This document discusses open location data and linked open data. It describes a faceted search interface and SPARQL form for accessing semantic data about the capital region. It also notes challenges in scaling semantic web data due to generic data models and ontologies. Linking data is discussed, noting issues with duplicate and heterogeneous data from sources like Geonames and DBpedia. An Areastats demo is described that uses KML files and point-in-polygon checks to visualize location data. Lastly, the HTML5 GeoLocation API for accessing location via JavaScript is briefly outlined.

1. Open Location Data
and Linked Open Data
Timo Westkämper
Mysema Oy
Email : timo.westkamper@mysema.com

2. semantic.hri.fi
Capital region data
● Faceted search interface
● SPARQL form and interface
● Map visualization (GoogleMaps based)

3. semantic.hri.fi
Material
● Aluesarjat data in RDF
● Town part borders as KML-files
● DBpedia town part descriptions

4. Semantic Web challenges
Scaling
● too generic model, difficult to index
● optimization of RDF storage difficult, no
standards
● SPARQL is a generic interface, difficult to
optimize

5. Linked Open Data challenges
● Poor quality of data foundation, e.g. GeoNames
● Heterogenic ontologies and resource
identification
● Crowd-sourcing material as foundation

6. Linking in practice
● Geonames material has lots of duplicates
● DBpedia has mostly description, not much
semantics
● Linking easiest via owl:sameAs predicate

7. Areastats demo
Material
● semantic.hri.fi material
● Java service uses KML files for point-in-polygon
check
● http://en.wikipedia.org/wiki/Point_in_polygon

8. HTML5 GeoLocation API
geo-location-javascript wrapper API for various GEO API
implementations
if (geo_position_js.init()) {
geo_position_js.getCurrentPosition(
geo_success, geo_error);
}
function geo_success(p) {
alert("Found you at latitude "
+ p.coords.latitude + ", longitude "
+ p.coords.longitude);
}

9. Questions?