Mapping Relational Databases (RDB) to RDF is an active field of research. The majority of data on the current Web is stored in RDBs. Therefore, bridging the conceptual gap between the relational model and RDF is needed to make the data available on the Semantic Web. In addition, recent research has shown that Semantic Web technologies are useful beyond the Web, especially if data from different sources has to be exchanged or integrated. Many mapping languages and approaches were explored leading to the ongoing standardization effort of the World Wide Web Consortium (W3C) carried out in the RDB2RDF Working Group (WG). The goal and contribution of this paper is to provide a featurebased comparison of the state-of-the-art RDB-to-RDF mapping languages. It should act as a guide in selecting a RDB-to-RDF mapping language for a given application scenario and its requirements w.r.t. mapping features. Our comparison framework is based on use cases and requirements for mapping RDBs to RDF as identified by the RDB2RDF WG. We apply this comparison framework to the state-of-the-art RDB-to-RDF mapping languages and report the findings in this paper. As a result, our classification proposes four categories of mapping languages: direct mapping, read-only general-purpose mapping, readwrite general-purpose mapping, and special-purpose mapping. We further provide recommendations for selecting a mapping language. WG). The goal and contribution of this paper is to provide a feature-based comparison of the state-of-the-art RDB-to-RDF mapping languages. It should act as a guide in selecting a RDB-to-RDF mapping language for a given application scenario and its requirements w.r.t. mapping features. Our comparison framework is based on use cases and requirements for mapping RDBs to RDF as identified by the RDB2RDF WG. We apply this comparison framework to the state-of-the-art RDB-to-RDF mapping languages and report the findings in this paper. As a result, our classification proposes four categories of mapping languages: direct mapping, read-only general-purpose mapping, readwrite general-purpose mapping, and special-purpose mapping. We further provide recommendations for selecting a mapping language. A Comparison of RDB-to-RDF Mapping Languages

The feature list of modern IDEs is growing steadily and mastering these tools becomes more and more demanding, especially for novice programmers. Despite their remarkable capabilities, IDEs often still cannot directly answer the questions that arise during program comprehension tasks. Instead developers have to map their questions to multiple concrete queries that can be answered only by combining several tools and examining the output of each of them manually to distill an appropriate answer. Existing approaches have in common that they are either limited to a set of predefined, hardcoded questions, or that they require to learn a specific query language only suitable for that limited purpose. We present a framework to query for information about a software system using guided-input natural language resembling plain English. For that, we model data extracted by classical software analysis tools with an OWL ontology and use knowledge processing technologies from the Semantic Web to query it. We also present a case study that demonstrates how our framework can be used to answer queries about static source code information for program comprehension purposes. Supporting Developers with Natural Language QueriesMichael Würsch, Giacomo Ghezzi, Gerald Reif, and Harald C. Gall {wuersch,ghezzi,reif,gall}@ifi.uzh.ch s.e.a.l. -software architecture and evolution lab Department of Informatics University of Zurich, Switzerland ABSTRACTThe feature list of modern IDEs is steadily growing and mastering these tools becomes more and more demanding, especially for novice programmers. Despite their remarkable capabilities, IDEs often still cannot directly answer the questions that arise during program comprehension tasks. Instead developers have to map their questions to multiple concrete queries that can be answered only by combining several tools and examining the output of each of them manually to distill an appropriate answer. Existing approaches have in common that they are either limited to a set of predefined, hardcoded questions, or that they require to learn a specific query language only suitable for that limited purpose. We present a framework to query for information about a software system using guided-input natural language resembling plain English.For that, we model data extracted by classical software analysis tools with an OWL ontology and use knowledge processing technologies from the Semantic Web to query it. We use a case study to demonstrate how our framework can be used to answer queries about static source code information for program comprehension purposes.

Relational Databases (RDBs) are used in most current enterprise environments to store and manage data. The semantics of the data is not explicitly encoded in the relational model, but implicitly at the application level. Ontologies and Semantic Web technologies provide explicit semantics that allows data to be shared and reused across application, enterprise, and community boundaries. Converting all relational data to RDF is often not feasible, therefore we adopt a mediation approach for ontology-based access to RDBs. Existing mapping approaches focus on read-only access via SPARQL or as Linked Data but other data access interfaces exist, including approaches for updating RDF data. In this paper we present OntoAccess, an extensible platform for ontology-based read and write access to existing relational data. It encapsulates the translation logic in the core layer that provides the foundation of an extensible set of data access interfaces in the interface layer. We further present the formal definition of our RDB-to-RDF mapping, the architecture of our mediator platform, and a performance evaluation of the prototype implementation. Updating Relational Data via SPARQL/Update ABSTRACTRelational Databases are used in most current enterprise environments to store and manage data. The semantics of the data is not explicitly encoded in the relational model, but implicitly on the application level. Ontologies and Semantic Web technologies provide explicit semantics that allows data to be shared and reused across application, enterprise, and community boundaries. Converting all relational data to RDF is often not feasible, therefore we adopt an ontology-based access to relational databases. While existing approaches focus on read-only access, we present our approach OntoAccess that adds ontology-based write access to relational data. OntoAccess consists of the updateaware RDB to RDF mapping language R3M and algorithms for translating SPARQL/Update operations to SQL. This paper presents the mapping language, the translation algorithms, and a prototype implementation of OntoAccess.

With the recent advances in mobile computing, distributed organizations are facing a growing need for advanced Information and Communication Technologies (ICT) that support mobile working. The ability to use information effectively anywhere and anytime has become a key business success factor: Although many Computer Supported Collaborative Work (CSCW) systems have been introduced to date, technologies and architectures that support the collaboration of nomadic workers on a wide range of mobile devices, notebooks and personal computers is still a challenge. The Mobile Teamwork Infrastructure for Organizations Networking (MOTION}' project is aiming to design a highlyjexible, open and scalable ICT architecture for mobile collaboration. In this papeq we present the mobile collaboration requirements of two MOTION industry case studies, and highlight the advantages of a Web-based peer-to-peer architecture and for nomadic working.

No abstract