Algorithms, Performance (2008)
Markus Stocker, Christoph Kiefer
In this paper, we formalize the problem of Basic Graph Pattern (BGP) optimization for SPARQL queries and main memory graph implementations of RDF data. We define and analyze the characteristics of...
Retrieval–query formulation, search process (2008)
Abraham Bernstein, Christoph Kiefer
Traditional semantic web query languages support a logicbased access to the semantic web. They offer a retrieval (or reasoning) of data based on facts. On the traditional web and in databases,...
Imprecise SPARQL: Towards a Unified Framework for Similarity-Based Semantic Web Tasks (2008)
Abstract. This proposal explores a unified framework to solve Semantic Web tasks that often require similarity measures, such as RDF retrieval, ontology alignment, and semantic service matchmaking....
Christoph Kiefer, Abraham Bernstein, Markus Stocker
Abstract. This research explores three SPARQL-based techniques to solve Semantic Web tasks that often require similarity measures, such as semantic data integration, ontology mapping, and Semantic...
Organization Workshop Organizers (2008)
Stephan Bloehdorn, Marko Grobelnik, Peter Mika, Thanh Tran Duc, Bettina Berendt, Paul Buitelaar, ...
International Workshop located at the
Semantic Process Retrieval with iSPARQL (2007)
Christoph Kiefer, Abraham Bernstein, Mark Klein, Markus Stocker
Abstract. The vision of semantic business processes is to enable the integration and inter-operability of business processes across organizational boundaries. Since different organizations model...
SPARQL Query Optimization Using Selectivity Estimation (2007)
Abraham Bernstein, Markus Stocker, Christoph Kiefer
Abstract. This poster describes three static SPARQL optimization approaches for in-memory RDF graphs: (1) a selectivity estimation index (SEI) for single query triple patterns; (2) a query pattern...
OptARQ: A SPARQL Optimization Approach based on Triple Pattern Selectivity Estimation (2007)
Abraham Bernstein, Christoph Kiefer, Markus Stocker
Abstract Query engines for ontological data based on graph models mostly execute user queries without considering any optimization. Especially for large ontologies, optimization techniques are...
Imprecise SPARQL: Towards a Unified Framework for Similarity-Based Semantic Web Tasks (2007)
Abstract. This proposal explores a unified framework to solve Semantic Web tasks that often require similarity measures, such as RDF retrieval, ontology alignment, and semantic service matchmaking....
Abraham Bernstein, Esther Kaufmann, Christian Kaiser, Christoph Kiefer
The Semantic Web presents the vision of a distributed, dynamically growing knowledge base founded on formal logic. Common users, however, seem to have problems even with the simplest Boolean...
Generic Similarity Detection in Ontologies with the (2006)
Patrick Ziegler, Christoph Kiefer, Christoph Sturm, Klaus R. Dittrich, Abraham Bernstein
Ontologies are increasingly used to represent the intended real-world semantics of data and services in information systems. Unfortunately, di#erent data sources often do not relate to the same...
Detecting Similarities in Ontologies with the SOQA-SimPack Toolkit (2006)
Patrick Ziegler, Christoph Kiefer, Christoph Sturm, Klaus R. Dittrich, Abraham Bernstein
Ontologies are increasingly used to represent the intended real-world semantics of data and services in information systems. Unfortunately, di#erent databases often do not relate to the same...
Detecting Similar Java Classes Using Tree Algorithms (2006)
Tobias Sager, Abraham Bernstein, Martin Pinzger, Christoph Kiefer
Similarity analysis of source code is helpful during development to provide, for instance, better support for code reuse. Consider a development environment that analyzes code while typing and that...
Michael Würsch, Prof Dr, Harald C. Gall, Beat Fluri, Christoph Kiefer
This document sets the direction for my diploma thesis on the subject how applying similarity measures might improve abstract syntax tree based source code change detection. It defines the main...
Querying ontologies: A controlled english interface for end-users (2005)
Abraham Bernstein, Esther Kaufmann, Anne Göhring, Christoph Kiefer
Abstract. The semantic web presents the vision of a distributed, dynamically growing knowledge base founded on formal logic. Common users, however, seem to have problems even with the simplest...
Querying ontologies: A controlled english interface for end-users (2005)
Abraham Bernstein, Esther Kaufmann, Anne Göhring, Christoph Kiefer
Abstract. The semantic web presents the vision of a distributed, dynamically growing knowledge base founded on formal logic. Common users, however, seem to have problems even with the simplest...
SimPack: A Generic Java Library for Similarity Measures in Ontologies (2005)
Abraham Bernstein, Esther Kaufmann, Christoph Kiefer, Christoph Bürki
Abstract Good similarity measures are central for techniques such as retrieval, matchmaking, clustering, data-mining, ontology translations, automatic database schema matching, and simple object...
Christoph Kiefer, Advisor Martin Spengler, Prof B. Schiele
People tracking is one major part of visual surveillance systems. A number of different people trackers exist nowadays. One of those multi-people trackers is the Reading People Tracker. It consists...