Abstract The workshop on The Cultural Heritage of Historic European Cities and Public Participatory GIS aims at outlining the challenges to develop a ppGIS which can integrate data from different ages, authorities, and formats. This data ranges from archival catalogs, maps, photographs, film, aural archives over archaeological data to interpretative studies. With respect to spatial resolution, data should be available down to the level of single streets or even specific properties. Instead of a static approach, users should also be able to contribute new data to the system. This raises a couple of questions which are also relevant in a broader context, namely the ontological representation of and reasoning about geographic places. This paper introduces the challenges of modeling places in such a heterogeneous setting, outlines steps towards a three layered solution on how to represent, reference, and reason about geographic places, and finally sketches how to deal with inconsistent and contradictory knowledge.

Janowicz, K. (2009): The Role of Place for the Spatial Referencing of Heritage Data. The Cultural Heritage of Historic European Cities and Public Participatory GIS Workshop. The University of York, UK 17-18 September 2009

We just finished a substantially extended and rewritten version of the poster accepted for EuroSSC 2009 (update: the paper was accepted, see below):

Abstract Building on abstract reference models, the Open Geospatial Consortium (OGC) has established standards for storing, discovering, and processing geographical information. These standards act as basis for the implementation of specific services and Spatial Data Infrastructures (SDI). Research on geo-semantics plays an increasing role to support complex queries and retrieval across heterogeneous information sources, as well as for service orchestration, semantic translation, and on-the-fly integration. So fa r, this research targets individual solutions or focuses on the Semantic Web, leaving the integration into SDI aside. What is missing is a shared and transparent semantic enablement layer for Spatial Data Infrastructures which also integrates reasoning services known from the Semantic Web. Focusing on Sensor Web Enablement (SWE) we outline how Spatial Data Infrastructures in general can benefit from such a semantic enablement layer. Instead of developing new semantically enabled services from scratch, we propose to create profiles of existing services that implement a transparent mapping between the OGC and the Semantic Web world.

Janowicz, K. Schade, S., Bröring, A., Keßler, C., and Stasch, C. (2009; forthcomming): A Transparent Semantic Enablement Layer for the Geospatial Web. Terra Cognita 2009 Workshop In conjunction with the 8th International Semantic Web Conference (ISWC 2009), October 26, 2009.

A short paper that we have submitted today as part of the 52° North semantics community (update: it has been accepted for the EuroSSC 2009).

Abstract 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 groundwork for the implementation of concrete services and Spatial Data Infrastructures (SDI). Research on geo-semantics plays an increasing role to support complex queries and discovery across heterogeneous information sources, as well as for on-the-fly integration and semantic translation. So far, existing approaches only target individual solutions or focus on the Semantic Web, leaving the integration into SDI aside. What is missing is a common semantic enablement layer on top of spatial data infrastructures which also integrates reasoning services from the semantic web. Focusing on Sensor Web Enablement (SWE) we outline how spatial data infrastructures can benefit from such semantic enablement layer.

Krzysztof Janowicz, Carsten Keßler, Arne Bröring, and Christoph Stasch. Towards Semantic Enablement for Spatial Data Infrastructures

We finally managed to write down our vision for the next generation of gazetteers, the work that has already been done in this area, and point to the missing pieces to make this vision come true. attached is a link to our draft, I will replace it if the paper gets accepted (update: the paper has been accepted, see below).

Abstract: Gazetteers are key components of georeferenced information systems, including  applications such as Web-based mapping services. Existing gazetteers lack the capabilities to fully integrate user-contributed and vernacular geographic information, as well as to support complex queries. To address these issues, a next generation gazetteer should leverage formal semantics, harvesting of implicit geographic information — such as geotagged photos — as well as models of trust for contributors. In this paper, we discuss these requirements in detail. We elucidate how existing standards can be integrated to realize a gazetteer infrastructure allowing for bottom-up contribution as well as information exchange between different gazetteers. We show how to ensure the quality of user-contributed information and demonstrate how to improve querying and navigation using semantics-based information retrieval.

Kessler, C., Janowicz, K., and Bishr, M. (2009; forthcoming): An Agenda For The Next Generation Gazetteer: Geographic Information Contribution and Retrieval. In International Conference on Advances in Geographic Information Systems 2009 (ACM SIGSPATIAL GIS 2009)

Abstract. While semantic similarity plays a crucial role for human categorization and reasoning, computational similarity measures have also been applied to fields such as semantics-based information retrieval or ontology engineering. Several measures have been developed to compare concepts specified in various description logics. In most cases, these measures are either structural or require a populated ontology. Structural measures fail with an increasing expressivity of the used description logic, while several ontologies, e.g., geographic feature type ontologies, are not populated at all. In this paper, we present an approach to reduce inter-concept to inter-instance similarity and thereby avoid the canonization problem of structural measures. The novel approach, called SIM-DL_A, reuses existing similarity functions such as co-occurrence or network measures from our previous SIM-DL measure. The required instances for comparison are derived from the completion tree of a slightly modified DL-tableau algorithm as used for satisfiability checking. Instead of trying to find one (clash-free) model, the new algorithm generates a set of proxy individuals used for comparison. The paper presents the algorithm, alignment matrix, and similarity functions as well as a detailed example.

Janowicz, K. and Wilkes, M. (2009; forthcoming): SIM-DL_A: A Novel Semantic Similarity Measure for Description Logics Reducing Inter-Concept to Inter-Instance Similarity. The 6th Annual European Semantic Web Conference (ESWC2009). Lecture Notes in Computer Science 5554, Springer. pp. 353-367, 2009.