BibSonomy publications for /user/davidlan/ontologiesMon Mar 16 20:30:03 CET 2009{IEEE} {TRANSACTIONS} {ON} {KNOWLEDGE} {AND} {DATA} {ENGINEERING}February2261--272An adaptation of the vector-space model for ontology-based information retrieval192007ir ontologies semantic vector-space Semantic search has been one of the motivations of the Semantic Web since it was envisioned. We propose a model for the exploitation of ontology-based knowledge bases to improve search over large document repositories. In our view of Information Retrieval on the Semantic Web, a search engine returns documents rather than, or in addition to, exact values in response to user queries. For this purpose, our approach includes an ontology-based scheme for the semiautomatic annotation of documents and a retrieval system. The retrieval model is based on an adaptation of the classic vector-space model, including an annotation weighting algorithm, and a ranking algorithm. Semantic search is combined with conventional keyword-based retrieval to achieve tolerance to knowledge base incompleteness. Experiments are shown where our approach is tested on corpora of significant scale, showing clear improvements with respect to keyword-based search.Mon Mar 16 20:28:54 CET 2009The Semantic Web: Research and Applications455--470An {Ontology-Based} Information Retrieval Model2005ir ontologies semantic Semantic search has been one of the motivations of the Semantic Web since it was envisioned. We propose a model for the exploitation of ontology-based {KBs} to improve search over large document repositories. Our approach includes an ontology-based scheme for the semi-automatic annotation of documents, and a retrieval system. The retrieval model is based on an adaptation of the classic vector-space model, including an annotation weighting algorithm, and a ranking algorithm. Semantic search is combined with keyword-based search to achieve tolerance to {KB} incompleteness. Our proposal is illustrated with sample experiments showing improvements with respect to keyword-based search, and providing ground for further research and discussion.Mon Mar 16 20:28:11 CET 2009The Semantic Web523--536Ontology-Based Interpretation of Keywords for Semantic Search2008Keywords ontologies search semantic Current information retrieval (IR) approaches do not formally capture the explicit meaning of a keyword query but provide a comfortable way for the user to specify information needs on the basis of keywords. Ontology-based approaches allow for sophisticated semantic search but impose a query syntax more difficult to handle. In this paper, we present an approach for translating keyword queries to DL conjunctive queries using background knowledge available in ontologies. We present an implementation which shows that this interpretation of keywords can then be used for both exploration of asserted knowledge and for a semantics-based declarative query answering process. We also present an evaluation of our system and a discussion of the limitations of the approach with respect to our underlying assumptions which directly points to issues for future work.Mon Mar 16 20:27:28 CET 2009The Semantic Web931--935Ontology Mapping: An Information Retrieval and Interactive Activation Network Based Approach2008ir ontologies ontology_mapping Ontology mapping is to find semantic correspondences between similar elements of different ontologies. It is critical to achieve semantic interoperability in the WWW. This paper proposes a new generic and scalable ontology mapping approach based on propagation theory, information retrieval technique and artificial intelligence model. The approach utilizes both linguistic and structural information, measures the similarity of different elements of ontologies in a vector space model, and deals with constraints using the interactive activation network. The results of pilot study, the PRIOR, are promising and scalable.Mon Mar 16 20:22:30 CET 20091st International Workshop on Ambient Data Integration(to appear)Improving Search and Navigation by Combining Ontologies and Social Tags2008folksonomies ontologies search tagonto Mon Mar 16 20:22:01 CET 2009BIS36-47Lecture Notes in Business Information ProcessingTurning a Corporate Folksonomy into a Lightweight Corporate Ontology.72008folksology folksonomies ontologies Mon Mar 16 19:46:05 CET 2009Bridging the Gep between Semantic Web and Web 2.0 (SemNet 2007)30-43Bridging the Gap Between Folksonomies and the Semantic Web: An Experience Report2007folksonomies ontologies semantic While folksonomies allow tagging of similar resources with a variety of tags, their content retrieval mechanisms are severely hampered by being agnostic to the relations that exist between these tags. To overcome this limitation, several methods have been proposed to find groups of implicitly inter-related tags. We believe that content retrieval can be further improved by making the relations between tags explicit. In this paper we propose the semantic enrichment of folksonomy tags with explicit relations by harvesting the Semantic Web, i.e., dynamically selecting and combining relevant bits of knowledge from online ontologies. Our experimental results show that, while semantic enrichment needs to be aware of the particular characteristics of folksonomies and the Semantic Web, it is beneficial for both.Mon Mar 16 19:45:31 CET 2009Bridging the Gep between Semantic Web and Web 2.0 (SemNet 2007)57-70FolksOntology: An Integrated Approach for Turning Folksonomies into Ontologies2007folksonomies folksontology ontologies We can observe that the amount of non-toy domain ontologies is still very limited for many areas of interest. In contrast, folksonomies are widely in use for (1) tagging Web pages (e.g. del.icio.us), (2) annotating pictures (e.g. flickr), or (3) classifying scholarly publications (e.g. bibsonomy). However, such folksonomies cannot offer the expressivity of ontologies, and the respective tags often lack a context-independent and intersubjective definition of meaning. Also, folksonomies and other unsupervised vocabularies frequently suffer from inconsistencies and redundancies. In this paper, we argue that the social interaction manifested in folksonomies and in their usage should be exploited for building and maintaining ontologies. Then, we sketch a comprehensive approach for deriving ontologies from folksonomies by integrating multiple resources and techniques. In detail, we suggest combining (1) the statistical analysis of folksonomies, associated usage data, and their implicit social networks, (2) online lexical resources like dictionaries, Wordnet, Google and Wikipedia, (3) ontologies and Semantic Web resources, (4) ontology mapping and matching approaches, and (5) functionality that helps human actors in achieving and maintaining consensus over ontology element suggestions resulting from the preceding steps.Mon Mar 16 19:42:48 CET 2009Bridging the Gep between Semantic Web and Web 2.0 (SemNet 2007)127-138myOntology: The Marriage of Ontology Engineering and Collective Intelligence2007folksonomies ontologies semantic Despite very active research on ontologies, only few useful ontologies can be found on the Web. The reasons for this are manifold, but a major obstacle is that ontology engineering environments impose high entrance barriers on users, and that the community does not have control over the ontology evolution. Wikis are a way to allow a wide range of users to contribute to Web representations without requiring more than basic Web editing skills. In the myOntology project, we propose the use of wiki technology in order to enable collaborative and community-driven ontology building by giving users with no or little expertise in ontology engineering the opportunity to contribute. In this paper, we describe the myOntology project in which the challenges of collaborative, community-driven, and wiki-based ontology engineering are investigated. Our approach combines the simplicity of wikis with intuitive visualization techniques and small yet efficient helper functionality plus consensus finding support exploiting the collective intelligence of a community.Mon Mar 16 19:40:36 CET 2009Boulder, ColoradoProceedings of the First International Conference on Weblogs and Social Media (ICWSM)March{Using Ontologies to Strengthen Folksonomies and Enrich Information Retrieval in Weblogs}2007folksonomies ir ontologies While free-tagging classification is widely used in social software implementations and especially in weblogs, it raises various issues regarding information retrieval. In this paper, we describe an approach that mixes folksonomies and semantic web technologies in order to solve some of these problems, and to enrich information retrieval capabilities among blog posts. We first introduce the corporate context of the study and the issues we have faced that motivated our approach. Then, we argue how the use of domain ontologies combined with the SIOC vocabulary on the top of an existing folksonomy and weblogging platform offers a way to get rid of free-tagging classification flaws, and enhances information retrieval by suggesting related blog posts. Aside of the theoretical background, this paper also focuses on implementation. We present experimental results of this approach through the example of add-ons to a corporate blogging platform and the associated semantic web search engine, that extensively uses RDF and other semantic web technologies to find appropriate information and suggest related posts.Mon Mar 16 13:34:17 CET 2009Bridging the Gep between Semantic Web and Web 2.0 (SemNet 2007)14-21Combining Social and Semantic Metadata for Search in a Document Repository2007folksonomies ontologies search semantic social With the success of social applications like Flickr, del.icio.us and YouTube, social software has become the focus of several research initiatives. Especially the idea of combining social and semantic aspects has been recently gaining significant attention in the semantic web community. In this paper we research and discuss the properties of metadata in social systems (folksonomies) compared to metadata in semantic systems (ontologies). We then present our idea for creating a link between a folksonomy and an ontology in order to combine the usability and flexibility of folksonomies with the precision of ontologies for a semantic search application. Our approach is motivated by the requirements of the OnTourism project, which has the goal of creating a document repository which benefits from both ontology and folksonomy metadata.