Architecture for Including Personalization in a Mobile GIS via Semantic Web Techniques - Geographical Information Systems: Trends and Technologies - page 216

PREFIX : <http://www.itinera.cat/ontology/itinera core.owl#>
SELECT ?resource
WHERE { :SagradaFamilia :hasResource ?resource }
The query asks for the resources related with the Sagrada Familia instance.
In the case of Fig. 1, the result of this query would be the instance Photo .
GeoSPARQL
Spatial information can also be tagged as triplets in RDF data, resulting
in what is called RDF spatial data. In this case, the difference is that RDF
semantic data is tagged with geographical position. Thus, tools are required
to perform spatial operations, defi ne spatial relations and infer deductions
over geographic RDF data, which are different from non-spatial RDF
data.
Therefore, the question is: does SPARQL language support geospatial
data? The answer is it does not. Without spatial reasoning, the value of the
spatial context and geographic data is limited. In order to meet this need
GeoSPARQL language has been introduced (Battle and Kolas 2011).
GeoSPARQL language is a standard from the Open Geospatial
Consortium (OGC) for querying and reasoning geospatial data represented
in RDF format, from simple points of interest to complex geospatial data
sources. The main advantage is that it provides the ability to query and fi lter
the relationships between geospatial entities (Battle and Kolas 2011).
Reasoners
Besides ontologies, the other important mechanisms of Semantic Web are
the reasoners. As already mentioned, a reasoner infers logical consequences
from a given knowledge base (Mishra and Kumar 2010). There are multiple
reasoners to work with semantic data depending on the language they are
written, the logic or the algorithms they use. The most well-known are
FaCT++ (Tsarkov and Horrocks 2006), Pellet (Clark and Parsia 2011) and
HermiT (University of Oxford) # . For a deeper benchmark about reasoners
see Dentler et al . (2011).
In order to understand the benefi ts of using a reasoner, we follow the
previous example of the ontology in Fig. 1. In that case, the ontology declares
that La Sagrada Familia is A Monument and a Monument is Historic . Then, a
Semantic Web program with a reasoner can add the statement La Sagrada
Familia is A Historic to the set of relationships, although it was not part of
the original data. This is only a simple example of inference of knowledge,
but we can use the reasoners for more complex tasks.
# http://www.cs.ox.ac.uk/projects/HermiT/