achievements of existing approaches w.r.t. Stream Reasoning Challenges
• Open problems and a revised Stream Reasoning research agenda
• Open Q/A