Kim Viljanen

MuseumFinland-Finnish museums on the semantic web

This article presents the semantic portal MuseumFinland for publishing heterogeneous museum collections on the Semantic Web. It is shown how museums with their semantically rich and interrelated collection content can create a large, consolidated semantic collection portal together on the web. By sharing a set of ontologies, it is possible to make collections semantically interoperable, and provide the museum visitors with intelligent content-based search and browsing services to the global collection base. The architecture underlying MuseumFinland separates generic search and browsing services from the underlying application dependent schemas and metadata by a layer of logical rules. As a result, the portal creation framework and software developed has been applied successfully to other domains as well. MuseumFinland got the Semantic Web Challence Award (second prize) in 2004.

Application of Ontology Techniques to View-Based Semantic Search and Browsing

We show how the benefits of the view-based search method, developed within the information retrieval community, can be extended with ontology-based search, developed within the Semantic Web community, and with semantic recommendations. As a proof of the concept, we have implemented an ontology- and view-based search engine and recommendation system Ontogator for RDF(S) repositories. Ontogator is innovative in two ways. Firstly, the RDFS-based ontologies used for annotating metadata are used in the user interface to facilitate view-based information retrieval. The views provide the user with an overview of the repository contents and a vocabulary for expressing search queries. Secondly, a semantic browsing function is provided by a recommender system. This system enriches instance level metadata by ontologies and provides the user with links to semantically related relevant resources. The semantic linkage is specified in terms of logical rules. To illustrate and discuss the ideas, a deployed application of Ontogator to a photo repository of the Helsinki University Museum is presented.

Ontoviews: a tool for creating semantic web portals

This paper presents a semantic web portal tool OntoViews for publishing RDF content on the web. OntoViews provides the portal designer with a content-based search engine server, Ontogator, and a link recommendation system server, Ontodella. The user interface is created by combining these servers with the Apache Cocoon framework. From the end-users viewpoint, the key idea of OntoViews is to combine the multi-facet search paradigm, developed within the information retrieval research community, with semantic web RDFS ontologies, and extend the search service with a semantic browsing facility based on ontological reasoning. Onto Views is presented from the viewpoints of the end-user, architecture, and implementation. The implementation described is modular, easily modified and extended, and provides a good practical basis for creating semantic portals on the web. As a proof of concept, application of Onto Views to a deployed semantic web portal is discussed.

Normalized Access to Ontology Repositories

Ontology repositories, such as NCBO Bioportal, ONKI and Cupboard, help finding and using ontologies on the Semantic Web. However, currently each ontology repository constitutes a separate island with its own user interface, APIs, users, ontology languages and set of ontologies. Because there is not a universal way to access all ontology repositories, doing global search, browsing, and inference over all available ontology repositories turns out to be technically difficult and is generally not done. Ontologies are not reused as much as they could and hence the full potential of ontologies is not achieved. To address the problem, we propose the Normalized Ontology Repository (NOR) approach to make the ontology repositories universally accessible while maintaining their unique functionalities and strengths. The SKOS language is used as the lowest common denominator for presenting the ontologies. In addition, a simple API for searching and accessing the ontologies is defined. As a proof-of-concept evaluation, we present three case implementations to demonstrate the NOR approach: 1) the distributed architecture of the ONKI repository, 2) the metasearch for ONKI and NCBO Bioportal, and 3) publishing informal ontological concept collections as NOR end-points, demonstrated with the semantic portal Culture Sampo and the metadata editor SAHA.

A logic-based semantic web html generator - a poor man's publishing approach

This paper presents a method and a tool for publishing semantic web content in RDF(S) for the humans as a static HTML page site.