Carsten Keßler

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A tool for spatially related discussions which is easily adaptable to different use cases can be utilized in numerous fields of application. This thesis presents a prototype implementation serving for asynchronous, distributed, spatially related discussions which is based on the argumentation map model introduced by Rinner (1999). Different approaches are(More)
Similarity measurement is currently being established as a method to explore content on the Semantic Web. Semantically annotated content requires formal concept specifications. Such concepts are dynamic and their semantics can change depending on the current context. The influence of context on similarity measurement is beyond dispute and reflected in(More)
High availability and diversity make Volunteered Geographic Information (VGI) an interesting source of information for an increasing number of use cases. Varying quality, however, is a concern often raised when it comes to using VGI in professional applications. Recent research directs towards the estimation of VGI quality through the notion of trust as a(More)
Geographical information retrieval (GIR) can benefit from context information to adapt the results to a user’s current situation and personal preferences. In this respect, semantics-based GIR is especially challenging because context information – such as collected from sensors – is often provided through numeric values, which need to be mapped to(More)
As directories of named places, gazetteers link the names to geographic footprints and place types. Most existing gazetteers are managed strictly top-down: entries can only be added or changed by the responsible toponymic authority. The covered vocabulary is therefore often limited to an administrative view on places, using only official place names. In(More)
Based on abstract reference models, the Open Geospatial Consortium (OGC) has established standards for the storage, retrieval, and processing of geographical information. These standards act as foundation for the implementation of concrete services and Spatial Data Infrastructures (SDI). Research on geo-semantics plays an increasing role to support complex(More)
Technologies associated with the second-generation of the World-Wide Web enable virtually anyone to share their data, documents, observations, and opinions on the Internet. In less than three years, mapping platforms such as Google Maps have sparked an exponential growth in user-generated geographically referenced content. However, the “serious”(More)
Carsten Keßler, Claus Rinner, Martin Raubal 1 Institute for Geoinformatics (IfGI), University of Münster Robert-Koch-Str. 26-28, 48149 Münster, Germany carsten.kessler |, phone +49-251-83-39769, fax +49-251-83-39763 2 Department of Geography, University of Toronto 100 St. George Street, Toronto ON M5S 3G3, Canada(More)
Gazetteers are more than basic place name directories containing names and locations for named geographic places. Most of them contain additional information, including a categorization of gazetteer entries using a typing scheme. This paper focuses on the nature of these categorization schemes. We argue that gazetteers can benefit from an ontological(More)