Browsing Research Institutes and Centres by Author "Umbrich, Jürgen"

Now showing items 1-11 of 11

    • Building a Semantic Web Search Engine: Challenges and Solutions 

      Harth, Andreas; Hogan, Aidan; Umbrich, Jürgen; Decker, Stefan (2008)
      Current web search engines return links to documents for user-specified keywords queries. Users have to then manually trawl through lists of links and glean the required information from documents. In contrast, semantic ...

    • DING! Dataset Ranking using Formal Descriptions 

      Toupikov, Nickolai; Umbrich, Jürgen; Delbru, Renaud; Hausenblas, Michael; Tummarello, Giovanni (2009)
      Considering that thousands if not millions of linked datasets will be published soon, we motivate in this paper the need for an efficient and effective way to rank interlinked datasets based on formal descriptions of their ...

    • Fast and Scalable Pattern Mining for Media-Type Focused Crawling 

      Umbrich, Jürgen; Karnstedt, Marcel; Harth, Andreas (2009)
      Search engines targeting content other than hypertext documents require a crawler that discovers resources identifying files of certain media types. Naive crawling approaches do not guarantee a sufficient supply of new ...

    • Four Heuristics to Guide Structured Content Crawling 

      Umbrich, Jürgen; Harth, Andreas; Hogan, Aidan; Decker, Stefan (2008)
      Search engines focusing on particular media types face difficulties in discovering suitable URIs on the Web. Since the engines are only interested in a small fraction of the Web, a crawler should use heuristics to concentrate ...

    • Freshening up while Staying Fast: Towards Hybrid SPARQL Queries 

      Umbrich, Jürgen; Karnstedt, Marcel; Hogan, Aidan; Parreira, Josiane Xavier (2012)

    • Querying over Federated SPARQL Endpoints - A State of the Art Survey 

      Rakhmawati, Nur; Umbrich, Jürgen; Karnstedt, Marcel; Hasnain, Ali; Hausenblas, Michael (2013)
      The increasing amount of Linked Data and its inherent distributed nature have attracted significant attention throughout the research community and amongst practitioners to search data, in the past years. Inspired by ...

    • SWSE: Answers Before Links! 

      Harth, Andreas; Hogan, Aidan; Delbru, Renaud; Umbrich, Jürgen; O'Riain, Sean; Decker, Stefan (CEUR-WS.org, 2007)
      We present a system that improves on current document- centric Web search engine technology; adopting an entity-centric perspective, we are able to integrate data from both static and live sources into a coherent, interlinked ...

    • SWSE: Objects before documents! 

      Harth, Andreas; Hogan, Aidan; Umbrich, Jürgen; Decker, Stefan (2008)
      Web search engines are immensely useful for locating documents online. However, with more and more structured data being published online, the restriction to the hyperdocument model impairs the usefulness for searching and ...

    • Towards Dataset Dynamics: Change Frequency of Linked Open Data Sources 

      Umbrich, Jürgen; Hausenblas, Michael; Hogan, Aidan; Polleres, Axel; Decker, Stefan (CEUR, 2010)
      Datasets in the LOD cloud are far from being static in their nature and how they are exposed. As resources are added and new links are set, applications consuming the data should be able to deal with these changes. In ...

    • Web of Data Plumbing - Lowering the Barriers to Entry 

      Umbrich, Jürgen; Hastrup, Tuukka; Hausenblas, Michael (2009)
      Publishing and consuming content on the Web of Data often requires considerable expertise in the underlying technologies, as the expected services to achieve this are either not packaged in a simple and accessible manner, ...

    • YARS2: A Federated Repository for Querying Graph Structured Data from the Web 

      Harth, Andreas; Umbrich, Jürgen; Hogan, Aidan; Decker, Stefan (2007)
      We present the architecture of an end-to-end semantic search engine that uses a graph data model to enable interactive query answering over structured and interlinked data collected from many disparate sources on the Web. ...