Projects

ORKG: Open Research Knowledge Graph

The Open Research Knowledge Graph (ORKG) is a research infrastructure for FAIR scholarly literature.

TIB — Leibniz Information Centre for Science and Technology, Hannover, Germany, January 2018

Mohamad Yaser Jaradeh, Allard Oelen, Kheir Eddine Farfar, Manuel Prinz, Jennifer D’Souza, Gábor Kismihók, Markus Stocker, and Sören Auer (2019). Open Research Knowledge Graph: Next Generation Infrastructure for Semantic Scholarly Knowledge. In Proceedings of the 10th International Conference on Knowledge Capture (K-CAP ’19), November 19–21, 2019, Marina Del Rey, CA, USA. ACM, New York, NY, USA, 4 pages. https://doi.org/10.1145/3360901.3364435

Emrooz: A Scalable Database for SSN and QB Observations

Emrooz consumes and persists sensor observations represented according to the Semantic Sensor Network ontology (SSN) and dataset observations represented according to the RDF Data Cube Vocabulary (QB) in RDF. Retrieval of observations is supported by SPARQL. Emrooz builds on Apache Cassandra and is several orders of magnitude faster in answering queries compared to state of the art RDF triple stores. The Emrooz source code is available at GitHub.

University of Eastern Finland, Kuopio, Finland, June 2015

Markus Stocker, Narasinha Shurpali, Kerry Taylor, George Burba, Mauno Rönkkö, and Mikko Kolehmainen (2015). Emrooz: A Scalable Database for SSN Observations. In Joint Proceedings of the 1st Joint International Workshop on Semantic Sensor Networks and Terra Cognita and the 4th International Workshop on Ordering and Reasoning co-located with the 14th International Semantic Web Conference, volume 1488, pp. 1-12, Bethlehem, PA, USA, October 11. CEUR-WS.
Full Text

Wavellite: Situation Awareness in Environmental Monitoring

Wavellite is a software framework for situation awareness in environmental monitoring. It supports the development of applications that aim at the representation of situational knowledge extracted from processed data acquired from environmental sensor networks. The source code is archived at Zenodo.

University of Eastern Finland, Kuopio, Finland, March 2013

Markus Stocker, Elham Baranizadeh, Harri Portin, Mika Komppula, Mauno Rönkkö, Amar Hamed, Annele Virtanen, Kari Lehtinen, Ari Laaksonen, and Mikko Kolehmainen (2014). Representing Situational Knowledge Acquired from Sensor Data for Atmospheric Phenomena. Environmental Modelling & Software, 58:27-47. https://doi.org/10.1016/j.envsoft.2014.04.006

Markus Stocker, Mauno Rönkkö, and Mikko Kolehmainen (2014). Situational Knowledge Representation for Traffic Observed by a Pavement Vibration Sensor Network. IEEE Transactions on Intelligent Transportation Systems, 15(4):1441-1450. https://doi.org/10.1109/TITS.2013.2296697

PelletSpatial: RCC Reasoning and Query Engine

PelletSpatial is a reasoning and query engine built on top of Pellet tailored for spatial data represented with the Region Connection Calculus (RCC). PelletSpatial supports RDF, RCC relations represented in RDF, RDF annotation of RCC regions, and (a subset of) SPARQL.

Ascona, Switzerland, June 2009

Markus Stocker and Evren Sirin (2009). PelletSpatial: A Hybrid RCC-8 and RDF/OWL Reasoning and Query Engine. In Proceedings of the 5th International OWLED Workshop, Chantilly, Virginia, USA, October 23-24.
Full Text

Owlgres: A Scalable OWL Reasoner

Owlgres is a scalable reasoner for OWL 2 written in Java on top of PostgreSQL. Owlgres combines Description Logic reasoning with the data management and performance properties of a RDBMS. Owlgres’s primary service is conjunctive query answering, using SPARQL-DL.

Clark & Parsia, Washington, DC, USA, June 2008

Markus Stocker and Michael Smith (2008). Owlgres: A Scalable OWL Reasoner. In Proceedings of the 4th International OWLED Workshop, Karlsruhe, Germany, October 26-27.
Full Text

ARQ-Optimizer: Selectivity Based SPARQL Optimization

A selectivity based basic graph pattern static optimizer for ARQ and Jena in-memory models. The optimizer is inspired by selectivity based optimization techniques originally developed for relational database management systems.

HP Labs, Bristol, UK, August 2007

Markus Stocker, Andy Seaborne, Abraham Bernstein, Christoph Kiefer, and Dave Reynolds (2008). SPARQL Basic Graph Pattern Optimization Using Selectivity Estimation. In Proceedings of the 17th International World Wide Web Conference, pp. 595-604, Beijing, China, April 21-25. https://doi.org/10.1145/1367497.1367578
Full Text

Markus Stocker and Andy Seaborne (2007). ARQo: The Architecture for an ARQ Static Query Optimizer. Technical report HPL-2007-92, HP Laboratories Bristol.
Full Text