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Featured Publications

The “standard reference” for the Optique, giving the best high-level overview of the project as a whole, is currently:

M. Giese, A. Soylu, G. Vega-Gorgojo, A. Waaler, P. Haase, E. Jimenez-Ruiz, D. Lanti, M. Rezk, M., G. Xiao, Ö. Özcep, R. Rosati, Optique: Zooming in on Big Data, IEEE Computer vol. 48, issue 3., 2015.

Query Formulation (WP3)

A. Soylu , M. Giese, E. Jimenez-Ruiz, G. Vega-Gorgojo, I. Horrocks,
Experiencing OptiqueVQS: a multi-paradigm and ontology-based visual query system for end users, Universal Access in the Information Society, Springer, 2015.

This article introduces a novel ontology-based visual query system, named OptiqueVQS, for end users. OptiqueVQS is built on a powerful and scalable data access platform and has a user-centric design supported by a widget-based flexible and extensible architecture.

Bootstrapping and Mapping Analysis (WP4)

E. Jimenez-Ruiz, E. Kharlamov, D. Zheleznyakov, I. Horrocks, C. Pinkel, M. G. Skjæveland, E. Thorstensen, and J. Mora,
BootOX: Practical Mapping of RDBs to OWL 2, Proc. of International Semantic Web Conference (ISWC), 2015.

In this work we present BootOX, a system that aims at facilitating ontology and mapping development by their automatic extraction (i.e., bootstrapping) from RDBs, and our experience with the use of BootOX in industrial and research contexts.

D. Lembo, J. Mora, R. Rosati, D. F. Savo, and E. Thorstensen,
Mapping Analysis in Ontology-based Data Access: Algorithms and Complexity, Proc. of International Semantic Web Conference (ISWC), 2015.

In this paper we focus on the problem of identifying mapping inconsistency and redundancy, two of the most important anomalies for mappings in OBDA. We consider a wide range of ontology languages that comprises OWL 2 and all its profiles, and examine mapping languages of different expressiveness over relational databases.

Queries over Time- and Stream-based data (WP5)

L. Özçep, R. Möller, and C. Neuenstadt,
Stream-Query Compilation with Ontologies, in Poceedings of the 28th Australasian Joint Conference on Artificial Intelligence 2015 (AI 2015), 2015.

Rational agents perceiving data from a dynamic environment and acting in it have to be equipped with capabilities such as decision making, planning etc. We assume that these capabilities are based on query answering with respect to (high-level) streams of symbolic descriptions, which are grounded in (low-level) data streams. Queries need to be answered w.r.t. an ontology. The central idea is to compile ontology-based stream queries (continuous or historical) to relational data processing technology, for which efficient implementations are available.

Query Transformation (WP6)

D. Calvanese, B. Cogrel, S. Komla Ebri, R. Kontchakov, D. Lanti, M. Rezk, M. Rodriguez-Muro, and G. Xiao,
Ontop: Answering SPARQL Queries over Relational Databases, Semantic Web Journal, 2016.

We present Ontop, an open-source Ontology-Based Data Access (OBDA) system that allows for querying relational data sources through a conceptual representation of the domain of interest, provided in terms of an ontology, to which the data sources are mapped. Key features of Ontop are its solid theoretical foundations, a virtual approach to OBDA, which avoids materializing triples and is implemented through the query rewriting technique, extensive optimizations exploiting all elements of the OBDA architecture, its compliance to all relevant W3C recommendations (including SPARQL queries, R2RML mappings, and OWL 2 QL and RDFS ontologies), and its support for all major relational databases.

Distributed and Cloud based Query Execution (WP7)

C. Svingos, T. Mailis, H. Kllapi, L. Stamatogiannakis, Y. Kotidis, and Y. Ioannidis, “Real Time Processing of Streaming and Static Information,” in 2016 IEEE International Conference on Big Data, 2016.

Big data applications require real-time processing of complex computations on streaming and static information. In this work we present Exastream, a data stream management system that is scalable, has declarative semantics, supports user defined functions, and allows for the stream and static data integration.

Siemens Use Case (WP8)

E. Kharlamov, N. Solomakhina, O. Oezcep, D. Zheleznyakov, T. Hubauer, S. Lamparter, M. Roshchin, and A. Soylu,
How Semantic Technologies can Enhance Data Access at Siemens Energy, in Proc. of International Semantic Web Conference (ISWC), 2014.

We present a description and analysis of the data access challenge in the Siemens Energy. We advocate for Ontology Based Data Access (OBDA) as a suitable Semantic Web driven technology to address the challenge. We derive requirements for applying OBDA in Siemens, review existing OBDA systems and discuss their limitations with respect to the Siemens requirements. We then introduce the Optique platform as a suitable OBDA solution for Siemens. Finally, we describe our preliminary installation and evaluation of the platform in Siemens.

Statoil Use Case (WP9)

E. Kharlamov, D. Hovland, E. Jimenez-Ruiz, D. Lanti, H. Lie, C. Pinkel, M. Rezk, M. G. Skjæveland, E. Thorstensen, G. Xiao, D. Zheleznyakov, I. Horrocks,
Ontology Based Access to Exploration Data at Statoil, in Proc. of International Semantic Web Conference (ISWC), 2015.

In this work we present data access challenges in the data-intensive petroleum company Statoil and our experience in addressing these challenges with OBDA technology. In particular, we have developed a deployment module to create ontologies and mappings from relational databases in a semi-automatic fashion, and a query processing module to perform and optimise the process of translating ontological queries into data queries and their execution.

All Publications

  • [2016,article] bibtex
    E. Kharlamov, Y. Kotidis, T. Mailis, C. Neuenstadt, C. Nikolaou, Ö. L. Özçep, C. Svingos, D. Zheleznyakov, S. Lamparter, I. Horrocks, Y. E. Ioannidis, and R. Möller, "Towards Analytics Aware Ontology Based Access to Static and Streaming Data (Extended Version)," CoRR, vol. abs/1607.05351, 2016.
    @article{DBLP:journals/corr/KharlamovKMNNOS16, audience = {academic},
      author = {Kharlamov, Evgeny and Kotidis, Yannis and Mailis, Theofilos and Neuenstadt, Christian and Nikolaou, Charalampos and {\"{O}}z{\c{c}}ep, {\"{O}}zg{\"{u}}r L. and Svingos, Christoforos and Zheleznyakov, Dmitriy and Lamparter, Steffen and Horrocks, Ian and Ioannidis, Yannis E. and M{\"{o}}ller, Ralf},
      interhash = {399f648eec68d1421dbe1569ab4e708f},
      intrahash = {a36ff76766f825592a3b4e8d2154f6ef},
      journal = {CoRR},
      partneroptique = {UOXF},
      title = {Towards Analytics Aware Ontology Based Access to Static and Streaming Data (Extended Version)},
      volume = {abs/1607.05351},
      wpoptique = {WP5},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    D. Zheleznyakov, E. Kharlamov, V. Klungre, M. G. Skjæveland, D. Hovland, M. Giese, I. Horrocks, and A. Waaler, "KeywDB: A System for Keyword-Driven Ontology-to-RDB Mapping Construction," in Proceedings of the ISWC 2016 Posters & Demonstrations Track co-located with 15th International Semantic Web Conference (ISWC 2016), Kobe, Japan, October 19, 2016., 2016.
    @inproceedings{DBLP:conf/semweb/ZheleznyakovKKS16, audience = {academic},
      author = {Zheleznyakov, Dmitriy and Kharlamov, Evgeny and Klungre, Vidar and Skj{\ae}veland, Martin G. and Hovland, Dag and Giese, Martin and Horrocks, Ian and Waaler, Arild},
      booktitle = {Proceedings of the {ISWC} 2016 Posters {\&} Demonstrations Track co-located with 15th International Semantic Web Conference {(ISWC} 2016), Kobe, Japan, October 19, 2016.},
      interhash = {2f523901f83c81c8c5fe5c8d6073a8a3},
      intrahash = {9e55411157496ba4c401437edb931968},
      partneroptique = {UOXF},
      title = {KeywDB: {A} System for Keyword-Driven Ontology-to-RDB Mapping Construction},
      wpoptique = {WP3},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    E. Kharlamov, B. C. Grau, E. Jiménez-Ruiz, S. Lamparter, G. Mehdi, M. Ringsquandl, Y. Nenov, S. Grimm, M. Roshchin, and I. Horrocks, "Capturing Industrial Information Models with Ontologies and Constraints," in The Semantic Web – ISWC 2016 – 15th International Semantic Web Conference, Kobe, Japan, October 17-21, 2016, Proceedings, Part II, 2016, pp. 325-343.
    @inproceedings{DBLP:conf/semweb/KharlamovGJLMRN16a, audience = {academic},
      author = {Kharlamov, Evgeny and Grau, Bernardo Cuenca and Jim{\'{e}}nez{-}Ruiz, Ernesto and Lamparter, Steffen and Mehdi, Gulnar and Ringsquandl, Martin and Nenov, Yavor and Grimm, Stephan and Roshchin, Mikhail and Horrocks, Ian},
      booktitle = {The Semantic Web - {ISWC} 2016 - 15th International Semantic Web Conference, Kobe, Japan, October 17-21, 2016, Proceedings, Part {II}},
      interhash = {70ac2212e992b3eb6bd96582f186789d},
      intrahash = {e37138205059fc3a3a57c0cd0bdb2d86},
      pages = {325--343},
      partneroptique = {UOXF},
      title = {Capturing Industrial Information Models with Ontologies and Constraints},
      wpoptique = {WP11},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    E. Kharlamov, B. C. Grau, E. Jiménez-Ruiz, S. Lamparter, G. Mehdi, M. Ringsquandl, Y. Nenov, S. Grimm, M. Roshchin, and I. Horrocks, "SOMM: Industry Oriented Ontology Management Tool," in Proceedings of the ISWC 2016 Posters & Demonstrations Track co-located with 15th International Semantic Web Conference (ISWC 2016), Kobe, Japan, October 19, 2016., 2016.
    @inproceedings{DBLP:conf/semweb/KharlamovGJLMRN16, audience = {academic},
      author = {Kharlamov, Evgeny and Grau, Bernardo Cuenca and Jim{\'{e}}nez{-}Ruiz, Ernesto and Lamparter, Steffen and Mehdi, Gulnar and Ringsquandl, Martin and Nenov, Yavor and Grimm, Stephan and Roshchin, Mikhail and Horrocks, Ian},
      booktitle = {Proceedings of the {ISWC} 2016 Posters {\&} Demonstrations Track co-located with 15th International Semantic Web Conference {(ISWC} 2016), Kobe, Japan, October 19, 2016.},
      interhash = {a5c444814c252005790955725255c7dd},
      intrahash = {49b2017c6861428fc85142d5ff3b2a1b},
      partneroptique = {UOXF},
      title = {{SOMM:} Industry Oriented Ontology Management Tool},
      wpoptique = {WP11},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    B. C. Grau, E. Kharlamov, S. Marciuska, D. Zheleznyakov, and M. Arenas, "SemFacet: Faceted Search over Ontology Enhanced Knowledge Graphs," in Proceedings of the ISWC 2016 Posters & Demonstrations Track co-located with 15th International Semantic Web Conference (ISWC 2016), Kobe, Japan, October 19, 2016., 2016.
    @inproceedings{DBLP:conf/semweb/GrauKMZA16, audience = {academic},
      author = {Grau, Bernardo Cuenca and Kharlamov, Evgeny and Marciuska, Sarunas and Zheleznyakov, Dmitriy and Arenas, Marcelo},
      booktitle = {Proceedings of the {ISWC} 2016 Posters {\&} Demonstrations Track co-located with 15th International Semantic Web Conference {(ISWC} 2016), Kobe, Japan, October 19, 2016.},
      interhash = {df5a7a6984f59b51d4b463ade8b82cf0},
      intrahash = {b7eba8ab8b21fad32c1c5b1d9bc9e75f},
      partneroptique = {UOXF},
      title = {SemFacet: Faceted Search over Ontology Enhanced Knowledge Graphs},
      wpoptique = {WP3},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    E. Kharlamov, S. Brandt, M. Giese, E. Jiménez-Ruiz, Y. Kotidis, S. Lamparter, T. Mailis, C. Neuenstadt, Ö. L. Özçep, C. Pinkel, A. Soylu, C. Svingos, D. Zheleznyakov, I. Horrocks, Y. E. Ioannidis, R. Möller, and A. Waaler, "Enabling semantic access to static and streaming distributed data with optique: demo," in Proceedings of the 10th ACM International Conference on Distributed and Event-based Systems, DEBS ’16, Irvine, CA, USA, June 20 – 24, 2016, 2016, pp. 350-353.
    @inproceedings{DBLP:conf/debs/KharlamovBGJKLM16, audience = {academic},
      author = {Kharlamov, Evgeny and Brandt, Sebastian and Giese, Martin and Jim{\'{e}}nez{-}Ruiz, Ernesto and Kotidis, Yannis and Lamparter, Steffen and Mailis, Theofilos and Neuenstadt, Christian and {\"{O}}z{\c{c}}ep, {\"{O}}zg{\"{u}}r L. and Pinkel, Christoph and Soylu, Ahmet and Svingos, Christoforos and Zheleznyakov, Dmitriy and Horrocks, Ian and Ioannidis, Yannis E. and M{\"{o}}ller, Ralf and Waaler, Arild},
      booktitle = {Proceedings of the 10th {ACM} International Conference on Distributed and Event-based Systems, {DEBS} '16, Irvine, CA, USA, June 20 - 24, 2016},
      interhash = {c405369435fa70bf13b6386db5bcb788},
      intrahash = {48231d11b0d2c8d5161f5f880243e397},
      pages = {350--353},
      partneroptique = {UOXF},
      title = {Enabling semantic access to static and streaming distributed data with optique: demo},
      wpoptique = {WP10},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,article] bibtex
    M. Arenas, B. C. Grau, E. Kharlamov, S. Marciuska, and D. Zheleznyakov, "Faceted search over RDF-based knowledge graphs," J. Web Sem., vol. 37, pp. 55-74, 2016.
    @article{DBLP:journals/ws/ArenasGKMZ16, audience = {academic},
      author = {Arenas, Marcelo and Grau, Bernardo Cuenca and Kharlamov, Evgeny and Marciuska, Sarunas and Zheleznyakov, Dmitriy},
      interhash = {96be84e39a21fd74afc639e85ddfc738},
      intrahash = {a092419c58a30619c18f5c5f219d1811},
      journal = {J. Web Sem.},
      pages = {55--74},
      partneroptique = {UOXF},
      title = {Faceted search over RDF-based knowledge graphs},
      volume = 37, wpoptique = {WP3},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    D. Lanti, G. Xiao, and D. Calvanese, "An Evaluation of VIG with the BSBM Benchmark," in Proceedings of the ISWC~2016 Posters & Demonstrations Track. Co-located with the 15th International Semantic Web Conference (ISWC~2016), 2016.
    @inproceedings{2016-ISWC-poster-vig, abstract = {In this paper we present an experimental evaluation of VIG, a data scaler for OBDA benchmarks. Data scaling is a relatively recent approach, proposed in the database community, that allows for quickly scaling an input data instance to s times its size, while preserving certain application-specific characteristics. The advantages of scaling are that the generator is general, in the sense that it can be re-used on different database schemas, and that users are not required to manually input the data characteristics. VIG lifts the scaling approach from the database level to the OBDA level, where the domain information of ontologies and mappings has to be taken into account as well. To evaluate the quality of VIG, in this paper we use it to generate data for the Berlin SPARQL Benchmark (BSBM), and compare it with the official BSBM data generator.},
      audience = {academic},
      author = {Lanti, Davide and Xiao, Guohui and Calvanese, Diego},
      booktitle = {Proceedings of the ISWC~2016 Posters {\&} Demonstrations Track. Co-located with the 15th International Semantic Web Conference (ISWC~2016)},
      interhash = {d569fbbf98afd5ed0e325febb1714fa6},
      intrahash = {0691386eae7f7aa01df2f7362e7b2049},
      partneroptique = {FUB},
      publisher = {CEUR-WS.org},
      series = {CEUR Electronic Workshop Proceedings},
      title = {An Evaluation of {VIG} with the {BSBM} Benchmark},
      volume = 1690, wpoptique = {WP6},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    E. Botoeva, D. Calvanese, B. Cogrel, M. Rezk, and G. Xiao, "OBDA Beyond Relational DBs: A Study for MongoDB," in Proceedings of the 29th International Workshop on Description Logics (DL~2016), 2016.
    @inproceedings{2016-DL-obda-mongo, abstract = {The database landscape has been significantly diversified during the last decade, resulting in the emergence of a variety of non-relational (also called NoSQL) databases, e.g., XML and JSON-document databases, key-value stores, and graph databases. To facilitate access to such databases and to enable data integration of non-relational data sources, we generalize the well-known ontology based data access (OBDA) framework so as to allow for querying arbitrary databases through a mediating ontology. We instantiate this framework to MongoDB, a popular JSON-document database, and implement an prototype extension of the virtual OBDA system Ontop for answering SPARQL queries over MongoDB.},
      audience = {academic},
      author = {Botoeva, Elena and Calvanese, Diego and Cogrel, Benjamin and Rezk, Martin and Xiao, Guohui},
      booktitle = {Proceedings of the 29th International Workshop on Description Logics (DL~2016)},
      interhash = {ab36720ed4bad93a85594c2dad26b7ba},
      intrahash = {66196d60dbe53531497b44aeb761137b},
      partneroptique = {FUB},
      publisher = {CEUR-WS.org},
      series = {CEUR Electronic Workshop Proceedings},
      title = {{OBDA} Beyond Relational {DBs}: {A} Study for {MongoDB}},
      volume = 1577, wpoptique = {WP6},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    K. Bereta, G. Xiao, M. Koubarakis, M. Hodrius, C. Bielski, and G. Zeug, "Ontop-spatial: Geospatial Data Integration using GeoSPARQL-to-SQL Translation," in Proceedings of the ISWC~2016 Posters & Demonstrations Track. Co-located with the 15th International Semantic Web Conference (ISWC~2016), 2016.
    @inproceedings{2016-ISWC-poster-spatial, abstract = {We present Ontop-spatial, a geospatial extension of the well-known OBDA system Ontop, that leverages the technologies of geospatial databases and enables GeoSPARQL-to-SQL translation. We showcase the functionalities of the system in real-world use cases which require data integration of different geospatial sources.},
      audience = {academic},
      author = {Bereta, Konstantina and Xiao, Guohui and Koubarakis, Manolis and Hodrius, Martina and Bielski, Conrad and Zeug, Gunter},
      booktitle = {Proceedings of the ISWC~2016 Posters {\&} Demonstrations Track. Co-located with the 15th International Semantic Web Conference (ISWC~2016)},
      interhash = {74b564af95860b3edb54a59b81400fb8},
      intrahash = {fef966694b1fb646969d7655a7f0002c},
      partneroptique = {FUB},
      publisher = {CEUR-WS.org},
      series = {CEUR Electronic Workshop Proceedings},
      title = {Ontop-spatial: Geospatial Data Integration using {GeoSPARQL-to-SQL} Translation},
      volume = 1690, wpoptique = {WP6},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,article] bibtex
    D. Calvanese, P. Liuzzo, A. Mosca, J. Remesal, M. Rezk, and G. Rull, "Ontology-Based Data Integration in EPNet: Production and Distribution of Food During the Roman Empire," Engineering Applications of Artificial Intelligence, vol. 51, pp. 212-229, 2016.
    @article{EAAI-2016, abstract = {Semantic technologies are rapidly changing the historical research. Over the last decades, an immense amount of new quantifiable data have been accumulated, and made available in interchangeable formats, in social sciences and humanities, opening up new possibilities for solving old questions and posing new ones. This paper introduces a framework that eases the access of scholars to historical and cultural data about food production and commercial trade system during the Roman Empire, distributed across different data sources. The proposed approach relies on the Ontology-Based Data Access (OBDA) paradigm, where the different datasets are virtually integrated by a conceptual layer (an ontology) that provides to the user a clear point of access and a unified and unambiguous conceptual view.},
      audience = {academic},
      author = {Calvanese, Diego and Liuzzo, Pietro and Mosca, Alessandro and Remesal, Jose and Rezk, Martin and Rull, Guillem},
      doi = {10.1016/j.engappai.2016.01.005},
      interhash = {336f4f7bf7ba16b1862d7f82847b48ef},
      intrahash = {7ff44d0f77f2afec5c408a70eaec63d7},
      journal = {Engineering Applications of Artificial Intelligence},
      pages = {212--229},
      partneroptique = {FUB},
      title = {Ontology-Based Data Integration in {EPNet}: {Production} and Distribution of Food During the {Roman} {Empire}},
      volume = 51, wpoptique = {WP6},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    E. Botoeva, C. Lutz, V. Ryzhikov, F. Wolter, and M. Zakharyaschev, "Query-Based Entailment and Inseparability for ALC Ontologies," in Proceedings of the 25th introduce Joint Conference on Artificial Intelligence (IJCAI~2016), 2016, pp. 1001-1007.
    @inproceedings{2016-IJCAI-alc-inseparability, abstract = {We investigate the problem whether two ALC knowledge bases are indistinguishable by queries over a given vocabulary. We give model-theoretic criteria and prove that this problem is undecidable for conjunctive queries (CQs) but decidable in 2EXPTIME for unions of rooted CQs. We also consider the problem whether two ALC TBoxes give the same answers to any query in a given vocabulary over all ABoxes, and show that for CQs this problem is undecidable, too, but becomes decidable and 2EXPTIME-complete in Horn-ALC, and even EXPTIME-complete in Horn-ALC when restricted to (unions of) rooted CQs.},
      audience = {academic},
      author = {Botoeva, Elena and Lutz, Carsten and Ryzhikov, Vladislav and Wolter, Frank and Zakharyaschev, Michael},
      booktitle = {Proceedings of the 25th introduce Joint Conference on Artificial Intelligence (IJCAI~2016)},
      interhash = {b76788c33e4ce5fdb6dfe8f4240074c4},
      intrahash = {62489894d624a774413ac46dea1c74c1},
      pages = {1001--1007},
      partneroptique = {FUB},
      publisher = {AAAI Press},
      title = {Query-Based Entailment and Inseparability for {ALC} Ontologies},
      wpoptique = {WP6},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    S. Brüggemann, K. Bereta, G. Xiao, and M. Koubarakis, "Ontology-based Data Access for Maritime Security," in Proceedings of the 13th International Extended Semantic Web Conference (ESWC~2016), 2016.
    @inproceedings{2016-ESWC-maritime, abstract = {The maritime security domain is challenged by a number of data analysis needs focusing on increasing the maritime situation awareness, i.e., detection and analysis of abnormal vessel behaviors and suspicious vessel movements. The need for efficient processing of dynamic and/or static vessel data that come from different heterogeneous sources is emerged. In this paper we describe how we address the challenge of combining and processing real-time and static data from different sources using ontology-based data access techniques, and we explain how the application of semantic web technologies increases the value of data and improves the processing workflow in the maritime domain.},
      audience = {academic},
      author = {Br{\"u}ggemann, Stefan and Bereta, Konstantina and Xiao, Guohui and Koubarakis, Manolis},
      booktitle = {Proceedings of the 13th International Extended Semantic Web Conference (ESWC~2016)},
      interhash = {09b5d547c7d2c11fcb1786f6cf1cfdcd},
      intrahash = {e6da898c58545c85295b9de25b3c80d1},
      partneroptique = {FUB},
      publisher = {Springer},
      series = {Lecture Notes in Computer Science},
      title = {Ontology-based Data Access for Maritime Security},
      volume = 9678, wpoptique = {WP6},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    E. Botoeva, D. Calvanese, V. Santarelli, D. F. Savo, A. Solimando, and G. Xiao, "Beyond OWL~2~QL in OBDA: Rewritings and Approximations," in Proceedings of the 30th AAAI Conference on Artificial Intelligence (AAAI~2016), 2016.
    @inproceedings{2016-AAAI-ontoprox, abstract = {Ontology-based data access (OBDA) is a novel paradigm facilitating access to relational data, realized by linking data sources to an ontology by means of declarative mappings. DL-LiteR, which is the logic underpinning the W3C ontology language OWL 2 QL and the current language of choice for OBDA, has been designed with the goal of delegating query answering to the underlying database engine, and thus is restricted in expressive power. E.g., it does not allow one to express disjunctive information, and any form of recursion on the data. The aim of this paper is to overcome these limitations of DL-LiteR, and extend OBDA to more expressive ontology languages, while still leveraging the underlying relational technology for query answering. We achieve this by relying on two well-known mechanisms, namely conservative rewriting and approximation, but significantly extend their practical impact by bringing into the picture the mapping, an essential component of OBDA. Specifically, we develop techniques to rewrite OBDA specifications with an expressive ontology to ``equivalent'' ones with a DL-LiteR ontology, if possible, and to approximate them otherwise. We do so by exploiting the high expressive power of the mapping layer to capture part of the domain semantics of rich ontology languages. We have implemented our techniques in the prototype system ONTOPROX, making use of the state-of-the art OBDA system ONTOP and the query answering system CLIPPER, and we have shown their feasibility and effectiveness with experiments on synthetic and real-world data.},
      audience = {academic},
      author = {Botoeva, Elena and Calvanese, Diego and Santarelli, Valerio and Savo, Domenico F. and Solimando, Alessandro and Xiao, Guohui},
      booktitle = {Proceedings of the 30th {AAAI} Conference on Artificial Intelligence (AAAI~2016)},
      interhash = {47bbd5b0ed8157bc2ae63b6d5d07f608},
      intrahash = {892b6f22ea51d8dcbbdde8ba6df22fd6},
      partneroptique = {FUB},
      title = {Beyond {OWL~2~QL} in {OBDA}: {Rewritings} and Approximations},
      wpoptique = {WP6},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    E. Botoeva, D. Calvanese, B. Cogrel, M. Rezk, and G. Xiao, "OBDA Over Non-Relational DBs," in Proceedings of the 10th Alberto Mendelzon International Workshop on Foundations of Data Management (AMW~2016), 2016.
    @inproceedings{2016-AMW-obda-mongo, abstract = {The database landscape has been significantly diversified during the last decade, resulting in the emergence of a variety of non-relational (also called NoSQL) databases, e.g., XML and JSON-document databases, key-value stores, and graph databases. To facilitate access to such databases and to enable data integration of non-relational data sources, we generalize the well-known ontology based data access (OBDA) framework so as to allow for querying arbitrary databases through a mediating ontology. We instantiate this framework to MongoDB, a popular JSON-document database, and implement a prototype extension of the virtual OBDA system Ontop for answering SPARQL queries over MongoDB.},
      audience = {academic},
      author = {Botoeva, Elena and Calvanese, Diego and Cogrel, Benjamin and Rezk, Martin and Xiao, Guohui},
      booktitle = {Proceedings of the 10th Alberto Mendelzon International Workshop on Foundations of Data Management (AMW~2016)},
      interhash = {5ce168e86c93e9c02911006fb7b616f9},
      intrahash = {873225ee5c206db88ed57941904e5457},
      partneroptique = {FUB},
      title = {{OBDA} Over Non-Relational {DBs}},
      wpoptique = {WP6},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,article] bibtex
    D. Calvanese, B. Cogrel, S. Komla-Ebri, R. Kontchakov, D. Lanti, M. Rezk, M. Rodriguez-Muro, and G. Xiao, "Ontop: Answering SPARQL Queries over Relational Databases," Semantic Web Journal, 2016.
    @article{2016-SWJ-ontop, abstract = {We present Ontop, an open-source Ontology-Based Data Access (OBDA) system that allows for querying relational data sources through a conceptual representation of the domain of interest, provided in terms of an ontology, to which the data sources are mapped. Key features of Ontop are its solid theoretical foundations, a virtual approach to OBDA, which avoids materializing triples and is implemented through the query rewriting technique, extensive optimizations exploiting all elements of the OBDA architecture, its compliance to all relevant W3C recommendations (including SPARQL queries, R2RML mappings, and OWL 2 QL and RDFS ontologies), and its support for all major relational databases.},
      audience = {academic},
      author = {Calvanese, Diego and Cogrel, Benjamin and Komla-Ebri, Sarah and Kontchakov, Roman and Lanti, Davide and Rezk, Martin and Rodriguez-Muro, Mariano and Xiao, Guohui},
      interhash = {1e9aa89bcd0375655f2846c6bd8479d2},
      intrahash = {6f37fabac0fd1fb78a7b4512eed91af8},
      journal = {Semantic Web Journal},
      partneroptique = {FUB},
      title = {Ontop: Answering {SPARQL} Queries over Relational Databases},
      wpoptique = {WP6},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,article] bibtex Go to document
    M. Arenas, E. Botoeva, D. Calvanese, and V. Ryzhikov, "Knowledge Base Exchange: The Case of OWL 2 QL," Artificial Intelligence, vol. 238, pp. 11-62, 2016.
    @article{2016-AIJ-kb-exchange, abstract = {In this article, we define and study the problem of exchanging knowledge between a source and a target knowledge base (KB), connected through mappings. Differently from the traditional database exchange setting, which considers only the exchange of data, we are interested in exchanging implicit knowledge. As representation formalism we use Description Logics (DLs), thus assuming that the source and target KBs are given as a DL TBox+ABox, while the mappings have the form of DL TBox assertions. We define a general framework of KB exchange, and study the problem of translating the knowledge in the source KB according to the mappings expressed in OWL 2 QL, the profile of the standard Web Ontology Language OWL 2 based on the description logic DL-LiteR. We develop novel game- and automata-theoretic techniques, and we provide complexity results that range from NLogSpace to ExpTime.},
      audience = {academic},
      author = {Arenas, Marcelo and Botoeva, Elena and Calvanese, Diego and Ryzhikov, Vladislav},
      doi = {10.1016/j.artint.2016.05.002},
      interhash = {a6da17df2ae054335d54087f40c0e0ee},
      intrahash = {187a75ff58a632834520bcd21ff1e298},
      journal = {Artificial Intelligence},
      pages = {11--62},
      partneroptique = {FUB},
      title = {Knowledge Base Exchange: {The} Case of {OWL 2 QL}},
      url = {http://www.sciencedirect.com/science/article/pii/S0004370216300522},
      volume = 238, wpoptique = {WP6},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    D. Calvanese, E. G. Kalayci, V. Ryzhikov, and G. Xiao, "Towards Practical OBDA with Temporal Ontologies – (Position Paper)," in Proceedings of the 10th International Conference on Web Reasoning and Rule Systems (RR~2016), 2016, pp. 18-24.
    @inproceedings{2016-RR-temporal, abstract = {The temporal dimension of data, which contains such important information as duration or sequence of events and is present in many applications of ontology-based data access (OBDA) concerned with logs or streams, is getting growing attention in the community. To give a proper treatment to the events occurring in the data from the ontological perspective, we assume in our approach that every concept is temporalized, i.e., has temporal validity time, and the ontology language expresses the constraints between validity times of concepts. In this paper we outline the state of art and the future challenges of our research. On the theoretical side, we are interested in enriching the ontology languages with the operators for constructing the temporal concepts that are expressive enough to capture the patterns required by industrial use-cases. On the practical side, we are interested in implementing the ontology-mediated query answering with temporalized concepts in the OBDA system Ontop and performing extensive evaluations using large amounts of real-world data.},
      audience = {academic},
      author = {Calvanese, Diego and Kalayci, Elem G{\"u}zel and Ryzhikov, Vladislav and Xiao, Guohui},
      booktitle = {Proceedings of the 10th International Conference on Web Reasoning and Rule Systems (RR~2016)},
      interhash = {f05959e3fcd05cd831f796fcef04b5c8},
      intrahash = {fadd8300be9d50e36cea6148ef063104},
      pages = {18--24},
      partneroptique = {FUB},
      publisher = {Springer},
      series = {Lecture Notes in Computer Science},
      title = {Towards Practical {OBDA} with Temporal Ontologies - ({Position} Paper)},
      volume = 9898, wpoptique = {WP6},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    D. Hovland, D. Lanti, M. Rezk, and G. Xiao, "OBDA Constraints for Effective Query Answering," in Proceedings of the 10th International Symposium on Rule Technologies. Research, Tools, and Applications (RuleML~2016), 2016.
    @inproceedings{2016-ruleml-constraint, abstract = {In Ontology Based Data Access (OBDA) users pose SPARQL queries over an ontology that lies on top of relational datasources. These queries are translated on-the-fly into SQL queries by OBDA systems. Standard SPARQL-to-SQL translation techniques in OBDA often produce SQL queries containing redundant joins and unions, even after a number of semantic and structural optimizations. These redundancies are detrimental to the performance of query answering, especially in complex industrial OBDA scenarios with large enterprise databases. To address this issue, we introduce two novel notions of OBDA constraints and show how to exploit them for efficient query answering. We conduct an extensive set of experiments on large datasets using real world data a nd queries, showing that these techniques strongly improve the performance of query answering up to orders of magnitude.},
      audience = {academic},
      author = {Hovland, Dag and Lanti, Davide and Rezk, Martin and Xiao, Guohui},
      booktitle = {Proceedings of the 10th International Symposium on Rule Technologies. Research, Tools, and Applications (RuleML~2016)},
      interhash = {a9676486aad0e7e7683d54d4e3fbbc5c},
      intrahash = {ab7164176bd2c4e6675c6f0ab094215e},
      partneroptique = {FUB},
      publisher = {Springer},
      series = {Lecture Notes in Computer Science},
      title = {{OBDA} Constraints for Effective Query Answering},
      volume = 9718, wpoptique = {WP6},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    D. Lanti, G. Xiao, and D. Calvanese, "Fast and Simple Data Scaling for OBDA Benchmarks," in Proc.\ of the Workshop on Benchmarking Linked Data (BLINK~2016), 2016.
    @inproceedings{2016-BLINK-vig, abstract = {In this paper we describe VIG, a data scaler for OBDA benchmarks. Data scaling is a relatively recent approach, proposed in the database community, that allows for quickly scaling an input data instance to n times its size, while preserving certain application-specific characteristics. The advantages of the scaling approach are that the same generator is general, in the sense that it can be re-used on different database schemas, and that users are not required to manually input the data characteristics. In the VIG system, we lift the scaling approach from the pure database level to the OBDA level, where the domain information of ontologies and mappings has to be taken into account as well. VIG is efficient and notably each tuple is generated in constant time. VIG has been successfully used in the NPD benchmark, but it provides a general approach that can be re-used to scale any data instance in any OBDA setting},
      audience = {academic},
      author = {Lanti, Davide and Xiao, Guohui and Calvanese, Diego},
      booktitle = {Proc.\ of the Workshop on Benchmarking Linked Data (BLINK~2016)},
      interhash = {57b18da646f6bd9e4354bf911d0c627f},
      intrahash = {a50e4ac773bb85409fdce83415eb8086},
      partneroptique = {FUB},
      title = {Fast and Simple Data Scaling for {OBDA} Benchmarks},
      wpoptique = {WP6},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,article] bibtex Go to document
    E. Botoeva, R. Kontchakov, V. Ryzhikov, F. Wolter, and M. Zakharyaschev, "Games for Query Inseparability of Description Logic Knowledge Bases," Artificial Intelligence, vol. 234, pp. 78-119, 2016.
    @article{2016-AIJ-games-inseparability, abstract = {We consider conjunctive query inseparability of description logic knowledge bases with respect to a given signature—a fundamental problem in knowledge base versioning, module extraction, forgetting and knowledge exchange. We give a uniform game-theoretic characterisation of knowledge base conjunctive query inseparability and develop worst-case optimal decision algorithms for fragments of Horn-ALCHI, including the description logics underpinning OWL 2 QL and OWL 2 EL. We also determine the data and combined complexity of deciding query inseparability. While query inseparability for all of these logics is P-complete for data complexity, the combined complexity ranges from P- to ExpTime- to 2ExpTime-completeness. We use these results to resolve two major open problems for OWL 2 QL by showing that TBox query inseparability and the membership problem for universal conjunctive query solutions in knowledge exchange are both ExpTime-complete for combined complexity. Finally, we introduce a more flexible notion of inseparability which compares answers to conjunctive queries in a given signature over a given set of individuals. In this case, checking query inseparability becomes NP-complete for data complexity, but the ExpTime- and 2ExpTime-completeness combined complexity results are preserved.},
      audience = {academic},
      author = {Botoeva, Elena and Kontchakov, Roman and Ryzhikov, Vladislav and Wolter, Frank and Zakharyaschev, Michael},
      doi = {10.1016/j.artint.2016.01.010},
      interhash = {96e7cd7aef687fa785777d1ff4c33185},
      intrahash = {b781b04a7bdba12b3c03054570667469},
      journal = {Artificial Intelligence},
      pages = {78--119},
      partneroptique = {FUB},
      title = {Games for Query Inseparability of Description Logic Knowledge Bases},
      url = {http://www.sciencedirect.com/science/article/pii/S0004370216300017},
      volume = 234, wpoptique = {WP6},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    E. Botoeva, D. Calvanese, V. Santarelli, D. F. Savo, A. Solimando, and G. Xiao, "Virtual OBDA over Expressive Ontologies: Rewritings and Approximations," in Proceedings of the 29th International Workshop on Description Logics (DL~2016), 2016.
    @inproceedings{2016-DL-ontoprox, abstract = {In this paper we extend virtual OBDA to more expressive ontology languages than that of DL-LiteR, which is the logic underpinning the W3C ontology language OWL 2. We achieve this by relying on two well-known mechanisms, namely conservative rewriting and approximation, and compiling some of the domain semantics into OBDA mappings.},
      audience = {academic},
      author = {Botoeva, Elena and Calvanese, Diego and Santarelli, Valerio and Savo, Domenico Fabio and Solimando, Alessandro and Xiao, Guohui},
      booktitle = {Proceedings of the 29th International Workshop on Description Logics (DL~2016)},
      interhash = {ad3e6c3cf8c166f5c19c6083c5491892},
      intrahash = {820162843eeecff57f39a16bd87f8ac4},
      partneroptique = {FUB},
      publisher = {CEUR-WS.org},
      series = {CEUR Electronic Workshop Proceedings},
      title = {Virtual {OBDA} over Expressive Ontologies: {Rewritings} and Approximations},
      volume = 1577, wpoptique = {WP6},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    A. Soylu, M. Giese, E. Jimenez-Ruiz, E. Kharlamov, R. Schlatte, C. Neuenstadt, &. L. Özcep, H. Lie, S. Brandt, and I. Horrocks, "Ontology-based Visual Querying with OptiqueVQS: Statoil and Siemens Cases," in Norwegian Big Data Symposium (NOBIDS) 2016, Trondheim, Norway, 2016.
    @inproceedings{NOBIDS2016, audience = {general},
      author = {Soylu, Ahmet and Giese, Martin and Jimenez-Ruiz, Ernesto and Kharlamov, Evgeny and Schlatte, Rudolf and Neuenstadt, Christian and Özcep, Özgür Lütfü and Lie, Hallstein and Brandt, Sebastian and Horrocks, Ian},
      booktitle = {Norwegian Big Data Symposium (NOBIDS) 2016, Trondheim, Norway},
      editor = {Gulla, Jon Atle and Svendsen, Rolf Dyrnes and Özgöbek, Özlem and Marco, Cristina},
      interhash = {d8f327d4fb43f13577dbe9213633ad60},
      intrahash = {09363feb43aacbc7c7e4d024ec7f486a},
      note = {To appear},
      openaccess = {Yes},
      partneroptique = {UiO},
      publisher = {CEUR},
      series = {CEUR Workshop Proceedings},
      title = {Ontology-based Visual Querying with OptiqueVQS: Statoil and Siemens Cases},
      wpoptique = {WP10},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex Go to document
    D. Zheleznyakov, E. Kharlamov, V. Klungre, M. G. Skjæveland, D. Hovland, M. Giese, I. Horrocks, and A. Waaler, "KeywDB: A System for Keyword-Driven Ontology-to-RDB Mapping Construction," in Proceedings of the ISWC 2016 Posters & Demonstrations Track co-located with 15th International Semantic Web Conference (ISWC 2016), Kobe, Japan, October 19, 2016., 2016.
    @inproceedings{DBLP:conf/semweb/ZheleznyakovKKS16, audience = {academic},
      author = {Zheleznyakov, Dmitriy and Kharlamov, Evgeny and Klungre, Vidar and Skj{\ae}veland, Martin G. and Hovland, Dag and Giese, Martin and Horrocks, Ian and Waaler, Arild},
      booktitle = {Proceedings of the {ISWC} 2016 Posters {\&} Demonstrations Track co-located with 15th International Semantic Web Conference {(ISWC} 2016), Kobe, Japan, October 19, 2016.},
      editor = {Kawamura, Takahiro and Paulheim, Heiko},
      interhash = {2f523901f83c81c8c5fe5c8d6073a8a3},
      intrahash = {ed957edd91ec9bbc4341ace1448094a0},
      openaccess = {Yes},
      partneroptique = {UOXF},
      publisher = {CEUR-WS.org},
      series = {{CEUR} Workshop Proceedings},
      title = {KeywDB: {A} System for Keyword-Driven Ontology-to-RDB Mapping Construction},
      url = {http://ceur-ws.org/Vol-1690/paper73.pdf},
      volume = 1690, wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex Go to document
    E. Kharlamov, S. Brandt, M. Giese, E. Jiménez-Ruiz, Y. Kotidis, S. Lamparter, T. Mailis, C. Neuenstadt, Ö. L. Özçep, C. Pinkel, A. Soylu, C. Svingos, D. Zheleznyakov, I. Horrocks, Y. E. Ioannidis, R. Möller, and A. Waaler, "Scalable Semantic Access to Siemens Static and Streaming Distributed Data," in Proceedings of the ISWC 2016 Posters & Demonstrations Track, co-located with 15th International Semantic Web Conference (ISWC 2016), Kobe, Japan, October 19, 2016., 2016.
    @inproceedings{DBLP:conf/semweb/KharlamovBGJKLM16, audience = {academic},
      author = {Kharlamov, Evgeny and Brandt, Sebastian and Giese, Martin and Jim{\'{e}}nez{-}Ruiz, Ernesto and Kotidis, Yannis and Lamparter, Steffen and Mailis, Theofilos and Neuenstadt, Christian and {\"{O}}z{\c{c}}ep, {\"{O}}zg{\"{u}}r L{\"{u}}tf{\"{u}} and Pinkel, Christoph and Soylu, Ahmet and Svingos, Christoforos and Zheleznyakov, Dmitriy and Horrocks, Ian and Ioannidis, Yannis E. and M{\"{o}}ller, Ralf and Waaler, Arild},
      booktitle = {Proceedings of the {ISWC} 2016 Posters {\&} Demonstrations Track, co-located with 15th International Semantic Web Conference {(ISWC} 2016), Kobe, Japan, October 19, 2016.},
      editor = {Kawamura, Takahiro and Paulheim, Heiko},
      interhash = {f3c8b4f3be2dec2d79f9e604055a0b27},
      intrahash = {f582003131424be43b97305ad030e004},
      openaccess = {Yes},
      partneroptique = {UOXF},
      publisher = {CEUR-WS.org},
      series = {{CEUR} Workshop Proceedings},
      title = {Scalable Semantic Access to Siemens Static and Streaming Distributed Data},
      url = {http://ceur-ws.org/Vol-1690/paper16.pdf},
      urn = {urn:nbn:de:0074-1690-5},
      volume = 1690, wpoptique = {WP10},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex Go to document
    A. Soylu, M. Giese, R. Schlatte, E. Jiménez-Ruiz, &. L. Özçep, and S. Brandt, "A Visual Query System for Stream Data Access over Ontologies," in The Semantic Web – ESWC 2016 Satellite Events, Heraklion, Crete, Greece, May 29 – June 2, 2016, Revised Selected Papers, 2016, pp. 161-166.
    @inproceedings{DBLP:conf/esws/SoyluGSJOB16a, audience = {academic},
      author = {Soylu, Ahmet and Giese, Martin and Schlatte, Rudolf and Jim{\'{e}}nez{-}Ruiz, Ernesto and Özçep, Özgur L. and Brandt, Sebastian},
      booktitle = {The Semantic Web - {ESWC} 2016 Satellite Events, Heraklion, Crete, Greece, May 29 - June 2, 2016, Revised Selected Papers},
      doi = {10.1007/978-3-319-47602-5_32},
      editor = {Sack, Harald and Rizzo, Giuseppe and Steinmetz, Nadine and Mladenic, Dunja and Auer, S{\"{o}}ren and Lange, Christoph},
      interhash = {7c69d8214514f3ad4d8b42eab60ca2b6},
      intrahash = {e4337cf70b2dc95f54928270244c1297},
      isbn = {978-3-319-47601-8},
      openaccess = {Yes},
      pages = {161--166},
      partneroptique = {UiO},
      series = {Lecture Notes in Computer Science},
      title = {A Visual Query System for Stream Data Access over Ontologies},
      url = {http://dx.doi.org/10.1007/978-3-319-47602-5_32},
      volume = 9989, wpoptique = {WP3},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex Go to document
    G. Vega-Gorgojo, L. Slaughter, M. Giese, S. Heggestøyl, J. W. Klüwer, and A. Waaler, "PepeSearch: Easy to Use and Easy to Install Semantic Data Search," in The Semantic Web – ESWC 2016 Satellite Events, Heraklion, Crete, Greece, May 29 – June 2, 2016, Revised Selected Papers, 2016, pp. 146-150.
    @inproceedings{DBLP:conf/esws/Vega-GorgojoSGH16, audience = {academic},
      author = {Vega-Gorgojo, Guillermo and Slaughter, Laura and Giese, Martin and Heggest{\o}yl, Simen and Klüwer, Johan W. and Waaler, Arild},
      booktitle = {The Semantic Web - {ESWC} 2016 Satellite Events, Heraklion, Crete, Greece, May 29 - June 2, 2016, Revised Selected Papers},
      doi = {10.1007/978-3-319-47602-5_29},
      editor = {Sack, Harald and Rizzo, Giuseppe and Steinmetz, Nadine and Mladenic, Dunja and Auer, S{\"{o}}ren and Lange, Christoph},
      interhash = {75268b6f23bae3499849bab91e0297af},
      intrahash = {edb470e7d599da0df71fb515aba287cc},
      isbn = {978-3-319-47601-8},
      openaccess = {Yes},
      pages = {146--150},
      partneroptique = {UiO},
      series = {Lecture Notes in Computer Science},
      title = {PepeSearch: Easy to Use and Easy to Install Semantic Data Search},
      url = {http://dx.doi.org/10.1007/978-3-319-47602-5_29},
      volume = 9989, wpoptique = {WP3},
      year = 2016, yearoptique = {WP4}
    }
  • [2016,article] bibtex Go to document
    A. Soylu, M. Giese, E. Jimenez-Ruiz, E. Kharlamov, D. Zheleznyakov, and I. Horrocks, "Ontology-based End-user Visual Query Formulation: Why, what, who, how, and which?," Universal Access in Information Society, 2016.
    @article{Soylu2016, audience = {academic},
      author = {Soylu, Ahmet and Giese, Martin and Jimenez-Ruiz, Ernesto and Kharlamov, Evgeny and Zheleznyakov, Dmitriy and Horrocks, Ian},
      doi = {10.1007/s10209-016-0465-0},
      interhash = {48664fb45475489510a801b06f5ad89b},
      intrahash = {ae45da28b7c4b7e6ddaff3b40e1de510},
      journal = {Universal Access in Information Society},
      note = {appeared online.},
      openaccess = {Yes},
      partneroptique = {UiO},
      title = {Ontology-based End-user Visual Query Formulation: Why, what, who, how, and which?},
      url = {http://www.ahmetsoylu.com/wp-content/uploads/2016/02/Soylu_et_al_UAIS_2016.pdf},
      wpoptique = {WP3},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex Go to document
    A. Soylu, M. Giese, R. Schlatte, E. Jimenez-Ruiz, O. Ozcep, and S. Brandt, "Domain Experts Surfing on Stream Sensor Data over Ontologies," in Proceedings of the 1st Workshop on Semantic Web Technologies for Mobile and Pervasive Environments (SEMPER@ESWC 2016), Heraklion, Greece, 2016.
    @inproceedings{Soylu2016c, address = {Heraklion, Greece},
      audience = {academic},
      author = {Soylu, Ahmet and Giese, Martin and Schlatte, Rudolf and Jimenez-Ruiz, Ernesto and Ozcep, Ozgur and Brandt, Sebastian},
      booktitle = {Proceedings of the 1st Workshop on Semantic Web Technologies for Mobile and Pervasive Environments (SEMPER@ESWC 2016)},
      interhash = {80206f166f03004f5e0f770687724fc2},
      intrahash = {9c72705252934fb7c0934b0264dc4bd6},
      openaccess = {Yes},
      partneroptique = {UiO},
      publisher = {CEUR-WS.org},
      title = {Domain Experts Surfing on Stream Sensor Data over Ontologies },
      url = {http://ceur-ws.org/Vol-1588/paper4.pdf},
      volume = 1588, wpoptique = {WP3},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,article] bibtex Go to document
    A. Solimando, E. Jimenez-Ruiz, and G. Guerrini, "Minimizing Conservativity Violations in Ontology Alignments: Algorithms and Evaluation," Knowledge and Information Systems, 2016.
    @article{kais_sjg_2016, abstract = {In order to enable interoperability between ontology-based systems, ontology matching techniques have been proposed. However, when the generated mappings lead to undesired logical consequences, their usefulness may be diminished. In this paper, we present an approach to detect and minimize the violations of the so-called conservativity principle where novel subsumption entailments between named concepts in one of the input ontologies are considered as unwanted. The practical applicability of the proposed approach is experimentally demonstrated on the datasets from the Ontology Alignment Evaluation Initiative.},
      audience = {academic},
      author = {Solimando, Alessandro and Jimenez-Ruiz, Ernesto and Guerrini, Giovanna},
      doi = {10.1007/s10115-016-0983-3},
      interhash = {f895ccb64707fff208f8e18005a74662},
      intrahash = {3a32b428a161f4929cd06f0c599e36a9},
      journal = {Knowledge and Information Systems},
      openaccess = {No},
      partneroptique = {UOXF},
      publisher = {Springer},
      title = {Minimizing Conservativity Violations in Ontology Alignments: Algorithms and Evaluation},
      url = {https://github.com/asolimando/logmap-conservativity/},
      wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    Z. Dragisic, V. Ivanova, P. Lambrix, D. Faria, E. Jimenez-Ruiz, and C. Pesquita, "User validation in ontology alignment," in Proceedings of the International Semantic Web Conference, 2016.
    @inproceedings{iswc16_oa, abstract = {User validation is one of the challenges facing the ontology alignment community, as there are limits to the quality of automated alignment algorithms. In this paper we present a broad study on user validation of ontology alignments that encompasses three distinct but interrelated aspects: the profile of the user, the services of the alignment system, and its user interface. We discuss key issues pertaining to the alignment validation process under each of these aspects, and provide an overview of how current systems address them. Finally, we use experiments from the Interactive Matching track of the Ontology Alignment Evaluation Initiative (OAEI) 2015 to assess the impact of errors in alignment validation, and how systems cope with them as function of their services.},
      audience = {academic},
      author = {Dragisic, Zlatan and Ivanova, Valentina and Lambrix, Patrick and Faria, Daniel and Jimenez-Ruiz, Ernesto and Pesquita, Catia},
      booktitle = {Proceedings of the International Semantic Web Conference},
      doi = {10.1007/978-3-319-46523-4_13},
      interhash = {0ed1c84a7de5f57c1a84f897822d453a},
      intrahash = {005baa1f964a416b145bee313ad40d4c},
      month = {October},
      openaccess = {No},
      partneroptique = {UOXF},
      series = {LNCS},
      title = {User validation in ontology alignment},
      volume = 9981, wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex Go to document
    E. Jiménez-Ruiz, T. R. Payne, A. Solimando, and V. A. M. Tamma, "Limiting Logical Violations in Ontology Alignnment Through Negotiation," in Principles of Knowledge Representation and Reasoning: Proceedings of the Fifteenth International Conference, KR 2016, Cape Town, South Africa, April 25-29, 2016., 2016, pp. 217-226.
    @inproceedings{DBLP:conf/kr/Jimenez-RuizPST16, abstract = {Ontology alignment (also called ontology matching) is the process of identifying correspondences between entities in different, possibly heterogeneous, ontologies. Traditional ontology alignment techniques rely on the full disclosure of the ontological models; however, within open and opportunistic environments, such approaches may not always be pragmatic or even acceptable (due to privacy concerns). Several studies have focussed on collaborative, decentralised approaches to ontology alignment, where agents negotiate the acceptability of single correspondences acquired from past encounters, or try to ascertain novel correspondences on the fly. However, such approaches can lead to logical violations that may undermine their utility. In this paper, we extend a dialogical approach to correspondence negotiation, whereby agents not only exchange details of possible correspondences, but also identify potential violations to the consistency and conservativity principles. We present a formal model of the dialogue, and show how agents can repair logical violations during the dialogue by invoking a correspondence repair, thus negotiating and exchanging repair plans. We illustrate this opportunistic alignment mechanism with an example and we empirically show that allowing agents to strategically reject or weaken correspondences when these cause violations does not degrade the effectiveness of the alignment computed, whilst reducing the number of residual violations.},
      audience = {academic},
      author = {Jim{\'{e}}nez{-}Ruiz, Ernesto and Payne, Terry R. and Solimando, Alessandro and Tamma, Valentina A. M.},
      booktitle = {Principles of Knowledge Representation and Reasoning: Proceedings of the Fifteenth International Conference, {KR} 2016, Cape Town, South Africa, April 25-29, 2016.},
      interhash = {ad575d12d0bd1b0f46023d0ceb098903},
      intrahash = {14bf5060a4af093245404eca9c0dd002},
      openaccess = {Yes},
      pages = {217--226},
      partneroptique = {UOXF},
      title = {Limiting Logical Violations in Ontology Alignnment Through Negotiation},
      url = {http://www.aaai.org/ocs/index.php/KR/KR16/paper/view/12893},
      wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,article] bibtex
    G. Vega-Gorgojo, R. Fjellheim, D. Roman, R. Akerkar, and A. Waaler, "Big Data in the Oil & Gas Upstream Industry," OIL GAS European Magazine, vol. 42, iss. 2, pp. 67-77, 2016.
    @article{vega2016big, audience = {academic},
      author = {Vega-Gorgojo, Guillermo and Fjellheim, Roar and Roman, Dumitru and Akerkar, Rajendra and Waaler, Arild},
      doi = {unknown},
      interhash = {b3f746ab9e21f944d5681116bfb9a9ce},
      intrahash = {8fbbf806ece576c9d1e5ac13fe51ff32},
      journal = {OIL GAS European Magazine},
      number = 2, openaccess = {No},
      pages = {67-77},
      partneroptique = {UiO},
      title = {Big Data in the Oil & Gas Upstream Industry},
      volume = 42, wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex Go to document
    S. Brüggemann, K. Bereta, G. Xiao, and M. Koubarakis, "Ontology-Based Data Access for Maritime Security," in The Semantic Web. Latest Advances and New Domains – 13th International Conference, ESWC 2016, Heraklion, Crete, Greece, May 29 – June 2, 2016, Proceedings, 2016, pp. 741-757.
    @inproceedings{DBLP:conf/esws/BruggemannBXK16, abstract = {The maritime security domain is challenged by a number of data analysis needs focusing on increasing the maritime situation awareness, i.e., detection and analysis of abnormal vessel behaviors and suspicious vessel movements. The need for efficient processing of dynamic and/or static vessel data that come from different heterogeneous sources is emerged. In this paper we describe how we address the challenge of combining and processing real-time and static data from different sources using ontology-based data access techniques, and we explain how the application of semantic web technologies increases the value of data and improves the processing workflow in the maritime domain. },
      audience = {industry},
      author = {Br{\"{u}}ggemann, Stefan and Bereta, Konstantina and Xiao, Guohui and Koubarakis, Manolis},
      bdsk-url-1 = {http://dx.doi.org/10.1007/978-3-319-34129-3_45},
      bibsource = {dblp computer science bibliography, http://dblp.org},
      booktitle = {The Semantic Web. Latest Advances and New Domains - 13th International Conference, {ESWC} 2016, Heraklion, Crete, Greece, May 29 - June 2, 2016, Proceedings},
      crossref = {DBLP:conf/esws/2016},
      date-added = {2016-10-25 06:55:00 +0000},
      date-modified = {2016-10-25 07:32:51 +0000},
      doi = {10.1007/978-3-319-34129-3_45},
      interhash = {09b5d547c7d2c11fcb1786f6cf1cfdcd},
      intrahash = {bfbf3a4cb53bcdd0ba88bbda0334d589},
      openaccess = {Yes},
      pages = {741--757},
      partneroptique = {UoA},
      title = {Ontology-Based Data Access for Maritime Security},
      url = {http://dx.doi.org/10.1007/978-3-319-34129-3_45},
      wpoptique = {WP7},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex Go to document
    E. Kharlamov, S. Brandt, E. Jiménez-Ruiz, Y. Kotidis, S. Lamparter, T. Mailis, C. Neuenstadt, Ö. L. Özçep, C. Pinkel, C. Svingos, D. Zheleznyakov, I. Horrocks, Y. E. Ioannidis, and R. Möller, "Ontology-Based Integration of Streaming and Static Relational Data with Optique," in Proceedings of the 2016 International Conference on Management of Data, SIGMOD Conference 2016, San Francisco, CA, USA, June 26 – July 01, 2016, 2016, pp. 2109-2112.
    @inproceedings{DBLP:conf/sigmod/KharlamovBJKLMN16, abstract = {Real-time processing of data coming from multiple heterogeneous data streams and static databases is a typical task in many industrial scenarios such as diagnostics of large machines. A complex diagnostic task may require a collection of up to hundreds of queries over such data. Although many of these queries retrieve data of the same kind, such as temperature measurements, they access structurally different data sources. In this work we show how Semantic Technologies implemented in our system Optique can simplify such complex diagnostics by providing an abstraction layer---ontology---that integrates heterogeneous data. In a nutshell, Optique allows complex diagnostic tasks to be expressed with just a few high-level semantic queries. The system can then automatically enrich these queries, translate them into a collection with a large number of low-level data queries, and finally optimise and efficiently execute the collection in a heavily distributed environment. We will demo the benefits of Optique on a real world scenario from Siemens. },
      audience = {general},
      author = {Kharlamov, Evgeny and Brandt, Sebastian and Jim{\'{e}}nez{-}Ruiz, Ernesto and Kotidis, Yannis and Lamparter, Steffen and Mailis, Theofilos and Neuenstadt, Christian and {\"{O}}z{\c{c}}ep, {\"{O}}zg{\"{u}}r L. and Pinkel, Christoph and Svingos, Christoforos and Zheleznyakov, Dmitriy and Horrocks, Ian and Ioannidis, Yannis E. and M{\"{o}}ller, Ralf},
      bdsk-url-1 = {http://doi.acm.org/10.1145/2882903.2899385},
      bdsk-url-2 = {http://dx.doi.org/10.1145/2882903.2899385},
      bibsource = {dblp computer science bibliography, http://dblp.org},
      booktitle = {Proceedings of the 2016 International Conference on Management of Data, {SIGMOD} Conference 2016, San Francisco, CA, USA, June 26 - July 01, 2016},
      crossref = {DBLP:conf/sigmod/2016},
      date-added = {2016-10-25 06:46:24 +0000},
      date-modified = {2016-10-25 07:31:37 +0000},
      doi = {10.1145/2882903.2899385},
      interhash = {5282a79bfa6250248b23b04058bcc028},
      intrahash = {b6a83eafddd7db32a827d5eb2061f3ae},
      openaccess = {Yes},
      pages = {2109--2112},
      partneroptique = {UoA},
      title = {Ontology-Based Integration of Streaming and Static Relational Data with Optique},
      url = {http://doi.acm.org/10.1145/2882903.2899385},
      wpoptique = {WP7},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex Go to document
    K. Bereta and M. Koubarakis, "Ontop of Geospatial Databases," in The Semantic Web – ISWC 2016 – 15th International Semantic Web Conference, Kobe, Japan, October 17-21, 2016, Proceedings, Part I, 2016, pp. 37-52.
    @inproceedings{DBLP:conf/semweb/BeretaK16, abstract = {We propose an OBDA approach for accessing geospatial data stored in relational databases, using the OGC standard GeoSPARQL and R2RML or OBDA mappings. We introduce extensions to an existing SPARQL-to-SQL translation method to support GeoSPARQL features. We describe the implementation of our approach in the system ontop-spatial, an extension of the OBDA system Ontop for creating virtual geospatial RDF graphs on top of geospatial relational databases. We present an experimental evaluation of our system using and extending a state-of-the-art benchmark. To measure the performance of our system, we compare it to a state-of-the-art geospatial RDF store and confirm its efficiency.},
      audience = {general},
      author = {Bereta, Konstantina and Koubarakis, Manolis},
      bdsk-url-1 = {http://dx.doi.org/10.1007/978-3-319-46523-4_3},
      bibsource = {dblp computer science bibliography, http://dblp.org},
      booktitle = {The Semantic Web - {ISWC} 2016 - 15th International Semantic Web Conference, Kobe, Japan, October 17-21, 2016, Proceedings, Part {I}},
      crossref = {DBLP:conf/semweb/2016-1},
      date-added = {2016-10-25 06:55:09 +0000},
      date-modified = {2016-10-25 07:29:30 +0000},
      doi = {10.1007/978-3-319-46523-4_3},
      interhash = {c493c1351021da98cfe391e18321c4f7},
      intrahash = {94a965121d14ffc081e7b7fdf922d92c},
      openaccess = {Yes},
      pages = {37--52},
      partneroptique = {UoA},
      title = {Ontop of Geospatial Databases},
      url = {http://dx.doi.org/10.1007/978-3-319-46523-4_3},
      wpoptique = {WP7},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    C. Svingos, T. Mailis, H. Kllapi, L. Stamatogiannakis, Y. Kotidis, and Y. Ioannidis, "Real Time Processing of Streaming and Static Information," in 2016 IEEE International Conference on Big Data, 2016.
    @inproceedings{svingos2016bigdata, abstract = {Big Data applications require real-time processing of complex computations on streaming and static information. Applications such as the diagnosis of power generating turbines and tsunami warning systems require the integration of high velocity streaming and large volume of static data from multiple sources. In this paper we study various optimisations related to efficiently processing of streaming and static information. We introduce novel indexing structures for stream processing and a query-planner component that decides when their creation is beneficial; we suggest optimisations for efficient CPU and memory handling; we propose appropriate structures to archive streaming information; and we suggest intuitive precomputed summarisations on archived measurements to accelerate streaming and static information processing. To put our ideas into practise, we have developed \exastream, a data stream management system that is scalable, has declarative semantics, supports user defined functions, and allows for the stream and static data integration. Our work is accompanied by an empirical evaluation of our optimisation techniques.},
      audience = {general},
      author = {Svingos, Christoforos and Mailis, Theofilos and Kllapi, Herald and Stamatogiannakis, Lefteris and Kotidis, Yannis and Ioannidis, Yannis},
      booktitle = {2016 {IEEE} International Conference on Big Data},
      date-added = {2016-10-25 06:59:09 +0000},
      date-modified = {2016-10-25 07:27:36 +0000},
      interhash = {63e4be1da8a0796edafbbcb595790af1},
      intrahash = {19211111987e93fe3107de2b64a9dc2a},
      openaccess = {Yes},
      partneroptique = {UoA},
      title = {{Real Time Processing of Streaming and Static Information}},
      wpoptique = {WP7},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex Go to document
    Y. Chronis, Y. Foufoulas, V. Nikolopoulos, A. Papadopoulos, L. Stamatogiannakis, C. Svingos, and Y. E. Ioannidis, "A Relational Approach to Complex Dataflows," in Proceedings of the Workshops of the EDBT/ICDT 2016 Joint Conference, EDBT/ICDT Workshops 2016, Bordeaux, France, March 15, 2016., 2016.
    @inproceedings{DBLP:conf/edbt/ChronisFNPSSI16, abstract = {Clouds have become an attractive platform for highly scalable processing of Big Data, especially due to the concept of elasticity, which characterizes them. Several languages and systems for cloud-based data processing have been proposed in the past, with the most popular among them being based on MapReduce. In this paper, we present Exareme, a system for elastic large-scale data processing on the cloud that follows a more general paradigm. Exareme is an open source project. The system offers a declarative language which is based on SQL with user-defined functions (UDFs) extended with parallelism primitives and an inverted syntax to easily express data pipelines. Exareme is designed to take advantage of clouds by dynamically allocating and deallocating compute resources, offering trade-offs between execution time and monetary cost.},
      audience = {general},
      author = {Chronis, Yannis and Foufoulas, Yannis and Nikolopoulos, Vaggelis and Papadopoulos, Alexandros and Stamatogiannakis, Lefteris and Svingos, Christoforos and Ioannidis, Yannis E.},
      bdsk-url-1 = {http://ceur-ws.org/Vol-1558/paper45.pdf},
      bibsource = {dblp computer science bibliography, http://dblp.org},
      booktitle = {Proceedings of the Workshops of the {EDBT/ICDT} 2016 Joint Conference, {EDBT/ICDT} Workshops 2016, Bordeaux, France, March 15, 2016.},
      crossref = {DBLP:conf/edbt/2016w},
      date-added = {2016-10-25 06:47:34 +0000},
      date-modified = {2016-10-25 07:35:42 +0000},
      interhash = {26036932737429d4d248bacc9978ee4a},
      intrahash = {f4a250fb03f11a57ad0e41271bbc09c7},
      openaccess = {Yes},
      partneroptique = {UoA},
      title = {A Relational Approach to Complex Dataflows},
      url = {http://ceur-ws.org/Vol-1558/paper45.pdf},
      wpoptique = {WP7},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,article] bibtex
    G. Vega-Gorgojo, L. Slaughter, M. Giese, S. Heggestøyl, A. Soylu, and A. Waaler, "Visual query interfaces for semantic datasets: An evaluation study," Web Semantics: Science, Services and Agents on the World Wide Web, 2016.
    @article{vega2016visual, audience = {academic},
      author = {Vega-Gorgojo, Guillermo and Slaughter, Laura and Giese, Martin and Heggest{\o}yl, Simen and Soylu, Ahmet and Waaler, Arild},
      doi = {http://dx.doi.org/10.1016/j.websem.2016.01.002},
      interhash = {c2403efd6b4d0dbccd3a94fec8b9ced7},
      intrahash = {57f08da57247091ef35e687463ad398a},
      journal = {Web Semantics: Science, Services and Agents on the World Wide Web},
      openaccess = {No},
      partneroptique = {UiO},
      publisher = {Elsevier},
      title = {Visual query interfaces for semantic datasets: An evaluation study},
      wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,article] bibtex
    G. Vega-Gorgojo, M. Giese, S. Heggestøyl, A. Soylu, and A. Waaler, "PepeSearch: Semantic Data for the Masses," PloS one, vol. 11, iss. 3, p. 0151573, 2016.
    @article{vega2016pepesearch, audience = {academic},
      author = {Vega-Gorgojo, Guillermo and Giese, Martin and Heggest{\o}yl, Simen and Soylu, Ahmet and Waaler, Arild},
      doi = {10.1371/journal.pone.0151573},
      interhash = {2c99cfe4555d9aa56f09d382ff793daa},
      intrahash = {735f87a69a9b2821bd05f0000c1dcb11},
      journal = {PloS one},
      number = 3, openaccess = {Yes},
      pages = {e0151573},
      partneroptique = {UiO},
      publisher = {Public Library of Science},
      title = {PepeSearch: Semantic Data for the Masses},
      volume = 11, wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,article] bibtex
    G. D. Giacomo, A. E. Gerevini, F. Patrizi, A. Saetti, and S. Sardina, "Agent planning programs," Artificial Intelligence, vol. 231, pp. 64-106, 2016.
    @article{DGPSS-J-16, abstract = { This work proposes a novel high-level paradigm, agent planning programs, for modeling agents behavior, which suitably mixes automated planning with agent-oriented programming. Agent planning programs are finite-state programs, possibly containing loops, whose atomic instructions consist of a guard, a maintenance goal, and an achievement goal, which act as precondition-invariance-postcondition assertions in program specification. Such programs are to be executed in possibly nondeterministic planning domains and their execution requires generating plans that meet the goals specified in the atomic instructions, while respecting the program control flow. In this paper, we define the problem of automatically synthesizing the required plans to execute an agent planning program, propose a solution technique based on model checking of two-player game structures, and use it to characterize the worst-case computational complexity of the problem as EXPTIME-complete. Then, we consider the case of deterministic domains and propose a different technique to solve agent planning programs, which is based on iteratively solving classical planning problems and on exploiting goal preferences and plan adaptation methods. Finally, we study the effectiveness of this approach for deterministic domains through an experimental analysis on well-known planning domains.},
      audience = {academic},
      author = {Giacomo, Giuseppe De and Gerevini, Alfonso Emilio and Patrizi, Fabio and Saetti, Alessandro and Sardina, Sebastian},
      doi = {10.1016/j.artint.2015.10.001},
      interhash = {6a403688a7534379569cc409c0ca13ea},
      intrahash = {e6357d213672f0ec0b2697cf45b3d8ce},
      issn = {0004-3702},
      journal = {Artificial Intelligence},
      month = {2},
      openaccess = {No},
      pages = {64--106},
      partneroptique = {UNIROMA1},
      publisher = {Elsevier},
      title = {Agent planning programs},
      volume = 231, wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    D. Calvanese, G. D. Giacomo, M. Montali, and F. Patrizi, "On First-Order mu-Calculus over Situation Calculus Action Theories," in Principles of Knowledge Representation and Reasoning: Proceedings of the Fifteenth International Conference, KR 2016, Cape Town, South Africa, April 25-29, 2016., 2016, pp. 411-420.
    @inproceedings{CDMP-P-16, abstract = {In this paper we study verification of situation calculus action theories against first-order mu-calculus with quantification across situations. Specifically, we consider mu-La and mu-Lp, the two variants of mu-calculus introduced in the literature for verification of data-aware processes. The former requires that quantification ranges over objects in the current active domain, while the latter additionally requires that objects assigned to variables persist across situations. Each of these two logics has a distinct corresponding notion of bisimulation. In spite of the differences we show that the two notions of bisimulation collapse for dynamic systems that are generic, which include all those systems specified through a situation calculus action theory. Then, by exploiting this result, we show that for bounded situation calculus action theories, mu-La and mu-Lp have exactly the same expressive power. Finally, we prove decidability of verification of mu-La properties over bounded action theories, using finite faithful abstractions. Differently from the mu-Lp case, these abstractions must depend on the number of quantified variables in the mu-La formula.},
      audience = {academic},
      author = {Calvanese, Diego and Giacomo, Giuseppe De and Montali, Marco and Patrizi, Fabio},
      booktitle = {Principles of Knowledge Representation and Reasoning: Proceedings of the Fifteenth International Conference, {KR} 2016, Cape Town, South Africa, April 25-29, 2016.},
      interhash = {8494e3da170930fcd6bba5fe6d5c7181},
      intrahash = {6dfb34e06f75e874f3f423722f74cef6},
      openaccess = {Yes},
      pages = {411--420},
      partneroptique = {UNIROMA1},
      title = {On First-Order mu-Calculus over Situation Calculus Action Theories},
      wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    M. Bienvenu and R. Rosati, "Query-Based Comparison of Mappings in Ontology-Based Data Access," in Principles of Knowledge Representation and Reasoning: Proceedings of the Fifteenth International Conference, KR 2016, Cape Town, South Africa, April 25-29, 2016., 2016, pp. 197-206.
    @inproceedings{BR-KR-16, abstract = {An ontology-based data access (OBDA) system is composed of one or more data sources, an ontology that provides a conceptual view of the data, and declarative mappings that relate the data and ontology schemas. In order to debug and optimize such systems, it is important to be able to analyze and compare OBDA specifications. Recent work in this direction compared specifications using classical notions of equivalence and entailment, but an interesting alternative is to consider query-based notions, in which two specifications are deemed equivalent if they give the same answers to the considered query or class of queries for all possible data sources. In this paper, we define such query-based notions of entailment and equivalence of OBDA specifications and investigate the complexity of the resulting analysis tasks when the ontology is formulated in (fragments of) DL-LiteR.},
      audience = {academic},
      author = {Bienvenu, Meghyn and Rosati, Riccardo},
      booktitle = {Principles of Knowledge Representation and Reasoning: Proceedings of the Fifteenth International Conference, {KR} 2016, Cape Town, South Africa, April 25-29, 2016.},
      interhash = {056baf1a3692289c279e330f328613af},
      intrahash = {db2e242983c7b4687a2876873b61364c},
      openaccess = {Yes},
      pages = {197--206},
      partneroptique = {UNIROMA1},
      title = {Query-Based Comparison of Mappings in Ontology-Based Data Access},
      wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    C. Civili and R. Rosati, "Bounded Implication for Existential Rules (Extended Abstract)," in Proceedings of the 29th International Workshop on Description Logics, Cape Town, South Africa, April 22-25, 2016., 2016.
    @inproceedings{CS-DL-16, audience = {academic},
      author = {Civili, Cristina and Rosati, Riccardo},
      booktitle = {Proceedings of the 29th International Workshop on Description Logics, Cape Town, South Africa, April 22-25, 2016.},
      interhash = {c83e128161e34376c32360c47ad98d00},
      intrahash = {80cb49a08b1c8181df5484b26e416d0f},
      openaccess = {Yes},
      partneroptique = {UNIROMA1},
      title = {Bounded Implication for Existential Rules (Extended Abstract)},
      wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    C. Civili, J. Mora, R. Rosati, M. Ruzzi, and V. Santarelli, "Semantic Analysis of R2RML Mappings for Ontology-Based Data Access," in Web Reasoning and Rule Systems – 10th International Conference, RR 2016, Aberdeen, UK, September 9-11, 2016, Proceedings, 2016, pp. 25-38.
    @inproceedings{CMRRSS-RR-2016, abstract = {Ontology-based data access (OBDA) deals with the problem of accessing autonomous data sources through a shared, virtual ontology, and declarative mappings connecting the data sources to the ontology. The W3C standard R2RML allows for mapping relational data sources to RDFS/OWL ontologies. In this paper, we present algorithms for the semantic analysis of R2RML mappings in the OBDA setting, when the ontology is expressed in OWL 2 QL. The focus of such algorithms is to identify the main semantical anomalies (inconsistency and redundancy) of a mapping specification with respect to the ontology and/or the data sources. Such algorithms have been implemented in the mapping analysis tool developed within the Optique European project. We also report on the experiments conducted within the Optique project use cases.},
      audience = {academic},
      author = {Civili, Cristina and Mora, Jos{\'{e}} and Rosati, Riccardo and Ruzzi, Marco and Santarelli, Valerio},
      booktitle = {Web Reasoning and Rule Systems - 10th International Conference, {RR} 2016, Aberdeen, UK, September 9-11, 2016, Proceedings},
      doi = {10.1007/978-3-319-45276-0_3},
      interhash = {b736620db6a58a4cb0b3a582b25fa1b6},
      intrahash = {81a7c5995f0435495b6ea484916864ee},
      openaccess = {No},
      pages = {25--38},
      partneroptique = {UNIROMA1},
      title = {Semantic Analysis of {R2RML} Mappings for Ontology-Based Data Access},
      wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    D. Lembo, D. Pantaleone, V. Santarelli, and D. F. Savo, "Easy OWL Drawing with the Graphol Visual Ontology Language," in Principles of Knowledge Representation and Reasoning: Proceedings of the Fifteenth International Conference, KR 2016, Cape Town, South Africa, April 25-29, 2016., 2016, pp. 573-576.
    @inproceedings{LPSS-KR-16, abstract = {Graphol is a visual language designed to help non-experts to understand and specify ontologies. Our language builds on the Entity-Relationship model, but has a formal semantics and higher expressiveness. Notably, OWL 2 can be completely encoded in Graphol. Thanks to the novel open-source Eddy ontology editor, designers can easily draw Graphol diagrams corresponding to OWL ontologies and export them into standard OWL 2 format. Both Graphol and Eddy have been used in several successful industrial projects and are currently under active development. This paper reports on our more recent progresses.},
      audience = {academic},
      author = {Lembo, Domenico and Pantaleone, Daniele and Santarelli, Valerio and Savo, Domenico Fabio},
      booktitle = {Principles of Knowledge Representation and Reasoning: Proceedings of the Fifteenth International Conference, {KR} 2016, Cape Town, South Africa, April 25-29, 2016.},
      interhash = {0a44b0a6acad8e77cea400449fec9715},
      intrahash = {3b933de869a07f7d7a8f4d1914277cae},
      openaccess = {Yes},
      pages = {573--576},
      partneroptique = {UNIROMA1},
      title = {Easy {OWL} Drawing with the Graphol Visual Ontology Language},
      wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    E. Botoeva, D. Calvanese, V. Santarelli, D. F. Savo, A. Solimando, and G. Xiao, "Beyond OWL 2 QL in OBDA: Rewritings and Approximations," in Proceedings of the Thirtieth AAAI Conference on Artificial Intelligence, February 12-17, 2016, Phoenix, Arizona, USA., 2016, pp. 921-928.
    @inproceedings{BCSSSX-AAAI-16, abstract = {Ontology-based data access (OBDA) is a novel paradigm facilitating access to relational data, realized by linking data sources to an ontology by means of declarative mappings. DL-Lite_R, which is the logic underpinning the W3C ontology language OWL 2 QL and the current language of choice for OBDA, has been designed with the goal of delegating query answering to the underlying database engine, and thus is restricted in expressive power. E.g., it does not allow one to express disjunctive information, and any form of recursion on the data. The aim of this paper is to overcome these limitations of DL-Lite_R, and extend OBDA to more expressive ontology languages, while still leveraging the underlying relational technology for query answering. We achieve this by relying on two well-known mechanisms, namely conservative rewriting and approximation, but significantly extend their practical impact by bringing into the picture the mapping, an essential component of OBDA. Specifically, we develop techniques to rewrite OBDA specifications with an expressive ontology to "equivalent" ones with a DL-Lite_R ontology, if possible, and to approximate them otherwise. We do so by exploiting the high expressive power of the mapping layer to capture part of the domain semantics of rich ontology languages. We have implemented our techniques in the prototype system OntoProx, making use of the state-of-the-art OBDA system Ontop and the query answering system Clipper, and we have shown their feasibility and effectiveness with experiments on synthetic and real-world data.},
      audience = {academic},
      author = {Botoeva, Elena and Calvanese, Diego and Santarelli, Valerio and Savo, Domenico Fabio and Solimando, Alessandro and Xiao, Guohui},
      booktitle = {Proceedings of the Thirtieth {AAAI} Conference on Artificial Intelligence, February 12-17, 2016, Phoenix, Arizona, {USA.}},
      interhash = {47bbd5b0ed8157bc2ae63b6d5d07f608},
      intrahash = {29067cd43a3c8962ffbbac0e03af6dd5},
      openaccess = {Yes},
      pages = {921--928},
      partneroptique = {UNIROMA1},
      title = {Beyond {OWL} 2 {QL} in {OBDA:} Rewritings and Approximations},
      wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    E. Botoeva, D. Calvanese, V. Santarelli, D. F. Savo, A. Solimando, and G. Xiao, "Virtual OBDA over Expressive Ontologies: Rewritings and Approximations," in Proceedings of the 29th International Workshop on Description Logics, Cape Town, South Africa, April 22-25, 2016., 2016.
    @inproceedings{BCSSSX-DL-16, abstract = { In this paper we extend virtual OBDA to more expressive ontology languages than that of DL-LiteR, which is the logic underpinning the W3C ontology language OWL 2. We achieve this by relying on two well-known mechanisms, namely conservative rewriting and approximation, and compiling some of the domain semantics into OBDA mappings. },
      audience = {academic},
      author = {Botoeva, Elena and Calvanese, Diego and Santarelli, Valerio and Savo, Domenico Fabio and Solimando, Alessandro and Xiao, Guohui},
      booktitle = {Proceedings of the 29th International Workshop on Description Logics, Cape Town, South Africa, April 22-25, 2016.},
      interhash = {ad3e6c3cf8c166f5c19c6083c5491892},
      intrahash = {4f62ccfaae3e901143d3434fedff5c5f},
      openaccess = {Yes},
      partneroptique = {UNIROMA1},
      title = {Virtual {OBDA} over Expressive Ontologies: Rewritings and Approximations},
      wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    D. Lembo, R. Rosati, V. Santarelli, D. F. Savo, and E. Thorstensen, "Approaching OBDA Evolution through Mapping Repair," in Proceedings of the 29th International Workshop on Description Logics, Cape Town, South Africa, April 22-25, 2016., 2016.
    @inproceedings{LRSST, audience = {academic},
      author = {Lembo, Domenico and Rosati, Riccardo and Santarelli, Valerio and Savo, Domenico Fabio and Thorstensen, Evgenij},
      booktitle = {Proceedings of the 29th International Workshop on Description Logics, Cape Town, South Africa, April 22-25, 2016.},
      interhash = {8fc92f36e51e58546d0bbf07a0c68d95},
      intrahash = {d537337f076301ab2c36014f0159996e},
      openaccess = {Yes},
      partneroptique = {UNIROMA1},
      title = {Approaching {OBDA} Evolution through Mapping Repair},
      wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    D. Lembo, D. Pantaleone, V. Santarelli, and D. F. Savo, "Eddy: A Graphical Editor for OWL 2 Ontologies," in Proceedings of the Twenty-Fifth International Joint Conference on Artificial Intelligence, IJCAI 2016, New York, NY, USA, 9-15 July 2016, 2016, pp. 4252-4253.
    @inproceedings{LPSS-IJCAI-16, abstract = { We demonstrate Eddy, a new tool for designing ontologies specified in the Graphol language. Graphol is completely visual and fully captures OWL 2. Thus Eddy is the first ontology editor that allows to create OWL 2 ontologies by only using simple graphical editing features.},
      audience = {academic},
      author = {Lembo, Domenico and Pantaleone, Daniele and Santarelli, Valerio and Savo, Domenico Fabio},
      booktitle = {Proceedings of the Twenty-Fifth International Joint Conference on Artificial Intelligence, {IJCAI} 2016, New York, NY, USA, 9-15 July 2016},
      interhash = {30b892336e4c9bfaea66c576200c5d78},
      intrahash = {19caa995b3b8158f842457bc6d74a02a},
      openaccess = {Yes},
      pages = {4252--4253},
      partneroptique = {UNIROMA1},
      title = {Eddy: {A} Graphical Editor for {OWL} 2 Ontologies},
      wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    G. D. Giacomo, X. Oriol, R. Rosati, and D. F. Savo, "Updating DL-Lite Ontologies Through First-Order Queries," in The Semantic Web – ISWC 2016 – 15th International Semantic Web Conference, Kobe, Japan, October 17-21, 2016, Proceedings, Part I, 2016, pp. 167-183.
    @inproceedings{DORS-P-16, abstract = {In this paper we study instance-level update in DL-LiteA, the description logic underlying the OWL 2 QL standard. In particular we focus on formula-based approaches to ABox insertion and deletion. We show that DL-LiteA, which is well-known for enjoying first-order rewritability of query answering, enjoys a first-order rewritability property also for updates. That is, every update can be reformulated into a set of insertion and deletion instructions computable through a non-recursive datalog program. Such a program is readily translatable into a first-order query over the ABox considered as a database, and hence into SQL. By exploiting this result, we implement an update component for DL-LiteA-based systems and perform some experiments showing that the approach works in practice.},
      audience = {academic},
      author = {Giacomo, Giuseppe De and Oriol, Xavier and Rosati, Riccardo and Savo, Domenico Fabio},
      booktitle = {The Semantic Web - {ISWC} 2016 - 15th International Semantic Web Conference, Kobe, Japan, October 17-21, 2016, Proceedings, Part {I}},
      doi = {10.1007/978-3-319-46523-4_11},
      interhash = {38aee409d347d54d5f8986f7430a6a11},
      intrahash = {965a5575c3e4552ae227a4b2f310c9b2},
      openaccess = {No},
      pages = {167--183},
      partneroptique = {UNIROMA1},
      title = {Updating DL-Lite Ontologies Through First-Order Queries},
      wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    M. Lenzerini, L. Lepore, and A. Poggi, "Answering Metaqueries over Hi OWL 2 QL Ontologies," in Proceedings of the Twenty-Fifth International Joint Conference on Artificial Intelligence, IJCAI 2016, New York, NY, USA, 9-15 July 2016, 2016, pp. 1174-1180.
    @inproceedings{LLP-IJCA-P-16, abstract = {Hi(OWL 2 QL) is a new ontology language with the OWL2QL syntax and a specific semantics designed to support metamodeling and meta-querying. In this paper we investigate the problem of answering metaqueries in Hi(OWL 2 QL), which are unions of conjunctive queries with both ABox and TBox atoms. We first focus on a specific class of ontologies, called TBox-complete, where there is no uncertainty about TBox axioms, and show that query answering in this case has the same complexity (both data and combined) as in OWL2QL. We then move to general ontologies and show that answering metaqueries is coNP-complete with respect to ontology complexity, Π2p-complete with respect to combined complexity, and remains AC0 with respect to ABox complexity. Finally, we present an optimized query answering algorithm that can be used for TBox-complete ontologies.},
      audience = {academic},
      author = {Lenzerini, Maurizio and Lepore, Lorenzo and Poggi, Antonella},
      booktitle = {Proceedings of the Twenty-Fifth International Joint Conference on Artificial Intelligence, {IJCAI} 2016, New York, NY, USA, 9-15 July 2016},
      interhash = {559fa2be8c63df63213de0293c628b0d},
      intrahash = {e7c3ab833738ad71fa0dc20909dc7ce1},
      openaccess = {Yes},
      pages = {1174--1180},
      partneroptique = {UNIROMA1},
      title = {Answering Metaqueries over Hi OWL 2 QL Ontologies},
      wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex
    M. Lenzerini, L. Lepore, and A. Poggi, "A Higher-Order Semantics for Metaquerying in OWL 2 QL," in Principles of Knowledge Representation and Reasoning: Proceedings of the Fifteenth International Conference, KR 2016, Cape Town, South Africa, April 25-29, 2016., 2016, pp. 577-580.
    @inproceedings{LLP-KR-P-16, abstract = {Inspired by recent work on higher-order Description Logics, we propose HOS, a new semantics for OWL 2 QL ontologies. We then consider SPARQL queries which are legal under the direct semantics entailment regime,we extend them with logical union, existential variables, and unrestricted use of variables so as to express meaningful meta-level queries. We show that both satisfiability checking and answering instance queries with metavariables have the same ABox complexity as under direct semantics.},
      audience = {academic},
      author = {Lenzerini, Maurizio and Lepore, Lorenzo and Poggi, Antonella},
      booktitle = {Principles of Knowledge Representation and Reasoning: Proceedings of the Fifteenth International Conference, {KR} 2016, Cape Town, South Africa, April 25-29, 2016.},
      interhash = {cff59bd4421cc714838f0721835d4558},
      intrahash = {a484dd363871f4b8a82b91698002e239},
      openaccess = {Yes},
      pages = {577--580},
      partneroptique = {UNIROMA1},
      title = {A Higher-Order Semantics for Metaquerying in OWL 2 QL},
      wpoptique = {WP4},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,article] bibtex
    R. Möller, &. Özcep, V. Haarslev, A. Nafissi, and M. Wessel, "Abductive Conjunctive Query Answering w.r.t. Ontologies," KI – Künstliche Intelligenz, vol. 30, iss. 2, pp. 177-182, 2016.
    @article{moeller16abductive, abstract = {In this article we investigate abductive conjunctive query answering w.r.t. ontologies and show how use cases can benefit from this kind of query answering service. While practical reasoning systems such as Racer have supported abductive conjunctive query answering for 10 years now, and many projects have exploited this feature, few publications deal with A-box abduction from an implementation perspective. This article gives a generalized overview on features provided by practical systems and also explains optimization techniques needed to meet practical requirements.},
      audience = {academic},
      author = {Möller, Ralf and Özcep, Özgür and Haarslev, Volker and Nafissi, Anahita and Wessel, Michael},
      doi = {doi:10.1007/s13218-015-0399-3},
      interhash = {f7eccaf70229922443a11807beaa23c4},
      intrahash = {9d75c7ee0b4facbaec01bf71511a62b0},
      journal = {{KI - Künstliche Intelligenz}},
      number = 2, openaccess = {No},
      pages = {177--182},
      partneroptique = {UZL},
      title = {{Abductive Conjunctive Query Answering w.r.t. Ontologies}},
      volume = 30, wpoptique = {WP5},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex Go to document
    E. Kharlamov, Y. Kotidis, T. Mailis, C. Neuenstadt, C. Nikolaou, &. L. Özcep, C. Svingos, D. Zheleznyakov, S. Brandt, I. Horrocks, Y. E. Ioannidis, S. Lamparter, and R. Möller, "Towards Analytics Aware Ontology Based Access to Static and Streaming Data," in The Semantic Web – ISWC 2016 – 15th International Semantic Web Conference, Kobe, Japan, October 17-21, 2016, Proceedings, Part II, 2016, pp. 344-362.
    @inproceedings{kharlamov16towardsISWC16, abstract = {Real-time analytics that requires integration and aggregation of heterogeneous and distributed streaming and static data is a typical task in many industrial scenarios such as diagnostics of turbines in Siemens. OBDA approach has a great potential to facilitate such tasks; however, it has a number of limitations in dealing with analytics that restrict its use in important industrial applications. Based on our experience with Siemens, we argue that in order to overcome those limitations OBDA should be extended and become analytics, source, and cost aware. In this work we propose such an extension. In particular, we propose an ontology, mapping, and query language for OBDA, where aggregate and other analytical functions are first class citizens. Moreover, we develop query optimisation techniques that allow to efficiently process analytical tasks over static and streaming data. We implement our approach in a system and evaluate our system with Siemens turbine data.},
      audience = {academic},
      author = {Kharlamov, Evgeny and Kotidis, Yannis and Mailis, Theofilos and Neuenstadt, Christian and Nikolaou, Charalampos and Özcep, Özgür L. and Svingos, Christoforos and Zheleznyakov, Dmitriy and Brandt, Sebastian and Horrocks, Ian and Ioannidis, Yannis E. and Lamparter, Steffen and Möller, Ralf},
      bibsource = {dblp computer science bibliography, http://dblp.org},
      booktitle = {The Semantic Web - {ISWC} 2016 - 15th International Semantic Web Conference, Kobe, Japan, October 17-21, 2016, Proceedings, Part {II}},
      date-added = {2016-10-11 09:15:40 +0000},
      date-modified = {2016-10-11 09:15:40 +0000},
      doi = {10.1007/978-3-319-46547-0_31},
      editor = {Groth, Paul T. and Simperl, Elena and Gray, Alasdair J. G. and Sabou, Marta and Kr{\"{o}}tzsch, Markus and L{\'{e}}cu{\'{e}},
      Freddy and Fl{\"{o}}ck, Fabian and Gil, Yolanda},
      interhash = {1861af957de6c481e190213306fa48c3},
      intrahash = {4e85e22c3819272c249e322f381efeec},
      openaccess = {No},
      pages = {344--362},
      partneroptique = {UOXL},
      series = {Lecture Notes in Computer Science},
      title = {Towards Analytics Aware Ontology Based Access to Static and Streaming Data},
      url = {http://dx.doi.org/10.1007/978-3-319-46547-0_31},
      volume = 9982, wpoptique = {WP5},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,inproceedings] bibtex Go to document
    &. L. Özcep, "Iterated Ontology Revision by Reinterpretation," in Proceedings of the 16th International Workshop on Non-Monotonic Reasoning (NMR-2016), 2016, pp. 105-114.
    @inproceedings{oezcep16NMR, abstract = {Iterated applications of belief change operators are essential for different scenarios such as that of ontology evolution where new information is not presented at once but only in piecemeal fashion within a sequence. I discuss iterated applications of so called reinterpretation operators that trace conflicts between ontologies back to the ambiguous of symbols and that provide conflict resolution strategies with bridging axioms. The discussion centers on adaptations of the classical iteration postulates according to Darwiche and Pearl. The main result of the paper is that reinterpretation operators fulfill the postulates for sequences containing only atomic triggers. For complex triggers, a fulfillment is not guaranteed and indeed there are different reasons for the different postulates why they should not be fulfilled in the particular scenario of ontology revision with well developed ontologies.},
      audience = {academic},
      author = {Özcep, Özgür L.},
      booktitle = {Proceedings of the 16th International Workshop on Non-Monotonic Reasoning {(NMR-2016)}},
      date-added = {2016-03-15 12:03:18 +0000},
      date-modified = {2016-05-31 15:06:36 +0000},
      editor = {Kern-Isberner, Gabriele and Wassermann, Renata},
      interhash = {3f1acc4622928156387fc500a0a73abb},
      intrahash = {eba99d5c240ddb4b916731039a8a02f2},
      openaccess = {yes},
      pages = {105--114},
      partneroptique = {UZL},
      title = {Iterated Ontology Revision by Reinterpretation},
      url = {http://nmr2016.cs.uct.ac.za/proceedings_nmr2016_online.pdf},
      wpoptique = {WP5},
      year = 2016, yearoptique = {Y4}
    }
  • [2016,proceedings] bibtex Go to document
    2016 IEEE Second International Conference on Big Data Computing Service and Applications (BigDataService)IEEE, 2016.
    @proceedings{BigDataService2016, audience = {academic},
      doi = {10.1109/BigDataService.2016.5},
      editor = {Gao, Jerry and Giese, Martin and Zeng, Yifeng and Zhu, Hong},
      interhash = {f968acc7c022db7f36c1986887c1a001},
      intrahash = {c7ecb84298b664616268d44d529ad2f6},
      openaccess = {No},
      organization = {IEEE},
      partneroptique = {UiO},
      publisher = {IEEE},
      title = {2016 IEEE Second International Conference on Big Data Computing Service and Applications (BigDataService)},
      url = {http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=7474310},
      wpoptique = {WP10},
      year = 2016, yearoptique = {Y4}
    }
  • [2015,inproceedings] bibtex Go to document
    V. Thost, J. Holste, and &. L. Özcep, "On Implementing Temporal Query Answering in DL-Lite (extended abstract)," in Proceedings of the 28th International Workshop on Description Logics, Athens,Greece, June 7-10, 2015., 2015.
    @inproceedings{DBLP:conf/dlog/ThostHO15, audience = {academic},
      author = {Thost, Veronika and Holste, Jan and Özcep, Özgür L.},
      bibsource = {dblp computer science bibliography, http://dblp.org},
      booktitle = {Proceedings of the 28th International Workshop on Description Logics, Athens,Greece, June 7-10, 2015.},
      editor = {Calvanese, Diego and Konev, Boris},
      interhash = {26b31f17e697c56835c179fd5644b65e},
      intrahash = {1315a7c42cf991b2179ac5dc6d24bbc5},
      openaccess = {Yes},
      partneroptique = {UzL},
      publisher = {CEUR-WS.org},
      series = {{CEUR} Workshop Proceedings},
      title = {On Implementing Temporal Query Answering in DL-Lite (extended abstract)},
      url = {http://ceur-ws.org/Vol-1350/paper-63.pdf},
      volume = 1350, wpoptique = {WP5},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    E. Kharlamov, E. Jimenez-Ruiz, C. Pinkel, M. Rezk, M. G. Skjæveland, A. Soylu, G. Xiao, M. G. Dmitriy Zheleznyakov, I. Horrocks, and A. Waaler, "Optique: Ontology-Based Data Access Platform," in International Semantic Web Conference (posters \& demos), 2015.
    @inproceedings{statoil2015demo, audience = {academic},
      author = {Kharlamov, Evgeny and Jimenez-Ruiz, Ernesto and Pinkel, Christoph and Rezk, Martin and Skj{\ae}veland, Martin G. and Soylu, Ahmet and Xiao, Guohui and Dmitriy Zheleznyakov, Martin Giese and Horrocks, Ian and Waaler, Arild},
      booktitle = {International Semantic Web Conference (posters \& demos)},
      interhash = {ce361c44e46fbc8f566abf257b3e95f6},
      intrahash = {22a0784ca4ce10c61b884a9046c379e5},
      openaccess = {Yes},
      partneroptique = {UOXF},
      title = {{Optique: Ontology-Based Data Access Platform}},
      wpoptique = {WP9},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    E. Jiménez-Ruiz, A. Solimando, T. Payne, and V. Tamma, "Avoiding Alignment-based Conservativity Violations through Dialogue," in 12th OWL: Experiences and Directions Workshop (OWLED), 2015.
    @inproceedings{owled2015, audience = {academic},
      author = {Jim{\'{e}}nez{-}Ruiz, Ernesto and Solimando, Alessandro and Payne, Terry and Tamma, Valentina},
      booktitle = {12th OWL: Experiences and Directions Workshop (OWLED)},
      interhash = {ff1b9d30b58cbdf7859709697bd7ea0a},
      intrahash = {de907611ca00b1501b4f7bc8de3a9474},
      partneroptique = {UOXF},
      title = {Avoiding Alignment-based Conservativity Violations through Dialogue},
      wpoptique = {WP4},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex Go to document
    A. Khiat, G. Diallo, B. Yaman, E. Jiménez-Ruiz, and M. Benaissa, "ABOM and ADOM: Arabic Datasets for the Ontology Alignment Evaluation Campaign," in On the Move to Meaningful Internet Systems: OTM 2015 Conferences – Confederated International Conferences: CoopIS, ODBASE, and C&TC 2015, Rhodes, Greece, October 26-30, 2015, Proceedings, 2015, pp. 545-553.
    @inproceedings{DBLP:conf/otm/KhiatDYJB15, audience = {academic},
      author = {Khiat, Abderrahmane and Diallo, Gayo and Yaman, Beyza and Jim{\'{e}}nez{-}Ruiz, Ernesto and Benaissa, Moussa},
      booktitle = {On the Move to Meaningful Internet Systems: {OTM} 2015 Conferences - Confederated International Conferences: CoopIS, ODBASE, and C{\&}TC 2015, Rhodes, Greece, October 26-30, 2015, Proceedings},
      interhash = {59df8abdadd05045123f8a931115eac1},
      intrahash = {0067ddd387dcd7e8041986dec5459001},
      pages = {545--553},
      partneroptique = {UOXF},
      title = {{ABOM} and {ADOM:} Arabic Datasets for the Ontology Alignment Evaluation Campaign},
      url = {http://dx.doi.org/10.1007/978-3-319-26148-5_37},
      wpoptique = {WP4},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex Go to document
    A. Solimando, E. Jiménez-Ruiz, and G. Guerrini, "On the Feasibility of Using OWL 2 Reasoners in Ontology Alignment Repair Problems," in Informal Proceedings of the 4th International Workshop on OWL Reasoner Evaluation (ORE-2015) co-located with the 28th International Workshop on Description Logics (DL 2015), Athens, Greece, June 6, 2015., 2015, pp. 60-67.
    @inproceedings{DBLP:conf/ore/SolimandoJG15, audience = {academic},
      author = {Solimando, Alessandro and Jim{\'{e}}nez{-}Ruiz, Ernesto and Guerrini, Giovanna},
      booktitle = {Informal Proceedings of the 4th International Workshop on {OWL} Reasoner Evaluation {(ORE-2015)} co-located with the 28th International Workshop on Description Logics {(DL} 2015), Athens, Greece, June 6, 2015.},
      interhash = {5a1c211f0f908fa2d9072d9b771ddb09},
      intrahash = {50559c70a43a83fde4ef2f692617f6c8},
      pages = {60--67},
      partneroptique = {UOXF},
      title = {On the Feasibility of Using {OWL} 2 Reasoners in Ontology Alignment Repair Problems},
      url = {http://ceur-ws.org/Vol-1387/paper_7.pdf},
      wpoptique = {WP4},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    S. Borgwardt, T. Mailis, R. Peñaloza, and A. Turhan, "Poster Presentation at DL 2015: Conjunctive Query Answering with Finitely Many Truth Degrees," , Athens,Greece, 2015.
    @inproceedings{borgwardtconjunctive, abstract = { We study fuzzy extensions of conjunctive queries (CQs) over the DL SROIQ based on finite chains of degrees of truth. To answer such queries, we extend a well-known technique that reduces the fuzzy ontology to a classical one, and use classical DL reasoners as a black box.},
      address = {Athens,Greece},
      audience = {academic},
      author = {Borgwardt, Stefan and Mailis, Theofilos and Pe{\~n}aloza, Rafael and Turhan, Anni-Yasmin},
      interhash = {625da6071b256de4a95a26e479d6fb4d},
      intrahash = {298a1b40e402fa529ab4ebfb8c82a090},
      openaccess = {Yes},
      partneroptique = {UoA},
      presenter = {Theofilos Mailis},
      title = {Poster Presentation at DL 2015: Conjunctive Query Answering with Finitely Many Truth Degrees},
      wpoptique = {WP7},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,article] bibtex Go to document
    M. G. Skjæveland, M. Giese, D. Hovland, E. H. Lian, and A. Waaler, "Engineering ontology-based access to real-world data sources.," Web Semantics: Science, Services and Agents on the World Wide Web, vol. 33, pp. 112-140, 2015.
    @article{SkGiHoEtAl-JWS2015, abstract = {The preparation of existing real-world datasets for publication as high-quality semantic web data is a complex task that requires the concerted execution of a variety of processing steps using a range of different tools. Faced with both changing input data and evolving requirements on the produced output, we face a significant engineering task for schema and data transformation. We argue that to achieve a robust and flexible transformation process, a high-level declarative description is needed, that can be used to drive the entire tool chain. We have implemented this idea for the deployment of ontology-based data access (OBDA) solutions, where semantically annotated views that integrate multiple data sources on different formats are created, based on an ontology and a collection of mappings. Furthermore, we exemplify our approach and show how a single declarative description helps to orchestrate a complete tool chain, beginning with the download of datasets, and through to the installation of the datasets for a variety of tool applications, including data and query transformation processes and reasoning services. Our case study is based on several publicly available tabular and relational datasets concerning the operations of the petroleum industry in Norway. We include a discussion of the relative performance of the used tools on our case study, and an overview of lessons learnt for practical deployment of \{OBDA\} on real-world datasets. },
      audience = {academic},
      author = {Skjæveland, Martin G. and Giese, Martin and Hovland, Dag and Lian, Espen H. and Waaler, Arild},
      doi = {10.1016/j.websem.2015.03.002},
      interhash = {daf499c11faac8d9ec1cb6944a17d961},
      intrahash = {ad2107c509c9cbf59bfcadf32e0270f7},
      issn = {1570-8268},
      journal = {Web Semantics: Science, Services and Agents on the World Wide Web},
      openaccess = {No},
      pages = {112--140},
      partneroptique = {UiO},
      title = {Engineering ontology-based access to real-world data sources.},
      url = {http://dx.doi.org/10.1016/j.websem.2015.03.002},
      volume = 33, wpoptique = {WP09},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,article] bibtex Go to document
    R. De Masellis, D. Lembo, M. Montali, and D. Solomakhin, "Semantic Enrichment of GSM-Based Artifact-Centric Models," Journal on Data Semantics, vol. 4, iss. 1, pp. 3-27, 2015.
    @article{demasellisJDS15, abstract = { We provide a comprehensive framework for semantic GSM artifacts, discuss in detail its properties, and present main software engineering architectures it is able to capture. The distinguishing aspect of our framework is that it allows for expressing both the data and the lifecycle schema of GSM artifacts in terms of an ontology, i.e., a shared and formalized conceptualization of the domain of interest. To guide the modeling of data and lifecycle we provide an upper ontology, which is specialized in each artifact with specific lifecycle elements, relations, and business objects. The framework thus obtained allows to achieve several advantages. On the one hand, it makes the specification of conditions on data and artifact status attribute fully declarative and enables semantic reasoning over them. On the other, it fosters the monitoring of artifacts and the interoperation and cooperation among different artifact systems. To fully achieve such an interoperation, we enrich our framework by enabling the linkage of the ontology to autonomous database systems through the use of mappings. We then discuss two scenarios of practical interest that show how mappings can be used in the presence of multiple systems. For one of these scenarios we also describe a concrete instantiation of the framework and its application to a real-world use case in the energy domain, investigated in the context of the EU project ACSI. },
      audience = {academic},
      author = {De Masellis, Riccardo and Lembo, Domenico and Montali, Marco and Solomakhin, Dmitry},
      doi = {10.1007/s13740-014-0036-6},
      interhash = {b86d091b93923847b8463b198e503fca},
      intrahash = {1690f9816543d3e682468633ae02d2fb},
      issn = {1861-2032},
      journal = {Journal on Data Semantics},
      language = {English},
      number = 1, openaccess = {No},
      pages = {3-27},
      partneroptique = {UNIROMA1},
      publisher = {Springer Berlin Heidelberg},
      title = {Semantic Enrichment of GSM-Based Artifact-Centric Models},
      url = {http://dx.doi.org/10.1007/s13740-014-0036-6},
      volume = 4, wpoptique = {WP4},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    M. Bienvenu and R. Rosati, "Query-based comparison of OBDA specifications," in Proceedings of the 28th International Workshop on Description Logics, Athens,Greece, June 7-10, 2015., 2015.
    @inproceedings{BienvenuR15, abstract = { An ontology-based data access (OBDA) system is composed of one or more data sources, an ontology that provides a conceptual view of the data, and declarative mappings that relate the data and ontology schemas. In order to debug and optimize such systems, it is important to be able to analyze and compare OBDA specifications. Recent work in this direction compared specifications using classical notions of equivalence and entailment, but an interesting alternative is to consider query-based notions, in which two specifications are deemed equivalent if they give the same answers to the considered query or class of queries for all possible data sources. In this paper, we define such query-based notions of entailment and equivalence of OBDA specifications and investigate the complexity of the resulting analysis tasks when the ontology is formulated in DL-LiteR. },
      audience = {academic},
      author = {Bienvenu, Meghyn and Rosati, Riccardo},
      booktitle = {Proceedings of the 28th International Workshop on Description Logics, Athens,Greece, June 7-10, 2015.},
      interhash = {0ab03c5c211bc7e724afd84f15e3383c},
      intrahash = {42e1b110029bcf4220e38a6ee7aff4a8},
      openaccess = {Yes},
      partneroptique = {UNIROMA1},
      title = {Query-based comparison of {OBDA} specifications},
      wpoptique = {WP4},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    C. Civili and R. Rosati, "On the first-order rewritability of conjunctive queries over binary guarded existential rules (extended abstract)," in Proceedings of the 30th Italian Conference on Computational Logic, Genova, Italy, July 1-3, 2015., 2015, pp. 25-30.
    @inproceedings{CivR15, abstract = {We study conjunctive query answering and first-order rewritability of conjunctive queries for binary guarded existential rules. In particular, we prove that the problem of establishing whether a given set of binary guarded existential rules is such that all conjunctive queries admit a first-order rewriting is decidable, and present a technique for solving this problem. These results have a important practical impact, since they make it possible to identify those sets of binary guarded existential rules for which it is possible to answer every conjunctive query through query rewriting and standard evaluation of a first-order query (actually, a union of conjunctive queries) over a relational database system. },
      audience = {academic},
      author = {Civili, Cristina and Rosati, Riccardo},
      booktitle = {Proceedings of the 30th Italian Conference on Computational Logic, Genova, Italy, July 1-3, 2015.},
      interhash = {3de0b83c1faf24cbe5ea3261ca86ed1f},
      intrahash = {ff62d91713df774ae7419ff3153268fe},
      openaccess = {Yes},
      pages = {25--30},
      partneroptique = {UNIROMA1},
      title = {On the first-order rewritability of conjunctive queries over binary guarded existential rules (extended abstract)},
      wpoptique = {WP4},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    D. Lembo, J. Mora, R. Rosati, D. F. Savo, and E. Thorstensen, "Mapping Analysis in Ontology-based Data Access: Algorithms and Complexity (Extended Abstract)," in Proceedings of the 28th International Workshop on Description Logics, Athens,Greece, June 7-10, 2015., 2015.
    @inproceedings{LemboMRST15, abstract = { We study the formal analysis of mappings in ontology-based data access (OBDA). Specifically, we focus on the problem of identifying mapping inconsistency and redundancy, two of the most important anomalies for mappings in OBDA. We consider a wide range of ontology languages that comprises OWL 2 and all its profiles, and examine mapping languages of different expressiveness over relational databases. We establish tight complexity bounds for the decision problems associated with mapping inconsistency and redundancy. },
      audience = {academic},
      author = {Lembo, Domenico and Mora, Jos{\'{e}} and Rosati, Riccardo and Savo, Domenico Fabio and Thorstensen, Evgenij},
      booktitle = {Proceedings of the 28th International Workshop on Description Logics, Athens,Greece, June 7-10, 2015.},
      interhash = {eff0e56397a43c85edb31f9d53d2f4a0},
      intrahash = {4f8d0f977740a0de9e7a46dc22bb8987},
      openaccess = {Yes},
      partneroptique = {UNIROMA1},
      title = {Mapping Analysis in Ontology-based Data Access: Algorithms and Complexity (Extended Abstract)},
      wpoptique = {WP4},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    D. Lembo, J. Mora, R. Rosati, D. F. Savo, and E. Thorstensen, "Mapping Analysis in Ontology-based Data Access: Algorithms and Complexity," in Proceedings of the 14th International Semantic Web Conference, Bethlehem,Pennsylvania, October 11-15, 2015., 2015.
    @inproceedings{lemboISWC14, abstract = { Ontology-based data access (OBDA) is a recent paradigm for accessing data sources through an ontology that acts as a conceptual, integrated view of the data, and declarative mappings that connect the ontology to the data sources. We study the formal analysis of mappings in OBDA. Specifically, we focus on the problem of identifying mapping inconsistency and redundancy, two of the most important anomalies for mappings in OBDA. We consider a wide range of ontology languages that comprises OWL 2 and all its profiles, and examine mapping languages of different expressiveness over relational databases. We provide algorithms and establish tight complexity bounds for the decision problems associated with mapping inconsistency and redundancy. Our results prove that, in our general framework, such forms of mapping analysis enjoy nice computational properties, in the sense that they are not harder than standard reasoning tasks over the ontology or over the relational database schema.},
      audience = {academic},
      author = {Lembo, Domenico and Mora, Jos{\'{e}} and Rosati, Riccardo and Savo, Domenico Fabio and Thorstensen, Evgenij},
      booktitle = {Proceedings of the 14th International Semantic Web Conference, Bethlehem,Pennsylvania, October 11-15, 2015.},
      doi = {10.1007/978-3-319-25007-6_13},
      interhash = {3d634ab255cff7303f57ddeedac1ba17},
      intrahash = {1cfb8def6fd9ef45b819b05f8fc31aa1},
      openaccess = {No},
      partneroptique = {UNIROMA1},
      title = {Mapping Analysis in Ontology-based Data Access: Algorithms and Complexity},
      wpoptique = {WP4},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    D. Lembo, J. Mora, R. Rosati, D. F. Savo, and E. Thorstensen, "Mapping Analysis in Ontology-based Data Access: Algorithms and Complexity (Discussion Paper)," in Proceedings of the 23rd Italian Symposium on Advanced Database Systems, 2015.
    @inproceedings{LMRST15b, abstract = { We study the formal analysis of mappings in ontology-based data access (OBDA). Specifically, we focus on the problem of identifying mapping inconsistency and redundancy, two of the most important anomalies for mappings in OBDA. We consider a wide range of ontology languages that comprises OWL 2 and all its profiles, and examine mapping languages of different expressiveness over relational databases. We establish tight complexity bounds for the decision problems associated with mapping inconsistency and redundancy. },
      audience = {academic},
      author = {Lembo, Domenico and Mora, Jos{\'{e}} and Rosati, Riccardo and Savo, Domenico Fabio and Thorstensen, Evgenij},
      booktitle = {Proceedings of the 23rd Italian Symposium on Advanced Database Systems},
      interhash = {c37b47c5a3af66e49727ea401cb784f9},
      intrahash = {d8786928c98abef00bbf2bb7ce77db57},
      openaccess = {Yes},
      partneroptique = {UNIROMA1},
      title = { Mapping Analysis in Ontology-based Data Access: Algorithms and Complexity (Discussion Paper)},
      wpoptique = {WP4},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,article] bibtex Go to document
    D. Lembo, M. Lenzerini, R. Rosati, M. Ruzzi, and D. F. Savo, "Inconsistency-tolerant query answering in ontology-based data access," J. Web Sem., vol. 33, pp. 3-29, 2015.
    @article{LemboLRRS15, abstract = { Ontology-based data access (OBDA) is receiving great attention as a new paradigm for managing information systems through semantic technologies. According to this paradigm, a Description Logic ontology provides an abstract and formal representation of the domain of interest to the information system, and is used as a sophisticated schema for accessing the data and formulating queries over them. In this paper, we address the problem of dealing with inconsistencies in OBDA. Our general goal is both to study DL semantical frameworks that are inconsistency-tolerant, and to devise techniques for answering unions of conjunctive queries under such inconsistency-tolerant semantics. Our work is inspired by the approaches to consistent query answering in databases, which are based on the idea of living with inconsistencies in the database, but trying to obtain only consistent information during query answering, by relying on the notion of database repair. We first adapt the notion of database repair to our context, and show that, according to such a notion, inconsistency-tolerant query answering is intractable, even for very simple DLs. Therefore, we propose a different repair-based semantics, with the goal of reaching a good compromise between the expressive power of the semantics and the computational complexity of inconsistency-tolerant query answering. Indeed, we show that query answering under the new semantics is first-order rewritable in OBDA, even if the ontology is expressed in one of the most expressive members of the DL-Lite family.},
      audience = {academic},
      author = {Lembo, Domenico and Lenzerini, Maurizio and Rosati, Riccardo and Ruzzi, Marco and Savo, Domenico Fabio},
      doi = {10.1016/j.websem.2015.04.002},
      interhash = {8784084a6d6f83d24405b86df2d00be8},
      intrahash = {d4bb15f764b0457d56be89820b66ecab},
      journal = {J. Web Sem.},
      openaccess = {No},
      pages = {3--29},
      partneroptique = {UNIROMA1},
      title = {Inconsistency-tolerant query answering in ontology-based data access},
      url = {http://dx.doi.org/10.1016/j.websem.2015.04.002},
      volume = 33, wpoptique = {WP4},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,article] bibtex Go to document
    G. Martin, S. Ahmet, V. Guillermo, W. Arild, H. Peter, J. Ernesto, L. Davide, R. Martín, X. Guohui, &. &. L., and R. Riccardo, "Optique: Zooming in on Big Data," IEEE Computer, vol. 48, iss. 3, pp. 60-67, 2015.
    @article{martin2015optique, abstract = {Optique overcomes problems in current ontology-based data access systems pertaining to installation overhead, usability, scalability, and scope by integrating a user-oriented query interface, semi-automated managing methods, new query rewriting techniques, and temporal and streaming data processing in one platform.},
      audience = {academic},
      author = {Martin, Giese and Ahmet, Soylu and Guillermo, Vega-Gorgojo and Arild, Waaler and Peter, Haase and Ernesto, Jiménez-Ruiz and Davide, Lanti and Martín, Rezk and Guohui, Xiao and L., Özçep Özgür and Riccardo, Rosati},
      doi = {10.1109/MC.2015.82},
      interhash = {df8408d6d5478e022a668b32c1a9633b},
      intrahash = {8aad249caffaea16d96d7a466370e970},
      journal = {IEEE Computer},
      number = 3, openaccess = {No},
      pages = {60--67},
      partneroptique = {UNIROMA1},
      title = {Optique: Zooming in on Big Data},
      url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=7063162},
      volume = 48, wpoptique = {WP4},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    E. Kharlamov, S. Brands, M. Giese, E. Jimenez-Ruiz, S. Lamparter, C. Neuenstadt, Ö. L. Özçep, C. Pinkel, A. Soylu, D. Zheleznyakov, M. Roshchin, S. Watson, and I. Horrocks, "Semantic Access to Siemens Streaming Data: the OPTIQUE Way," in Proc.\ of International Semantic Web Conference ISWC, Posters & Demonstrations Track, 2015.
    @inproceedings{iswc2015demoSiemens, audience = {academic},
      author = {Kharlamov, Evgeny and Brands, Sebastian and Giese, Martin and Jimenez-Ruiz, Ernesto and Lamparter, Steffen and Neuenstadt, Christian and {\"{O}}z{\c{c}}ep, {\"{O}}zg{\"{u}}r L{\"{u}}tf{\"{u}} and Pinkel, Christoph and Soylu, Ahmet and Zheleznyakov, Dmitriy and Roshchin, M. and Watson, S and Horrocks, Ian},
      booktitle = {{Proc.\ of International Semantic Web Conference {ISWC},
      Posters {\&} Demonstrations Track}},
      interhash = {f1d11fd8f7c00b4dd253f8c4b3f2e3f9},
      intrahash = {aaa96b66108291365d300c67a4730821},
      partneroptique = {UOXF},
      title = {{Semantic Access to Siemens Streaming Data: the OPTIQUE Way}},
      wpoptique = {WP3},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    E. Kharlamov, D. Hovland, E. Jimenez-Ruiz, D. Lanti, H. Lie, C. Pinkel, M. Rezk, M. G. Skjæveland, E. Thorstensen, G. Xiao, D. Zheleznyakov, and I. Horrocks, "Ontology Based Access to Exploration Data at Statoil," in Proc.\ of International Semantic Web Conference (ISWC), 2015.
    @inproceedings{iswc15-statoil, audience = {academic, industry},
      author = {Kharlamov, Evgeny and Hovland, Dag and Jimenez-Ruiz, Ernesto and Lanti, Davide and Lie, Hallstein and Pinkel, Christoph and Rezk, Martin and Skj{\ae}veland, Martin G. and Thorstensen, Evgenij and Xiao, Guohui and Zheleznyakov, Dmitriy and Horrocks, Ian},
      booktitle = {{Proc.\ of International Semantic Web Conference (ISWC)}},
      interhash = {b064e1c6d4a3d72e04440edd84378d29},
      intrahash = {2ce58fc6d3f66fa7ebd5e8b859a23c18},
      partneroptique = {UOXF},
      title = {{Ontology Based Access to Exploration Data at Statoil}},
      wpoptique = {WP9},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex Go to document
    E. Jimenez-Ruiz, E. Kharlamov, D. Zheleznyakov, I. Horrocks, C. Pinkel, M. G. Skjæveland, E. Thorstensen, and J. Mora, "BootOX: Practical Mapping of RDBs to OWL 2," in Proc.\ of International Semantic Web Conference (ISWC), 2015.
    @inproceedings{bootox_iswc_2015, audience = {academic, industry},
      author = {Jimenez-Ruiz, Ernesto and Kharlamov, Evgeny and Zheleznyakov, Dmitriy and Horrocks, Ian and Pinkel, Christoph and Skj{\ae}veland, Martin G. and Thorstensen, Evgenij and Mora, Jose},
      booktitle = {Proc.\ of International Semantic Web Conference (ISWC)},
      interhash = {cdc5179d3297a91066c14f8c1fc76cf3},
      intrahash = {8f90b35a0397d4a75f30dc01dbd3697e},
      partneroptique = {UOXF},
      title = {{BootOX: Practical Mapping of RDBs to OWL 2}},
      url = {http://www.cs.ox.ac.uk/isg/tools/BootOX/},
      wpoptique = {WP4},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    B. C. Grau, E. Kharlamov, E. V. Kostylev, and D. Zheleznyakov, "Controlled Query Evaluation for Datalog and OWL 2 Profile Ontologies," in Proc.\ of International Joint Conference on Artificial Intelligence (IJCAI), 2015, pp. 2883-2889.
    @inproceedings{ijcai2015privacy, audience = {academic},
      author = {Grau, Bernardo Cuenca and Kharlamov, Evgeny and Kostylev, Egor V. and Zheleznyakov, Dmitriy},
      booktitle = {{Proc.\ of International Joint Conference on Artificial Intelligence (IJCAI)}},
      interhash = {88822d353a40bea9326cf71edbeed072},
      intrahash = {8c063e5d1fce700df7038f119eaa2459},
      pages = {2883-2889},
      partneroptique = {UOXF},
      title = {{Controlled Query Evaluation for Datalog and OWL 2 Profile Ontologies}},
      wpoptique = {WP3},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    E. Jimenez-Ruiz, E. Kharlamov, D. Zheleznyakov, I. Horrocks, C. Pinkel, M. G. Skjæveland, E. Thorstensen, and J. Mora, "BOOTOX: Bootstrapping OWL 2 ontologies and R2RML mappings from Relational Databases," in Proc. of International Semantic Web Conference ISWC, Posters & Demonstrations Track, 2015.
    @inproceedings{iswc2015demoBootox, audience = {academic},
      author = {Jimenez-Ruiz, Ernesto and Kharlamov, Evgeny and Zheleznyakov, Dmitriy and Horrocks, Ian and Pinkel, Christoph and Skj{\ae}veland, Martin G. and Thorstensen, Evgenij and Mora, Jose},
      booktitle = {Proc. of International Semantic Web Conference {ISWC},
      Posters {\&} Demonstrations Track},
      interhash = {f1a9fe5bfba0353967b524a30051f898},
      intrahash = {59399143f46050519063651033938b1c},
      partneroptique = {UOXF},
      title = {{BOOTOX: Bootstrapping OWL 2 ontologies and R2RML mappings from Relational Databases}},
      wpoptique = {WP3},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    A. Soylu, E. Kharlamov, D. Zheleznyakov, E. Jimenez-Ruiz, M. Giese, and I. Horrocks, "Ontology-based Visual Query Formulation: An Industry Experience," in 11th International Symposium on Visual Computing (ISVC 2015), 2015.
    @inproceedings{soylu2015ontologybased, audience = {academic},
      author = {Soylu, Ahmet and Kharlamov, Evgeny and Zheleznyakov, Dmitriy and Jimenez-Ruiz, Ernesto and Giese, Martin and Horrocks, Ian},
      booktitle = {11th International Symposium on Visual Computing (ISVC 2015)},
      doi = {10.1007/978-3-319-27857-5_75},
      interhash = {c18395dfb4d2960c64e7179e0f83a90f},
      intrahash = {f9aadb94e4a7267e6e1ba0855ca01534},
      openaccess = {No},
      partneroptique = {UiO},
      publisher = {Springer},
      series = {LNCS},
      title = {Ontology-based Visual Query Formulation: An Industry Experience},
      wpoptique = {WP3},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex Go to document
    A. Soylu, E. Kharlamov, D. Zheleznyakov, E. Jiménez-Ruiz, M. Giese, and I. Horrocks, "OptiqueVQS: Ontology-Based Visual Querying," in Visualizations and User Interfaces for Ontologies and Linked Data (VOILA 2015), 2015, p. 91.
    @inproceedings{conf/semweb/SoyluKZJGH15, audience = {academic},
      author = {Soylu, Ahmet and Kharlamov, Evgeny and Zheleznyakov, Dmitriy and Jiménez-Ruiz, Ernesto and Giese, Martin and Horrocks, Ian},
      booktitle = {Visualizations and User Interfaces for Ontologies and Linked Data (VOILA 2015)},
      crossref = {conf/semweb/2015voila},
      editor = {Ivanova, Valentina and Lambrix, Patrick and Lohmann, Steffen and Pesquita, Catia},
      interhash = {9364e865d581c547fc5048e1b1c6511b},
      intrahash = {8c35cfe01bbbe1cfbd8c7d3e183360ee},
      openaccess = {Yes},
      pages = 91, partneroptique = {UiO},
      publisher = {CEUR-WS.org},
      series = {CEUR Workshop Proceedings},
      title = {OptiqueVQS: Ontology-Based Visual Querying},
      url = {http://dblp.uni-trier.de/db/conf/semweb/voila2015.html#SoyluKZJGH15},
      volume = 1456, wpoptique = {WP3},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    A. Soylu and M. Giese, "Qualifying Ontology-based Visual Query Formulation," in Flexible Query Answering Systems (FQAS 2015), Cracow, Poland, 2015.
    @inproceedings{soylu2015qualifying, address = {Cracow, Poland},
      audience = {academic},
      author = {Soylu, Ahmet and Giese, Martin},
      booktitle = {Flexible Query Answering Systems (FQAS 2015)},
      doi = {10.1007/978-3-319-26154-6_19},
      interhash = {36314ee509bdd25688a47723a006a1a2},
      intrahash = {4c52828a41084452daaf758e9efc53d7},
      openaccess = {No},
      partneroptique = {UiO},
      publisher = {Springer},
      series = {Advances in Intelligent Systems and Computing},
      title = {Qualifying Ontology-based Visual Query Formulation},
      volume = 400, wpoptique = {WP3},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex Go to document
    A. Nakkerud and E. Thorstensen, "Heuristics for Applying Cached OBDA Rewritings," in Proceedings of the 28th International Workshop on Description Logics, Athens,Greece, June 7-10, 2015., 2015.
    @inproceedings{DBLP:conf/dlog/NakkerudT15, abstract = {In OBDA systems, cached rewritings can be used to significantly shorten the process of finding rewritings of bigger queries. The main challenge in using cached rewritings is finding the optimal combination to apply, a problem which is NP-complete. In this paper, we present a way to calculate the value of a cached rewriting, and propose using this value to decide which cached rewritings to apply. The idea behind our technique is to estimate how much computation, in particular optimization, has gone into the rewriting. This can tell us something about which cached rewritings we should prioritise, and also when to cache a rewriting. In order to quantify optimization, we define a measure of UCQs, and calculate this measure at different stages of the rewriting.},
      audience = {academic},
      author = {Nakkerud, Andreas and Thorstensen, Evgenij},
      bibsource = {dblp computer science bibliography, http://dblp.org},
      booktitle = {Proceedings of the 28th International Workshop on Description Logics, Athens,Greece, June 7-10, 2015.},
      editor = {Calvanese, Diego and Konev, Boris},
      interhash = {4528aaa91d89fbfaaccb30b4f5aa6404},
      intrahash = {f81552b6e74b3e5c5bdc6eca6b0a3456},
      partneroptique = {UiO},
      publisher = {CEUR-WS.org},
      series = {{CEUR} Workshop Proceedings},
      title = {Heuristics for Applying Cached {OBDA} Rewritings},
      url = {http://ceur-ws.org/Vol-1350/paper-58.pdf},
      volume = 1350, wpoptique = {WP6},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    C. Neuenstadt, R. Möller, and &. L. Özcep, "OBDA for Temporal Querying and Streams with STARQL," in HiDeSt ’15—Proceedings of the First Workshop on High-Level Declarative Stream Processing (co-located with KI 2015), 2015, pp. 70-75.
    @inproceedings{neuenstadt15OBDA, abstract = {Data changes worldwide in size and over time and when new data arrives rapidly from different sources, an easy access to dynamic data becomes a key factor. Therefore, temporalizing and streamifying ontology-based data access (OBDA) is a very important topic today, where the industry still relies on algebraic queries. We contribute to the practical efforts in this field by showing how a specific ontology-based stream querying language can be transformed with respect to mappings into standard SQL queries. For that purpose we choose the stream and temporal reasoning query language STARQL. STARQL is motivated by industrial usecases and evaluated in the European research project Optique. It offers access to temporal and streaming data as well for reactive diagnosis or continuous monitoring.},
      audience = {academic},
      author = {Neuenstadt, Christian and Möller, Ralf and Özcep, Özgür L.},
      booktitle = {{HiDeSt '15}---Proceedings of the First Workshop on High-Level Declarative Stream Processing (co-located with {KI 2015})},
      editor = {Nicklas, Daniela and Özcep, Özgür L.},
      interhash = {efc1043889bdfb7a627ed9d703ab322e},
      intrahash = {8b47b6be5e46780ed83581fa2153763c},
      openaccess = {Yes},
      pages = {70--75},
      partneroptique = {UzL},
      publisher = {CEUR-WS.org},
      series = {{CEUR} Workshop Proceedings},
      title = {{OBDA} for Temporal Querying and Streams with {STARQL}},
      volume = 1447, wpoptique = {WP5},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    R. Möller, C. Neuenstadt, and &. L. Özcep, "Stream-temporal Querying with Ontologies," in HiDeSt ’15—Proceedings of the First Workshop on High-Level Declarative Stream Processing (co-located with KI 2015), 2015, pp. 42-55.
    @inproceedings{moeller15stream-temporal, abstract = {Recent years have seen theoretical and practical efforts on temporalizing and streamifying ontology-based data access (OBDA). This paper contributes to the practical efforts with a description/evaluation of a prototype implementation for the stream-temporal query language framework STARQL. STARQL serves the needs for industrially motivated scenarios, providing the same interface for querying historical data (reactive diagnostics) and for querying streamed data (continuous monitoring, predictive analytics). We show how to transform STARQL queries w.r.t.\ mappings into standard SQL queries, the difference between historical and continuous querying relying only in the use of a static window table vs.\ an incrementally updated window table. Experiments with a STARQL prototype engine using the PostgreSQL DBMS show the implementability and feasibility of our approach. },
      audience = {academic},
      author = {Möller, Ralf and Neuenstadt, Christian and Özcep, Özgür L.},
      booktitle = {{HiDeSt '15}---Proceedings of the First Workshop on High-Level Declarative Stream Processing (co-located with {KI 2015})},
      editor = {Nicklas, Daniela and {\"Oz\c{c}ep},
      {\"Ozg\"ur} L.},
      interhash = {3844c6b890392cea44e37b792585ea0f},
      intrahash = {8d2e62b5a9d0f1a41262766db247b117},
      openaccess = {Yes},
      pages = {42--55},
      partneroptique = {UzL},
      publisher = {CEUR-WS.org},
      series = {CEUR Workshop Proceedings},
      title = {Stream-temporal Querying with Ontologies},
      volume = 1447, wpoptique = {WP5},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    &. L. Özcep, R. Möller, and C. Neuenstadt, "Stream-Query Compilation with Ontologies," in Poceedings of the 28th Australasian Joint Conference on Artificial Intelligence 2015 (AI 2015), 2015.
    @inproceedings{oezcep15stream-query, abstract = {Rational agents perceiving data from a dynamic environment and acting in it have to be equipped with capabilities such as decision making, planning etc. We assume that these capabilities are based on query answering with respect to (high-level) streams of symbolic descriptions, which are grounded in (low-level) data streams. Queries need to be answered w.r.t. an ontology. The central idea is to compile ontology-based stream queries (continuous or historical) to relational data processing technology, for which efficient implementations are available. We motivate our query language STARQL (Streaming and Temporal ontology Access with a Reasoning-Based Query Language) with a sensor data processing scenario, and compare the approach realized in the STARQL framework with related approaches regarding expressivity. },
      audience = {academic},
      author = {Özcep, Özgür L. and Möller, Ralf and Neuenstadt, Christian},
      booktitle = {Poceedings of the 28th Australasian Joint Conference on Artificial Intelligence 2015 {(AI 2015)}},
      doi = {10.1007/978-3-319-26350-2_40},
      editor = {Pfahringer, Bernhard and Renz, Jochen},
      interhash = {0ae563f8045d8c4bee3980f4763bd174},
      intrahash = {6945446ca169e5d7c01eb745778d8786},
      openaccess = {No},
      partneroptique = {UzL},
      publisher = {Springer International Publishing},
      series = {LNAI},
      title = {Stream-Query Compilation with Ontologies},
      volume = 9457, wpoptique = {WP5},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex Go to document
    C. Pinkel, C. Binnig, E. Jiménez-Ruiz, W. May, D. Ritze, M. G. Skjæveland, A. Solimando, and E. Kharlamov, "RODI: A Benchmark for Automatic Mapping Generation in Relational-to-Ontology Data Integration.," in ESWC, 2015, pp. 21-37.
    @inproceedings{conf/esws/PinkelBJMRSSK15, audience = {academic},
      author = {Pinkel, Christoph and Binnig, Carsten and Jiménez-Ruiz, Ernesto and May, Wolfgang and Ritze, Dominique and Skjæveland, Martin G. and Solimando, Alessandro and Kharlamov, Evgeny},
      booktitle = {ESWC},
      crossref = {conf/esws/2015},
      editor = {Gandon, Fabien and Sabou, Marta and Sack, Harald and d'Amato, Claudia and Cudré-Mauroux, Philippe and Zimmermann, Antoine},
      interhash = {2c20b3ade3611b9cb89ed3cc80ed108a},
      intrahash = {8c5c2237ab297186ad4a4b7a74b58211},
      pages = {21-37},
      partneroptique = {FOPS},
      publisher = {Springer},
      series = {Lecture Notes in Computer Science},
      title = {RODI: A Benchmark for Automatic Mapping Generation in Relational-to-Ontology Data Integration.},
      url = {http://dblp.uni-trier.de/db/conf/esws/eswc2015.html#PinkelBJMRSSK15},
      volume = 9088, wpoptique = {WP4},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    D. Calvanese, M. Montali, A. Syamsiyah, and W. M. P. van der Aalst, "Ontology-Driven Extraction of Event Logs from Relational Databases," in Proceedings of the 11th International Workshop on Business Process Intelligence (BPI), 2015.
    @inproceedings{calvanese-etal-BPI-2015, abstract = {Process mining is an emerging discipline whose aim is to discover, monitor and improve real processes by extracting knowledge from event logs representing actual process executions in a given organizational setting. In this light, it can be applied only if faithful event logs, adhering to accepted standards (such as XES), are available. In many real-world settings, though, such event logs are not explicitly given, but are instead implicitly represented inside legacy information systems of organizations, which are typically managed through relational technology. In this work, we devise a novel framework that supports domain experts in the extraction of XES event log information from legacy relational databases, and consequently enables the application of standard process mining tools on such data. Differently from previous work, the extraction is driven by a conceptual representation of the domain of interest in terms of an ontology. On the one hand, this ontology is linked to the underlying legacy data leveraging the well-established ontology-based data access (OBDA) paradigm. On the other hand, our framework allows one to enrich the ontology through user-oriented log extraction annotations, which can be flexibly used to provide different log-oriented views over the data. Different data access modes are then devised so as to view the legacy data through the lens of XES.},
      audience = {academic},
      author = {Calvanese, Diego and Montali, Marco and Syamsiyah, Alifah and van der Aalst, Wil M. P.},
      booktitle = {Proceedings of the 11th International Workshop on Business Process Intelligence (BPI)},
      interhash = {ca87ae60ab537e54b2d67dca0210792f},
      intrahash = {8814a53a4ff99f222d30d4b697c3816b},
      partneroptique = {FUB},
      title = {Ontology-Driven Extraction of Event Logs from Relational Databases},
      wpoptique = {WP6},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    D. Calvanese, M. Giese, D. Hovland, and M. Rezk, "Ontology-based Integration of Cross-linked Datasets," in Proceedings of the 14th International Semantic Web Conference (ISWC), 2015.
    @inproceedings{calvanese-etal-ISWC-2015, abstract = {In this paper we tackle the problem of answering SPARQL queries over virtually integrated databases. We assume that the entity resolution problem has already been solved and explicit information is available about which records in the different databases refer to the same real world entity. Surprisingly, to the best of our knowledge, there has been no attempt to extend the standard Ontology-Based Data Access (OBDA) setting to take into account these DB links for SPARQL query-answering and consistency checking. This is partly because the OWL built-in same-as property, the most natural representation of links between data sets, is not included in OWL~2~QL, the de facto ontology language for OBDA. We formally treat several fundamental questions in this context: how links over database identifiers can be represented in terms of same-as statements, how to recover rewritability of SPARQL into SQL (lost because of same-as statements), and how to check consistency. Moreover, we investigate how our solution can be made to scale up to large enterprise datasets. We have implemented the approach, and carried out an extensive set of experiments showing its scalability.},
      audience = {academic},
      author = {Calvanese, Diego and Giese, Martin and Hovland, Dag and Rezk, Martin},
      booktitle = {Proceedings of the 14th International Semantic Web Conference (ISWC)},
      interhash = {34a538edea040bbb4c4f3e9782b24a6f},
      intrahash = {6161b09a205580c2345fbdaef6a94957},
      partneroptique = {FUB},
      publisher = {Springer},
      series = {Lecture Notes in Computer Science},
      title = {Ontology-based Integration of Cross-linked Datasets},
      wpoptique = {WP6},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex Go to document
    D. Lanti, M. Rezk, G. Xiao, and D. Calvanese, "The NPD Benchmark: Reality Check for OBDA Systems," in Proceedings of the 18th International Conference on Extending Database Technology (EDBT), 2015, pp. 617-628.
    @inproceedings{lanti-etal-EDBT-2015, abstract = {In the last decades we moved from a world in which an enterprise had one central database---rather small for todays' standards---to a world in which many different---and big---databases must interact and operate, providing the user an integrated and understandable view of the data. Ontology-Based Data Access (OBDA) is becoming a popular approach to cope with this new scenario. OBDA separates the user from the data sources by means of a conceptual view of the data (ontology) that provides clients with a convenient query vocabulary. The ontology is connected to the data sources through a declarative specification given in terms of mappings. Although prototype OBDA systems providing the ability to answer SPARQL queries over the ontology are available, a significant challenge remains when it comes to use these systems in industrial environments: performance. To properly evaluate OBDA systems, benchmarks tailored towards the requirements in this setting are needed. In this work, we propose a novel benchmark for OBDA systems based on real data coming from the oil industry: the Norwegian Petroleum Directorate (NPD) FactPages. Our benchmark comes with novel techniques to generate, from the NPD data, datasets of increasing size, taking into account the requirements dictated by the OBDA setting. We validate our benchmark on significant OBDA systems, showing that it is more adequate than previous benchmarks not tailored for OBDA.},
      audience = {academic},
      author = {Lanti, Davide and Rezk, Martin and Xiao, Guohui and Calvanese, Diego},
      booktitle = {Proceedings of the 18th International Conference on Extending Database Technology (EDBT)},
      doi = {10.5441/002/edbt.2015.62},
      interhash = {86a12a16d01d470590416619d13dd339},
      intrahash = {0db73b6d7579c09fb2dbea0e34f5d85f},
      isbn = {978-3-89318-067-7},
      pages = {617-628},
      partneroptique = {FUB},
      publisher = {OpenProceedings.org},
      title = {The {NPD} Benchmark: Reality Check for {OBDA} Systems},
      url = {http://openproceedings.org/2015/conf/edbt/paper-350.pdf},
      wpoptique = {WP6},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    D. Calvanese, A. Mosca, J. Remesal, M. Rezk, and G. Rull, "A ‘Historical Case’ of Ontology-Based Data Access," in Proceedings of Digital Heritage 2015 (DH), 2015.
    @inproceedings{calvanese-etal-DigitalHeritage-2015, abstract = {Historical research has steadily been adopting semantic technologies to tackle several recent problems in the field, such as making explicit the semantics contained in the historical sources, formalising them and linking them. Over the last decades, in social sciences and humanities an immense amount of new quantifiable data have been accumulated and made available in interchangeable formats, opening up new possibilities for solving old questions and posing new ones. This paper introduces a web-based platform to ease the access of scholars to historical and cultural data distributed across different data sources. The approach relies on the Ontology-Based Data Access (OBDA) paradigm, where the different datasets are virtually integrated by a conceptual layer (an ontology). This work is focused on investigating the mechanisms and characteristics of the food production and commercial trade system during the Roman Empire.},
      audience = {academic},
      author = {Calvanese, Diego and Mosca, Alessandro and Remesal, Jose and Rezk, Martin and Rull, Guillem},
      booktitle = {Proceedings of Digital Heritage 2015 (DH)},
      interhash = {f062f788098b9d6da2dd8a23adada086},
      intrahash = {033485b7730e8ffab613cf7f27b69d4b},
      partneroptique = {FUB},
      publisher = {IEEE Computer Society Press},
      title = {A 'Historical Case' of Ontology-Based Data Access},
      wpoptique = {WP6},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,proceedings] bibtex Go to document
    Proceedings of the 34th ACM SIGACT SIGMOD SIGAI Symposium on Principles of Database Systems (PODS)ACM, 2015.
    @proceedings{milo-calvanese-PODS-2015-ed, audience = {academic},
      editor = {Milo, Tova and Calvanese, Diego},
      interhash = {f59825112a1ee039bc7f4a108d075286},
      intrahash = {b05b86983ed322c709b116f876f98676},
      isbn = {978-1-4503-2757-2},
      partneroptique = {FUB},
      publisher = {ACM},
      title = {Proceedings of the 34th ACM SIGACT SIGMOD SIGAI Symposium on Principles of Database Systems (PODS)},
      url = {http://dl.acm.org/citation.cfm?id=2745754},
      wpoptique = {WP6},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    D. Calvanese, B. Cogrel, E. Guzel Kalayci, S. Komla Ebri, R. Kontchakov, D. Lanti, M. Rezk, M. Rodriguez-Muro, and G. Xiao, "OBDA with the Ontop Framework," in Proceedings of the 23rd Italian Symposium on Advanced Database Systems (SEBD), 2015.
    @inproceedings{calvanese-etal-SEBD-2015, abstract = {Ontology-based data access (OBDA) has become a popular paradigm for accessing data stored in legacy sources using Semantic Web technologies. In the OBDA setting, users access the data through a conceptual layer, which provides a convenient query vocabulary abstracting from specific aspects related to the data sources. This conceptual layer is typically expressed as an RDF(S) or OWL ontology, and it is connected to the underlying relational databases using R2RML mappings. When the ontology is queried in SPARQL, the OBDA system exploits the mappings to retrieve elements from the data sources and construct the answers expected by the user. Different approaches for query processing in OBDA have been proposed. We focus here on the virtual approach, which avoids materializing triples retrieved through mappings and answers the SPARQL queries by translating them into SQL queries over the data sources. In this paper we present our mature open-source OBDA framework Ontop, which supports all W3C standards related to OBDA, and which produces efficiently executable SQL queries.},
      audience = {academic},
      author = {Calvanese, Diego and Cogrel, Benjamin and Guzel Kalayci, Elem and Komla Ebri, Sarah and Kontchakov, Roman and Lanti, Davide and Rezk, Martin and Rodriguez-Muro, Mariano and Xiao, Guohui},
      booktitle = {Proceedings of the 23rd Italian Symposium on Advanced Database Systems (SEBD)},
      interhash = {9122f0232736d94539eb09e6da281323},
      intrahash = {311bd26df1b4be201492d8c693f06f67},
      partneroptique = {FUB},
      title = {{OBDA} with the {Ontop} Framework},
      wpoptique = {WP6},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex Go to document
    D. Calvanese, G. De Giacomo, D. Lembo, M. Lenzerini, and R. Rosati, "Data Complexity of Query Answering in Description Logics (Extended Abstract)," in Proceedings of the 24th International Joint Conf.\ on Artificial Intelligence (IJCAI), 2015, pp. 4163-4167.
    @inproceedings{calvanese-etal-IJCAI-2015-AIJ, abstract = {We study the data complexity of answering conjunctive queries over Description Logic knowledge bases constituted by a TBox and an ABox. In particular, we are interested in characterizing the FO-rewritability and the polynomial tractability boundaries of conjunctive query answering, depending on the expressive power of the DL used to express the knowledge base. What emerges from our complexity analysis is that the Description Logics of the DL-Lite family are essentially the maximal logics allowing for conjunctive query answering through standard database technology.},
      audience = {academic},
      author = {Calvanese, Diego and De Giacomo, Giuseppe and Lembo, Domenico and Lenzerini, Maurizio and Rosati, Riccardo},
      booktitle = {Proceedings of the 24th International Joint Conf.\ on Artificial Intelligence (IJCAI)},
      interhash = {1a4caf81551ff00209bf91939105b5de},
      intrahash = {ed1111157f7c50a76171c6bf68773e0b},
      isbn = {978-1-57735-738-4},
      pages = {4163--4167},
      partneroptique = {FUB},
      publisher = {AAAI Press},
      title = {Data Complexity of Query Answering in Description Logics ({E}xtended Abstract)},
      url = {http://ijcai.org/papers15/Abstracts/IJCAI15-588.html},
      wpoptique = {WP6},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex Go to document
    D. Calvanese, M. Montali, F. Patrizi, and A. Rivkin, "Implementing Data-Centric Dynamic Systems over a Relational DBMS," in Proceedings of the 9th Alberto Mendelzon International Workshop on Foundations of Data Management (AMW), 2015.
    @inproceedings{calvanese-etal-AMW-2015, abstract = {We base our work on a model called data-centric dynamic system (DCDS), which can be seen as a framework for modeling and verification of systems where both the process controlling the dynamics and the manipulation of data are equally central. More specifically, a DCDS consists of a data layer and a process layer, interacting as follows: the data layer stores all the data of interest in a relational database, and the process layer modifies and evolves such data by executing actions under the control of a process, and possibly injecting into the system external data retrieved through service calls. In this work, we propose an implementation of DCDSs in which all aspects concerning not only the data layer but also the process layer, are realized by means of functionalities provided by a relational DBMS. We present the architecture of our prototype system, describe its functionality, and discuss the next steps we intend to take towards realizing a full-fledged DCDS-based system that supports verification of rich temporal properties.},
      audience = {academic},
      author = {Calvanese, Diego and Montali, Marco and Patrizi, Fabio and Rivkin, Andrey},
      booktitle = {Proceedings of the 9th Alberto Mendelzon International Workshop on Foundations of Data Management (AMW)},
      interhash = {489916ea284a86c5e69542d5b6b78f45},
      intrahash = {8362f240146312bfac3309c8083192e9},
      issn = {1613-0073},
      partneroptique = {FUB},
      scopus = {84937438315},
      series = {CEUR Electronic Workshop Proceedings, {\upshape\protect\url{http://ceur-ws.org/}}},
      title = {Implementing {D}ata-{C}entric {D}ynamic {S}ystems over a Relational {DBMS}},
      url = {http://ceur-ws.org/Vol-1378/AMW_2015_paper_39.pdf},
      volume = 1378, wpoptique = {WP6},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,article] bibtex Go to document
    D. Calvanese, M. Koubarakis, and D. Toman, "Preface to the Special Issue on Ontology-Based Data Access," Journal of Web Semantics, vol. 33, pp. 1-2, 2015.
    @article{calvanese-etal-JWS-2015-editorial, audience = {academic},
      author = {Calvanese, Diego and Koubarakis, Manolis and Toman, David},
      doi = {10.1016/j.websem.2015.06.001},
      interhash = {986c83946f4f758244087225959df0d4},
      intrahash = {3479a09f25b10b57bc3a1ee42eb88d77},
      issn = {1570-8268},
      journal = {Journal of Web Semantics},
      pages = {1--2},
      partneroptique = {FUB},
      title = {Preface to the Special Issue on Ontology-Based Data Access},
      url = {http://www.sciencedirect.com/science/article/pii/S1570826815000451},
      volume = 33, wpoptique = {WP6},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex Go to document
    A. Ahmeti, D. Calvanese, A. Polleres, and V. Savenkov, "Dealing with Inconsistencies due to Class Disjointness in SPARQL Update," in Proceedings of the 28th International Workshop on Description Logics (DL), 2015.
    @inproceedings{ahmeti-etal-DL-2015, abstract = {The problem of updating ontologies has received increased attention in recent years. In the approaches proposed so far, either the update language is restricted to (sets of) atomic updates, or, where the full SPARQL Update language is allowed, the TBox language is restricted to RDFS where no inconsistencies can arise. In this paper we discuss directions to overcome these limitations. Starting from a DL-Lite fragment covering RDFS and concept/class disjointness axioms, we define two semantics for SPARQL Update: under cautious semantics, inconsistencies are resolved by rejecting \emph{all} updates potentially introducing conflicts; under brave semantics, instead, conflicts are overridden in favor of new information where possible. The latter approach builds upon existing work on the evolution of DL-Lite knowledge bases, setting it in the context of generic SPARQL updates.},
      audience = {academic},
      author = {Ahmeti, Albin and Calvanese, Diego and Polleres, Axel and Savenkov, Vadim},
      booktitle = {Proceedings of the 28th International Workshop on Description Logics (DL)},
      interhash = {cfc60c23fbb63d5a1a6ef703499b3280},
      intrahash = {78769e55b456298cd0e5cd1bcc9af26c},
      issn = {1613-0073},
      partneroptique = {FUB},
      series = {CEUR Electronic Workshop Proceedings, {\upshape\protect\url{http://ceur-ws.org/}}},
      title = {Dealing with Inconsistencies due to Class Disjointness in {SPARQL} Update},
      url = {http://ceur-ws.org/Vol-1350/paper-05.pdf},
      volume = 1350, wpoptique = {WP6},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,inproceedings] bibtex
    D. Calvanese, M. Montali, F. Patrizi, and A. Rivkin, "Leveraging Relational Technology for Data-Centric Dynamic Systems," in Proceedings of the 23rd Italian Symposium on Advanced Database Systems (SEBD), 2015.
    @inproceedings{calvanese-etal-SEBD-2015-dcds-db, abstract = {We base our work on a model called data-centric dynamic system (DCDS), which can be seen as a framework for modeling and verification of systems where both the process controlling the dynamics and the manipulation of data are equally central. More specifically, a DCDS consists of a data layer and a process layer, interacting as follows: the data layer stores all the data of interest in a relational database, and the process layer modifies and evolves such data by executing actions under the control of a process, and possibly injecting into the system external data retrieved through service calls. In this work, we propose an implementation of DCDSs in which all aspects concerning not only the data layer but also the process layer, are realized by means of functionalities provided by a relational DBMS. We present the architecture of our prototype system, describe its functionality, and discuss the next steps we intend to take towards realizing a full-fledged DCDS-based system that supports verification of rich temporal properties.},
      audience = {academic},
      author = {Calvanese, Diego and Montali, Marco and Patrizi, Fabio and Rivkin, Andrey},
      booktitle = {Proceedings of the 23rd Italian Symposium on Advanced Database Systems (SEBD)},
      interhash = {2895457c164c55084faf6b725e62237a},
      intrahash = {d1d10ff58fc24ccc24769cf8cd3a0f15},
      partneroptique = {FUB},
      title = {Leveraging Relational Technology for Data-Centric Dynamic Systems},
      wpoptique = {WP6},
      year = 2015, yearoptique = {Y3}
    }
  • [2015,proceedings] bibtex Go to document
    Proceedings of the 28th International Workshop on Description Logics (DL), 2015.
    @proceedings{calvanese-konev-DL-2015-ed, audience = {academic},
      editor = {Calvanese, Diego and Konev, Boris},
      interhash = {25676477678ed9be8c407b8549825132},
      intrahash = {54c9419d56c5b93d81ac51f35ce6b582},
      issn = {1613-0073},
      partneroptique = {FUB},
      series = {CEUR Electronic Workshop Proceedings, {\upshape\protect\url{http://ceur-ws.org/}}},
      title = {Proceedings of the 28th International Workshop on Description Logics (DL)},
      url = {http://ceur-ws.org/Vol-1350/},
      volume = 1350, wpoptique = {WP6},
      year = 2015, yearoptique = {Y3}
    }
  • [2016,article] bibtex Go to document
    A. Soylu, M. Giese, E. Jimenez-Ruiz, G. Vega-Gorgojo, and I. Horrocks, "Experiencing OptiqueVQS: a multi-paradigm and ontology-based visual query system for end users," Universal Access in the Information Society, vol. 15, iss. 1, pp. 129-152, 2016.
    @article{ahmetsoylu2015experiencing, audience = {academic},
      author = {Soylu, Ahmet and Giese, Martin and Jimenez-Ruiz, Ernesto and Vega-Gorgojo, Guillermo and Horrocks, Ian},
      doi = {10.1007/s10209-015-0404-5},
      interhash = {037feab1e07485f778bc1a82b63a3ead},
      intrahash = {804b686cf96e5edabeb74113621032a6},
      journal = {Universal Access in the Information Society},
      number = 1, openaccess = {No},
      pages = {129-152},
      partneroptique = {UiO},
      title = {Experiencing OptiqueVQS: a multi-paradigm and ontology-based visual query system for end users},
      url = {http://doi.org/10.1007/s10209-015-0404-5},
      volume = 15, wpoptique = {WP3},
      year = 2016, yearoptique = {Y3}
    }
  • [2014,inproceedings] bibtex Go to document
    T. Bagosi, D. Calvanese, J. Hardi, S. Komla-Ebri, D. Lanti, M. Rezk, M. Rodriguez-Muro, M. Slusnys, and G. Xiao, "The Ontop Framework for Ontology Based Data Access," in Proc.\ of the 8th Chinese Semantic Web Symposium \& Web Science Conference (Posters and Demos), Wuhan, China, 2014.
    @inproceedings{csws-14-ontop, address = {Wuhan, China},
      audience = {academic},
      author = {Bagosi, Timea and Calvanese, Diego and Hardi, Josef and Komla-Ebri, Sarah and Lanti, Davide and Rezk, Martin and Rodriguez-Muro, Mariano and Slusnys, Mindaugas and Xiao, Guohui},
      booktitle = {Proc.\ of the 8th Chinese Semantic Web Symposium \& Web Science Conference (Posters and Demos)},
      doi = {10.1007/978-3-662-45495-4_6},
      interhash = {5ce4fd97be10f7813a4ef84a56f440e8},
      intrahash = {d04f4435831f23ea5ca82ce69afbf631},
      month = {August},
      openaccess = {No},
      partneroptique = {FUB},
      title = {The Ontop Framework for Ontology Based Data Access},
      url = {http://www.ghxiao.org/publications/2014-csws-ontop.pdf},
      wpoptique = {WP6},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    B. Cuenca Grau, E. Kharlamov, S. Marciuska, D. Zheleznyakov, and Y. Zhou, "Querying Life Science Ontologies with SemFacet," in Semantic Web Applications and Tools for Life Sciences (SWAT4LS), 2014.
    @inproceedings{cuencagrau2014querying, audience = {academic},
      author = {Cuenca Grau, Bernardo and Kharlamov, Evgeny and Marciuska, Sarunas and Zheleznyakov, Dmitriy and Zhou, Yujiao},
      booktitle = {Semantic Web Applications and Tools for Life Sciences (SWAT4LS)},
      interhash = {ddd9f3be3a19dd15f6a87711f26bba06},
      intrahash = {b1a70234fe91f0f60e9e13b34af1e5e4},
      partneroptique = {UOXF},
      title = {Querying Life Science Ontologies with SemFacet},
      wpoptique = {WP3},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    M. Bienvenu, D. Calvanese, M. Ortiz, and M. Simkus, "Nested Regular Path Queries in Description Logics," in Proceedings of the 14th International Conference on the Principles of Knowledge Representation and Reasoning (KR), 2014.
    @inproceedings{BCOS-KR-2014-nested-rpqs, abstract = {Two-way regular path queries (2RPQs) have received increased attention recently due to their ability to relate pairs of objects by flexibly navigating graph structured data. They are present in property paths in SPARQL~1.1, the new standard RDF query language, and in the XML query language XPath. In line with XPath, we consider the extension of 2RPQs with nesting, which allows one to require that objects along a path satisfy complex conditions, in turn expressed through (nested) 2RPQs. We study the computational complexity of answering nested 2RPQs and conjunctions thereof (CN2RPQs) in the presence of domain knowledge expressed in description logics (DLs). We establish tight complexity bounds in data and combined complexity for a variety of DLs, ranging from lightweight DLs (DL-Lite, EL) up to highly expressive ones. Interestingly, we are able to show that adding nesting to (C)2RPQs does not affect worst-case data complexity of query answering for any of the considered DLs. However, in the case of lightweight DLs, adding nesting to 2RPQs leads to a surprising jump in combined complexity, from P-complete to ExpTime-complete.},
      audience = {academic},
      author = {Bienvenu, Meghyn and Calvanese, Diego and Ortiz, Magdalena and Simkus, Mantas},
      booktitle = {Proceedings of the 14th International Conference on the Principles of Knowledge Representation and Reasoning (KR)},
      interhash = {f5a176cd7fbda750b83c560f7b366daa},
      intrahash = {b95e64a65a3075c546b8b9261bfac195},
      isbn = {978-1-57735-657-8},
      partneroptique = {FUB},
      publisher = {AAAI Press},
      title = {Nested Regular Path Queries in Description Logics},
      wpoptique = {WP6},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,article] bibtex
    D. Calvanese, T. Eiter, and M. Ortiz, "Answering Regular Path Queries in Expressive Description Logics via Alternating Tree-Automata," Information and Computation, vol. 237, pp. 12-55, 2014.
    @article{CEO-IC-2014, abstract = {Expressive Description Logics (DLs) have been advocated as formalisms for modeling the domain of interest in various application areas, including the Semantic Web, data and information integration, peer-to-peer data management, and ontology-based data access. An important requirement there is the ability to answer complex queries beyond instance retrieval, taking into account constraints expressed in a knowledge base. We consider this task for \emph{positive 2-way regular path queries (P2RPQs)} over knowledge bases in the expressive DL $\mathcal{ZIQ}$. P2RPQs are more general than conjunctive queries, union of conjunctive queries, and regular path queries from the literature. They allow regular expressions over roles and data joins that require inverse paths. The DL $\matcal{ZIQ}$ extends the core DL $\mathcal{ALC}$ with qualified number restrictions, inverse roles, safe Boolean role expressions, regular expressions over roles, and concepts of the form $\exists{P}{\mathsf{Self}}$ in the style of the DL $\mathcal{SRIQ}$. Using techniques based on two-way tree-automata, we first provide as a stepping stone an elegant characterization of TBox and ABox satisfiability testing which gives us a tight \textsc{ExpTime} bound for this problem (under unary number encoding). We then establish a double exponential upper bound for answering P2RPQs over $\mathcal{ZIQ}$ knowledge bases; this bound is tight. Our result significantly pushes the frontier of 2\textsc{ExpTime} decidability of query answering in expressive DLs, both with respect to the query language and the considered DL. Furthermore, by reducing the well known DL $\mathcal{SRIQ}$ to $\mathcal{ZIQ}$ (with an exponential blow-up in the size of the knowledge base), we also provide a tight 2\textsc{ExpTime} upper bound for knowledge base satisfiability in $\mathcal{SRIQ}$ and establish the decidability of query answering for this significant fragment of the new OWL~2 standard.},
      audience = {academic},
      author = {Calvanese, Diego and Eiter, Thomas and Ortiz, Magdalena},
      doi = {10.1016/j.ic.2014.04.002},
      interhash = {e01975f8548deaee390f7ef9637cbba4},
      intrahash = {ba78923b112ccf824c365835ebb38646},
      issn = {0890-5401},
      journal = {Information and Computation},
      pages = {12-55},
      partneroptique = {FUB},
      title = {Answering Regular Path Queries in Expressive Description Logics via Alternating Tree-Automata},
      volume = 237, wpoptique = {WP6},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex Go to document
    D. Calvanese, "Query Answering over Description Logic Ontologies," in Proceedings of the 14th European Conference on Logics in Artificial Intelligence (JELIA), 2014.
    @inproceedings{Calvanese-JELIA-2014-queries, abstract = {Description Logics (DLs) provide the formal foundation for ontology languages, and they have been advocated as formalisms for modeling the domain of interest in various settings, including the Semantic Web, data and information integration, and ontology-based data access. An important requirement there is the ability to answer complex database-like queries, while taking into account both extensional and intensional domain knowledge. The task of answering queries has been investigated intensively in the last years for a variety of DLs, and considering both data complexity, i.e., the complexity measured in the size of the extensional information only, and combined complexity. On the one hand, it has been shown to be in general (exponentially) more difficult than the standard reasoning tasks of concept satisfiability and subsumption; on the other hand a broad range of techniques have been developed. We overview here some of the key techniques developed in the last years for query answering over DL ontologies, ranging from rewriting based approaches for lightweight DLs, to tableaux algorithms, and techniques based on automata on infinite trees for very expressive DLs. The associated results, accompanied by matching lower bounds, have contributed to shaping the computational complexity picture for ontology-based query answering.},
      audience = {academic},
      author = {Calvanese, Diego},
      booktitle = {Proceedings of the 14th European Conference on Logics in Artificial Intelligence (JELIA)},
      doi = {10.1007/978-3-319-11558-0_1},
      interhash = {6e3204e569c9df57995d36a9d50c523d},
      intrahash = {25d05a7b7916fa7fa545d7a2585332da},
      isbn = {978-3-319-11557-3},
      partneroptique = {FUB},
      publisher = {Springer},
      series = {Lecture Notes in Computer Science},
      title = {Query Answering over Description Logic Ontologies},
      url = {http://link.springer.com/chapter/10.1007/978-3-319-11558-0_1},
      volume = 8761, wpoptique = {WP6},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex Go to document
    M. Bienvenu, D. Calvanese, M. Ortiz, and M. Simkus, "Nested Regular Path Queries in Description Logics (Extended Abstract)," in Proceedings of the 8th Alberto Mendelzon International Workshop on Foundations of Data Management (AMW), 2014.
    @inproceedings{BCOS-AMW-2014-nested-rpqs, abstract = {We consider the extension of two-way regular path queries (2RPQs) with nesting, which allows one to require that objects along a path satisfy complex conditions, in turn expressed through (nested) 2RPQs. We study the computational complexity of answering nested 2RPQs and conjunctions thereof (CN2RPQs) in the presence of domain knowledge expressed in description logics (DLs). We establish tight complexity bounds in data and combined complexity for a variety of DLs, ranging from lightweight DLs up to highly expressive ones.},
      audience = {academic},
      author = {Bienvenu, Meghyn and Calvanese, Diego and Ortiz, Magdalena and Simkus, Mantas},
      booktitle = {Proceedings of the 8th Alberto Mendelzon International Workshop on Foundations of Data Management (AMW)},
      interhash = {72236dea1371fca4fa89d986f5238a2c},
      intrahash = {1a23bf1f9f728fe2762a92f43a6c92cc},
      issn = {1613-0073},
      partneroptique = {FUB},
      series = {CEUR Electronic Workshop Proceedings, {\upshape\protect\url{http://ceur-ws.org/}}},
      title = {Nested Regular Path Queries in Description Logics (Extended Abstract)},
      url = {http://ceur-ws.org/Vol-1189/paper_34.pdf},
      volume = 1189, wpoptique = {WP6},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex Go to document
    S. Ahmetaj, D. Calvanese, M. Ortiz, and M. Simkus, "Managing Change in Graph-structured Data Using Description Logics," in Proceedings of the 28th AAAI Conference on Artificial Intelligence (AAAI), 2014, pp. 966-973.
    @inproceedings{ACOS-AAAI-2014-graph-dbs, abstract = {In this paper, we consider the setting of graph-structured data that evolves as a result of operations carried out by users or applications. We study different reasoning problems, which range from ensuring the satisfaction of a given set of integrity constraints after a given sequence of updates, to deciding the (non-)existence of a sequence of actions that would take the data to an (un)desirable state, starting either from a specific data instance or from an incomplete description of it. We consider an action language in which actions are finite sequences of conditional insertions and deletions of nodes and labels, and use Description Logics for describing integrity constraints and (partial) states of the data. We then formalize the above data management problems as a static verification problem and several planning problems. We provide algorithms and tight complexity bounds for the formalized problems, both for an expressive DL and for a variant of DL-Lite.},
      audience = {academic},
      author = {Ahmetaj, Shqiponja and Calvanese, Diego and Ortiz, Magdalena and Simkus, Mantas},
      booktitle = {Proceedings of the 28th AAAI Conference on Artificial Intelligence (AAAI)},
      interhash = {1833b946aedc8038348994a351282704},
      intrahash = {8662c325d8e223f99d9fe20fb837b59b},
      isbn = {978-1-57735-661-5},
      pages = {966-973},
      partneroptique = {FUB},
      publisher = {AAAI Press},
      title = {Managing Change in Graph-structured Data Using Description Logics},
      url = {http://www.aaai.org/ocs/index.php/AAAI/AAAI14/paper/view/8238},
      wpoptique = {WP6},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex Go to document
    A. Ahmeti, D. Calvanese, and A. Polleres, "Updating RDFS ABoxes and TBoxes in SPARQL," in Proceedings of the 13th International Semantic Web Conference (ISWC), 2014, pp. 441-456.
    @inproceedings{ACP-ISWC-2014, abstract = { Updates in RDF stores have recently been standardised in the SPARQL~1.1 Update specification. However, computing answers entailed by ontologies in triple stores is usually treated orthogonally to updates. Even W3C's SPARQL~1.1 Update language and SPARQL~1.1 Entailment Regimes specifications explicitly exclude a standard behaviour for entailment regimes other than simple entailment in the context of updates. In this paper, we take a first step to close this gap. We define a fragment of SPARQL basic graph patterns corresponding to (the RDFS fragment of) \dllite and the corresponding SPARQL update language, dealing with updates both of ABox and of TBox statements. We discuss possible semantics along with potential strategies for implementing them. In particular, we treat both, (i)~materialised RDF stores, which store all entailed triples explicitly, and (ii)~reduced RDF Stores, that is, redundancy-free RDF stores that do not store any RDF triples (corresponding to \dllite ABox statements) entailed by others already. We have implemented all semantics prototypically on top of an off-the-shelf triple store and present some indications on practically feasibility.},
      audience = {academic},
      author = {Ahmeti, Albin and Calvanese, Diego and Polleres, Axel},
      booktitle = {Proceedings of the 13th International Semantic Web Conference (ISWC)},
      doi = {10.1007/978-3-319-11964-9_28},
      interhash = {278a737dbf63c7959bd59c6c3054e0e6},
      intrahash = {0399fc82d1f0a74a5821531786d919c6},
      isbn = {978-3-319-11963-2},
      pages = {441-456},
      partneroptique = {FUB},
      publisher = {Springer},
      series = {Lecture Notes in Computer Science},
      title = {Updating {RDFS} {ABoxes} and {TBoxes} in {SPARQL}},
      url = {http://link.springer.com/chapter/10.1007/978-3-319-11964-9_28},
      volume = 8796, wpoptique = {WP6},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex Go to document
    A. Ahmeti, D. Calvanese, and A. Polleres, "SPARQL Update for Materialized Triple Stores under DL-Lite$_\mathitRDFS$ Entailment," in Proceedings of the 27th International Workshop on Description Logics (DL), 2014, pp. 8-20.
    @inproceedings{ACP-DL-2014-sparql-update, abstract = {Updates in RDF stores have recently been standardised in the SPARQL~1.1 Update specification. However, computing answers entailed by ontologies in triple stores is usually treated orthogonally to updates. Even W3C's SPARQL~1.1 Update language and SPARQL~1.1 Entailment Regimes specifications explicitly exclude a standard behaviour for entailment regimes other than simple entailment in the context of updates. In this paper, we take a first step to close this gap. We define a fragment of SPARQL basic graph patterns corresponding to (the RDFS fragment of) DL-Lite and the corresponding SPARQL update language, dealing with updates both of ABox and of TBox statements. We discuss possible semantics along with potential strategies for implementing them. Particularly, we treat materialised RDF stores, which store all entailed triples explicitly, and preservation of materialisation upon ABox and TBox updates.},
      audience = {academic},
      author = {Ahmeti, Albin and Calvanese, Diego and Polleres, Axel},
      booktitle = {Proceedings of the 27th International Workshop on Description Logics (DL)},
      interhash = {006169f6d23011bfd9ccf5711f018a22},
      intrahash = {0f6a56a0066045fcb41c9d78b36b9305},
      issn = {1613-0073},
      pages = {8-20},
      partneroptique = {FUB},
      series = {CEUR Electronic Workshop Proceedings, {\upshape\protect\url{http://ceur-ws.org/}}},
      title = {{SPARQL} Update for Materialized Triple Stores under DL-Lite$_\mathit{RDFS}$ Entailment},
      url = {http://ceur-ws.org/Vol-1193/paper_7.pdf},
      volume = 1193, wpoptique = {WP6},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex Go to document
    D. Calvanese, W. Fischl, R. Pichler, E. Sallinger, and M. Simkus, "Capturing Relational Schemas and Functional Dependencies in RDFS," in Proceedings of the 28th AAAI Conference on Artificial Intelligence (AAAI), 2014, pp. 1003-1011.
    @inproceedings{CFPSS-AAAI-2014-dlnf, abstract = {Mapping relational data to RDF is an important task for the development of the Semantic Web. To this end, the W3C has recently released a Recommendation for the so-called direct mapping of relational data to RDF. In this work, we propose an enrichment of the direct mapping to make it more faithful by transferring also semantic information present in the relational schema from the relational world to the RDF world. We thus introduce expressive identification constraints to capture functional dependencies and define an RDF Normal Form, which precisely captures the classical Boyce-Codd Normal Form of relational schemas.},
      audience = {academic},
      author = {Calvanese, Diego and Fischl, Wolfgang and Pichler, Reinhard and Sallinger, Emanuel and Simkus, Mantas},
      booktitle = {Proceedings of the 28th AAAI Conference on Artificial Intelligence (AAAI)},
      interhash = {e6c195607d2cc3b3783e750aa2e08f51},
      intrahash = {ce2afe216ce5976e24fdc16e38833172},
      isbn = {978-1-57735-661-5},
      pages = {1003-1011},
      partneroptique = {FUB},
      publisher = {AAAI Press},
      title = {Capturing Relational Schemas and Functional Dependencies in {RDFS}},
      url = {http://www.aaai.org/ocs/index.php/AAAI/AAAI14/paper/view/8487},
      wpoptique = {WP6},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex Go to document
    D. Calvanese, W. Fischl, R. Pichler, E. Sallinger, and M. Simkus, "Expressive Identification Constraints to Capture Functional Dependencies in Description Logics," in Proceedings of the 27th International Workshop on Description Logics (DL), 2014, pp. 416-420.
    @inproceedings{CFPSS-DL-2014-dlnf, abstract = {Mapping relational data to RDF is an important task for the development of the Semantic Web. To this end, the W3C has recently released a Recommendation for the so-called direct mapping of relational data to RDF. In this work, we propose an enrichment of the direct mapping to make it more faithful by transferring also semantic information present in the relational schema from the relational world to the RDF world. For this purpose we enrich DL-Lite$_{\mathit{RDFS}}$ with expressive identification constraints to capture functional dependencies and define an RDF Normal Form, which precisely captures the classical Boyce-Codd Normal Form of relational schemas.},
      audience = {academic},
      author = {Calvanese, Diego and Fischl, Wolfgang and Pichler, Reinhard and Sallinger, Emanuel and Simkus, Mantas},
      booktitle = {Proceedings of the 27th International Workshop on Description Logics (DL)},
      interhash = {2f61320c9eed0bf1ba40c789019c6712},
      intrahash = {b01e5ebd5e4832b9f1166c701aa6486d},
      issn = {1613-0073},
      pages = {416-420},
      partneroptique = {FUB},
      series = {CEUR Electronic Workshop Proceedings, {\upshape\protect\url{http://ceur-ws.org/}}},
      title = {Expressive Identification Constraints to Capture Functional Dependencies in Description Logics},
      url = {http://ceur-ws.org/Vol-1193/paper_48.pdf},
      volume = 1193, wpoptique = {WP6},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    C. Pinkel, C. Binnig, P. Haase, C. Martin, K. Sengupta, and J. Trame, "How to Best Find a Partner? An Evaluation of Editing Approaches to Construct R2RML Mapping," in ESWC, 2014.
    @inproceedings{pinkel2014partner, audience = {academic},
      author = {Pinkel, Christoph and Binnig, Carsten and Haase, Peter and Martin, Clemens and Sengupta, Kunal and Trame, Johannes},
      booktitle = {ESWC},
      interhash = {61ba05d0a6652a3f579934ecbf02edf7},
      intrahash = {2a585820d4ca30336acb18b1cc51fb0f},
      partneroptique = {FOPS},
      title = {How to Best Find a Partner? An Evaluation of Editing Approaches to Construct R2RML Mapping},
      wpoptique = {WP2},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    M. Montali, D. Calvanese, and G. De Giacomo, "Verification of Data-Aware Commitment-Based Multiagent System," in In Proceedings of the 2014 international conference on Autonomous agents and multi-agent systems, 2014, pp. 157-164.
    @inproceedings{montali2014verification, abstract = {In this paper we investigate multiagent systems whose agent interaction is based on social commitments that evolve over time, in presence of (possibly incomplete) data. In particular, we are interested in modeling and verifying how data maintained by the agents impact on the dynamics of such systems, and on the evolution of their commitments. This requires to lift the commitment-related conditions studied in the literature, which are typically based on propositional logics, to a first-order setting. To this purpose, we propose a rich framework for modeling data-aware commitment-based multiagent systems. In this framework, we study verification of rich temporal properties, establishing its decidability under the condition of “state-boundedness”, i.e., data items come from an infinite domain but, at every time point, each agent can store only a bounded number of them.},
      audience = {academic},
      author = {Montali, Marco and Calvanese, Diego and De Giacomo, Giuseppe},
      booktitle = {In Proceedings of the 2014 international conference on Autonomous agents and multi-agent systems},
      interhash = {495d7fa881e48d0c8eb9020c360cd8ef},
      intrahash = {95a1ca9b3637564c627ef503e21b8dd4},
      openaccess = {Yes},
      pages = {157-164},
      partneroptique = {UNIROMA1},
      title = {Verification of Data-Aware Commitment-Based Multiagent System},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    G. De Giacomo, R. De Masellis, and M. Marco, "Reasoning on LTL on Finite Traces: Insensitivity to Infiniteness.," in Proceedings of the Twenty-Eighth AAAI Conference on Artificial Intelligence, 2014, pp. 1027-1033.
    @inproceedings{degiacomo2014reasoning, abstract = {In this paper we study when an LTL formula on finite traces (LTLf formula) is insensitive to infiniteness, that is,it can be correctly handled as a formula on infinite traces under the assumption that at a certain point the infinite trace starts repeating an end event forever, trivializing all other propositions to false. This intuition has been put forward and (wrongly) assumed to hold in general in the literature. We define a necessary and sufficient condition to characterize whether an LTLf formula is insensitive to infiniteness, which can be automatically checked by any LTL reasoner. Then, we show that typical LTLf specification patterns used in process and service modeling in CS, as well as trajectory constraints in Planning and transition-based LTLf specifications of action domains in KR, are indeed very often insensitive to infiniteness. This may help to explain why the assumption of interpreting LTL on finite and on infinite traces has been (wrongly) blurred. Possibly be- cause of this blurring, virtually all literature detours to Buchi automata for constructing the NFA that accepts the traces satisfying an LTLf formula. As a further contribution, we give a simple direct algorithm for computing such NFA.},
      audience = {academic},
      author = {De Giacomo, Giuseppe and De Masellis, Riccardo and Marco, Montali},
      booktitle = {Proceedings of the Twenty-Eighth AAAI Conference on Artificial Intelligence},
      interhash = {b5f8415a7a92dfa47c1b5b53f0459460},
      intrahash = {3110caac7cbb0b720a90fdc52dab0c29},
      openaccess = {Yes},
      pages = {1027-1033},
      partneroptique = {UNIROMA1},
      publisher = {AAAI Press},
      title = {Reasoning on LTL on Finite Traces: Insensitivity to Infiniteness.},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    G. De Giacomo, R. De Masellis, M. Grasso, F. M. Maggi, and M. Marco, "Monitoring Business Metaconstraints Based on LTL & LDL for Finite Traces.," in Journal on Data Semantics, 2014, pp. 1-25.
    @inproceedings{noauthororeditor, abstract = {Runtime monitoring is one of the central tasks to provide operational decision support to running business processes, and check on-the-fly whether they comply with constraints and rules. We study runtime monitoring of properties expressed in LTL on finite traces (LTLf) and its extension LDLf. LDLf is a powerful logic that captures all monadic second order logic on finite traces, which is obtained by combining regular expressions with LTLf , adopting the syntax of propositional dynamic logic (PDL). Interestingly, in spite of its greater expressivity, LDLf has exactly the same computational complexity of LTLf. We show that LDLf is able to capture, in the logic itself, not only the constraints to be monitored, but also the de-facto standard RV-LTL monitors. This makes it possible to declaratively capture monitoring metaconstraints, i.e., constraints about the evolution of other constraints, and check them by relying on usual logical services for temporal logics instead of ad-hoc algorithms. This, in turn, enables to flexibly monitor constraints depending on the monitoring state of other constraints, e.g., “compensation” constraints that are only checked when others are detected to be violated. In addition, we devise a direct translation of LDLf formulas into nondeterministic automata, avoiding to detour to Buchi automata or alternating automata, and we use it to implement a monitoring plug-in for the PROM suite.},
      audience = {academic},
      author = {De Giacomo, Giuseppe and De Masellis, Riccardo and Grasso, Marco and Maggi, Fabrizio Maria and Marco, Montali},
      booktitle = {Journal on Data Semantics },
      doi = {10.1007/978-3-319-10172-9_1},
      interhash = {80c5c618fdda116567b3a706754c8aa8},
      intrahash = {90c12c46ee704c014a2509afd6689541},
      openaccess = {No},
      pages = {1-25},
      partneroptique = {UNIROMA1},
      title = {Monitoring Business Metaconstraints Based on LTL & LDL for Finite Traces. },
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex Go to document
    E. Jiménez-Ruiz, B. C. Grau, W. Xia, A. Solimando, X. Chen, V. Cross, Y. Gong, S. Zhang, and A. Rekha, "LogMap family results for OAEI 2014," in Proc. of the 9th Ontology Matching Workshop, 2014.
    @inproceedings{jimenezruiz2014logmap, abstract = {We present the results obtained in the OAEI 2014 campaign by our ontology matching system LogMap and its variants: LogMap-C, LogMap-Bio and LogMapLt. The LogMap project started in January 2011 with the objective of developing a scalable and logic-based ontology matching system. This is our fifth participation in the OAEI and the experience has so far been very positive. },
      audience = {academic},
      author = {Jiménez-Ruiz, Ernesto and Grau, Bernardo Cuenca and Xia, Weiguo and Solimando, Alessandro and Chen, Xi and Cross, Valerie and Gong, Yuan and Zhang, Shuo and Rekha, Anu},
      booktitle = {Proc. of the 9th Ontology Matching Workshop},
      interhash = {d7a4bc11c801a356e78eda872be3248e},
      intrahash = {55efa85f67057ea44bf30b764e8b4f66},
      partneroptique = {UOXF},
      title = {LogMap family results for OAEI 2014},
      url = {http://www.dit.unitn.it/~p2p/OM-2014/oaei14_paper6.pdf},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    R. De Masellis, D. Lembo, M. Montali, and D. Solomakhin, "Semantic Enrichment of GSM-Based Artifact-Centric Models," in Principles of Knowledge Representation and Reasoning: Proceedings of the Fourteenth International Conference, KR, 2014.
    @inproceedings{demasellis2014semantic, abstract = {We provide a comprehensive framework for semantic GSM artifacts, discuss in detail its properties, and present main software engineering architectures it is able to capture. The distinguishing aspect of our framework is that it allows for expressing both the data and the lifecycle schema of GSM artifacts in terms of an ontology, i.e., a shared and formalized conceptualization of the domain of interest. To guide the modeling of data and lifecycle we provide an upper ontology, which is specialized in each artifact with specific lifecycle elements, relations, and business objects. The framework thus obtained allows to achieve several advantages. On the one hand, it makes the specification of conditions on data and artifact status attribute fully declarative, and enable semantic reasoning over them. On the other, it fosters the monitoring of artifacts and the interoperation and cooperation among different artifact systems. To fully achieve such an interoperation, we enrich our framework by enabling the linkage of the ontology to autonomous database systems through the use of mappings. We then discuss two scenarios of practical interest that show how mappings can be used in the presence of multiple systems. For one of these scenarios we also describe a concrete instantiation of the framework and its application to a real-world use case in the energy domain.},
      audience = {academic},
      author = {De Masellis, Riccardo and Lembo, Domenico and Montali, Marco and Solomakhin, Dmitry},
      booktitle = {Principles of Knowledge Representation and Reasoning: Proceedings of the Fourteenth International Conference, KR},
      interhash = {5bacb5eaf398301118dbafdfeb162d57},
      intrahash = {76d5676ed7d698435de984e532e8224e},
      openaccess = {Yes},
      partneroptique = {UNIROMA1},
      publisher = {AAAI Press},
      title = {Semantic Enrichment of GSM-Based Artifact-Centric Models},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    G. De Giacomo, Y. Lespérance, F. Patrizi, and S. Vassos, "Progression and verification of situation calculus agents with bounded beliefs," in International conference on Autonomous Agents and Multi-Agent Systems, 2014, pp. 141-148.
    @inproceedings{degiacomo2014progression, abstract = {In this paper we investigate agents that have incomplete information and make decisions based on their beliefs, expressed as situation calculus bounded action theories. Such theories have an infinite object domain, but the number of objects that belong to fluents at each time point is bounded by a given constant. Recently it has been shown that verifying temporal properties over such theories is decidable. Here, we first show that we can actually check whether an arbitrary action theory maintains boundedness. Secondly, we examine progression. Progression can be thought of as capturing the notion of belief states resulting from actions in the situation calculus. In the general case, such belief states can be expressed only in second-order logic. Here, we show that for bounded action theories, progression, and hence belief states, can always be represented in first-order logic. Based on this result, we further prove decidability of temporal verification over online executions, i.e., those executions resulting from agents performing only actions that are feasible according to their beliefs. },
      audience = {academic},
      author = {De Giacomo, Giuseppe and Lespérance, Yves and Patrizi, Fabio and Vassos, Stavros},
      booktitle = {International conference on Autonomous Agents and Multi-Agent Systems},
      doi = {10.1007/s11225-015-9626-z},
      interhash = {3c554afba1e0e18775880b83cc0a1760},
      intrahash = {1971b32dc8abd0be66598c00200ba204},
      openaccess = {Yes},
      pages = {141-148},
      partneroptique = {UNIROMA1},
      title = {Progression and verification of situation calculus agents with bounded beliefs},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    G. De Giacomo, Y. Lespérance, F. Patrizi, and S. Vassos, "LTL Verification of Online Executions with Sensing in Bounded Situation Calculus," in ECAI 2014 – 21st European Conference on Artificial Intelligence, 2014, pp. 369-374.
    @inproceedings{degiacomo2014verification, abstract = {We look at agents reasoning about actions from a first-person perspective. The agent has a representation of world as situation calculus action theory. It can perform sensing actions to acquire information. The agent acts “online”, i.e., it performs an action only if it is certain that the action can be executed, and collects sensing results from the actual world. When the agent reasons about its future actions, it indeed considers that it is acting online; however only possible sensing values are available. The kind of reasoning about actions we consider for the agent is verifying a first-order (FO) variant (without quantification across situations) of linear time temporal logic (LTL) . We mainly focus on bounded action theories, where the number of facts that are true in any situation is bounded. The main results of this paper are: (i) possible sensing values can be based on consistency if the initial situation description is FO; (ii) for bounded action theories, progression over histories that include sensing results is always FO; (iii) for bounded theories, verifying our FO LTL against online executions with sensing is decidable.},
      audience = {academic},
      author = {De Giacomo, Giuseppe and Lespérance, Yves and Patrizi, Fabio and Vassos, Stavros},
      booktitle = {ECAI 2014 - 21st European Conference on Artificial Intelligence},
      doi = {10.3233/978-1-61499-419-0-369},
      interhash = {b4e5580891cb93b9fe8833bbfddb993e},
      intrahash = {cc6ef32f8bde6607e41c870bf4678ad7},
      openaccess = {Yes},
      pages = {369-374},
      partneroptique = {UNIROMA1},
      title = {LTL Verification of Online Executions with Sensing in Bounded Situation Calculus},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    F. Patrizi and S. Vassos, "Action Theories over Generalized Databases with Equality Constraints," in Logics in Artificial Intelligence – 14th European Conference, JELIA, 2014, pp. 472-485.
    @inproceedings{patrizi2014action, abstract = {In this work we focus on situation calculus action theories over generalized databases with equality constraints, here called GFDBs, which are able to finitely represent complete information over a possibly infinite number of objects. We contribute with the following: i) we show that GFDBs characterize the class of definitional KBs and that they are closed under progression; ii) we show that temporal projection queries are decidable for theories with an initial KB expressed as a GFDB, which we call GFDB-BATs; iii) we extend the notion of boundedness to allow for infinite objects in the extensions of fluents and prove that a wide class of generalized projection queries is decidable for GFDB-BAT under a restriction we call C-boundedness; iv) we show that checking whether C-boundedness holds for a given bound is decidable. The proposed action theories are to date the most expressive ones for which there are decidable methods for computing both progression and generalized projection.},
      audience = {academic},
      author = {Patrizi, Fabio and Vassos, Stavros},
      booktitle = {Logics in Artificial Intelligence - 14th European Conference, JELIA},
      doi = {10.1007/978-3-319-11558-0_33},
      interhash = {9b490f336c8fcff199c8e514f1e35206},
      intrahash = {73189371bb8894e34d2c03897bc1d696},
      openaccess = {No},
      pages = {472-485},
      partneroptique = {UNIROMA1},
      title = {Action Theories over Generalized Databases with Equality Constraints},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    F. Patrizi and S. Vassos, "Action Theories over Generalized Databases with Equality Constraints (Extended Abstract)." 2014.
    @inproceedings{patrizi2014action, abstract = {In this work we study action theories of the situation calculus such that the initial KB is a generalized database with equality constraints (GFDBs). We show that GFDBs characterize the class of definitional KBs and that they are closed under progression. We also show that, under conditions, generalized projection queries can be decided based on an induced transition system and evaluation of local conditions over states.},
      audience = {academic},
      author = {Patrizi, Fabio and Vassos, Stavros},
      interhash = {2141427e764ad9cb91c7334fb3460a15},
      intrahash = {cecf9298a5865bc5e9740d2c51386322},
      openaccess = {Yes},
      partneroptique = {UNIROMA1},
      title = {Action Theories over Generalized Databases with Equality Constraints (Extended Abstract)},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    C. Civili, "Query Answering over Ontologies Specified via Database Dependencies," in In Proceedings of the 2014 SIGMOD PhD symposium, 2014, p. p. 36-40.
    @inproceedings{civili2014query, abstract = {In this work we present a novel graph-based approach for studying the tractability of query answering over ontologies expressed by means of tuple-generating dependencies (TGDs). We do this by defining a new class of TGDs that subsumes all the other known classes that enjoy a particularly desirable property called first-order rewritability of query answering.},
      audience = {academic},
      author = {Civili, Cristina},
      booktitle = { In Proceedings of the 2014 SIGMOD PhD symposium },
      interhash = {c55eb35add48d10edeb2a84cef97770d},
      intrahash = {fe9fdb06058f378fc6dbc26b9ec9f41a},
      openaccess = {Yes},
      pages = {p. 36-40},
      partneroptique = {UNIROMA1},
      title = {Query Answering over Ontologies Specified via Database Dependencies},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    M. Lenzerini and M. Console, "Reducing global consistency to local consistency in Ontology-based Data Access.," in ECAI 2014 – 21st European Conference on Artificial Intelligence, 2014, pp. 219-224.
    @inproceedings{lenzerini2014reducing, abstract = {Ontology-based data access (OBDA) is a new paradigm aiming at accessing and managing data by means of an ontology, i.e., a conceptual representation of the domain of interest in the underlying information system. In the last years, this new paradigm has been used for providing users with suitable mechanisms for querying the data residing at the information system sources. Most of the research has been concentrating on making query answering efficient. Howeverquery answering is not the only service that an OBDA system must provide. Another crucial service is consistency checking. Current approaches to this problem involves executing expensive queries at run-time. In this paper we address a fundamental problem for OBDA system: given an OBDA specification, can we avoid the consistency check on the whole OBDA system (global consistency check), and rely instead on the constraint checking carried out by the DBMS on the data source (local consistency checking)? We present algorithms and complexity analysis for this problem, showing that it can be solved efficiently for a class of OBDA systems that is very relevant in practice.},
      audience = {academic},
      author = {Lenzerini, Maurizio and Console, Marco},
      booktitle = {ECAI 2014 - 21st European Conference on Artificial Intelligence},
      doi = {10.3233/978-1-61499-419-0-219},
      interhash = {b0bb0b286ba36a41673ddb625e82d31a},
      intrahash = {e869d6828db91ec84d367441c91639ac},
      openaccess = {No},
      pages = {219-224},
      partneroptique = {UNIROMA1},
      title = {Reducing global consistency to local consistency in Ontology-based Data Access.},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    M. Lenzerini and M. Console, "Reducing Global Consistency to Local Consistency in Ontology-based Data Access – Extended Abstract.," in Informal Proceedings of the 27th International Workshop on Description Logics, 2014, pp. 496-499.
    @inproceedings{lenzerini2014reducing, audience = {academic},
      author = {Lenzerini, Maurizio and Console, Marco},
      booktitle = {Informal Proceedings of the 27th International Workshop on Description Logics},
      interhash = {2a12a7ad3b069300afe398e8c96aacb2},
      intrahash = {e4145bf7bd5b9849d0c0af6f61f1a702},
      openaccess = {Yes},
      pages = {496-499},
      partneroptique = {UNIROMA1},
      title = {Reducing Global Consistency to Local Consistency in Ontology-based Data Access - Extended Abstract.},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    M. Lenzerini and M. Console, "Data Quality in Ontology-based Data Access: The Case of Consistency," in Proceedings of the Twenty-Eighth AAAI Conference on Artificial Intelligence, 2014, pp. 1020-1026.
    @inproceedings{lenzerini2014quality, abstract = {Ontology-based data access (OBDA) is a new paradigm aiming at accessing and managing data by means of an ontology, i.e., a conceptual representation of the domain of interest in the underlying information system. In the last years, this new paradigm has been used for providing users with abstract (independent from technological and system-oriented aspects), effective, and reasoning-intensive mechanisms for querying the data residing at the information system sources. In this paper we argue that OBDA, besides querying data, provides the right principles for devising a formal approach to data quality. In particular, we concentrate on one of the most important dimensions considered both in the literature and in the practice of data quality, namely consistency. We define a general framework for data consistency in OBDA, and present algorithms and complexity analysis for several relevant tasks related to the problem of checking data quality under this dimension, both at the extensional level (content of the data sources), and at the intensional level (schema of the data sources).},
      audience = {academic},
      author = {Lenzerini, Maurizio and Console, Marco},
      booktitle = {Proceedings of the Twenty-Eighth AAAI Conference on Artificial Intelligence},
      interhash = {a78e94e9f9d54dd052bd4f5408e069e0},
      intrahash = {c5ae43245ed7d140ed2d4a22e22a8bba},
      openaccess = {Yes},
      pages = {1020-1026},
      partneroptique = {UNIROMA1},
      title = {Data Quality in Ontology-based Data Access: The Case of Consistency},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    M. Lenzerini, L. Lepore, and A. Poggi, "Practical Query Answering over HI(DL-LiteR) Knoledge Bases," in Informal Proceedings of the 27th International Workshop on Description Logics, 2014, pp. 608-619.
    @inproceedings{lenzerini2014practical, abstract = {The language Hi(DL-LiteR) is obtained from DL-LiteR by adding meta-modeling features, and is equipped with a query language that is able to express higher-order queries. We investigate the problem of answering a particular class of such queries, called instance higher-order queries posed over Hi(DL-LiteR) knowledge bases (KBs). The only existing algorithm for this problem is based on the idea of reducing the evaluation of a higher-order query Q over a Hi(DL-LiteR) KB to the evaluation of a union of first-order queries over a DL-LiteR KB, built from Q by instantiating all metavariables in all possible ways. Even though of polynomial time complexity with respect to the size of the KB, this algorithm turns out to be inefficient in practice. In this paper we present a new algorithm, called Smart Binding Planner (SBP), that compiles Q into a program, that issues a sequence of first-order conjunctive queries, where each query has the goal of providing the bindings for meta-variables of the next ones, and the last one completes the process by computing the answers to Q. We also illustrate some experiments showing that, in practice, SBP is significantly more efficient than the previous approach.},
      audience = {academic},
      author = {Lenzerini, Maurizio and Lepore, Lorenzo and Poggi, Antonella},
      booktitle = {Informal Proceedings of the 27th International Workshop on Description Logics},
      interhash = {b43268173507c92b2cffb6f68613563c},
      intrahash = {a22b1374b5d412240d30666bf9a9a7a4},
      openaccess = {Yes},
      pages = {608-619},
      partneroptique = {UNIROMA1},
      title = {Practical Query Answering over HI(DL-LiteR) Knoledge Bases},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    M. Console, J. Mora, R. Rosati, V. Santarelli, and D. F. Savo, "Effective computation of maximal sound approximations of Description Logic ontologies," in The Semantic Web – ISWC 2014 – 13th International Semantic Web Conference, 2014, pp. 164-179.
    @inproceedings{console2014effective, abstract = {We study the problem of approximating Description Logic (DL) ontologies specified in a source language L S in terms of a less expressive target language L T . This problem is getting very relevant in practice: e.g., approximation is often needed in ontology-based data access systems, which are able to deal with ontology languages of a limited expressiveness. We first provide a general, parametric, and semantically well-founded definition of maximal sound approximation of a DL ontology. Then, we present an algorithm that is able to effectively compute two different notions of maximal sound approximation according to the above parametric semantics when the source ontology language is OWL 2 and the target ontology language is OWL 2 QL. Finally, we experiment the above algorithm by computing the two OWL 2 QL approximations of a large set of existing OWL 2 ontologies. The experimental results allow us both to evaluate the effectiveness of the proposed notions of approximation and to compare the two different notions of approximation in real cases.},
      audience = {academic},
      author = {Console, Marco and Mora, Jose and Rosati, Ricardo and Santarelli, Valerio and Savo, Domenico Fabio},
      booktitle = {The Semantic Web - ISWC 2014 - 13th International Semantic Web Conference},
      doi = {DOI: 10.1007/978-3-319-11915-1_11},
      interhash = {f19b59af74e272f11a55fd3feb32cd36},
      intrahash = {e500b3d0c67d616dba79fabe6d61bb55},
      openaccess = {No},
      pages = {164-179},
      partneroptique = {UNIROMA1},
      title = {Effective computation of maximal sound approximations of Description Logic ontologies},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    D. Lembo, J. Mora, R. Rosati, D. F. Savo, and E. Thorstensen, "Towards Mapping Analysis in Ontology-Based Data Access," in Web Reasoning and Rule Systems – 8th International Conference, RR, 2014, pp. 108-123.
    @inproceedings{lembotowards, abstract = {In this paper we study mapping analysis in ontology-based data access (OBDA), providing an initial set of foundational results for this problem. We start by defining general, language-independent notions of mapping inconsistency, mapping subsumption, and mapping redundancy in OBDA. Then, we focus on specific mapping languages for OBDA and illustrate techniques for verifying the above properties of mappings.},
      audience = {academic},
      author = {Lembo, Domenico and Mora, Jose and Rosati, Riccardo and Savo, Domenico Fabio and Thorstensen, Evgenij},
      booktitle = {Web Reasoning and Rule Systems - 8th International Conference, RR},
      doi = {10.1007/978-3-319-11113-1_8},
      interhash = {7072edd75ff644ece075cb3ba3638d43},
      intrahash = {02135d43e82f86dbb6046224b224ce1b},
      openaccess = {No},
      pages = {108-123},
      partneroptique = {UNIROMA1},
      title = {Towards Mapping Analysis in Ontology-Based Data Access},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    D. Lembo, R. Rosati, M. Ruzzi, D. F. Savo, and E. Tocci, "Visualization and Management of Mappings in Ontology-based Data Access (Progress Report).," in Informal Proceedings of the 27th International Workshop on Description Logics, 2014, pp. 595-607.
    @inproceedings{lembo2014visualization, abstract = {In this paper we present an in progress prototype for the graphical visualization and management of mappings for Ontology-based data access (OBDA). The tool supports the specification of expressive mappings linking a DL-Lite ontology to a relational source database, and allows the designer to graphically navigate them, according to various possible views, modify their textual representation, and validate their syntactic correctness. Furthermore, it gives preliminary support to the semantic analysis of the mappings, which aims to identify anomalies in the representation, like the specification of mapping queries that cannot return answers without contradicting the ontology. Such functionalities are currently being enhanced in our ongoing development of the tool.},
      audience = {academic},
      author = {Lembo, Domenico and Rosati, Riccardo and Ruzzi, Marco and Savo, Domenico Fabio and Tocci, Emanuele},
      booktitle = {Informal Proceedings of the 27th International Workshop on Description Logics},
      interhash = {d96854eff8ef7496bbf25a51422868b4},
      intrahash = {cfb11eb5937ce2c608b81f98bbc0f9cb},
      openaccess = {Yes},
      pages = {595-607},
      partneroptique = {UNIROMA1},
      title = {Visualization and Management of Mappings in Ontology-based Data Access (Progress Report).},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    J. Mora, R. Rosati, and &. Corcho, "Kyrie2: Query Rewriting under Extensional Constraints in ELHIO," in The Semantic Web – ISWC 2014 – 13th International Semantic Web Conference, 2014, pp. 568-583.
    @inproceedings{optiqueprojectobda2014kyrie2, abstract = {In this paper we study query answering and rewriting in ontology-based data access. Specifically, we present an algorithm for computing a perfect rewriting of unions of conjunctive queries posed over ontologies expressed in the description logic ELHIO, which covers the OWL 2 QL and OWL 2 EL profiles. The novelty of our algorithm is the use of a set of ABox dependencies, which are compiled into a so-called EBox, to limit the expansion of the rewriting. So far, EBoxes have only been used in query rewriting in the case of DL-Lite, which is less expressive than ELHIO. We have extensively evaluated our new query rewriting technique, and in this paper we discuss the tradeoff between the reduction of the size of the rewriting and the computational cost of our approach.},
      audience = {academic},
      author = {Mora, José and Rosati, Riccardo and Corcho, Óscar},
      booktitle = {The Semantic Web - ISWC 2014 - 13th International Semantic Web Conference},
      doi = {10.1007/978-3-319-11964-9_36},
      interhash = {4f3497ad27ac3823087e29e635db16f0},
      intrahash = {be9b07a434ee8495f68faee53d07aa6a},
      openaccess = {No},
      pages = {568-583},
      partneroptique = {UNIROMA1},
      title = {kyrie2: Query Rewriting under Extensional Constraints in ELHIO},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    X. Chen, W. Xia, E. Jimenez-Ruiz, and V. Cross, "Extending an ontology alignment system with BioPortal: a preliminary analysis," in Poster paper at International Semantic Web Conference (ISWC), 2014.
    @inproceedings{noauthororeditor2014extending, abstract = {This paper examines two practical uses of BIOPORTAL as a generalized yet also specialized background knowledge source for the biomedical domain. We provide a preliminary investigation of the results of these two uses of BIOPORTAL in the OAEI's anatomy track using the LogMap system.},
      audience = {academic},
      author = {Chen, Xi and Xia, Weiguo and Jimenez-Ruiz, Ernesto and Cross, Valerie},
      booktitle = {Poster paper at International Semantic Web Conference (ISWC)},
      interhash = {d131d09a089607da073362f79f011bce},
      intrahash = {93ebdd7484fdd3342cdc93918c450185},
      partneroptique = {UOXF},
      title = {Extending an ontology alignment system with BioPortal: a preliminary analysis},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex Go to document
    A. Solimando, E. Jimenez-Ruiz, and C. Pinkel, "Evaluating Ontology Alignment Systems in Query Answering Tasks," in Poster paper at International Semantic Web Conference (ISWC), 2014.
    @inproceedings{alessandrosolimandoernestojimenezruiz2014evaluating, abstract = {Ontology matching receives increasing attention and gained importance in more recent applications such as ontology-based data access (OBDA). However, query answering over aligned ontologies has not been addressed by any evaluation initiative so far. A novel Ontology Alignment Evaluation Initiative (OAEI) track, Ontology Alignment for Query Answering (OA4QA), introduced in the 2014 evaluation campaign, aims at bridging this gap in the practical evaluation of matching systems w.r.t. this key usage.},
      audience = {academic},
      author = {Solimando, Alessandro and Jimenez-Ruiz, Ernesto and Pinkel, Christoph},
      booktitle = {Poster paper at International Semantic Web Conference (ISWC)},
      interhash = {59ae99808bbbfb8a51e3551f4d793299},
      intrahash = {a430907ae3ea1276248a78450a45362d},
      partneroptique = {UOXF},
      title = {Evaluating Ontology Alignment Systems in Query Answering Tasks},
      url = {/brokenurl#Poster paper at International Semantic Web Conference (ISWC)},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex Go to document
    A. Solimando, E. Jiménez-Ruiz, and G. Guerrini, "A Multi-strategy Approach for Detecting and Correcting Conservativity Principle Violations in Ontology Alignments," in Proceedings of the 11th International Workshop on OWL: Experiences and Directions (OWLED 2014), 2014, pp. 13-24.
    @inproceedings{alessandrosolimandoernestojimenezruiz2014multistrategy, abstract = {In order to enable interoperability between ontology-based systems, ontology matching techniques have been proposed. However, when the generated mappings suffer from logical flaws, their usefulness may be diminished. In this paper we present a multi-strategy approach to detect and correct violations of the so-called conservativity principle where novel subsumption entailments between named concepts in one of the input ontologies are considered as unwanted. The practical applicability of the proposed approach is experimentally demonstrated on the datasets from the Ontology Alignment Evaluation Initiative (OAEI).},
      audience = {academic},
      author = {Solimando, Alessandro and Jiménez-Ruiz, Ernesto and Guerrini, Giovanna},
      booktitle = {Proceedings of the 11th International Workshop on OWL: Experiences and Directions (OWLED 2014)},
      interhash = {92dbd1c6d0ed46669251b724992f4298},
      intrahash = {ffbe6634725600cf49629f956fc3de03},
      pages = {13-24},
      partneroptique = {UOXF},
      title = {A Multi-strategy Approach for Detecting and Correcting Conservativity Principle Violations in Ontology Alignments },
      url = {http://ceur-ws.org/Vol-1265/owled2014_submission_2.pdf},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    T. Eiter, P. Schneider, M. vSimkus, and G. Xiao, "Using OpenStreetMap Data to Create Benchmarks for Description Logic Reasoners," in Proc.\ of the 3rd Int.\ Workshop on OWL Reasoner Evaluation (ORE~2014), 2014.
    @inproceedings{ESSX-ore2014, audience = {academic},
      author = {Eiter, Thomas and Schneider, Patrik and \v{S}imkus, Mantas and Xiao, Guohui},
      booktitle = {Proc.\ of the 3rd Int.\ Workshop on OWL Reasoner Evaluation (ORE~2014)},
      interhash = {dcf83235cb614b1debf800317bd04eee},
      intrahash = {a0586fd3adedc2d0117a8d0e32ca8af7},
      openaccess = {Yes},
      partneroptique = {FUB},
      series = {CEUR Workshop Proceedings},
      title = {Using {OpenStreetMap} Data to Create Benchmarks for Description Logic Reasoners},
      wpoptique = {WP6},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    D. Lanti, M. Rezk, M. Slusnys, G. Xiao, and D. Calvanese, "The NPD Benchmark for OBDA Systems," in Proc. 10th International Workshop on Scalable Semantic Web Knowledge Base Systems (SSWS 2014), 2014.
    @inproceedings{ssws2014-npd, audience = {academic},
      author = {Lanti, Davide and Rezk, Martin and Slusnys, Mindaugas and Xiao, Guohui and Calvanese, Diego},
      booktitle = {Proc. 10th International Workshop on Scalable Semantic Web Knowledge Base Systems (SSWS 2014)},
      interhash = {72b33e53a8a6bdccf1487fa30cc78fe5},
      intrahash = {2353881d48723adbbd49983e501beafb},
      openaccess = {Yes},
      partneroptique = {FUB},
      publisher = {CEUR-WS.org},
      title = {The {NPD} Benchmark for {OBDA} Systems},
      wpoptique = {WP6},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    G. Xiao, M. Rezk, M. Rodriguez-Muro, and D. Calvanese, "Rules and Ontology Based Data Access," in Proc.\ 8th International Conference on Web Reasoning and Rule Systems (RR~2014), 2014.
    @inproceedings{XRRC-rr14, audience = {academic},
      author = {Xiao, Guohui and Rezk, Martin and Rodriguez-Muro, Mariano and Calvanese, Diego},
      booktitle = {Proc.\ 8th International Conference on Web Reasoning and Rule Systems (RR~2014)},
      doi = {10.1007/978-3-319-11113-1_11},
      editor = {Mugnier, Marie-Laure and Kontchakov, Roman},
      interhash = {3ef64f77be93e0508f086c1bff894b23},
      intrahash = {380db67d7b1d3a153bc96a14875ed6f4},
      openaccess = {No},
      partneroptique = {FUB},
      publisher = {Springer},
      series = {Lecture Notes in Computer Science},
      title = {Rules and Ontology Based Data Access},
      wpoptique = {WP6},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    D. Calvanese, D. Lanti, M. Rezk, M. Slusnys, and G. Xiao, "A Scalable Benchmark for OBDA Systems: Preliminary Report," in Proc.\ of the 3rd Int.\ Workshop on OWL Reasoner Evaluation (ORE~2014), 2014.
    @inproceedings{CLRSX-ore14, audience = {academic},
      author = {Calvanese, Diego and Lanti, Davide and Rezk, Martin and Slusnys, Mindaugas and Xiao, Guohui},
      booktitle = {Proc.\ of the 3rd Int.\ Workshop on OWL Reasoner Evaluation (ORE~2014)},
      interhash = {b843b412574402a574b224577d588b69},
      intrahash = {646fc3cfddb781702ccc50e4d66de3a6},
      openaccess = {Yes},
      partneroptique = {FUB},
      series = {CEUR Workshop Proceedings},
      title = {A Scalable Benchmark for {OBDA} Systems: Preliminary Report},
      wpoptique = {WP6},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    R. Kontchakov, M. Rezk, M. Rodriguez-Muro, G. Xiao, and M. Zakharyaschev, "Answering SPARQL Queries over Databases under OWL 2 QL Entailment Regime," in Proc. of International Semantic Web Conference (ISWC~2014), 2014.
    @inproceedings{KRRXZ-iswc14, audience = {academic},
      author = {Kontchakov, Roman and Rezk, Martin and Rodriguez-Muro, Mariano and Xiao, Guohui and Zakharyaschev, Michael},
      booktitle = {Proc. of International Semantic Web Conference (ISWC~2014)},
      doi = {10.1007/978-3-319-11964-9_35},
      interhash = {0f58a142b470cb86d9ceff3ddb803fca},
      intrahash = {ddf0196729f5d41d796c7335db868150},
      openaccess = {No},
      partneroptique = {FUB},
      publisher = {Springer},
      series = {Lecture Notes in Computer Science},
      title = {Answering {SPARQL} Queries over Databases under {OWL 2 QL} Entailment Regime},
      wpoptique = {WP6},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex Go to document
    A. Solimando, E. Jiménez-Ruiz, and G. Guerrini, "Detecting and Correcting Conservativity Principle Violations in Ontology-to-Ontology Mappings," in The Semantic Web – ISWC 2014 – 13th International Semantic Web Conference, Riva del Garda, Italy, October 19-23, 2014. Proceedings, Part II, 2014, pp. 1-16.
    @inproceedings{DBLP:conf/semweb/SolimandoJG14, abstract = {In order to enable interoperability between ontology-based systems, ontology matching techniques have been proposed. However, when the generated mappings suffer from logical flaws, their usefulness may be diminished. In this paper we present an approximate method to detect and correct violations to the so-called conservativity principle where novel subsumption entailments between named concepts in one of the input ontologies are considered as unwanted. We show that this is indeed the case in our application domain based on the EU Optique project. Additionally, our extensive evaluation conducted with both the Optique use case and the data sets from the Ontology Alignment Evaluation Initiative (OAEI) suggests that our method is both useful and feasible in practice.},
      audience = {academic},
      author = {Solimando, Alessandro and Jim{\'{e}}nez{-}Ruiz, Ernesto and Guerrini, Giovanna},
      bibsource = {dblp computer science bibliography, http://dblp.org},
      booktitle = {The Semantic Web - {ISWC} 2014 - 13th International Semantic Web Conference, Riva del Garda, Italy, October 19-23, 2014. Proceedings, Part {II}},
      doi = {10.1007/978-3-319-11915-1_1},
      interhash = {0d284f8faa40c4157df1853da039c8eb},
      intrahash = {3ba99f9ac3969e90d0574540d8996135},
      pages = {1--16},
      partneroptique = {UOXF},
      title = {Detecting and Correcting Conservativity Principle Violations in Ontology-to-Ontology Mappings},
      url = {http://dx.doi.org/10.1007/978-3-319-11915-1_1},
      wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex Go to document
    D. Faria, E. Jiménez-Ruiz, C. Pesquita, E. Santos, and F. M. Couto, "Towards Annotating Potential Incoherences in BioPortal Mappings," in The Semantic Web – ISWC 2014 – 13th International Semantic Web Conference, Riva del Garda, Italy, October 19-23, 2014. Proceedings, Part II, 2014, pp. 17-32.
    @inproceedings{DBLP:conf/semweb/FariaJPSC14, abstract = {BioPortal is a repository for biomedical ontologies that also includes mappings between them from various sources. Considered as a whole, these mappings may cause logical errors, due to incompatibilities between the ontologies or even erroneous mappings. We have performed an automatic evaluation of BioPortal mappings between 19 ontology pairs using the mapping repair systems of LogMap and AgreementMakerLight. We found logical errors in 11 of these pairs, which on average involved 22% of the mappings between each pair. Furthermore, we conducted a manual evaluation of the repair results to identify the actual sources of error, verifying that erroneous mappings were behind over 60% of the repairs. Given the results of our analysis, we believe that annotating BioPortal mappings with information about their logical conflicts with other mappings would improve their usability for semantic web applications and facilitate the identification of erroneous mappings. In future work, we aim to collaborate with BioPortal developers in extending BioPortal with these annotations.},
      audience = {academic},
      author = {Faria, Daniel and Jim{\'{e}}nez{-}Ruiz, Ernesto and Pesquita, Catia and Santos, Emanuel and Couto, Francisco M.},
      bibsource = {dblp computer science bibliography, http://dblp.org},
      booktitle = {The Semantic Web - {ISWC} 2014 - 13th International Semantic Web Conference, Riva del Garda, Italy, October 19-23, 2014. Proceedings, Part {II}},
      doi = {10.1007/978-3-319-11915-1_2},
      interhash = {27604055722c81b88799a1078b05124b},
      intrahash = {fca9ebe536ac3feb56ed75d6cbc12578},
      pages = {17--32},
      partneroptique = {UOXF},
      publisher = {Springer},
      series = {Lecture Notes in Computer Science},
      title = {Towards Annotating Potential Incoherences in BioPortal Mappings},
      url = {http://dx.doi.org/10.1007/978-3-319-11915-1_2},
      volume = 8797, wpoptique = {WP4},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    &. L. Özcep and R. Möller, "Ontology Based Data Access on Temporal and Streaming Data," in Reasoning Web. Reasoning and the Web in the Big Data Era, 2014.
    @inproceedings{oezcep14RW2014, abstract = {Though processing time-dependent data has been investigated for a long time,  the research on temporal and especially stream reasoning over linked open data and ontologies is reaching its high point these days.  In this tutorial, we give an overview of state-of-the art query languages and engines for temporal and stream reasoning. On a more detailed level, we discuss  the new language STARQL (Reasoning-based Query Language for Streaming and Temporal ontology Access). STARQL is designed as an expressive and flexible stream query framework that offers the possibility to embed different (temporal) description logics as filter query languages over ontologies, and hence it can be used  within the  OBDA paradigm (Ontology Based Data Access in the classical sense) and within the ABDEO paradigm (Accessing Big Data over Expressive Ontologies).},
      audience = {academic},
      author = {Özcep, Özgür L. and Möller, Ralf},
      booktitle = {Reasoning Web. Reasoning and the Web in the Big Data Era},
      doi = {10.1007/978-3-319-10587-1_7},
      editor = {Koubarakis, M. and Stamou, G. and Stoilos, G. and Horrocks, I. and Kolaitis, P. and Lausen, G. and Weikum, G.},
      interhash = {c68aca64d2cdfc211a60cd82f66f5134},
      intrahash = {e8d4e20b22624e9e55eef5fd6ec3bd11},
      openaccess = {No},
      partneroptique = {TUHH},
      series = {Lecture Notes in Computer Science},
      title = {Ontology Based Data Access on Temporal and Streaming Data},
      volume = 8714, wpoptique = {WP5},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    Özgür L. Özçep, R. Möller, and C. Neuenstadt, "A Stream-Temporal Query Language for Ontology Based Data Access," in Proceedings of the 7th International Workshop on Description Logics (DL-2014), 2014.
    @inproceedings{oezcep14streamDL, abstract = {The paper contributes to the recent efforts on temporalizing and streamifiying ontology based data access (OBDA) by discussing aspects of rewritability, i.e., compilability of the TBox into ontology-level queries, and unfoldability, i.e., transformability of ontology-level queries to queries on datasource level, for the new query-language framework STARQL. The distinguishing feature of STARQL is its general stream windowing and ABox sequencing strategy which allows it to plugin well-known query languages such as unions of conjunctive queries (UCQs) in combination with TBox languages such as DL-Lite and do temporal reasoning with a sorted first-order logic on top of them. The paper discusses safety aspects under which STARQL queries that embed UCQs over DL-Lite ontologies can be rewritten and unfolded to back-end relational stream query languages such as CQL. With these results, the adoption of description logic technology in industrially relevant application areas such as industrial monitoring is crucially fostered.},
      audience = {academic},
      author = {{\"Ozg\"ur L. \"Oz\c{c}ep} and {M\"oller},
      Ralf and Neuenstadt, Christian},
      booktitle = {Proceedings of the 7th International Workshop on Description Logics (DL-2014)},
      editor = {Bienvenu, Meghyn and Ortiz, Magdalena and Rosati, Riccardo and Simkus, Mantas},
      interhash = {d469f349277c8aca1f1f0c5c25de1bf6},
      intrahash = {b7ba9ab3c576994db8ba4fc2251cb447},
      partneroptique = {TUHH},
      title = {A Stream-Temporal Query Language for Ontology Based Data Access},
      wpoptique = {WP5},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    &. L. Özcep, R. Möller, and C. Neuenstadt, "A Stream-Temporal Query Language for Ontology Based Data Access," in KI 2014, 2014, pp. 183-194.
    @inproceedings{oezcep14streamKI, abstract = {The paper contributes to the recent efforts on temporalizing and streamifiying ontology based data access (OBDA) by discussing aspects of rewritability, i.e., compilability of the TBox into ontology-level queries, and unfoldability, i.e., transformability of ontology-level queries to queries on datasource level, for the new query-language framework STARQL. The distinguishing feature of STARQL is its general stream windowing and ABox sequencing strategy which allows it to plugin well-known query languages such as unions of conjunctive queries (UCQs) in combination with TBox languages such as DL-Lite and do temporal reasoning with a sorted first-order logic on top of them. The paper discusses safety aspects under which STARQL queries that embed UCQs over DL-Lite ontologies can be rewritten and unfolded to back-end relational stream query languages such as CQL. With these results, the adoption of description logic technology in industrially relevant application areas such as industrial monitoring is crucially fostered.},
      audience = {academic},
      author = {Özcep, Özgür L. and Möller, Ralf and Neuenstadt, Christian},
      booktitle = {KI 2014},
      doi = {10.1007/978-3-319-11206-0_18},
      editor = {Lutz, Carsten and Thielscher, Michael},
      interhash = {bc3eae62d370be557050a5208d0d9f93},
      intrahash = {a9bf100030d75eed83e67b4f2ae5d875},
      openaccess = {No},
      pages = {183--194},
      partneroptique = {TUHH},
      publisher = {Springer International Publishing Switzerland},
      series = {LNCS},
      title = {A Stream-Temporal Query Language for Ontology Based Data Access},
      volume = 8736, wpoptique = {WP5},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    S. Heggestøyl, G. Vega-Gorgojo, and M. Giese, "Visual Query Formulation for Linked Open Data: The Norwegian Entity Registry Case." 2014.
    @inproceedings{heggestoyl2014visual, abstract = {The cloud of Linked Open Data is steadily growing, yet it remains largely inaccessible to the general public, due to the technical barrier posed by the requirement to know a formal query language such as SPARQL. In this article, we present a new approach for visual query formulation toward arbitrary SPARQL endpoints, and we show a working prototype developed to improve the accessibility to Linked Open Data sources for non-computer experts. We show how the prototype can be employed to simplify access to governmental Linked Open Data with a case study from the Norwegian Entity Registry.},
      audience = {academic},
      author = {Heggestøyl, Simen and Vega-Gorgojo, Guillermo and Giese, Martin},
      editor = {Nätt, Tom Heine},
      interhash = {daf6a4b8c0a462b4e5163b922dc1a912},
      intrahash = {1d731974e8387dfb6a935fb8b6269a95},
      openaccess = {Yes},
      partneroptique = {UIO},
      title = {Visual Query Formulation for Linked Open Data: The Norwegian Entity Registry Case},
      wpoptique = {WP3},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    M. Arenas, B. C. Grau, E. Kharlamov, S. Marciuska, and D. Zheleznyakov, "Enabling Faceted Search over OWL 2 with SemFacet," in 11th OWL: Experiences and Directions Workshop, 2014.
    @inproceedings{ArenasGKMZ14OWLED, audience = {academic},
      author = {Arenas, Marcelo and Grau, Bernardo Cuenca and Kharlamov, Evgeny and Marciuska, Sarunas and Zheleznyakov, Dmitriy},
      booktitle = {11th OWL: Experiences and Directions Workshop},
      interhash = {f258083192564f9b29c32f8af70a1d33},
      intrahash = {6bf8a826f92b1f0c9691172750c6c22b},
      partneroptique = {UOXF},
      title = {Enabling Faceted Search over OWL 2 with SemFacet},
      wpoptique = {WP3},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    E. Kharlamov, N. Solomakhina, O. Oezcep, D. Zheleznyakov, T. Hubauer, S. Lamparter, M. Roshchin, and A. Soylu, "How Semantic Technologies can Enhance Data Access at Siemens Energy," in Proc.\ International Semantic Web Conference, 2014.
    @inproceedings{iswc2014Optique, audience = {academic},
      author = {Kharlamov, Evgeny and Solomakhina, Nina and Oezcep, Oezgur and Zheleznyakov, Dmitriy and Hubauer, Thomas and Lamparter, Steffen and Roshchin, Mikhail and Soylu, Ahmet},
      booktitle = {Proc.\ International Semantic Web Conference},
      interhash = {3b708e3889098b0c4369ab9300d83acd},
      intrahash = {96864961ad559efa48aa6d7ecedafc7a},
      partneroptique = {UOXF},
      title = {How Semantic Technologies can Enhance Data Access at Siemens Energy},
      wpoptique = {WP8},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    M. Arenas, B. C. Grau, E. Kharlamov, V. M. s, and D. Zheleznyakov, "Faceted Search over Ontology-Enhanced RDF Data," in Proc.\ ACM International Conference on Information and Knowledge Management (CIKM), 2014.
    @inproceedings{cikm2014-Zheleznyakov, audience = {academic},
      author = {Arenas, Marcelo and Grau, Bernardo Cuenca and Kharlamov, Evgeny and \v{S}ar\={u}nas Marciu\v{s}ka and Zheleznyakov, Dmitriy},
      booktitle = {Proc.\ ACM International Conference on Information and Knowledge Management (CIKM)},
      interhash = {a0fa80af08e8c4eb9c3f218fed270621},
      intrahash = {5d0f439a8ea4b22d4fd1bc2b0fee81c5},
      note = {Acceptance rate: 21%},
      partneroptique = {UOXF},
      title = {Faceted Search over Ontology-Enhanced RDF Data},
      wpoptique = {WP3},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex Go to document
    B. C. Grau, E. Kharlamov, D. Zheleznyakov, M. Arenas, and S. Marciuska, "On Faceted Search over Knowledge Bases," in Informal Proceedings of the 27th International Workshop on Description Logics, Vienna, Austria, July 17-20, 2014., 2014, pp. 153-156.
    @inproceedings{DBLP:conf/dlog/GrauKZAM14, audience = {academic},
      author = {Grau, Bernardo Cuenca and Kharlamov, Evgeny and Zheleznyakov, Dmitriy and Arenas, Marcelo and Marciuska, Sarunas},
      booktitle = {Informal Proceedings of the 27th International Workshop on Description Logics, Vienna, Austria, July 17-20, 2014.},
      interhash = {947c4c396f49f6f297b69b5ec2da263e},
      intrahash = {445599f2fbd396df232233a8413cd569},
      pages = {153--156},
      partneroptique = {UOXF},
      title = {On Faceted Search over Knowledge Bases},
      url = {http://ceur-ws.org/Vol-1193/paper_89.pdf},
      wpoptique = {WP3},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex Go to document
    M. Arenas, B. C. Grau, E. Kharlamov, S. Marciuska, D. Zheleznyakov, and E. Jiménez-Ruiz, "SemFacet: semantic faceted search over yago," in 23rd International World Wide Web Conference, WWW ’14, Seoul, Republic of Korea, April 7-11, 2014, Companion Volume, 2014, pp. 123-126.
    @inproceedings{DBLP:conf/www/ArenasGKMZJ14, audience = {academic},
      author = {Arenas, Marcelo and Grau, Bernardo Cuenca and Kharlamov, Evgeny and Marciuska, Sarunas and Zheleznyakov, Dmitriy and Jim{\'{e}}nez{-}Ruiz, Ernesto},
      booktitle = {23rd International World Wide Web Conference, {WWW} '14, Seoul, Republic of Korea, April 7-11, 2014, Companion Volume},
      doi = {10.1145/2567948.2577011},
      interhash = {9d371ff8f760544dd0ef4c4ddea132e1},
      intrahash = {259da50f8ed1ce0151784cba5420afaa},
      pages = {123--126},
      partneroptique = {UOXF},
      title = {SemFacet: semantic faceted search over yago},
      url = {http://doi.acm.org/10.1145/2567948.2577011},
      wpoptique = {WP3},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex Go to document
    M. Arenas, B. C. Grau, E. Kharlamov, S. Marciuska, and D. Zheleznyakov, "Towards Semantic Faceted Search," in 23rd International World Wide Web Conference, WWW ’14, Seoul, Republic of Korea, April 7-11, 2014, Companion Volume, 2014, pp. 219-220.
    @inproceedings{DBLP:conf/www/ArenasGKMZ14, audience = {academic},
      author = {Arenas, Marcelo and Grau, Bernardo Cuenca and Kharlamov, Evgeny and Marciuska, Sarunas and Zheleznyakov, Dmitriy},
      booktitle = {23rd International World Wide Web Conference, {WWW} '14, Seoul, Republic of Korea, April 7-11, 2014, Companion Volume},
      doi = {10.1145/2567948.2577381},
      interhash = {c6fea3b8450ee1e427d855f6df684400},
      intrahash = {9cb04f73a0d3826aabcd4c0266f5e3ea},
      pages = {219--220},
      partneroptique = {UOXF},
      title = {Towards Semantic Faceted Search},
      url = {http://doi.acm.org/10.1145/2567948.2577381},
      wpoptique = {WP3},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    A. Soylu, E. Kharlamov, D. Zheleznyakov, E. Jimenez-Ruiz, M. Giese, and I. Horrocks, "OptiqueVQS: Visual Query Formulation for OBDA," in Proceedings of the 27th International Workshop on Description Logics (DL 2014), 2014, pp. 725-728.
    @inproceedings{soylu2014optiquevqs, audience = {academic},
      author = {Soylu, Ahmet and Kharlamov, Evgeny and Zheleznyakov, Dmitriy and Jimenez-Ruiz, Ernesto and Giese, Martin and Horrocks, Ian},
      booktitle = {Proceedings of the 27th International Workshop on Description Logics (DL 2014)},
      interhash = {e9bb047873f8db23d1b72e30dd30d4e1},
      intrahash = {6425cff2b24e8ef3b49b3d0909cc961e},
      openaccess = {Yes},
      pages = {725-728},
      partneroptique = {UiO},
      publisher = {CEUR-WS.org},
      title = {OptiqueVQS: Visual Query Formulation for OBDA},
      volume = 1193, wpoptique = {WP3},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    A. Soylu, M. Giese, E. Jimenez-Ruiz, E. Kharlamov, D. Zheleznyakov, and I. Horrocks, "Why not simply Google?," in Proceedings of the 8th Nordic Conference on Human-Computer Interaction (NordiCHI 2014), 2014, pp. 1039-1042.
    @inproceedings{soylu2014simply, abstract = {We demonstrate an ontology-based visual query system, namely OptiqueVQS, for end users without any technical background to formulate rather complex information needs into formal queries over databases. It is built on multiple and coordinated representation and interaction paradigms and a flexible widget-based architecture.},
      audience = {academic},
      author = {Soylu, Ahmet and Giese, Martin and Jimenez-Ruiz, Ernesto and Kharlamov, Evgeny and Zheleznyakov, Dmitriy and Horrocks, Ian},
      booktitle = {Proceedings of the 8th Nordic Conference on Human-Computer Interaction (NordiCHI 2014)},
      doi = {10.1145/2639189.2670270},
      interhash = {3a58036ac994468dccaa2f747156592c},
      intrahash = {25953e68cfdeae009a97c6e99c598f04},
      openaccess = {Yes},
      pages = {1039-1042 },
      partneroptique = {UiO},
      publisher = {ACM},
      title = {Why not simply Google?},
      wpoptique = {WP3},
      year = 2014, yearoptique = {Y2}
    }
  • [2014,inproceedings] bibtex
    A. Soylu, M. Giese, E. Jimenez-Ruiz, E. Kharlamov, D. Zheleznyakov, and I. Horrocks, "Towards Exploiting Query History for Adaptive Ontology-based Visual Query Formulation," in Proceedings of 8th Metadata and Semantics Research Conference (MTSR 2014), 2014.
    @inproceedings{soylu2014towards, abstract = {Grounded on real industrial use cases, we recently proposed an ontology-based visual query system for SPARQL, named OptiqueVQS. Ontology-based visual query systems employ ontologies and visual representations to depict the domain of interest and queries, and are promising to enable end users without any technical background to access data on their own. However, even with considerably small ontologies, the number of ontology elements to choose from increases drastically, and hence hinders usability. Therefore, in this paper, we propose a method using the log of past queries for ranking and suggesting query extensions as a user types a query, and identify emerging issues to be addressed.},
      audience = {academic},
      author = {Soylu, Ahmet and Giese, Martin and Jimenez-Ruiz, Ernesto and Kharlamov, Evgeny and Zheleznyakov, Dmitriy and Horrocks, Ian},
      booktitle = {Proceedings of 8th Metadata and Semantics Research Conference (MTSR 2014)},
      doi = {10.1007/978-3-319-13674-5_11},
      editor = {Closs, Sissi and Studer, Rudi and Garoufallou, Emmanouel and Sicilia, Miguel-Angel},
      interhash = {79b6c221f42a48f266cf59970f92ca41},
      intrahash = {67645f0bc6080df0346bcac9fc75316c},
      number = {107-119},
      openaccess = {No},
      partneroptique = {UiO},
      publisher = {Springer},
      title = {Towards Exploiting Query History for Adaptive Ontology-based Visual Query Formulation},
      wpoptique = {WP3},
      year = 2014, yearoptique = {Y2}
    }
  • [2013,inproceedings] bibtex Go to document
    N. Antonioli, F. Castanò, C. Civili, S. Coletta, S. Grossi, D. Lembo, M. Lenzerini, A. Poggi, D. F. Savo, and E. Virardi, "Ontology-Based Data Access: The Experience at the Italian Department of Treasury.," in CAiSE Industrial Track, 2013, pp. 9-16.
    @inproceedings{conf/caise/AntonioliCCCGLLPSV13, abstract = {Ontology-based data access (OBDA) is a new paradigm for managing complex information systems through semantic technologies. In this paper we present what we believe is the first industrial experience of a comprehensive OBDA project, developed jointly by Sapienza University of Rome and the Department of Treasury of the Italian Ministry of Econonomy and Finance. After illustrating the state of the art of ODBA research at the beginning of the project, we describe the various steps we have carried out in order to apply the research results in a real-world settings, and the new techniques and tools we have devised to make the overall approach effective.},
      audience = {academic},
      author = {Antonioli, Natalia and Castanò, Francesco and Civili, Cristina and Coletta, Spartaco and Grossi, Stefano and Lembo, Domenico and Lenzerini, Maurizio and Poggi, Antonella and Savo, Domenico Fabio and Virardi, Emanuela},
      booktitle = {CAiSE Industrial Track},
      editor = {Pelechano, Vicente and Regev, Gil and Pigneur, Yves},
      ee = {http://ceur-ws.org/Vol-1017/Paper2CAiSE_IT2013.pdf},
      interhash = {bff474124b411cb2142417f58902358b},
      intrahash = {81d06a2bc21d987c427b06d7388313dd},
      openaccess = {Yes},
      pages = {9-16},
      partneroptique = {UNIROMA1},
      publisher = {CEUR-WS.org},
      series = {CEUR Workshop Proceedings},
      title = {Ontology-Based Data Access: The Experience at the Italian Department of Treasury.},
      url = {http://dblp.uni-trier.de/db/conf/caise/caiseit2013.html#AntonioliCCCGLLPSV13},
      volume = 1017, wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    M. Console, V. Santarelli, and D. F. Savo, "From OWL to DL- Lite through Efficient Ontology Approximation," in Web Reasoning and Rule Systems, 2013, pp. 229-234.
    @inproceedings{console2013owl, audience = {academic},
      author = {Console, Marco and Santarelli, Valerio and Savo, Domenico Fabio},
      booktitle = {Web Reasoning and Rule Systems},
      doi = {10.1007/978-3-642-39666-3_20},
      editor = {Faber, Wolfgang and Lembo, Domenico},
      interhash = {6c07ac3faf5f97001aefaba486af3df9},
      intrahash = {82fcb79be9c735234b9a736cd9930f5b},
      openaccess = {No},
      pages = {229--234},
      partneroptique = {UNIROMA1},
      publisher = {Springer Berlin Heidelberg},
      title = {From OWL to DL- Lite through Efficient Ontology Approximation},
      wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex Go to document
    D. Lembo, V. Santarelli, and D. F. Savo, "A Graph-Based Approach for Classifying OWL 2 QL Ontologies.," in Description Logics, 2013, pp. 747-759.
    @inproceedings{conf/dlog/LemboSS13, abstract = {Ontology classification is the reasoning service that computes all subsumption relationships inferred in an ontology between concept, role, and attribute names in the ontology signature. OWL 2 QL is a tractable profile of OWL 2 for which ontology classification is polynomial in the size of the ontology TBox. However, to date, no efficient methods and implementations specifically tailored to OWL 2 QL ontologies have been developed. In this paper, we provide a new algorithm for ontology classification in OWL 2 QL, which is based on the idea of encoding the ontology TBox into a directed graph and reducing core reasoning to computation of the transitive closure of the graph. We have implemented the algorithm in the QuOnto reasoner and extensively evaluated it over very large ontologies. Our experiments show that QuOnto outperforms various popular reasoners in classification of OWL 2 QL ontologies.},
      audience = {academic},
      author = {Lembo, Domenico and Santarelli, Valerio and Savo, Domenico Fabio},
      booktitle = {Description Logics},
      editor = {Eiter, Thomas and Glimm, Birte and Kazakov, Yevgeny and Krötzsch, Markus},
      ee = {http://ceur-ws.org/Vol-1014/paper_21.pdf},
      interhash = {b772c7c3f60d1c90c80b330996baaceb},
      intrahash = {4f9aaeca83bb1e33ed1b3727eaabd741},
      openaccess = {Yes},
      pages = {747-759},
      partneroptique = {UNIROMA1},
      publisher = {CEUR-WS.org},
      series = {CEUR Workshop Proceedings},
      title = {A Graph-Based Approach for Classifying OWL 2 QL Ontologies.},
      url = {http://dblp.uni-trier.de/db/conf/dlog/dlog2013.html#LemboSS13},
      volume = 1014, wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex Go to document
    M. Console, V. Santarelli, and D. F. Savo, "Efficient Approximation in DL-Lite of OWL 2 Ontologies.," in Description Logics, 2013, pp. 132-143.
    @inproceedings{conf/dlog/ConsoleSS13, abstract = {Ontologies, as a conceptualization of a domain of interest, can be used for different objectives, such as for providing a formal description of the domain of interest for documentation purposes, or for providing a mechanism for reasoning upon the domain. For instance, they are the core element of the OntologyBased Data Access paradigm, in which the ontology is utilized as a conceptual view, allowing user access to the underlying data sources. With the aim to use an ontology as a formal description of the domain of interest, the use of expressive languages proves to be useful. If instead the goal is to use the ontology for reasoning tasks which require low computational complexity, the high expressivity of the language used to model the ontology may be of hindrance. In this scenario, the approximation of ontologies expressed in very expressive languages through ontologies expressed in languages which keep the computational complexity of the reasoning tasks low is pivotal. In this work we present our notion of ontology approximation and present an algorithm for computing the approximation of OWL 2 ontologies by means of DL-Lite TBoxes. Moreover, we provide optimization techniques for this computation, and discuss the results of the implementation of these techniques.},
      audience = {academic},
      author = {Console, Marco and Santarelli, Valerio and Savo, Domenico Fabio},
      booktitle = {Description Logics},
      editor = {Eiter, Thomas and Glimm, Birte and Kazakov, Yevgeny and Krötzsch, Markus},
      ee = {http://ceur-ws.org/Vol-1014/paper_19.pdf},
      interhash = {ade3898bf8ab587a9f2b9d0f3f62c838},
      intrahash = {b5f40a176d472fbee075af88cc8d8462},
      openaccess = {Yes},
      pages = {132-143},
      partneroptique = {UNIROMA1},
      publisher = {CEUR-WS.org},
      series = {CEUR Workshop Proceedings},
      title = {Efficient Approximation in DL-Lite of OWL 2 Ontologies.},
      url = {http://dblp.uni-trier.de/db/conf/dlog/dlog2013.html#ConsoleSS13},
      volume = 1014, wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex Go to document
    D. Lembo, V. Santarelli, and D. F. Savo, "Graph-Based Ontology Classification in OWL 2 QL.," in ESWC, 2013, pp. 320-334.
    @inproceedings{conf/esws/LemboSS13, abstract = {Ontology classification is the reasoning service that computes all subsumption relationships inferred in an ontology between concept, role, and attribute names in the ontology signature. OWL 2 QL is a tractable profile of OWL 2 for which ontology classification is polynomial in the size of the ontology TBox. However, to date, no efficient methods and implementations specifically tailored to OWL 2 QL ontologies have been developed. In this paper, we provide a new algorithm for ontology classification in OWL 2 QL, which is based on the idea of encoding the ontology TBox into a directed graph and reducing core reasoning to computation of the transitive closure of the graph. We have implemented the algorithm in the QuOnto reasoner and extensively evaluated it over very large ontologies. Our experiments show that QuOnto outperforms various popular reasoners in classification of OWL 2 QL ontologies},
      audience = {academic},
      author = {Lembo, Domenico and Santarelli, Valerio and Savo, Domenico Fabio},
      booktitle = {ESWC},
      doi = {10.1007/978-3-642-38288-8_22},
      editor = {Cimiano, Philipp and Corcho, Óscar and Presutti, Valentina and Hollink, Laura and Rudolph, Sebastian},
      ee = {http://dx.doi.org/10.1007/978-3-642-38288-8_22},
      interhash = {a8d60f61e429cb131f3999b8b43a4d55},
      intrahash = {33668e58bcbae51a3cd60c91ca891971},
      isbn = {978-3-642-38288-8},
      openaccess = {No},
      pages = {320-334},
      partneroptique = {UNIROMA1},
      publisher = {Springer},
      series = {Lecture Notes in Computer Science},
      title = {Graph-Based Ontology Classification in OWL 2 QL.},
      url = {http://dblp.uni-trier.de/db/conf/esws/eswc2013.html#LemboSS13},
      volume = 7882, wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    F. Di Pinto, D. Lembo, M. Lenzerini, R. Mancini, A. Poggi, R. Rosati, M. Ruzzi, and D. F. Savo, "Optimizing query rewriting in ontology-based data access.," in EDBT, 2013, pp. 561-572.
    @inproceedings{dipinto2013edbt, abstract = {In ontology-based data access (OBDA), an ontology is connected to autonomous, and generally pre-existing, data repositories through mappings, so as to provide a high-level, conceptual view over such data. User queries are posed over the ontology, and answers are computed by reasoning both on the ontology and the mappings. Query answering in OBDA systems is typically performed through a query rewriting approach which is divided into two steps: (i) the query is rewritten with respect to the ontology (ontology rewriting of the query); (ii) the query thus obtained is then reformulated over the database schema using the mapping assertions (mapping rewriting of the query). In this paper we present a new approach to the optimization of query rewriting in OBDA. The key ideas of our approach are the usage of inclusion between mapping views and the usage of perfect mappings, which allow us to drastically lower the combinatorial explosion due to mapping rewriting. These ideas are formalized in PerfectMap, an algorithm for OBDA query rewriting. We have experimented PerfectMap in a real-world OBDA scenario: our experimental results clearly show that, in such a scenario, the optimizations of PerfectMap are crucial to effectively perform query answering.},
      audience = {academic},
      author = {Di Pinto, Floriana and Lembo, Domenico and Lenzerini, Maurizio and Mancini, Riccardo and Poggi, Antonella and Rosati, Riccardo and Ruzzi, Marco and Savo, Domenico Fabio},
      booktitle = {EDBT},
      doi = {10.1145/2452376.2452441},
      editor = {Guerrini, Giovanna and Paton, Norman W.},
      interhash = {bbf0edbb5552955fa19f44de9f567bbd},
      intrahash = {1e8e06a83286c67b6853e84db02800e2},
      openaccess = {Yes},
      pages = {561-572},
      partneroptique = {UNIROMA1},
      publisher = {ACM},
      title = {Optimizing query rewriting in ontology-based data access.},
      wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex Go to document
    G. D. Giacomo, Y. Lespérance, and F. Patrizi, "Bounded Epistemic Situation Calculus Theories.," in IJCAI, 2013.
    @inproceedings{conf/ijcai/GiacomoLP13, abstract = {We define the class of e-bounded theories in the epistemic situation calculus, where the number of fluent atoms that the agent thinks may be true is bounded by a constant. Such theories can still have an infinite domain and an infinite set of states. We show that for them verification of an expressive class of first-order mu-calculus temporal epistemic properties is decidable. We also show that if the agent’s knowledge in the initial situation is e-bounded and the objective part of an action theory maintains boundedness, then the entire epistemic theory is e-bounded.},
      audience = {academic},
      author = {Giacomo, Giuseppe De and Lespérance, Yves and Patrizi, Fabio},
      booktitle = {IJCAI},
      editor = {Rossi, Francesca},
      ee = {http://www.aaai.org/ocs/index.php/IJCAI/IJCAI13/paper/view/6649},
      interhash = {60a22b61f95b2e4445db2e5564138df9},
      intrahash = {2855536a14aac6d121ed9d17f4d2ed3b},
      isbn = {978-1-57735-633-2},
      openaccess = {Yes},
      partneroptique = {UNIROMA1},
      publisher = {IJCAI/AAAI},
      title = {Bounded Epistemic Situation Calculus Theories.},
      url = {http://dblp.uni-trier.de/db/conf/ijcai/ijcai2013.html#GiacomoLP13},
      wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,article] bibtex Go to document
    B. B. Hariri, D. Calvanese, M. Montali, G. D. Giacomo, R. D. Masellis, and P. Felli, "Description Logic Knowledge and Action Bases.," J. Artif. Intell. Res. (JAIR), vol. 46, pp. 651-686, 2013.
    @article{journals/jair/HaririCMGMF13, abstract = {Description logic Knowledge and Action Bases (KAB) are a mechanism for providing both a semantically rich representation of the information on the domain of interest in terms of a description logic knowledge base and actions to change such information over time, possibly introducing new objects. We resort to a variant of DL-Lite where the unique name assumption is not enforced and where equality between objects may be asserted and inferred. Actions are specified as sets of conditional effects, where conditions are based on epistemic queries over the knowledge base (TBox and ABox), and effects are expressed in terms of new ABoxes. In this setting, we address verification of temporal properties expressed in a variant of first-order mu-calculus with quantification across states. Notably, we show decidability of verification, under a suitable restriction inspired by the notion of weak acyclicity in data exchange.},
      audience = {academic},
      author = {Hariri, Babak Bagheri and Calvanese, Diego and Montali, Marco and Giacomo, Giuseppe De and Masellis, Riccardo De and Felli, Paolo},
      doi = {10.1613/jair.3826},
      ee = {http://dx.doi.org/10.1613/jair.3826},
      interhash = {67015d66daa39b321df3b04eb1ac59f3},
      intrahash = {d6d80ceb395412f1a6b9c8876ea45a05},
      journal = {J. Artif. Intell. Res. (JAIR)},
      openaccess = {Yes},
      pages = {651-686},
      partneroptique = {UNIROMA1, FUB},
      title = {Description Logic Knowledge and Action Bases.},
      url = {http://dblp.uni-trier.de/db/journals/jair/jair46.html#HaririCMGMF13},
      volume = 46, wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    D. Calvanese, G. De Giacomo, M. Montali, and F. Patrizi, "Verification and Synthesis in Description Logic Based Dynamic Systems," in RR, 2013, pp. 50-64.
    @inproceedings{calvanese2013verification, abstract = {In this paper, we devise a general framework for formalizing Description Logic Based Dynamic Systems that is parametric w.r.t. the description logic knowledge base and the progression mechanism of interest. Using this framework we study verification and adversarial synthesis for specifications expressed in a variant of first-order mu-calculus, with a controlled form of quantification across successive states. We provide key decidability results for both verification and synthesis, under a “bounded-state” assumption. We then study two instantiations of this general framework, where the description logic knowledge base is expressed in DL-Lite and ALCQI, respectively.},
      audience = {academic},
      author = {Calvanese, Diego and De Giacomo, Giuseppe and Montali, Marco and Patrizi, Fabio},
      booktitle = {RR},
      doi = {10.1007/978-3-642-39666-3_5},
      editor = {Faber, Wolfgang and Lembo, Domenico},
      interhash = {ab5cba6b0949af0630359ad04cc1515c},
      intrahash = {d3e3d8dcc9c8ba60a181500aac1d620e},
      openaccess = {No},
      pages = {50-64},
      partneroptique = {UNIROMA1, FUB},
      publisher = {Springer},
      series = {Lecture Notes in Computer Science},
      title = {Verification and Synthesis in Description Logic Based Dynamic Systems},
      volume = 7994, wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2012,article] bibtex Go to document
    D. Calvanese, G. D. Giacomo, M. Lenzerini, and M. Y. Vardi, "Query Processing under GLAV Mappings for Relational and Graph Databases.," PVLDB, vol. 6, iss. 2, pp. 61-72, 2012.
    @article{journals/pvldb/CalvaneseGLV12, abstract = {Schema mappings establish a correspondence between data stored in two databases, called source and target respectively. Query processing under schema mappings has been investigated extensively in the two cases where each target atom is mapped to a query over the source (called GAV, global-as-view), and where each source atom is mapped to a query over the target (called LAV, local-as-view). The general case, called GLAV, in which queries over the source are mapped to queries over the target, has attracted a lot of attention recently, especially for data exchange. However, query processing for GLAV mappings has been considered only for the basic service of query answering, and mainly in the context of conjunctive queries (CQs) in relational databases. In this paper we study query processing for GLAV mappings in a wider sense, considering not only query answering, but also query rewriting, perfectness (the property of a rewriting to compute exactly the certain answers), and query containment relative to a mapping. We deal both with the relational case, and with graph databases, where the basic querying mechanism is that of regular path queries. Query answering in GLAV can be smoothly reduced to a combination of the LAV and GAV cases, and for CQs this reduction can be exploited also for the remaining query processing tasks. In contrast, as we show, GLAV query processing for graph databases is non-trivial and requires new insights and techniques. We obtain upper bounds for answering, rewriting, and perfectness, and show decidability of relative containment.},
      audience = {academic},
      author = {Calvanese, Diego and Giacomo, Giuseppe De and Lenzerini, Maurizio and Vardi, Moshe Y.},
      ee = {http://www.vldb.org/pvldb/vol6/p61-calvanese.pdf},
      interhash = {68bf115699be6cfcd2059cb5fc3dd13c},
      intrahash = {3b78ae3e9e447ac8e9f27d215fb1333e},
      journal = {PVLDB},
      number = 2, openaccess = {Yes},
      pages = {61-72},
      partneroptique = {UNIROMA1, FUB},
      title = {Query Processing under GLAV Mappings for Relational and Graph Databases.},
      url = {http://dblp.uni-trier.de/db/journals/pvldb/pvldb6.html#CalvaneseGLV12},
      volume = 6, wpoptique = {WP4},
      year = 2012, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    C. Civili, M. Console, G. De Giacomo, D. Lembo, M. Lenzerini, L. Lepore, R. Mancini, A. Poggi, R. Rosati, M. Ruzzi, V. Santarelli, and D. F. Savo, "MASTRO STUDIO: Managing Ontology-Based Data Access applications," in VLDB, 2013.
    @inproceedings{civili2013mastro, abstract = {Ontology-based data access (OBDA) is a novel paradigm for accessing large data repositories through an ontology, that is a formal description of a domain of interest. Supporting the management of OBDA applications poses new challenges, as it requires to provide effective tools for (i) allowing both expert and non-expert users to analyze the OBDA specification, (ii) collaboratively documenting the ontology, (iii) exploiting OBDA services, such as query answering and automated reasoning over ontologies, e.g., to support data quality check, and (iv) tuning the OBDA application towards optimized performances. To fulfill these challenges, we have built a novel system, called MASTRO STUDIO, based on a tool for automated reasoning over ontologies, enhanced with a suite of tools and optimization facilities for managing OBDA applications. To show the effectiveness of MASTRO STUDIO, we demonstrate its usage in one OBDA application developed in collaboration with the Italian Ministry of Economy and Finance.},
      audience = {academic},
      author = {Civili, Cristina and Console, Marco and De Giacomo, Giuseppe and Lembo, Domenico and Lenzerini, Maurizio and Lepore, Lorenzo and Mancini, Riccardo and Poggi, Antonella and Rosati, Riccardo and Ruzzi, Marco and Santarelli, Valerio and Savo, Domenico Fabio},
      booktitle = {VLDB},
      interhash = {c270989d87db8b85e34e635385b925cc},
      intrahash = {46a8523aeec0b6c96f37f6fc471a033c},
      partneroptique = {UNIROMA1},
      title = {MASTRO STUDIO: Managing Ontology-Based Data Access applications},
      wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    C. Civili, M. Console, D. Lembo, L. Lepore, R. Mancini, A. Poggi, M. Ruzzi, V. Santarelli, and D. F. Savo, "Mastro Studio: a system for Ontology-Based Data Management," in OWLED, 2013.
    @inproceedings{civili2013owled, audience = {academic},
      author = {Civili, Cristina and Console, Marco and Lembo, Domenico and Lepore, Lorenzo and Mancini, Riccardo and Poggi, Antonella and Ruzzi, Marco and Santarelli, Valerio and Savo, Domenico Fabio},
      booktitle = {OWLED},
      interhash = {3b0372ce8bd1fd128a3257ecec9b6fdf},
      intrahash = {93ef321cdbcc00e8d3d9d90770c345e0},
      openaccess = {Yes},
      partneroptique = {UNIROMA1},
      title = {Mastro Studio: a system for Ontology-Based Data Management},
      wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex Go to document
    M. Bienvenu and R. Rosati, "Tractable Approximations of Consistent Query Answering for Robust Ontology-based Data Access.," in IJCAI, 2013.
    @inproceedings{conf/ijcai/BienvenuR13, abstract = {A robust system for ontology-based data access should provide meaningful answers to queries even when the data conflicts with the ontology. This can be accomplished by adopting an inconsistency-tolerant semantics, with the consistent query answering (CQA) semantics being the most prominent example. Unfortunately, query answering under the CQA semantics has been shown to be computationally intractable, even when extremely simple ontology languages are considered. In this paper, we address this problem by proposing two new families of inconsistency-tolerant semantics which approximate the CQA semantics from above and from below and converge to it in the limit. We study the data complexity of conjunctive query answering under these new semantics, and show a general tractability result for all known first-order rewritable ontology languages. We also analyze the combined complexity of query answering for ontology languages of the DL-Lite family},
      audience = {academic},
      author = {Bienvenu, Meghyn and Rosati, Riccardo},
      booktitle = {IJCAI},
      editor = {Rossi, Francesca},
      ee = {http://www.aaai.org/ocs/index.php/IJCAI/IJCAI13/paper/view/6904},
      interhash = {7576ed5df0f10357892294ee9738afc2},
      intrahash = {486a7e215d843130da556f51412c705d},
      isbn = {978-1-57735-633-2},
      openaccess = {Yes},
      partneroptique = {UNIROMA1},
      publisher = {IJCAI/AAAI},
      title = {Tractable Approximations of Consistent Query Answering for Robust Ontology-based Data Access.},
      url = {http://dblp.uni-trier.de/db/conf/ijcai/ijcai2013.html#BienvenuR13},
      wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex Go to document
    M. Bienvenu and R. Rosati, "New Inconsistency-Tolerant Semantics for Robust Ontology-Based Data Access.," in Description Logics, 2013, pp. 53-64.
    @inproceedings{conf/dlog/BienvenuR13, audience = {academic},
      author = {Bienvenu, Meghyn and Rosati, Riccardo},
      booktitle = {Description Logics},
      editor = {Eiter, Thomas and Glimm, Birte and Kazakov, Yevgeny and Krötzsch, Markus},
      ee = {http://ceur-ws.org/Vol-1014/paper_73.pdf},
      interhash = {e67367e6e08ec83e866309f0db4f09bb},
      intrahash = {327132acded56e59a2d2abda18937300},
      openaccess = {Yes},
      pages = {53-64},
      partneroptique = {UNIROMA1},
      publisher = {CEUR-WS.org},
      series = {CEUR Workshop Proceedings},
      title = {New Inconsistency-Tolerant Semantics for Robust Ontology-Based Data Access.},
      url = {http://dblp.uni-trier.de/db/conf/dlog/dlog2013.html#BienvenuR13},
      volume = 1014, wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    E. Franconi, C. Gutierrez, A. Mosca, G. Pirrò, and R. Rosati, "The Logic of Extensional RDFS." 2013.
    @inproceedings{franconi2013iswc, abstract = {The normative version of RDFS gives non-standard (intensional) interpretations to some standard notions such as classes and properties. In this paper we develop the extensional semantics for the RDFS vocabulary, which surprisingly preserves the simplicity and computational complexity of deduction of the intensional case. This result will impact current implementations in a positive sense, as reasoning in RDFS will follow common set-based intuitions and be compatible with OWL extensions; moreover, the rule system that we present is easily embeddable in existing libraries such as Jena.},
      audience = {academic},
      author = {Franconi, Enrico and Gutierrez, Claudio and Mosca, Alessandro and Pirrò, Giuseppe and Rosati, Riccardo},
      doi = {10.1007/978-3-642-41335-3_7},
      interhash = {d7ff177e44c3f1db567bc25f384c856b},
      intrahash = {c34fff0b8db4b465a8e79143ac9319af},
      openaccess = {No},
      partneroptique = {UNIROMA1, FUB},
      title = {The Logic of Extensional RDFS},
      wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex Go to document
    S. Vassos and F. Patrizi, "A Classification of First-Order Progressable Action Theories in Situation Calculus.," in IJCAI, 2013.
    @inproceedings{conf/ijcai/VassosP13, abstract = {Projection in the situation calculus refers to answering queries about the future evolutions of the modelled domain, while progression refers to updating the logical representation of the initial state so that it reflects the changes due to an executed action. In the general case projection is not decidable and progression may require second-order logic. In this paper we focus on a recent result about the decidability of projection and use it to drive results for the problem of progression. In particular we contribute with the following: (i) a major result showing that for a large class of intuitive action theories with bounded unknowns a first-order progression always exists and can be computed; (ii) a comprehensive classification of the known classes that can be progressed in first-order; (iii) a novel account of nondeterministic actions in the situation calculus.},
      audience = {academic},
      author = {Vassos, Stavros and Patrizi, Fabio},
      booktitle = {IJCAI},
      editor = {Rossi, Francesca},
      ee = {http://www.aaai.org/ocs/index.php/IJCAI/IJCAI13/paper/view/6646},
      interhash = {77497c275ff8ead9f33888219570e3ee},
      intrahash = {4eebb8f87cbdab88e45a761269b18f50},
      isbn = {978-1-57735-633-2},
      openaccess = {Yes},
      partneroptique = {UNIROMA1},
      publisher = {IJCAI/AAAI},
      title = {A Classification of First-Order Progressable Action Theories in Situation Calculus.},
      url = {http://dblp.uni-trier.de/db/conf/ijcai/ijcai2013.html#VassosP13},
      wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex Go to document
    M. Console, M. Lenzerini, R. Mancini, R. Rosati, and M. Ruzzi, "Synthesizing Extensional Constraints in Ontology-Based Data Access.," in Description Logics, 2013, pp. 628-639.
    @inproceedings{conf/dlog/ConsoleLMRR13, abstract = {Several recent techniques and tools for Ontology-based Data Access (OBDA) make use of the so-called extensional constraints (a.k.a. ABox dependencies). So far, extensional constraints have been mainly considered in a setting where data are represented in an ABox, instead of external data sources connected to the ontology through declarative mappings. Moreover, the issue of how to generate extensional constraints in practice has not been addressed yet. In this paper we first provide a formal account of the notion of extensional constraints in a full-fledged OBDA setting, where an ontology is connected to the data sources of the information system by means of mappings, and then present an approach to the automatic generation of extensional constraints in such a setting. The technique we propose is based on the use of a first-order theorem prover that checks validity of relevant formulas built over the mapping views. The experiments we have carried out in real-world OBDA projects show the effectiveness of our approach in discovering large collections of extensional constraints entailed by the OBDA specification.},
      audience = {academic},
      author = {Console, Marco and Lenzerini, Maurizio and Mancini, Riccardo and Rosati, Riccardo and Ruzzi, Marco},
      booktitle = {Description Logics},
      editor = {Eiter, Thomas and Glimm, Birte and Kazakov, Yevgeny and Krötzsch, Markus},
      ee = {http://ceur-ws.org/Vol-1014/paper_29.pdf},
      interhash = {33389042cfdf6bd0688360899067c634},
      intrahash = {20f8b69cf62bb505f4e0112785918219},
      openaccess = {Yes},
      pages = {628-639},
      partneroptique = {UNIROMA1},
      publisher = {CEUR-WS.org},
      series = {CEUR Workshop Proceedings},
      title = {Synthesizing Extensional Constraints in Ontology-Based Data Access.},
      url = {http://dblp.uni-trier.de/db/conf/dlog/dlog2013.html#ConsoleLMRR13},
      volume = 1014, wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,incollection] bibtex
    M. Giese, D. Calvanese, P. Haase, I. Horrocks, Y. Ioannidis, H. Kllapi, M. Koubarakis, M. Lenzerini, R. Möller, M. Rodriguez-Muro, &. Özcep, R. Rosati, R. Schlatte, M. Schmidt, A. Soylu, and A. Waaler, "Scalable End-User Access to Big Data," , Akerkar, R., Ed., CRC Press, 2013.
    @incollection{book-big-data-2013, abstract = {This chapter proposes steps towards the solution to the data access problem that end-users typically face when dealing with Big Data: (i) They need to pose ad hoc queries to a collection of data sources, possibly including streaming sources; (ii) They are unable to query those sources on their own, but are dependent on assistance from IT experts; (iii) The turnaround time for information requests is in the range of days, possibly weeks, due to the involvement of the IT personnel; (iv) The volume, complexity, variety and velocity of the underlying data sources put very high demands on the scalability of the solution. We propose to approach this problem using ontology-based data access (OBDA), the idea being to capture end-user conceptualizations in an ontology and use declarative mappings to connect the ontology to the underlying data sources. End user queries posed are posed in terms of concepts of the ontology and are then rewritten to queries against the sources.},
      audience = {industry},
      author = {Giese, Martin and Calvanese, Diego and Haase, Peter and Horrocks, Ian and Ioannidis, Yannis and Kllapi, Heralk and Koubarakis, Manolis and Lenzerini, Maurizio and Möller, Ralf and Rodriguez-Muro, Mariano and Özcep, Özgür and Rosati, Riccardo and Schlatte, Rudolf and Schmidt, Michael and Soylu, Ahmet and Waaler, Arild},
      booktitle = {Big Data Computing},
      editor = {Akerkar, Rajendra},
      interhash = {59f2232229c91cebbedfd930e811c67a},
      intrahash = {1f76b2d96eb19ce1207f2eace2b54912},
      openaccess = {No},
      partneroptique = {UiO},
      publisher = {CRC Press},
      title = {Scalable End-User Access to Big Data},
      wpoptique = {WP10},
      year = 2013, yearoptique = {Y2}
    }
  • [2013,inproceedings] bibtex
    M. G. Skjæveland and E. H. Lian, "Benefits of Publishing the Norwegian Petroleum Directorate’s FactPages as Linked Open Data," in Norsk informatikkonferanse (NIK 2013), 2013.
    @inproceedings{SkLi-NIK2013, abstract = {This paper presents the benefits from publishing the Norwegian Petroleum Directorate’s FactPages, a public and popular, freely available dataset, into semantically annotated and query enabled five star linked open data. We discuss and illustrate the added value of publishing open datasets on the Web using web standards, semantic web technologies and best practices---contrasted to the lesser suited, but more traditional methods—and offer advice to data providers on how to achieve these benefits.},
      audience = {academic},
      author = {Skj{\ae}veland, Martin G. and Lian, Espen H.},
      booktitle = {Norsk informatikkonferanse (NIK 2013)},
      interhash = {b2e82696ccf860ee0ed6bc5f79f6020c},
      intrahash = {28ab742560e17e4ab7a0cfb1f833e5b9},
      openaccess = {Yes},
      partneroptique = {UiO},
      publisher = {Tapir},
      title = {{Benefits of Publishing the Norwegian Petroleum Directorate's FactPages as Linked Open Data}},
      wpoptique = {WP10},
      year = 2013, yearoptique = {Y2}
    }
  • [2013,inproceedings] bibtex
    M. G. Skjæveland, E. H. Lian, and I. Horrocks, "Publishing the Norwegian Petroleum Directorate’s FactPages as Semantic Web Data," in The Semantic Web — ISWC 2013, 2013, pp. 162-177.
    @inproceedings{SkLiHo-ISWC2013, abstract = {This paper motivates, documents and evaluates the process and results of converting the Norwegian Petroleum Directorate's FactPages, a well-known and diverse set of tabular data, but with little and incomplete schema information, stepwise into other representations where in each step more semantics is added to the dataset. The different representations we consider are a regular relational database, a linked open data dataset, and an ontology. For each conversion step we explain and discuss necessary design choices which are due to the specific shape of the dataset, but also those due to the characteristics and idiosyncrasies of the representation formats. We additionally evaluate the output, performance and cost of querying the different formats using questions provided by users of the FactPages.},
      audience = {academic},
      author = {Skj{\ae}veland, Martin G. and Lian, Espen H. and Horrocks, Ian},
      booktitle = {The Semantic Web -- ISWC 2013},
      doi = {10.1007/978-3-642-41338-4_11},
      editor = {Alani, Harith and Kagal, Lalana and Fokoue, Achille and Groth, Paul and Biemann, Chris and Parreira, JosianeXavier and Aroyo, Lora and Noy, Natasha and Welty, Chris and Janowicz, Krzysztof},
      interhash = {96e5e9f2a9e35a9816a300c14d309e36},
      intrahash = {9d002eaea90a4c8b56c2e628b6e838b3},
      openaccess = {Yes},
      pages = {162-177},
      partneroptique = {UiO},
      publisher = {Springer Berlin Heidelberg},
      series = {LNCS},
      title = {{Publishing the Norwegian Petroleum Directorate's FactPages as Semantic Web Data}},
      volume = 8219, wpoptique = {WP10},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,article] bibtex
    D. Calvanese, M. Ortiz, M. Simkus, and G. Stefanoni, "Reasoning about Explanations for Negative Query Answers in DL-Lite," Journal of Artificial Intelligence Research, vol. 48, pp. 635-669, 2013.
    @article{calvanese-etal-JAIR-2013-explanation, abstract = {In order to meet usability requirements, most logic-based applications provide explanation facilities for reasoning services. This holds also for Description Logics, where research has focused on the explanation of both TBox reasoning and, more recently, query answering. Besides explaining the presence of a tuple in a query answer, it is important to explain also why a given tuple is missing. We address the latter problem for instance and conjunctive query answering over DL-Lite ontologies by adopting abductive reasoning; that is, we look for additions to the ABox that force a given tuple to be in the result. As reasoning tasks we consider existence and recognition of an explanation, and relevance and necessity of a given assertion for an explanation. We characterize the computational complexity of these problems for arbitrary, subset minimal, and cardinality minimal explanations. },
      audience = {academic},
      author = {Calvanese, Diego and Ortiz, Magdalena and Simkus, Mantas and Stefanoni, Giorgio},
      interhash = {974ee10f296c76dfb27dc826fdec9e11},
      intrahash = {ef142e6244d30ed2b34d656e7b5c8ee3},
      journal = {Journal of Artificial Intelligence Research},
      pages = {635-669},
      partneroptique = {FUB},
      title = {Reasoning about Explanations for Negative Query Answers in {DL-Lite}},
      volume = 48, wpoptique = {WP6},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    E. Jiménez-Ruiz, B. C. Grau, and I. Horrocks, "Is my ontology matching system similar to yours?," in 8th International Workshop on Ontology Matching, 2013.
    @inproceedings{ernestojimenezruizbernardocuencagrau2013ontology, abstract = {In this paper we extend the evaluation of the OAEI 2012 Large BioMed track, which involves the matching of the semantically rich ontologies FMA, NCI and SNOMED CT. Concretely, we report about the differences a nd similarities among the mappings computed by the participant ontology mat ching systems.},
      audience = {academic},
      author = {Jiménez-Ruiz, Ernesto and Grau, Bernardo Cuenca and Horrocks, Ian},
      booktitle = {8th International Workshop on Ontology Matching},
      interhash = {817617682f2d0df43d441d2ce69f3c2e},
      intrahash = {ffbba27578aecbdf3033312253ba9837},
      partneroptique = {UOXF},
      title = {Is my ontology matching system similar to yours?},
      wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    R. S. Gonçalves, S. Bail, E. Jiménez-Ruiz, N. Matentzoglu, B. Parsia, B. Glimm, and Y. Kazakov, "OWL Reasoner Evaluation (ORE) Workshop 2013 Results: Short Report," in ORE, 2013, pp. 1-18.
    @inproceedings{DBLP:conf/ore/GoncalvesBJMPGK13, abstract = {Results of the 2nd OWL Reasoner Evaluation (ORE) Workshop 2013.},
      audience = {academic},
      author = {Gon\c{c}alves, Rafael S. and Bail, Samantha and Jim{\'e}nez-Ruiz, Ernesto and Matentzoglu, Nicolas and Parsia, Bijan and Glimm, Birte and Kazakov, Yevgeny},
      bibsource = {DBLP, http://dblp.uni-trier.de},
      booktitle = {ORE},
      crossref = {DBLP:conf/ore/2013},
      editor = {Bail, Samantha and Glimm, Birte and Gon\c{c}alves, Rafael S. and Jim{\'e}nez-Ruiz, Ernesto and Kazakov, Yevgeny and Matentzoglu, Nicolas and Parsia, Bijan},
      ee = {http://ceur-ws.org/Vol-1015/ore2013_report.pdf},
      interhash = {7bf6b2edb22494fd3fdc8ad5d41ab108},
      intrahash = {c10944d8ca3c919e4c8fe44a2afa52d8},
      pages = {1-18},
      partneroptique = {UOXF},
      publisher = {CEUR-WS.org},
      series = {CEUR Workshop Proceedings},
      title = {OWL Reasoner Evaluation (ORE) Workshop 2013 Results: Short Report},
      volume = 1015, wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    A. A. Romero, B. C. Grau, I. Horrocks, and E. Jiménez-Ruiz, "MORe: a Modular OWL Reasoner for Ontology Classification," in ORE, 2013, pp. 61-67.
    @inproceedings{DBLP:conf/ore/RomeroGHJ13, abstract = {MORe exploits module extraction techniques to divide the workload of ontology classi cation between two reasoners: a reasoner for the lightweight pro le EL of OWL 2, and a fully edged OWL 2 reasoner. This division is carried out in such a way that the bulk of the workload is assigned, as much as possible, to the OWL 2 EL reasoner, in order to exploit the more ecient classi cation techniques speci c to this pro le.},
      audience = {academic},
      author = {Romero, Ana Armas and Grau, Bernardo Cuenca and Horrocks, Ian and Jim{\'e}nez-Ruiz, Ernesto},
      bibsource = {DBLP, http://dblp.uni-trier.de},
      booktitle = {ORE},
      crossref = {DBLP:conf/ore/2013},
      editor = {Bail, Samantha and Glimm, Birte and Gon\c{c}alves, Rafael S. and Jim{\'e}nez-Ruiz, Ernesto and Kazakov, Yevgeny and Matentzoglu, Nicolas and Parsia, Bijan},
      ee = {http://ceur-ws.org/Vol-1015/paper_8.pdf},
      interhash = {d490797b0e99c6e17e6cdae655531e4d},
      intrahash = {b34561171e32a3d1221e41efe88b9aab},
      pages = {61-67},
      partneroptique = {UOXF},
      publisher = {CEUR-WS.org},
      series = {CEUR Workshop Proceedings},
      title = {MORe: a Modular OWL Reasoner for Ontology Classification},
      volume = 1015, wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    E. Jiménez-Ruiz, C. Meilicke, B. C. Grau, and I. Horrocks, "Evaluating Mapping Repair Systems with Large Biomedical Ontologies," in 26th International Workshop on Description Logics, 2013, pp. 246-257.
    @inproceedings{DBLP:conf/dlog/Jimenez-RuizMGH13, abstract = {In this paper we provide empirical evidence of the necessity of integrating mapping repair techniques within the ontology ma tching process, an aspect that is neglected in many ontology matching systems. We also evaluate the feasibility of using state-of-the-art mapping repair techniques in practice, such as those implemented in Alcomo and LogMap. A preliminary evaluation was conducted in the context of the Ontology Alignment Evaluation Initiative (OAEI) 2012. We extend this evaluation and report about the results in detail.},
      audience = {academic},
      author = {Jim{\'e}nez-Ruiz, Ernesto and Meilicke, Christian and Grau, Bernardo Cuenca and Horrocks, Ian},
      bibsource = {DBLP, http://dblp.uni-trier.de},
      booktitle = {26th International Workshop on Description Logics},
      ee = {http://ceur-ws.org/Vol-1014/paper_63.pdf},
      interhash = {6dd62799b4b3cdff491a0b5349703301},
      intrahash = {e9b307a02e2c4b0d1c807f3ffaca9ca5},
      pages = {246-257},
      partneroptique = {UOXF},
      title = {Evaluating Mapping Repair Systems with Large Biomedical Ontologies},
      wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    R. Möller, C. Neuenstadt, &. L. Özcep, and S. Wandelt, "Advances in Accessing Big Data with Expressive Ontologies," in Description Logics, 2013, pp. 842-853.
    @inproceedings{DBLP:conf/dlog/MollerNOW13ohneCross, abstract = {Ontology-based query answering has to be supported w.r.t. secondary memory and very expressive ontologies to meet practical re-quirements in some applications. Recently, advances for the expressive DL SHI have been made in the dissertation of S. Wandelt for concept-based instance retrieval on Big Data descriptions stored in secondary memory. In this paper we extend this approach by investigating optimization algorithms for answering grounded conjunctive queries},
      audience = {academic},
      author = {Möller, Ralf and Neuenstadt, Christian and Özcep, Özgür L. and Wandelt, Sebastian},
      bibsource = {DBLP, http://dblp.uni-trier.de},
      booktitle = {Description Logics},
      date-added = {2013-10-24 11:05:24 +0200},
      date-modified = {2013-10-24 11:06:04 +0200},
      doi = {10.1007/978-3-642-40942-4_11},
      editor = {Eiter, Thomas and Glimm, Birte and Kazakov, Yevgeny and Kr{\"o}tzsch, Markus},
      ee = {http://ceur-ws.org/Vol-1014/paper_41.pdf},
      interhash = {dac3170bca96f42d46820533b668b89f},
      intrahash = {28052ff3f63d008fcfc7aa2d4c9df6f1},
      openaccess = {No},
      pages = {842--853},
      partneroptique = {TUHH},
      publisher = {CEUR-WS.org},
      series = {CEUR Workshop Proceedings},
      title = {Advances in Accessing Big Data with Expressive Ontologies},
      volume = 1014, wpoptique = {WP5},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    &. L. Özcep and R. Möller, "Spatial Semantics for Concepts," in Description Logics, 2013, pp. 816-828.
    @inproceedings{DBLP:conf/dlog/OzcepM13OhneCross, author = {Özcep, Özgür L. and Möller, Ralf},
      bibsource = {DBLP, http://dblp.uni-trier.de},
      booktitle = {Description Logics},
      date-added = {2013-10-24 11:00:27 +0200},
      date-modified = {2013-10-24 11:04:14 +0200},
      editor = {Eiter, Thomas and Glimm, Birte and Kazakov, Yevgeny and Kr{\"o}tzsch, Markus},
      ee = {http://ceur-ws.org/Vol-1014/paper_38.pdf},
      interhash = {f16e0bd31de46665a99a3a2a39db3e59},
      intrahash = {4da12836897528402c0aa196af603320},
      openaccess = {Yes},
      pages = {816--828},
      publisher = {CEUR-WS.org},
      series = {CEUR Workshop Proceedings},
      title = {Spatial Semantics for Concepts},
      volume = 1014, year = 2013 }
  • [2013,inproceedings] bibtex Go to document
    R. Möller, C. Neuenstadt, Ö. Ozçep, and S. Wandelt, "Advances in Accessing Big Data with Expressive Ontologies," in KI 2013: Advances in Artificial Intelligence, 2013, pp. 118-129.
    @inproceedings{moeller13advances, abstract = {Ontology-based query answering has to be supported w.r.t. secondary memory and very expressive ontologies to meet practical requirements in some applications. Recently, advances for the expressive DL SHI have been made in the dissertation of S. Wandelt for concept-based instance retrieval on Big Data descriptions stored in secondary memory. In this paper we extend this approach by investigating optimization algorithms for answering grounded conjunctive queries},
      audience = {academic},
      author = {M\"oller, Ralf and Neuenstadt, Christian and Oz\c{c}ep, \"Ozg\"ur and Wandelt, Sebastian},
      bdsk-url-1 = {http://dx.doi.org/10.1007/978-3-642-40942-4_11},
      booktitle = {KI 2013: Advances in Artificial Intelligence},
      date-added = {2013-10-17 10:49:56 +0200},
      date-modified = {2013-10-17 10:49:56 +0200},
      editor = {Timm, Ingo J. and Thimm, Matthias},
      interhash = {2fe8b1b7e441fe46265ebc9189dc0b10},
      intrahash = {a23ea537232050cd45a5cf58385b932e},
      pages = {118--129},
      partneroptique = {TUHH},
      publisher = {Springer Berlin Heidelberg},
      series = {{L}ecture {N}otes in {C}omputer {S}cience},
      title = {Advances in Accessing Big Data with Expressive Ontologies},
      url = {http://dx.doi.org/10.1007/978-3-642-40942-4_11},
      volume = 8077, wpoptique = {WP5},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    K. Sengupta, P. Haase, M. Schmidt, and P. Hitzler, "Editing R2RML Mappings Made Easy," in International Semantic Web Conference (Posters & Demos), 2013, pp. 101-104.
    @inproceedings{DBLP:conf/semweb/SenguptaHSH13, author = {Sengupta, Kunal and Haase, Peter and Schmidt, Michael and Hitzler, Pascal},
      bibsource = {DBLP, http://dblp.uni-trier.de},
      booktitle = {International Semantic Web Conference (Posters {\&} Demos)},
      crossref = {DBLP:conf/semweb/2013p},
      editor = {Blomqvist, Eva and Groza, Tudor},
      ee = {http://ceur-ws.org/Vol-1035/iswc2013_demo_26.pdf},
      interhash = {d9e4d9fa1a4c519958696a3842eb9676},
      intrahash = {94bf66ebe31dbef69ceaed99553c9f52},
      pages = {101-104},
      publisher = {CEUR-WS.org},
      series = {CEUR Workshop Proceedings},
      title = {Editing R2RML Mappings Made Easy},
      volume = 1035, year = 2013 }
  • [2013,inproceedings] bibtex Go to document
    M. Arenas, E. Botoeva, D. Calvanese, and V. Ryzhikov, "Exchanging OWL~2~QL Knowledge Bases," in Proceedings of the 23rd International Joint Conference on Artificial Intelligence (IJCAI), 2013.
    @inproceedings{conf/ijcai/ArenasBCR13, abstract = {The problem of exchanging knowledge between a source and a target knowledge base connected through a mapping has attracted attention recently both in databases and in knowledge representation. In this paper, we study this fundamental problem for knowledge bases and mappings expressed in the description logic DL-Lite_R, which is the formal counterpart of OWL 2 QL. More specifically, we consider the problem of computing universal solutions, which have been identified as one of the most desirable translations to be materialized, and the problem of representing a source TBox by means of a target TBox that captures at best the intensional source information according to a mapping. For the former we provide a novel automata-theoretic technique, and complexity results that range from NP to ExpTime, while for the latter we show NLogSpace-completeness for different variants. },
      audience = {academic},
      author = {Arenas, Marcelo and Botoeva, Elena and Calvanese, Diego and Ryzhikov, Vladislav},
      booktitle = {Proceedings of the 23rd International Joint Conference on Artificial Intelligence (IJCAI)},
      editor = {Rossi, Francesca},
      interhash = {0b3f02dc63a4aa9acb0a81373a8c1430},
      intrahash = {033d092cc2ec6b3f577e9ba38617b1fa},
      isbn = {978-1-57735-633-2},
      partneroptique = {FUB},
      publisher = {IJCAI/AAAI},
      title = {Exchanging {OWL~2~QL} Knowledge Bases},
      url = {http://www.aaai.org/ocs/index.php/IJCAI/IJCAI13/paper/view/6939},
      wpoptique = {WP6},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex Go to document
    M. Rodriguez-Muro, M. Rezk, J. Hardi, M. Slusnys, T. Bagosi, and D. Calvanese, "Evaluating SPARQL-to-SQL Translation in Ontop," in Proceedings of the 2nd International Workshop on OWL Reasoner Evaluation (ORE), 2013, pp. 94-100.
    @inproceedings{conf/ore/Rodriguez-MuroRHSBC13, abstract = {In this paper we evaluate the performance of the SQL queries generated by ontop, a system that uses a formal approach to translate and optimize SPARQL queries and R2RML mappings. We show that the performance of ontop's SQL queries is superior to that of the performance of well known systems that rely on SQL to execute SPARQL, and superior to to that of well-known triple stores. We highlight some of the techniques and factors that allow for this. },
      audience = {academic},
      author = {Rodriguez-Muro, Mariano and Rezk, Martín and Hardi, Josef and Slusnys, Mindaugas and Bagosi, Timea and Calvanese, Diego},
      booktitle = {Proceedings of the 2nd International Workshop on OWL Reasoner Evaluation (ORE)},
      interhash = {c5c1a09fb2df11bb9198aab9c1932917},
      intrahash = {2551475034879a06dcf3a75dc3a5fc2d},
      pages = {94-100},
      partneroptique = {FUB},
      publisher = {CEUR-WS.org},
      series = {CEUR Workshop Proceedings},
      title = {Evaluating {SPARQL-to-SQL} Translation in {Ontop}},
      url = {http://ceur-ws.org/Vol-1015/paper_16.pdf},
      volume = 1015, wpoptique = {WP6},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    K. Bereta, C. Nikolaou, M. Karpathiotakis, K. Kyzirakos, and M. Koubarakis, "SexTant: Visualizing Time-Evolving Linked Geospatial Data," in International Semantic Web Conference (Posters & Demos), 2013.
    @inproceedings{bereta2013sextant, audience = {academic},
      author = {Bereta, Konstantina and Nikolaou, Charalampos and Karpathiotakis, Manos and Kyzirakos, Kostis and Koubarakis, Manolis},
      booktitle = {International Semantic Web Conference (Posters & Demos)},
      editor = {Blomqvist, Eva and Groza, Tudor},
      interhash = {c9cb397798c9c75010a2295401d23c9f},
      intrahash = {f439c317a6ebebc4ddeeb0dcc6b10eea},
      openaccess = {yes},
      partneroptique = {UoA},
      title = {SexTant: Visualizing Time-Evolving Linked Geospatial Data},
      wpoptique = {WP7},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    B. Cuenca Grau, E. Kharlamov, . V. . Kostylev, and D. Zheleznyakov, "Controlled Query Evaluation over OWL 2 RL Ontologies," in Proc.\ International Semantic Web Conference (ISWC), 2013.
    @inproceedings{ZheleznyakovISWC2010privacy, author = {{Cuenca Grau},
      Bernardo and Kharlamov, Evgeny and Kostylev, {Egor V.} and Zheleznyakov, Dmitriy},
      booktitle = {Proc.\ International Semantic Web Conference (ISWC)},
      interhash = {b22e5bc4e4db93768ff2f2e380f6079b},
      intrahash = {daf1ebc0a157a311f873ecd1fdf4f4ff},
      title = {{Controlled Query Evaluation over OWL 2 RL Ontologies}},
      year = 2013 }
  • [2013,inproceedings] bibtex
    C. Pinkel, C. Binnig, E. Kharlamov, and P. Haase, "Pay-as-you-go Matching of Relational Schemata to OWL Ontologies With IncMap," in ISWC (Posters & Demos), 2013.
    @inproceedings{pinkel2013payasyougo, abstract = {Ontology Based Data Access (OBDA) enables access to re- lational data with a complex structure through ontologies as conceptual domain models. A key component of an OBDA system are mappings between the schematic elements in the ontology and their correspondences in the relational schema. Today, in existing OBDA systems these mappings typically need to be compiled by hand. In this paper we present IncMap, a system that supports a semi-automatic approach for matching relational schemata and ontologies. Our approach is based on a novel matching technique that represents the schematic elements of an ontology and a relational schema in a unified way. Finally, IncMap can extend user-verified mapping suggestions in a pay-as-you-go fashion. },
      audience = {academic},
      author = {Pinkel, Christoph and Binnig, Carsten and Kharlamov, Evgeny and Haase, Peter},
      booktitle = {ISWC (Posters & Demos)},
      interhash = {ddeb36412908f6164471f5292c89c49f},
      intrahash = {f791932dcd98372d1a9eb25645e5022f},
      partneroptique = {FOPS},
      title = {Pay-as-you-go Matching of Relational Schemata to OWL Ontologies With IncMap},
      wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    C. Pinkel, C. Binnig, E. Kharlamov, and P. Haase, "IncMap: Pay as you go Matching of Relational Schemata to OWL Ontologies," in OM, 2013.
    @inproceedings{pinkel2013incmap, abstract = {Ontology Based Data Access (OBDA) enables access to relational data with a complex structure through ontologies as conceptual domain models. A key component of an OBDA system are mappings between the schematic elements in the ontology and their correspondences in the relational schema. Today, in existing OBDA systems these mappings typically need to be compiled by hand, which is a complex and labor intensive task. In this paper we address the problem of creating such mappings and present IncMap, a system that supports a semi-automatic approach for matching relational schemata and ontologies. Our approach is based on a novel matching technique that represents the schematic elements of an ontology and a relational schema in a unified way. IncMap is designed to work in a query-driven, pay as you go fashion and leverages partial, user-verified mappings to improve subsequent mapping suggestions. This effectively reduces the overall effort compared to compiling a mappings in one step. Moreover, IncMap can incorporate knowledge from user queries to enhance suggestion quality.},
      audience = {academic},
      author = {Pinkel, Christoph and Binnig, Carsten and Kharlamov, Evgeny and Haase, Peter},
      booktitle = {OM},
      interhash = {eeb096cbc26148bc1cb945e3d90eaf27},
      intrahash = {525d8761eae525a05f18fcaa384bd9ee},
      partneroptique = {FOPS},
      title = {IncMap: Pay as you go Matching of Relational Schemata to OWL Ontologies},
      wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    E. Kharlamov, M. Giese, E. Jiménez-Ruiz, M. G. Skjæveland, A. Soylu, D. Zheleznyakov, T. Bagosi, M. Console, P. Haase, I. Horrocks, S. Marciuska, C. Pinkel, M. Rodriguez-Muro, M. Ruzzi, V. Santarelli, D. F. Savo, K. Sengupta, M. Schmidt, E. Thorstensen, J. Trame, and A. Waaler, "Optique 1.0: Semantic Access to Big Data: The Case of Norwegian Petroleum Directorate’s FactPages," in International Semantic Web Conference (Posters & Demos), 2013, pp. 65-68.
    @inproceedings{Optique_ISWC13, author = {Kharlamov, Evgeny and Giese, Martin and Jim{\'e}nez-Ruiz, Ernesto and Skj{\ae}veland, Martin G. and Soylu, Ahmet and Zheleznyakov, Dmitriy and Bagosi, Timea and Console, Marco and Haase, Peter and Horrocks, Ian and Marciuska, Sarunas and Pinkel, Christoph and Rodriguez-Muro, Mariano and Ruzzi, Marco and Santarelli, Valerio and Savo, Domenico Fabio and Sengupta, Kunal and Schmidt, Michael and Thorstensen, Evgenij and Trame, Johannes and Waaler, Arild},
      booktitle = {International Semantic Web Conference (Posters {\&} Demos)},
      interhash = {af13778a2070c8a907a6ba666074c7cb},
      intrahash = {fcd6802b20e45ae8c967649c41acc16a},
      pages = {65-68},
      title = {Optique 1.0: Semantic Access to Big Data: The Case of Norwegian Petroleum Directorate's FactPages},
      year = 2013 }
  • [2013,inproceedings] bibtex
    E. Kharlamov, E. Jiménez-Ruiz, D. Zheleznyakov, D. Bilidas, M. Giese, P. Haase, I. Horrocks, H. Kllapi, M. Koubarakis, Ö. L. Özçep, M. Rodriguez-Muro, R. Rosati, M. Schmidt, R. Schlatte, A. Soylu, and A. Waaler, "Optique: Towards OBDA Systems for Industry," in ESWC (Satellite Events), 2013, pp. 125-140.
    @inproceedings{Optique_ECWS13_2, author = {Kharlamov, Evgeny and Jim{\'e}nez-Ruiz, Ernesto and Zheleznyakov, Dmitriy and Bilidas, Dimitris and Giese, Martin and Haase, Peter and Horrocks, Ian and Kllapi, Herald and Koubarakis, Manolis and {\"O}z\c{c}ep, {\"O}zg{\"u}r L. and Rodriguez-Muro, Mariano and Rosati, Riccardo and Schmidt, Michael and Schlatte, Rudolf and Soylu, Ahmet and Waaler, Arild},
      booktitle = {ESWC (Satellite Events)},
      interhash = {21393006706776294f314bb865001e8f},
      intrahash = {fd1288bf9005328619f6d9f230c5f545},
      pages = {125-140},
      title = {Optique: Towards OBDA Systems for Industry},
      year = 2013 }
  • [2013,inproceedings] bibtex
    D. Calvanese, M. Giese, P. Haase, I. Horrocks, T. Hubauer, Y. E. Ioannidis, E. Jiménez-Ruiz, E. Kharlamov, H. Kllapi, J. W. Klüwer, M. Koubarakis, S. Lamparter, R. Möller, C. Neuenstadt, T. Nordtveit, Ö. L. Özçep, M. Rodriguez-Muro, M. Roshchin, D. F. Savo, M. Schmidt, A. Soylu, A. Waaler, and D. Zheleznyakov, "Optique: OBDA Solution for Big Data," in ESWC (Satellite Events), 2013, pp. 293-295.
    @inproceedings{Optique_ECWS13_1, author = {Calvanese, Diego and Giese, Martin and Haase, Peter and Horrocks, Ian and Hubauer, Thomas and Ioannidis, Yannis E. and Jim{\'e}nez-Ruiz, Ernesto and Kharlamov, Evgeny and Kllapi, Herald and Kl{\"u}wer, Johan W. and Koubarakis, Manolis and Lamparter, Steffen and M{\"o}ller, Ralf and Neuenstadt, Christian and Nordtveit, T. and {\"O}z\c{c}ep, {\"O}zg{\"u}r L. and Rodriguez-Muro, Mariano and Roshchin, Mikhail and Savo, Domenico Fabio and Schmidt, Michael and Soylu, Ahmet and Waaler, Arild and Zheleznyakov, Dmitriy},
      booktitle = {ESWC (Satellite Events)},
      interhash = {56a1eac8bb4ea0dfbae7bba0b58a104a},
      intrahash = {8a5742726c5c4b3bc7b851a2cc86f996},
      pages = {293-295},
      title = {Optique: OBDA Solution for Big Data},
      year = 2013 }
  • [2013,inproceedings] bibtex
    T. M. Hubauer, S. Lamparter, M. Roshchin, N. Solomakhina, and S. Watson, "Analysis of data quality issues in real-world industrial data," in Proceedings of the 2013 Annual Conference of the Prognostics and Health Management Society, 2013.
    @inproceedings{Hubauer2013, abstract = {In large industries usage of advanced technological methods and modern equipment comes with the problem of storing, interpreting and analyzing huge amount of information. Handling information becomes more complicated and important at the same time. So, data quality is one of major challenges considering a rapid growth of information, fragmentation of information systems, incorrect data formatting and other issues. The aim of this paper is to describe industrial data processing and analytics on the real-world use case. The most crucial data quality issues are described, examined and classified in terms of Data Quality Dimensions. Factual industrial information supports and illustrates each encountered data deficiency. In addition, we describe methods for elimination data quality issues and data analysis techniques, which are applied after cleaning data procedure. In addition, an approach to address data quality problems in large-scale industrial datasets is proposed. This techniques and methods comprise several well-known techniques, which come from both worlds of mathematical logic and also statistics, improving data quality procedure and cleaning results.},
      audience = {industrial},
      author = {Hubauer, Thomas M. and Lamparter, Steffen and Roshchin, Mikhail and Solomakhina, Nina and Watson, Stuart},
      booktitle = {Proceedings of the 2013 Annual Conference of the Prognostics and Health Management Society},
      interhash = {de6fdc2760c5843f4f93ddc0f4fed4ca},
      intrahash = {fbde32101039ca739d0e7fbd09b3f5d3},
      partneroptique = {SIE},
      title = {Analysis of data quality issues in real-world industrial data},
      wpoptique = {WP8},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    A. Soylu, M. G. Skjæveland, M. Giese, I. Horrocks, E. Jimenez-Ruiz, E. Kharlamov, and D. Zheleznyakov, "A Preliminary Approach on Ontology-based Visual Query Formulation for Big Data," in 7th Research Conference on Metadata and Semantics Research (MTSR 2013), 2013.
    @inproceedings{soylu2013preliminary, audience = {academic},
      author = {Soylu, Ahmet and Skjæveland, Martin G. and Giese, Martin and Horrocks, Ian and Jimenez-Ruiz, Ernesto and Kharlamov, Evgeny and Zheleznyakov, Dmitriy},
      booktitle = {7th Research Conference on Metadata and Semantics Research (MTSR 2013)},
      doi = {10.1007/978-3-319-03437-9_21},
      interhash = {fdce6e63469ef9b9f6908a72919e756a},
      intrahash = {7f261fb8e2118bc300da4e1bdde4bd54},
      openaccess = {No},
      partneroptique = {UiO},
      publisher = {Springer-Verlag},
      title = {A Preliminary Approach on Ontology-based Visual Query Formulation for Big Data},
      wpoptique = {WP3},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    A. Soylu, M. Giese, E. Jimenez-Ruiz, E. Kharlamov, D. Zheleznyakov, and I. Horrocks, "OptiqueVQS – Towards an Ontology-based Visual Query System for Big Data," in International Conference on Management of Emergent Digital EcoSystems (MEDES 2013), 2013.
    @inproceedings{soylu2013optiquevqs, audience = {academic},
      author = {Soylu, Ahmet and Giese, Martin and Jimenez-Ruiz, Ernesto and Kharlamov, Evgeny and Zheleznyakov, Dmitry and Horrocks, Ian},
      booktitle = {International Conference on Management of Emergent Digital EcoSystems (MEDES 2013)},
      doi = {10.1145/2536146.2536149},
      interhash = {ee5b6f6adc09099a8fa321214bd43a1e},
      intrahash = {b476878df4a4a4891c2377fa8ba3c522},
      openaccess = {No},
      partneroptique = {UiO},
      publisher = {ACM},
      title = {OptiqueVQS – Towards an Ontology-based Visual Query System for Big Data},
      wpoptique = {WP3},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    M. Bienvenu, M. Ortiz, M. Simkus, and G. Xiao, "Tractability Guarantees for DL-Lite Query Answering," in Informal Proceedings of the 26th International Workshop on Description Logics, Ulm, Germany, July 23 – 26, 2013, 2013, pp. 41-52.
    @inproceedings{BienvenuOSX-dl13, abstract = {It is a classic result in database theory that conjunctive query (CQ) answering, which is NP-complete in general, is feasible in polynomial time when restricted to acyclic queries. Subsequent results identified more general structural properties of CQs (like bounded treewidth) which ensure tractable query evaluation. In this paper, we lift these tractability results to knowledge bases formulated in the core dialect of DL-Lite. The proof exploits known properties of query matches in this logic and involves a query-dependent modification of the data. To obtain a more practical approach, we next propose a concrete polynomial-time algorithm for answering acyclic CQs based upon a rewriting into datalog. We also show how the algorithm can be extended to a larger class of (nearly acyclic) CQs. A preliminary evaluation of our proof-of-concept implementation suggests the interest of our approach for handling large acyclic CQs.},
      audience = {academic},
      author = {Bienvenu, Meghyn and Ortiz, Magdalena and Simkus, Mantas and Xiao, Guohui},
      booktitle = {Informal Proceedings of the 26th International Workshop on Description Logics, Ulm, Germany, July 23 - 26, 2013},
      editor = {Eiter, Thomas and Glimm, Birte and Kazakov, Yevgeny and Kr{\"o}tzsch, Markus},
      interhash = {16628740155947df4ba3ec1546f915c2},
      intrahash = {fa2e1973d362ebc08f35184ac088bf11},
      openaccess = {Yes},
      pages = {41-52},
      partneroptique = {FUB},
      publisher = {CEUR-WS.org},
      series = {CEUR Workshop Proceedings},
      title = {Tractability Guarantees for DL-Lite Query Answering},
      volume = 1014, wpoptique = {WP6},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex
    M. Bienvenu, M. Ortiz, M. Simkus, and G. Xiao, "Tractable Queries for Lightweight Description Logics," in IJCAI 2013, Proceedings of the 23rd International Joint Conference on Artificial Intelligence, Beijing, China, August 3-9, 2013, 2013.
    @inproceedings{DBLP:conf/ijcai/BienvenuOSX13, abstract = {It is a classic result in database theory that conjunctive query (CQ) answering, which is NP-complete in general, is feasible in polynomial time when restricted to acyclic queries. Subsequent results identified more general structural properties of CQs (like bounded treewidth) which ensure tractable query evaluation. In this paper, we lift these tractability results to knowledge bases formulated in the lightweight description logics DL-Lite and ELH. The proof exploits known properties of query matches in these logics and involves a query dependent modification of the data. To obtain a more practical approach, we propose a concrete polynomial-time algorithm for answering acyclic CQs based on rewriting queries into datalog programs. A preliminary evaluation suggests the interest of our approach for handling large acyclic CQs.},
      audience = {academic},
      author = {Bienvenu, Meghyn and Ortiz, Magdalena and Simkus, Mantas and Xiao, Guohui},
      booktitle = {IJCAI 2013, Proceedings of the 23rd International Joint Conference on Artificial Intelligence, Beijing, China, August 3-9, 2013},
      editor = {Rossi, Francesca},
      interhash = {ec03a805a1a1a619eba6894ccbef6675},
      intrahash = {f2183cceb3fa9f53bd67f5b7820e785e},
      openaccess = {Yes},
      partneroptique = {FUB},
      publisher = {IJCAI/AAAI},
      title = {Tractable Queries for Lightweight Description Logics},
      wpoptique = {WP6},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,article] bibtex Go to document
    E. Kharlamov, D. Zheleznyakov, and D. Calvanese, "Capturing Model-Based Ontology Evolution at the Instance Level: The Case of DL-Lite," Journal of Computer and System Sciences, vol. 79, iss. 6, pp. 835-872, 2013.
    @article{kharlamov2013capturing, abstract = {Evolution of Knowledge Bases (KBs) expressed in Description Logics (DLs) has gained a lot of attention lately. Recent studies on the topic have mostly focused on so-called model-based approaches (MBAs), where the evolution of a KB results in a set of models. For KBs expressed in tractable DLs, such as those of the DL-Lite family, which we consider here, it has been shown that one faces inexpressibility of evolution, i.e., the result of evolution of a DL-Lite KB in general cannot be expressed in DL-Lite, in other words, DL-Lite is not closed under evolution. What is still missing in these studies is a thorough understanding of various important aspects of the evolution problem for DL-Lite KBs: Which fragments of DL-Lite are closed under evolution? What causes the inexpressibility? Can one approximate evolution in DL-Lite, and if yes, how? This work provides some understanding of these issues for an important class of MBAs, which cover the cases of both update and revision. We describe what causes inexpressibility, and we propose techniques (based on what we call prototypes) that help to approximate evolution under the well-known approach by Winslett, which is inexpressible in DL-Lite. We also identify a fragment of DL-Lite closed under evolution, and for this fragment we provide polynomial-time algorithms to compute or approximate evolution results for various MBAs.},
      author = {Kharlamov, Evgeny and Zheleznyakov, Dmitriy and Calvanese, Diego},
      interhash = {4bcd77602bb52661c5309edcc04973e1},
      intrahash = {e4c2c5fe789dcef400a323831c2ac705},
      journal = {Journal of Computer and System Sciences},
      month = sep, number = 6, pages = {835-872},
      title = {Capturing Model-Based Ontology Evolution at the Instance Level: The Case of DL-Lite},
      url = {http://www.cs.ox.ac.uk/files/5554/main.pdf},
      volume = 79, year = 2013 }
  • [2013,inproceedings] bibtex Go to document
    P. Haase, I. Horrocks, D. Hovland, T. Hubauer, E. Jiménez-Ruiz, E. Kharlamov, J. Klüwer, C. Pinkel, R. Rosati, V. Santarelli, A. Soylu, and D. Zheleznyakov, "Optique System: Towards Ontology and Mapping Management in OBDA Solutions," in Workshop on Debugging Ontologies and Ontology Mappings (WoDOOM), 2013.
    @inproceedings{wodoom_wp4, abstract = {The Optique project aims at providing an end-to-end solution for scalable Ontology-Based Data Access to Big Data integration, where end-users will formulate queries based on a familiar conceptualization of the underlying domain, that is, over an ontology. From user queries the Optique platform will automatically generate appropriate queries over the underlying integrated data, optimize and execute them. The key components in the Optique platform are the ontology and mappings that provide the relationships between the ontology and the underlying data. In this paper we discuss the problem of bootstrapping and maintenance of ontologies and mappings. The important challenge in both tasks is debugging errors in ontologies and mappings. We will present examples of different kinds of error, and give our preliminary view on their debugging},
      audience = {academic},
      author = {Haase, Peter and Horrocks, Ian and Hovland, Dag and Hubauer, Thomas and Jim{\'e}nez-Ruiz, Ernesto and Kharlamov, Evgeny and Kl{\"u}wer, Johan and Pinkel, Christoph and Rosati, Riccardo and Santarelli, Valerio and Soylu, Ahmet and Zheleznyakov, Dmitriy},
      booktitle = {Workshop on Debugging Ontologies and Ontology Mappings (WoDOOM)},
      interhash = {4f82fbbe4a5e3edb09ddbb05103baf7c},
      intrahash = {8fa91236070d64bbf3be89ec3496753b},
      partneroptique = {UOXF},
      title = {{Optique System: Towards Ontology and Mapping Management in OBDA Solutions}},
      url = {http://www.cs.ox.ac.uk/files/5514/wodoom_wp4.pdf},
      wpoptique = {WP4},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex Go to document
    D. Calvanese, M. Giese, P. Haase, I. Horrocks, T. Hubauer, Y. Ioannidis, E. Jiménez-Ruiz, E. Kharlamov, H. Kllapi, J. Klüwer, M. Koubarakis, S. Lamparter, R. Möller, C. Neuenstadt, T. Nordtveit, Ö. Özcep, R. M. driguez Muro, M. Roshchin, M. Ruzzi, F. Savo, M. Schmidt, A. Soylu, A. Waaler, and D. Zheleznyakov, "Optique: OBDA Solution for Big Data," in Poster track of the Extended Semantic Web Conference, 2013.
    @inproceedings{eswc_wp2, abstract = {The Optique system will provide a novel end-to-end OBDA solution for Big Data access which will be integrated in the Information Workbench platform and address a number of important in-dustry requirements.},
      audience = {academic},
      author = {Calvanese, D. and Giese, M. and Haase, P. and Horrocks, I. and Hubauer, T. and Ioannidis, Y. and Jim\'{e}nez-Ruiz, E. and Kharlamov, E. and Kllapi, H. and Kl\"uwer, J. and Koubarakis, M. and Lamparter, S. and M\"oller, R. and Neuenstadt, C. and Nordtveit, T. and \"Ozcep, \"O. and driguez Muro, M. Ro\ and Roshchin, M. and Ruzzi, Marco and Savo, F. and Schmidt, M. and Soylu, A. and Waaler, A. and Zheleznyakov, D.},
      booktitle = {Poster track of the Extended Semantic Web Conference},
      interhash = {8d2de483ac7d2b0e889a4ee6fac4f54e},
      intrahash = {5548b53661cc296b54591966de365025},
      partneroptique = {UOXF},
      title = {{Optique: OBDA Solution for Big Data}},
      url = {http://www.cs.ox.ac.uk/files/5513/eswc_poster_wp2.pdf},
      wpoptique = {WP2},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex Go to document
    I. Horrocks, T. Hubauer, E. Jiménez-Ruiz, E. Kharlamov, M. Koubarakis, R. Möller, K. Bereta, C. Neuenstadt, Ö. Özçep, M. Roshchin, P. Smeros, and D. Zheleznyakov, "Addressing Streaming and Historical Data in OBDA Systems: Optique’s Approach (Statement of Interest)," in Workshop on Knowledge Discovery and Data Mining Meets Linked Open Data (Know@LOD), 2013.
    @inproceedings{kwnolod_wp5, abstract = {In large companies such as Siemens and Statoil monitoring tasks are of great importance, e.g., Siemens does monitoring of turbines and Statoil of oil behaviour in wells. This tasks bring up importance of both streaming and historical (temporal) data in the Big Data challenge for industries. We present the Optique project that addresses this problem by developing an Ontology Based Data Access (OBDA) system that incorporates novel tools and methodologies for processing and analyses of temporal and streaming data. In particular, we advocate for modelling time time aware data by temporal RDF and reduce monitoring tasks to knowledge discovery and data mining.},
      audience = {academic},
      author = {Horrocks, Ian and Hubauer, Thomas and Jim\'{e}nez-Ruiz, Ernesto and Kharlamov, Evgeny and Koubarakis, Manolis and M\"oller, Ralf and Bereta, Konstantina and Neuenstadt, Christian and \"Oz\c{c}ep, \"Ozg\"ur and Roshchin, Mikhail and Smeros, Panayiotis and Zheleznyakov, Dmitriy},
      booktitle = {Workshop on Knowledge Discovery and Data Mining Meets Linked Open Data (Know@LOD)},
      interhash = {a418e84834dd9ec52c34c0cf07b4e9b5},
      intrahash = {23dfd4317d59c272464b0562b26e07a3},
      partneroptique = {UOXF},
      title = {{Addressing Streaming and Historical Data in OBDA Systems: Optique's Approach (Statement of Interest)}},
      url = {http://www.cs.ox.ac.uk/files/5517/knowlod_wp5.pdf},
      wpoptique = {WP5},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex Go to document
    H. Kllapi, D. Bilidas, I. Horrocks, Y. Ioannidis, E. Jiménez-Ruiz, E. Kharlamov, M. Koubarakis, and D. Zheleznyakov, "Distributed Query Processing on the Cloud: the Optique Point of View (Short Paper)," in OWL Experiences and Directions Workshop (OWLED), 2013.
    @inproceedings{owled_wp7, abstract = {The Optique European project aims at providing an end-to-end solution for scalable access to Big Data integration, where end users will formulate queries based on a familiar conceptualization of the underlying domain. From the users’ queries the Optique platform will automatically generate appropriate queries over the underlying integrated data, optimize and execute them on the Cloud. In this paper we present the distributed query processing engine of the Optique platform. The efficient execution of complex queries posed by end users is an important and challenging task. The engine aims at providing a scalable solution for query execution in the Cloud, and should cope with heterogeneity of data sources as well as with temporal and streaming data.},
      audience = {academic},
      author = {Kllapi, Herald and Bilidas, Dimitris and Horrocks, Ian and Ioannidis, Yannis and Jim\'{e}nez-Ruiz, Ernesto and Kharlamov, Evgeny and Koubarakis, Manolis and Zheleznyakov, Dmitriy},
      booktitle = {OWL Experiences and Directions Workshop (OWLED)},
      interhash = {9a5084cf047bcbb8a630aad5619efe22},
      intrahash = {55d152ffdfd38c70984a20de386d56b3},
      partneroptique = {UOXF},
      title = {{Distributed Query Processing on the Cloud: the Optique Point of View (Short Paper)}},
      url = {http://www.cs.ox.ac.uk/files/5516/owled2013_wp7.pdf},
      wpoptique = {WP7},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex Go to document
    D. Calvanese, I. Horrocks, E. Jiménez-Ruiz, E. Kharlamov, M. Meier, M. Rodriguez-Muro, and D. Zheleznyakov, "On Rewriting and Answering Queries in OBDA Systems for Big Data (Short Paper)," in OWL Experiences and Directions Workshop (OWLED), 2013.
    @inproceedings{owled_wp6, abstract = {The project Optique aims at providing an end-to-end solution for scalable access to Big Data integration, were end users will formulate queries based on a familiar conceptualization of the underlying domain. From the users queries the Optique platform will automatically generate appropriate queries over the underlying integrated data, optimize and execute them. In this paper we discuss Optique's automatic generation of queries and two systems to support this process: Quest and Pegasus The automatic query generation is important and challenging, especially when the queries are over heterogeneous distributed databases and streams, and Optique will provide a scalable solution for it.},
      audience = {academic},
      author = {Calvanese, Diego and Horrocks, Ian and Jim\'{e}nez-Ruiz, Ernesto and Kharlamov, Evgeny and Meier, Michael and Rodriguez-Muro, Mariano and Zheleznyakov, Dmitriy},
      booktitle = {OWL Experiences and Directions Workshop (OWLED)},
      interhash = {60f257f709d9c345b7379656f1a28feb},
      intrahash = {a35cd55a5d04659d636a4a28fddc2a48},
      partneroptique = {UOXF},
      title = {{On Rewriting and Answering Queries in OBDA Systems for Big Data (Short Paper)}},
      url = {http://www.cs.ox.ac.uk/files/5515/owled2013_wp6.pdf},
      wpoptique = {WP6},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex Go to document
    B. Cuenca Grau, M. Giese, I. Horrocks, T. Hubauer, E. Jiménez-Ruiz, E. Kharlamov, M. Schmidt, A. Soylu, and D. Zheleznyakov, "Towards Query Formulation and Query-Driven Ontology Extensions in OBDA," in OWL Experiences and Directions Workshop (OWLED), 2013.
    @inproceedings{owled_wp3, abstract = {The process of translating end-users’ information needs into executable and optimised queries over the data is the main problem that end-users face in Big Data scenarios. In this paper we present the recently started EU project Optique, which advocates for a next generation of the well known Ontology-Based Data Access (OBDA) approach to address this problem. We discuss challenges, present ongoing work, and our current preliminary solutions with regards to the query formulation and query-driven ontology extension.},
      audience = {academic},
      author = {Cuenca Grau, Bernardo and Giese, Martin and Horrocks, Ian and Hubauer, Thomas and Jim\'{e}nez-Ruiz, Ernesto and Kharlamov, Evgeny and Schmidt, Michael and Soylu, Ahmet and Zheleznyakov, Dmitriy},
      booktitle = {OWL Experiences and Directions Workshop (OWLED)},
      interhash = {7462ba79fd00659297e6e7ac30fc03d6},
      intrahash = {95064d9fec4a65bd253cbb15592d85ab},
      partneroptique = {UOXF},
      title = {{Towards Query Formulation and Query-Driven Ontology Extensions in OBDA}},
      url = {http://www.cs.ox.ac.uk/files/5511/owled2013_wp3.pdf},
      wpoptique = {WP3},
      year = 2013, yearoptique = {Y1}
    }
  • [2013,inproceedings] bibtex Go to document
    D. Calvanese, M. Giese, P. Haase, I. Horrocks, T. Hubauer, Y. Ioannidis, E. Jiménez-Ruiz, E. Kharlamov, H. Kllapi, J. Klüwer, M. Koubarakis, S. Lamparter, R. Möller, C. Neuenstadt, T. Nordtveit, Ö. Özcep, R. M. driguez Muro, M. Roshchin, M. Ruzzi, F. Savo, M. Schmidt, A. Soylu, A. Waaler, and D. Zheleznyakov, "The Optique Project: Towards OBDA Systems for Industry (Short Paper)," in OWL Experiences and Directions Workshop (OWLED), 2013.
    @inproceedings{owled_wp2, abstract = {In this paper we present the EU Optique project that aims at developing an end-to-end OBDA system for managing Big Data in industries. We discuss limitations of state of the art OBDA systems and present the general architecture of the Optique’s OBDA system that aims at overcoming these limitations.},
      audience = {academic},
      author = {Calvanese, D. and Giese, M. and Haase, P. and Horrocks, I. and Hubauer, T. and Ioannidis, Y. and Jim\'{e}nez-Ruiz, E. and Kharlamov, E. and Kllapi, H. and Kl\"uwer, J. and Koubarakis, M. and Lamparter, S. and M\"oller, R. and Neuenstadt, C. and Nordtveit, T. and \"Ozcep, \"O. and driguez Muro, M. Ro\ and Roshchin, M. and Ruzzi, Marco and Savo, F. and Schmidt, M. and Soylu, A. and Waaler, A. and Zheleznyakov, D.},
      booktitle = {OWL Experiences and Directions Workshop (OWLED)},
      interhash = {c2564327af8d77cae5d2fcbaaa47179c},
      intrahash = {c52a02c7b0ab0197039fcddd9c938490},
      partneroptique = {UOXF},
      title = {{The Optique Project: Towards OBDA Systems for Industry (Short Paper)}},
      url = {http://www.cs.ox.ac.uk/files/5512/owled2013_wp2.pdf},
      wpoptique = {WP2},
      year = 2013, yearoptique = {Y1}
    }
  • [2012,inproceedings] bibtex Go to document
    &. L. Özçep and R. Möller, "Scalable Geo-thematic Query Answering," in International Semantic Web Conference (1), 2012, pp. 658-673.
    @inproceedings{conf/semweb/OzcepM12, abstract = {First order logic (FOL) rewritability is a desirable feature for query answering over geo-thematic ontologies because in most geo- processing scenarios one has to cope with large data volumes. Hence, there is a need for combined geo-thematic logics that provide a suf- ficiently expressive query language allowing for FOL rewritability. The DL-Lite family of description logics is tailored towards FOL rewritability of query answering for unions of conjunctive queries, hence it is a suit- able candidate for the thematic component of a combined geo-thematic logic. We show that a weak coupling of DL-Lite with the expressive region connection calculus RCC8 allows for FOL rewritability under a spatial completeness condition for the ABox. Stronger couplings allow- ing for FOL rewritability are possible only for spatial calculi as weak as the low-resolution calculus RCC2. Already a strong combination of DL-Lite with the low-resolution calculus RCC3 does not allow for FOL rewritability.},
      audience = {academic},
      author = {Özçep, Özgür Lütfü and Möller, Ralf},
      booktitle = {International Semantic Web Conference (1)},
      crossref = {conf/semweb/2012-1},
      doi = {http://dx.doi.org/10.1007/978-3-642-35176-1_41},
      editor = {Cudré-Mauroux, Philippe and Heflin, Jeff and Sirin, Evren and Tudorache, Tania and Euzenat, Jérôme and Hauswirth, Manfred and Parreira, Josiane Xavier and Hendler, Jim and Schreiber, Guus and Bernstein, Abraham and Blomqvist, Eva},
      ee = {http://dx.doi.org/10.1007/978-3-642-35176-1_41},
      interhash = {852b04faf304e0599da923e1baefc10e},
      intrahash = {c1892873d575b2c3284ea436ffc64c61},
      isbn = {978-3-642-35175-4},
      openaccess = {No},
      pages = {658--673},
      partneroptique = {TUHH},
      publisher = {Springer},
      series = {Lecture Notes in Computer Science},
      title = {Scalable Geo-thematic Query Answering},
      url = {http://dblp.uni-trier.de/db/conf/semweb/iswc2012-1.html#OzcepM12},
      volume = 7649, wpoptique = {WP5},
      year = 2012, yearoptique = {Y1}
    }
  • [2012,inproceedings] bibtex Go to document
    P. Haase and M. Schmidt, "On Demand Access to Big Data through Semantic Technologies," in Proceedings of the ISWC 2012 Industry Track, 2012.
    @inproceedings{peterhaase2012iswc2012, author = {Haase, Peter and Schmidt, Michael},
      booktitle = {Proceedings of the ISWC 2012 Industry Track},
      interhash = {4008f843a2dffc16f1741e32ecb7f851},
      intrahash = {120ce02cf5fb9b3c9a1dda8bb55fc21b},
      month = {November},
      title = {On Demand Access to Big Data through Semantic Technologies},
      url = {http://data.semanticweb.org/conference/iswc/2012/paper/industry-04},
      year = 2012 }
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