Geospatial Meaning

Geospatial Semantic Web Research. GeoWeb Trends

 

Posts Tagged ‘Geospatial Semantic Web’

Some CINeSPACE dissemination

We have entried in the last year of CINeSPACE project.

Mans Shapshak has written an excellent article in Directions Magazine about the project entitled Combining GIS and Semantic Technology to Create a Cultural Visualizer, which has been indexed by the ACM TechNews. Our work has also been reviewed by Roland Piquepaille in his Emerging Tech blog, with the article Discovering Venice with a CINeSPACE device.

Who doesn’t want to experience a CINeSPACE device???

Terra Cognita 2008. Geospatial Semantic Web Workshop.

Geospatial Semantic Web is gradually establishing as a Research proper field. Terra Cognita, a specialized Workshop in conjuntion with the 7th International Semantic Web Conference is going to be held in Karlsruhe, Germany.

A great chance to share experiences and ideas with geospatial and semantic web experts.

See you there.

Spatial queries and inference

The early attempts to store geographic data in standard relational tables failed. This issue gave rise to spatial databases, which extent the relational model providing specific representations for geospatial data.

As the number of geographic features in a database grew, it became evident that it was imposible to store all the relationships between geographic entities in a large GIS. So distances, intersections, centroids, etc. are easyly computed with built-in functions. Questions like the depicted in the image could be seen as real-time spatial inferencing.

Spatial inferencing

Is featureA within a 5km distance from the border of any water body feature?

When developing spatial reasoning support for Semantic Web we find the same problems. Description logic standards as OWL don’t provide specific spatial built-ins to enable real-time spatial inferencing or querying.

So we need the preprocessing of all spatial-related statements using spatial specific algorithms (or GIS) before adding them to the semantic KB or we need the adding of some kind of spatial layer that combines spatial queries with semantic queries to extent DL expressivity.

We use both approaches in our spatial model for CINeSPACE project:

  • A preprocessing of fuzzy spatial relationships such as mereology or neighbourhood, that are added to the KB. This is an feasible approach while the number of spatial elements remains low (hundreds of elements for each city) and the spatial extent of polygons remains constant (non-monotonicity will be reviewed in a future post).
  • A spatial layer used for dynamic queries, such as “Retrieve me Geoconcepts I am looking at”, where geoconcept is used to name any entity with an inherently or indirectly associated spatial dimension. SPARQL queries are used over the spatial results to refine the answer.

The need of extra spatial computation limits the success of Geospatial Semantic Web in terms of GIS professionals, who see Semantic Web as a complex world with not great benefits for dealing with space. A step forward spatial integration with DL logics. We are looking for researchers and people interested in this integration. Feel free to contact!!!

Thinking with Space

Istanbul Sultan Ahmed Mosque

We attended at the 5th Geographic Information Systems conference at Istanbul the 2-5 July, where we were introducing our Geoconcepts architecture. One of the main themes of the conference was Geographic Information Science Education. Robert S. Bednarz and Sarah W. Bednarz introduced us some key points in spatial thinking skills and explicit spatial training. They consider three main scenarios in spatial thinking:

  • Thinking IN space. This happens in our daily activities, when we move from one place to another, or when we arrange things in space, as these big amount of unread papers in my desk :-(
  • Thinking ABOUT space. This is more related to geographic science, and to the study of how reality is organized spatially. Maps and 3D models are convinient ways to think about space.
  • Thinking WITH space. Sometimes we use spatial representations for abstract or complex concepts or theories. An example could be a hierarchy diagram of an ontology classes. Also graphs, concept maps etc. are powerful tools to think with space.

These three contexts overlap so often. For instance, in Geospatial ontologies modeling, we use space (WITH space) to model how we think spatially (IN space), and try to approach our traditional ways to explain space (ABOUT space).

Information, Location aware or Vision aware?

CINeSPACE, experiencing urban film and cultural heritage while on the move, is a 6th Framework Programme european project in its second year. One of its main objetives is providing a rich media delivery platform for distributing specific, location-based urban, cultural and film information. The access to the content is semantically enhanced, so information can be filtered according to the context or user profiles.

As part of this project we are studing how humans interact with our physical context. The scenario changes when humans interact with the context, and with the multimedia available in that context. To model his scenario we should consider not only where we are but also where we are looking at.

We have analyzed geotagging process in social information spaces and found that there exists an ambivalent meaning for geographic points in such process. The geographic lat/long usually refers to the target of the video or photo, but sometimes the place where the photo was taken from is recorded. We call this issue the source-target problem in geotagging processes. Again, location and sight concepts are merged.

We have devised Geoconcepts ontology, which attempts at exploding the source-target problem. The results of this research will be presented at ICGIS 2008 conference.

Several new proposals are focusing on the “vision aware” context, and thanks to image recognition, providing related information. Some days ago Mans Shapshak introduced us Photosynth, a virtual 3D photo browser. It’s a pretty cool tool, which allows walking or flying through a virtual scene to see photos from any angle. But one thing is getting this working in a PC, and a different one to incorporate it to a mobile device.

Eyephone, in the other side, makes a realistic proposal for mobile device leaving all processing costs to server side. A demo is showed below. Using advanced object recognition from SuperWise Technologies they take as an input the GPS position, a photograph taken by the user, and the relative angle of vision to provide information about the location the user is looking at. You will think, It is perfect! Well, it would, if they had a prototype in the market…

We have made a small step in order to integrate vision and location to geospatial semantics, but more research is needed. Both meanings should be taken into account in systems which provide multimedia content while on the move, as in CINeSPACE.

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