1. http://streamreasoning.org/sr4ld2013
Virtual RDF views over data streams
1
Virtual RDF Stream
DSMS CEP Sensor
middleware
…
queries
users, applications
query processing
RDF Stream Processor
data layer

2. http://streamreasoning.org/sr4ld2013
Morph-streams: Overview
2
Query
rewriting
Query
Processing
Client
SPARQLStream
[tuples]
[triples/bin
dings]
Algebra
expression
R2RML
Mappings
Morph-streams procesing SPARQLStream queries
SELECT ?windspeed
FROM STREAM <http://ssg4env.eu/SensorReadings.srdf>
[NOW–5 HOUR]
WHERE {
?obs a ssn:ObservationValue;
qudt:numericalValue ?windspeed;
FILTER (?windspeed>10) }
SELECT sp_wind
FROM wan7.win:time(5 hour)
WHERE sp_wind >10
π timed,sp_wind
ω
σsp_wind>10
5 Hour
wan7
Data
translation
SNEE
Esper
GSN
Cosm
pull/push
https://github.com/jpcik/morph-streams
Other

3. http://streamreasoning.org/sr4ld2013
SPARQLStream: examples
3
PREFIX sr4ld: <http://www.streamreasoning.org/ontologies/socialsensor,owl#>
SELECT ?room
FROM NAMED STREAM <http://www.streamreasoning.org/streams/socialsensor.srdf> [NOW-10 S]
WHERE {
?obs sr4ld:observedBy ?sensor.
?obs sr4ld:where ?room.
}
SPARQLStream
All rooms where something was observed in the last 10s
PREFIX sr4ld: <http://www.streamreasoning.org/ontologies/socialsensor,owl#>
SELECT (COUNT(?person) AS ?nmb) ?room
FROM NAMED STREAM <http://www.streamreasoning.org/streams/socialsensor.srdf> [NOW-10 S]
WHERE {
?obs sr4ld:who ?pers.
?obs sr4ld:where ?room.
}
GROUP BY ?room
Number of persons observed in each room in the last 10s

4. http://streamreasoning.org/sr4ld2013
Underlying Query Processors
4
SELECT ?windspeed
FROM STREAM <http://ssg4env.eu/SensorReadings.srdf>
[NOW–5 HOUR TO NOW]
WHERE {
?obs a ssn:ObservationValue;
qudt:numericalValue ?windspeed;
FILTER (?windspeed>10) }
SELECT sp_wind FROM wan7 [FROM NOW-5 HOURS TO NOW]
WHERE sp_wind >10
timed,
sp_wind
π
ω
σsp_wind>10
5 Hour
wan7
SELECT sp_wind FROM wan7.win:time(5 hour)
WHERE sp_wind >10
http://montblanc.slf.ch:22001/multidata?vs[0]=wan7&
field[0]=wind_speed_scalar_av&c_min[0]=10&
from=15/05/2012+05:00:00&to=15/05/2012+10:00:00
http://api.cosm.com/v2/feeds/14321/datastreams/4?start=2012-05-
15T05:00:00Z&end=2012-05-15T10:00:00Z
Query
rewriting
R2RML
SNEE
(DSMS)
Esper
(DSMS)
GSN
(middlwr)
Cosm
SPARQLStream

5. http://streamreasoning.org/sr4ld2013
Resources
 Morph-Streams
• https://github.com/jpcik/morph-streams
• http://transporte.linkeddata.es
 Read out more
• Enabling Query Technologies for the Semantic Sensor Web. J.-P. Calbimonte, H. Jeung,
O. Corcho and K. Aberer. IJSWIS, Volume 8(1)., 2012
• Enabling Ontology-based Access to Streaming Data Sources. J.-P. Calbimonte, O.
Corcho and A. J. G. Gray. In ISWC 2010
 Contact point
• jp.calbimonte@upm.es
• ocorcho@fi.upm.es
5