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- ItemSCOAP³ – Towards a second phase(Amsterdam : IOS Press, 2016) Kutz, AngelikaThe global partnership SCOAP3 (Sponsoring Consortium for Open Access Publishing in Particle Physics) has reached the conversion of high-quality subscription journals in the field of High-Energy Physics to Open Access through redirection of existing subscription funds by installing the SCOAP3 Gold Open Access Repository providing free access to scientific articles in the field of High Energy Physics. This article describes the steps taken to enable a second phase (2017–2019) of this international project based on an output-based (fair share) financing model.
- ItemEnhancing Virtual Ontology Based Access over Tabular Data with Morph-CSV(Amsterdam : IOS Press, 2020) Chaves-Fraga, David; Ruckhaus, Edna; Priyatna, Freddy; Vidal, Maria-Esther; Corchio, OscarOntology-Based Data Access (OBDA) has traditionally focused on providing a unified view of heterogeneous datasets, either by materializing integrated data into RDF or by performing on-the fly querying via SPARQL query translation. In the specific case of tabular datasets represented as several CSV or Excel files, query translation approaches have been applied by considering each source as a single table that can be loaded into a relational database management system (RDBMS). Nevertheless, constraints over these tables are not represented; thus, neither consistency among attributes nor indexes over tables are enforced. As a consequence, efficiency of the SPARQL-to-SQL translation process may be affected, as well as the completeness of the answers produced during the evaluation of the generated SQL query. Our work is focused on applying implicit constraints on the OBDA query translation process over tabular data. We propose Morph-CSV, a framework for querying tabular data that exploits information from typical OBDA inputs (e.g., mappings, queries) to enforce constraints that can be used together with any SPARQL-to-SQL OBDA engine. Morph-CSV relies on both a constraint component and a set of constraint operators. For a given set of constraints, the operators are applied to each type of constraint with the aim of enhancing query completeness and performance. We evaluate Morph-CSV in several domains: e-commerce with the BSBM benchmark; transportation with a benchmark using the GTFS dataset from the Madrid subway; and biology with a use case extracted from the Bio2RDF project. We compare and report the performance of two SPARQL-to-SQL OBDA engines, without and with the incorporation of MorphCSV. The observed results suggest that Morph-CSV is able to speed up the total query execution time by up to two orders of magnitude, while it is able to produce all the query answers.
- ItemEditorial of the Special issue on Cultural heritage and semantic web(Amsterdam : IOS Press, 2022) Alam, Mehwish; de Boer, Victor; Daga, Enrico; van Erp, Marieke; Hyvönen, Eero; Meroño-Peñuela, Albert[no abstract available]