Curate and storyspace: an ontology and web-based environment for describing curatorial narratives

Existing metadata schemes and content management systems used by museums focus on describing the heritage objects that the museum holds in its collection. These are used to manage and describe individual heritage objects according to properties such as artist, date and preservation requirements. Curatorial narratives, such as physical or online exhibitions tell a story that spans across heritage objects and have a meaning that does not necessarily reside in the individual heritage objects themselves. Here we present curate, an ontology for describing curatorial narratives. This draws on structuralist accounts that distinguish the narrative from the story and plot, and also a detailed analysis of two museum exhibitions and the curatorial processes that contributed to them. Storyspace, our web based interface and API to the ontology, is being used by curatorial staff in two museums to model curatorial narratives and the processes through which they are constructed

SECF: Improving SPARQL Querying Performance with Proactive Fetching and Caching

Querying on SPARQL endpoints may be unsatisfactory due to high latency of connections to the endpoints. Caching is an important way to accelerate the query response speed. In this paper, we propose SPARQL Endpoint Caching Framework (SECF), a client-side caching framework for this purpose. In particular, we prefetch and cache the results of similar queries to recently cached query aiming to improve the overall querying performance. The similarity between queries are calculated via an improved Graph Edit Distance (GED) function. We also adapt a smoothing method to implement the cache replacement. The empirical evaluations on real world queries show that our approach has great potential to enhance the cache hit rate and accelerate the querying speed on SPARQL endpoints

Semantic web-based document: editing and browsing in AktiveDoc

This paper presents a tool for supporting sharing and reuse of knowledge in document creation (writing) and use (reading). Semantic Web technologies are used to support the production of ontology based annotations while the document is written. Free text annotations (comments) can be added to integrate the knowledge in the document. In addition the tool uses external services (e.g. a Semantic Web harvester) to propose relevant content to writing user, enabling easy knowledge reuse. Similar facilities are provided for readers when their task does not coincide with the author’s one. The tool is specifically designed for Knowledge Management in organisations. In this paper we present and discuss how Semantic Web technologies are designed and integrated in the system

Semantics, sensors, and the social web: The live social semantics experiments

The Live Social Semantics is an innovative application that encourages and guides social networking between researchers at conferences and similar events. The application integrates data and technologies from the Semantic Web, online social networks, and a face-to-face contact sensing platform. It helps researchers to find like-minded and influential researchers, to identify and meet people in their community of practice, and to capture and later retrace their real-world networking activities at conferences. The application was successfully deployed at two international conferences, attracting more than 300 users in total. This paper describes this application, and discusses and evaluates the results of its two deployment

Ontology Services for Knowledge Organization Systems

Ontologies and other knowledge organization systems, such as controlled vocabularies, can be used to enhance the findability of information. By describing the contents of documents using a shared, harmonized terminology, information systems can provide efficient search and browsing functionalities for the contents. Explicit descriptive metadata aims to solve some of the prevailing issues in full text search in many search engines, including the processing of synonyms and homonyms. The use of ontologies as domain models enables the machine-processability of contents, semantic reasoning, information integration, and other intelligent ways of processing the data. The utilization of knowledge organization systems in content indexing and information retrieval can be facilitated by providing automated tools for their efficient use. This thesis studies and presents novel methods and systems for publishing and using knowledge organization systems as ontology services. The research is conducted by designing and evaluating prototype systems that support the use of ontologies in real-life use cases. The research follows the principles of the design science and action research methodologies. The presented ONKI system provides user interface components and application programming interfaces that can be integrated into external applications to enable ontology-based workflows. The features of the system are based on analyzing the needs of the main user groups of ontologies. The common functionalities identified in ontology-based workflows include concept search, browsing, and selection. The thesis presents the Linked Open Ontology cloud approach for managing and publishing a set of interlinked ontologies in an ontology service. The system enables the users to use multiple ontologies as a single, interoperable, cross-domain representation instead of individual ontologies. For facilitating the simultaneous use of ontologies published in different ontology repositories, the Normalized Ontology Repository approach is presented. As a use case of managing and publishing a semantically rich knowledge organization system as an ontology, the thesis presents the Taxon Meta-Ontology model for biological nomenclatures and classifications. The model supports the representation of changes and differing opinions of taxonomic concepts. The ONKI system and the ontologies developed using the methods presented in this thesis have been provided as a living lab service http://onki.fi, which has been run since 2008. The service provides tools and support for the users of ontologies, including content indexers, information searchers, ontology developers, and application developers.Ontologioita ja muita tietämyksen järjestämisen menetelmiä, kuten kontrolloituja sanastoja, voidaan käyttää tiedon löytämisen parantamiseksi. Kun dokumenttien sisällöt kuvaillaan käyttämällä jaettua, yhtenäistettyä terminologiaa, tietojärjestelmät voivat tarjota tehokkaita haku- ja selaustoiminnallisuuksia sisältöihin. Eksplisiittisesti esitetty, kuvaileva metatieto pyrkii ratkaisemaan monien hakukoneiden käyttämän kokotekstihaun ongelmia, kuten synonyymien ja homonyymien huomioimisen. Ontologioiden käyttäminen käsitemalleina mahdollistaa sisältöjen koneellisen käsittelyn, semanttisen päättelyn, tiedon integroinnin ja muita älykkäitä menetelmiä. Tietämyksen järjestämisen menetelmien hyödyntämistä sisältöjen indeksoinnissa ja haussa voidaan helpottaa tarjoamalla käyttäjille automatisoituja työkaluja niiden tehokkaaseen käyttämiseen. Tässä väitöskirjassa tutkitaan ja esitetään uudenlaisia menetelmiä ja järjestelmiä tietämyksen järjestämisen menetelmien julkaisemiseksi ontologiapalveluina. Tutkimus on toteutettu suunnittelemalla ja arvioimalla prototyyppijärjestelmiä, jotka edistävät ontologioiden käyttämistä todellisissa käyttötapauksissa. Tutkimus nojautuu suunnittelutieteen ja toimintatutkimuksen metodologioiden periaatteisiin. Työssä esitetty ONKI-järjestelmä tarjoaa käyttöliittymäkomponentteja ja ohjelmallisia rajapintoja, jotka voidaan integroida ulkoisiin sovelluksiin ontologiaperustaisten työnkulkujen mahdollistamiseksi. Järjestelmän ominaisuudet on toteutettu perustuen ontologioiden keskeisten käyttäjäryhmien tarpeiden selvittämiseen. Ontologiaperustaisista työnkuluista tunnistettuja yleisiä toiminnallisuuksia ovat käsitteen haku, selailu ja valinta. Tässä työssä esitetään linkitetyn avoimen ontologiapilven menetelmä toisiinsa linkitettyjen ontologioiden ylläpitämiseen ja julkaisemiseen ontologiapalvelussa. Järjestelmän avulla käyttäjät voivat käyttää useita ontologioita yhtenä, yhteentoimivana, alat yhdistävänä kokonaisuutena erillisten ontologioiden sijaan. Eri ontologiapalveluissa julkaistujen ontologioiden samanaikaisen käytön helpottamiseksi esitetään normalisoidun ontologiapalvelun menetelmä. Käyttötapauksena semanttisesti rikkaan tietämyksen järjestämisen menetelmän ylläpitämisestä ja julkaisemisesta työssä esitetään biologisten nimistöjen ja luokitusten taksonominen ontologiamalli. Malli mahdollistaa taksonomisten käsitteiden muutosten ja toisistaan poikkeavien näkemysten esittämisen. ONKI-järjestelmä ja työssä esitetyillä menetelmillä kehitetyt ontologiat ovat olleet käytettävissä living lab -palvelussa http://onki.fi, joka on ollut toiminnassa vuodesta 2008 lähtien. Palvelu tarjoaa työkaluja ja tukea ontologioiden käyttäjille, kuten tiedon indeksoijille, hakijoille, ontologioiden kehittäjille ja sovelluskehittäjille

SW @ SPAIN

Executive Summary: This report provides information about the current state of the art in Semantic Web research in Spain. The contents of this report are mainly based on the information that was gathered during the workshop "Ontologías y Web Semántica 2005", which was held in Santiago de Compostela in November 2005, and the contributions that members from most of the research groups working in Semantic-Webrelated areas in Spain have provided. The field of Semantic Web is quite widespread in Spain, with important groups developing methods, techniques and tools to support different areas: Ontological Engineering, semantic extraction and annotation from heterogeneous sources, semantic search engines, personalisation and Semantic Web Services

Continuous client-side query evaluation over dynamic linked data

Existing solutions to query dynamic Linked Data sources extend the SPARQL language, and require continuous server processing for each query. Traditional SPARQL endpoints already accept highly expressive queries, so extending these endpoints for time-sensitive queries increases the server cost even further. To make continuous querying over dynamic Linked Data more affordable, we extend the low-cost Triple Pattern Fragments (TPF) interface with support for time-sensitive queries. In this paper, we introduce the TPF Query Streamer that allows clients to evaluate SPARQL queries with continuously updating results. Our experiments indicate that this extension significantly lowers the server complexity, at the expense of an increase in the execution time per query. We prove that by moving the complexity of continuously evaluating queries over dynamic Linked Data to the clients and thus increasing bandwidth usage, the cost at the server side is significantly reduced. Our results show that this solution makes real-time querying more scalable for a large amount of concurrent clients when compared to the alternatives