- KonferenzbeitragMapping Cognitive Models to Social Semantic Spaces – Collaborative Development of Project Ontologies(The Social Semantic Web 2007 – Proceedings of the 1st Conference on Social Semantic Web (CSSW), 2007) Riechert, Thomas; Lohmann, SteffenIn this paper, we present an approach that applies concepts from the areas of Social Software and Semantic Web to application development. We start with a short introduction into Semantic Based Requirements Engineering. Then, we present an ontology for capturing requirements and related information. Based on this ontology, we describe how stakeholders are enabled to directly participate in requirements elicitation and to collaboratively create a project ontology. Finally, we report about the application of the presented approach in a use case from the e-government domain.
- KonferenzbeitragCollaborative Metadata for Geographic Information(The Social Semantic Web 2007 – Proceedings of the 1st Conference on Social Semantic Web (CSSW), 2007) Maué, PatrickRetrieval of web-based geographic information (GI) for spatial decision- making processes can benefit from emerging semantic technologies. Ontology-supported metadata, collaboratively created by a social network of spatially-aware users, ensures efficient and precise discovery of maps published with the help of catalogs. The creation and maintenance of the metadata is driven by two forces: on the one hand experienced catalogers who ensure consistency and quality, on the other hand catalog users who continuously adapt and extend the metadata. We discuss the requirements for a catalog for GI which is able to capture the semantics emerging within a community and apply the results to the registered metadata.
- KonferenzbeitragImplementing SPARQL Support for Relational Databases and Possible Enhancements(The Social Semantic Web 2007 – Proceedings of the 1st Conference on Social Semantic Web (CSSW), 2007) Weiske, Christian; Auer, SörenIn order to make the Semantic Web real we need the infrastructure to store, query and update information adhering to the RDF paradigm. Such infrastructure can be developed from scratch or benefit from developments and experiences made in other science & technology realms such as within the database domain. For querying RDF data the World Wide Web Consortium released a Working Draft for the SPARQL query language. A large portion of the Web is meanwhile driven by server-side Web applications. PHP is the scripting language most widely used for Web applications. In this paper we present our PHP implementation of the SPARQL standard directly interacting with an underlying database system. The approach is based on the rationale of pushing as much work into the RDBMS as possible in order to profit most from the query optimization techniques developed for relational database systems. The article includes an evaluation of the performance and standard compliance, surveys limitations we discovered when using SPARQL for the implementation of real-life Semantic Web applications and suggests extensions to the SPARQL standard in order to solve these obstacles.
- KonferenzbeitragRDF Support in the Virtuoso DBMS(The Social Semantic Web 2007 – Proceedings of the 1st Conference on Social Semantic Web (CSSW), 2007) Erling, Orri; Mikhailov, IvanThis paper discusses RDF related work in the context of OpenLink Virtuoso, a general purpose relational / federated database and applications platform. We discuss adapting a relational engine for native RDF support with dedicated data types, bitmap indexing and SQL optimizer techniques. We further discuss mapping existing relational data into RDF for SPARQL access without converting the data into physical triples. We present conclusions and metrics as well as a number of use cases, from DBpedia to bio informatics and collaborative web applications.
- KonferenzbeitragA Prototype to Explore Content and Context on Social Community Sites(The Social Semantic Web 2007 – Proceedings of the 1st Conference on Social Semantic Web (CSSW), 2007) Bojārs, Uldis; Heitmann, BenjaminThe SIOC Ontology can be used to express information from the online community sites in a machine-readable form using RDF. This rich data structure allows us to easily analyse and extract social relations from these community sites. We use SIOC information to analyse the social relations between users through the content that they create. We introduce metrics for social neighbourhood and social reputation, formally expressed as SPARQL queries over SIOC data. Finally, we demonstrate these algorithms in our Social SIOC Explorer prototype.
- KonferenzbeitragWeaving Space into the Web of Trust: An Asymmetric Spatial Trust Model for Social Networks(The Social Semantic Web 2007 – Proceedings of the 1st Conference on Social Semantic Web (CSSW), 2007) Bishr, MohamedThe proliferation of Geo-Information (GI) production in web-based collaboration environments such as mapping mashups built on top of mapping APIs such as GoogleMaps API poses new challenges to GI Science. In this environment, millions of users are not only consumers of GI but they are also producers. A major challenge is how to manage this huge flow of information and identify high value contributions while discarding others. The social nature of the collaborative approaches to GI provides the inspiration for innovative solutions. In this paper, we propose a novel spatial trust model for social networks. This model is part of our research to formalize the spatio-temporal regularities of trust in social networks. The presented model provides a metric for trust as a proxy for GI quality to assess the value of collaborative contributions. We also introduce the underlying network for the model, which is a hybrid network structure for collaborative GI applications based on affiliation networks and one-mood continuous trust networks. Trust calculation in the affiliation network takes into account the geographic distance between the actors and their information contributions –also known as events–, while the one-mood network does not. This leads to an asymmetric model with respect to the representation of space.
- KonferenzbeitragCollaborative Web-Publishing with a Semantic Wiki(The Social Semantic Web 2007 – Proceedings of the 1st Conference on Social Semantic Web (CSSW), 2007) Landefeld, Rico; Sack, HaraldSemantic wikis have been introduced for collaborative authoring of ontologies as well as for annotating wiki content with semantic meta data. In this paper, we introduce a different approach for a semantic wiki based on an ontology meta model customized especially for the deployment within a wiki. For optimal usability client- side technologies have been combined with a simple semantic query language. Text fragments of a wiki page can be annotated in an interactive and rather intuitive way to minimize the additional effort that is necessary for adding semantic annotation. Thus, the productivity and efficiency of a semantic wiki system will open up for non expert users as well.
- KonferenzbeitragAlternative Searching Services: Seven Theses on the Importance of "Social Bookmarking"(The Social Semantic Web 2007 – Proceedings of the 1st Conference on Social Semantic Web (CSSW), 2007) Graefe, Gernot; Maaß, Christian; Heß, AndreasIn recent years social bookmark systems like del.icio.us Furl have become increasingly popular. These systems sometimes are regarded as alternatives to algorithmic search engines like Google. In this paper we develop seven theses on the potential of these systems in order to establish a conceptual basis for future research in this area. Thereby it becomes clear that social bookmarking systems complement rather than threaten algorithmic search engines.
- KonferenzbeitragSemantic Wikipedia – Checking the Premises(The Social Semantic Web 2007 – Proceedings of the 1st Conference on Social Semantic Web (CSSW), 2007) Hammwöhner, RainerEnhancing Wikipedia by means of semantic representations seems to be a promising issue. From a formal or technical point of view there are no major obstacles in the way. Nevertheless, a close look at Wikipedia, its structure and contents reveals that some questions have to be answered in advance. This paper will deal with these questions and present some first results based on empirical findings.