Jonas Jacobi
University of Oldenburg
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Publication
Featured researches published by Jonas Jacobi.
european semantic web conference | 2008
Andre Bolles; Marco Grawunder; Jonas Jacobi
A lot of work has been done in the area of data stream processing. Most of the previous approaches regard only relational or XML based streams but do not cover semantically richer RDF based stream elements. In our work, we extend SPARQL, the W3C recommendation for an RDF query language, to process RDF data streams. To describe the semantics of our enhancement, we extended the logical SPARQL algebra for stream processing on the foundation of a temporal relational algebra based on multi-sets and provide an algorithm to transform SPARQL queries to the new extended algebra. For each logical algebra operator, we define executable physical counterparts. To show the feasibility of our approach, we implemented it within our ODYSSEUS framework in the context of wind power plant monitoring.
database and expert systems applications | 2010
Andre Bolles; Marco Grawunder; Jonas Jacobi; Daniela Nicklas; H.-Jürgen Appelrath
Modern datastream management system (DSMS) assume sensor measurements to be constant valued until an update is measured. They do not consider continuously changing measurement values, although a lot of real world scenarios exist that need this essential property. For instance, modern cars use sensors, like radar, to periodically detect dynamic objects like other vehicles. The state of these objects (position and bearing) changes continuously, so that it must be predicted between two measurements. Therefore, in our work we develop a new bitemporal stream algebra for processing continuously changing stream data. One temporal dimension covers correct order of stream elements and the other covers continuously changing measurements. Our approach guarantees deterministic query results and correct optimizability. Our implementation shows that prediction functions can be processed very efficiently.
Computer Science - Research and Development | 2010
Jonas Jacobi; Andre Bolles; Marco Grawunder; Daniela Nicklas; H.-Jürgen Appelrath
GI Jahrestagung (2) | 2010
Andre Bolles; Dennis Geesen; Marco Grawunder; Jonas Jacobi; Daniela Nicklas; Hans-Jürgen Appelrath
BTW | 2011
Andre Bolles; Dennis Geesen; Marco Grawunder; Jonas Jacobi; Daniela Nicklas; Hans-Jürgen Appelrath; Marco Hannibal; Frank Köster
Grundlagen von Datenbanken | 2008
Jonas Jacobi; Marco Grawunder
GI Jahrestagung | 2009
Andre Bolles; Marco Grawunder; Jonas Jacobi; Daniela Nicklas; Hans-Jürgen Appelrath
BTW | 2009
Jonas Jacobi; Andre Bolles; Marco Grawunder; Daniela Nicklas; Hans-Jürgen Appelrath
BTW | 2011
Dennis Geesen; Andre Bolles; Marco Grawunder; Jonas Jacobi; Daniela Nicklas; Hans-Jürgen Appelrath
Grundlagen von Datenbanken | 2007
Jonas Jacobi; Marco Grawunder