TY - CHAP T1 - Seed Patterns for Modeling Trees T2 - Advances in Pattern-Based Ontology Engineering Y1 - 2021 A1 - Aaron Eberhart A1 - David Carral A1 - Pascal Hitzler A1 - Hilmar Lapp A1 - Sebastian Rudolph AB - Trees – i.e., the type of data structure known under this name – are central to many aspects of knowledge organization. We investigate some central design choices concerning the ontological modeling of such trees. In particular, we consider the limits of what is expressible in the Web Ontology Language and provide a reusable ontology design pattern for trees. JF - Advances in Pattern-Based Ontology Engineering PB - IOS Press ER - TY - CONF T1 - On the Ontological Modeling of Trees T2 - 8th Workshop on Ontology Design and Patterns - WOP2017 Y1 - 2017 A1 - David Carral A1 - Pascal Hitzler A1 - Hilmar Lapp A1 - Sebastian Rudolph JF - 8th Workshop on Ontology Design and Patterns - WOP2017 ER - TY - CONF T1 - All But Not Nothing: Left-Hand Side Universals for Tractable OWL Profiles T2 - Proceedings of the 11th International Workshop on OWL: Experiences and Directions (OWLED 2014) co-located with 13th International Semantic Web Conference on (ISWC 2014), Riva del Garda, Italy, October 17-18, 2014. Y1 - 2014 A1 - David Carral A1 - Adila Krisnadhi A1 - Sebastian Rudolph A1 - Pascal Hitzler ED - C. Maria Keet ED - Valentina A. M. Tamma KW - description logics KW - Horn Logics KW - OWL AB - We show that occurrences of the universal quantifier in the left-hand side of general concept inclusions can be rewritten into EL++ axioms under certain circumstances. I.e., this intuitive modeling feature is available for OWL EL while retaining tractability. Furthermore, this rewriting makes it possible to reason over corresponding extensions of EL++ and Horn-SROIQ using standard reasoners. JF - Proceedings of the 11th International Workshop on OWL: Experiences and Directions (OWLED 2014) co-located with 13th International Semantic Web Conference on (ISWC 2014), Riva del Garda, Italy, October 17-18, 2014. PB - CEUR-WS.org VL - 1265 UR - http://ceur-ws.org/Vol-1265/owled2014_submission_13.pdf ER - TY - JOUR T1 - Complexities of Horn Description Logics JF - ACM Trans. Comput. Log. Y1 - 2013 A1 - Markus Krötzsch A1 - Sebastian Rudolph A1 - Pascal Hitzler KW - computational complexity KW - description logics KW - Horn logic AB - Description Logics (DLs) have become a prominent paradigm for representing knowledge bases in a variety of application areas. Central to leveraging them for corresponding systems is the provision of a favourable balance between expressivity of the knowledge representation formalism on the one hand, and runtime performance of reasoning algorithms on the other. Due to this, Horn description logics (Horn DLs) have attracted attention since their (worst-case) data complexities are in general lower than their overall (i.e. combined) complexities, which makes them attractive for reasoning with large sets of instance data (ABoxes). However, the natural question whether Horn DLs also provide advantages for schema (TBox) reasoning has hardly been addressed so far. In this paper, we therefore provide a thorough and comprehensive analysis of the combined complexities of Horn DLs. While the combined complexity for many Horn DLs studied herein turns out to be the same as for their non-Horn counterparts, we identify subboolean DLs where Hornness simplifies reasoning. We also provide convenient normal forms for Horn DLs. VL - 14 UR - http://doi.acm.org/10.1145/2422085.2422087 ER - TY - CONF T1 - An Ontology Design Pattern for Cartographic Map Scaling T2 - The Semantic Web: Semantics and Big Data, 10th International Conference, ESWC 2013, Montpellier, France, May 26-30, 2013. Proceedings Y1 - 2013 A1 - David Carral A1 - Simon Scheider A1 - Krzysztof Janowicz A1 - Charles Vardeman A1 - Adila Krisnadhi A1 - Pascal Hitzler ED - Philipp Cimiano ED - Óscar Corcho ED - Valentina Presutti ED - Laura Hollink ED - Sebastian Rudolph KW - Map Scaling KW - Ontology Design Patterns KW - OWL AB -
The concepts of scale is at the core of cartographic abstraction and mapping. It defines which geographic phenomena should be displayed, which type of geometry and map symbol to use, which measures can be taken, as well as the degree to which features need to be exaggerated or spatially displaced. In this work, we present an ontology design pattern for map scaling using the Web Ontology Language (OWL) within a particular extension of the OWL RL profile. We explain how it can be used to describe scaling applications, to reason over scale levels, and geometric representations. We propose an axiomatization that allows us to impose meaningful constraints on the pattern, and, thus, to go beyond simple surface semantics. Interestingly, this includes several functional constraints currently not expressible in any of the OWL profiles. We show that for this specific scenario, the addition of such constraints does not increase the reasoning complexity which remains tractable.
JF - The Semantic Web: Semantics and Big Data, 10th International Conference, ESWC 2013, Montpellier, France, May 26-30, 2013. Proceedings PB - Springer VL - 7882 UR - http://dx.doi.org/10.1007/978-3-642-38288-8_6 ER - TY - BOOK T1 - 语义Web技术基础 Y1 - 2013 A1 - Pascal Hitzler A1 - Markus Krötzsch A1 - Sebastian Rudolph PB - Tsinghua University Press ER - TY - ICOMM T1 - OWL 2 Web Ontology Language: Primer (Second Edition) Y1 - 2012 A1 - Pascal Hitzler A1 - Markus Krötzsch A1 - Bijan Parsia A1 - Peter F. Patel-Schneider A1 - Sebastian Rudolph UR - http://www.w3.org/TR/owl2-primer ER - TY - JOUR T1 - Type-Elimination-Based Reasoning for the Description Logic SHIQbs using Decision Diagrams and Disjunctive Datalog JF - Logical Methods in Computer Science Y1 - 2012 A1 - Sebastian Rudolph A1 - Markus Krötzsch A1 - Pascal Hitzler KW - datalog KW - decision diagrams KW - description logics KW - type elimination AB - We propose a novel, type-elimination-based method for standard reasoning in the description logic SHIQbs extended by DL-safe rules. To this end, we first establish a knowledge compilation method converting the terminological part of an ALCIb knowledge base into an ordered binary decision diagram (OBDD) that represents a canonical model. This OBDD can in turn be transformed into disjunctive Datalog and merged with the assertional part of the knowledge base in order to perform combined reasoning. In order to leverage our technique for full SHIQbs, we provide a stepwise reduction from SHIQbs to ALCIb that preserves satisfiability and entailment of positive and negative ground facts. The proposed technique is shown to be worst-case optimal w.r.t. combined and data complexity. VL - 8 UR - http://dx.doi.org/10.2168/LMCS-8(1:12)2012 ER - TY - CONF T1 - Local Closed World Semantics: Grounded Circumscription for Description Logics T2 - Web Reasoning and Rule Systems - 5th International Conference, RR 2011, Galway, Ireland, August 29-30, 2011. Proceedings Y1 - 2011 A1 - Adila Krisnadhi A1 - Kunal Sengupta A1 - Pascal Hitzler ED - Sebastian Rudolph ED - Claudio Gutierrez AB - We present an improved local closed world extension for description logics. It is based on circumscription, and deviates from previous circumscriptive description logics in that extensions of minimized predicates may contain only extensions of named individuals in the knowledge base. Besides an (arguably) higher intuitive appeal, the improved semantics is applicable to expressive description logics without loss of decidability. JF - Web Reasoning and Rule Systems - 5th International Conference, RR 2011, Galway, Ireland, August 29-30, 2011. Proceedings PB - Springer VL - 6902 SN - 978-3-642-23579-5 UR - http://dx.doi.org/10.1007/978-3-642-23580-1 ER - TY - CONF T1 - Local Closed World Semantics: Keep it simple, stupid! T2 - Proceedings of the 24th International Workshop on Description Logics (DL 2011), Barcelona, Spain, July 13-16, 2011 Y1 - 2011 A1 - Adila Krisnadhi A1 - Kunal Sengupta A1 - Pascal Hitzler ED - Riccardo Rosati ED - Sebastian Rudolph ED - Michael Zakharyaschev KW - circumscription KW - closed world KW - decidability KW - Description Logic AB - A combination of open and closed-world reasoning (usually called local closed world reasoning) is a desirable capability of knowledge representation formalisms for Semantic Web applications. However, none of the proposals made to date for extending description logics with local closed world capabilities has had any significant impact on applications. We believe that one of the key reasons for this is that current proposals fail to provide approaches which are intuitively accessible for application developers and at the same time are applicable, as extensions, to expressive description logics such as SROIQ, which underlies the Web Ontology Language OWL. In this paper we propose a new approach which overcomes key limitations of other major proposals made to date. It is based on an adaptation of circumscriptive description logics which, in contrast to previously reported circumscription proposals, is applicable to SROIQ without rendering reasoning over the resulting language undecidable. JF - Proceedings of the 24th International Workshop on Description Logics (DL 2011), Barcelona, Spain, July 13-16, 2011 PB - CEUR-WS.org VL - 745 UR - http://ceur-ws.org/Vol-745/paper_12.pdf ER - TY - CONF T1 - Nominal Schemas for Integrating Rules and Description Logics T2 - Proceedings of the 24th International Workshop on Description Logics (DL 2011), Barcelona, Spain, July 13-16, 2011 Y1 - 2011 A1 - Markus Krötzsch A1 - Frederick Maier A1 - Adila Krisnadhi A1 - Pascal Hitzler ED - Riccardo Rosati ED - Sebastian Rudolph ED - Michael Zakharyaschev AB - We propose an extension of SROIQ with nominal schemas which can be used like “variable nominal concepts” within axioms. This feature allows us to express arbitrary DL-safe rules in description logic syntax. We show that adding nominal schemas to SROIQ does not increase its worst-case reasoning complexity, and we identify a family of tractable DLs SROELVn that allow for restricted use of nominal schemas. JF - Proceedings of the 24th International Workshop on Description Logics (DL 2011), Barcelona, Spain, July 13-16, 2011 PB - CEUR-WS.org VL - 745 UR - http://ceur-ws.org/Vol-745/paper_39.pdf ER - TY - CONF T1 - Paraconsistent Semantics for Hybrid MKNF Knowledge Bases T2 - Web Reasoning and Rule Systems - 5th International Conference, RR 2011 Y1 - 2011 A1 - Shasha Huang A1 - Qingguo Li A1 - Pascal Hitzler ED - Sebastian Rudolph ED - Claudio Gutierrez AB -Hybrid MKNF knowledge bases, originally based on the stable model semantics, is a mature method of combining rules and Description Logics (DLs). The well-founded semantics for such knowledge bases has been proposed subsequently for better efficiency of reasoning. However, integration of rules and DLs may give rise to inconsistencies, even if they are respectively consistent. Accordingly, reasoning systems based on the previous two semantics will break down. In this paper, we employ the four-valued logic proposed by Belnap, and present a paraconsistent semantics for Hybrid MKNF knowledge bases, which can detect inconsistencies and handle it effectively. Besides, we transform our proposed semantics to the stable model semantics via a linear transformation operator, which indicates that the data complexity in our paradigm is not higher than that of classical reasoning. Moreover, we provide a fixpoint algorithm for computing paraconsistent MKNF models.
JF - Web Reasoning and Rule Systems - 5th International Conference, RR 2011 PB - Springer CY - Galway, Ireland VL - 6902 UR - http://dx.doi.org/10.1007/978-3-642-23580-1_8 ER - TY - CONF T1 - An Evolutionary Computing Approach for Reasoning in the Semantic Web T2 - Poster at DECOI2009, the International Workshop on Collective Intelligence andEvolution Y1 - 2009 A1 - Gaston Tagni A1 - Christophe Gueret A1 - Stefan Schlobach A1 - Sebastian Rudolph A1 - Pascal Hitzler JF - Poster at DECOI2009, the International Workshop on Collective Intelligence andEvolution CY - Leiden, The Netherlands ER - TY - BOOK T1 - Foundations of Semantic Web Technologies T2 - Textbooks in Computing Y1 - 2009 A1 - Pascal Hitzler A1 - Markus Krötzsch A1 - Sebastian Rudolph JF - Textbooks in Computing PB - Chapman and Hall/CRC Press ER - TY - ICOMM T1 - OWL 2 Web Ontology Language: Primer Y1 - 2009 A1 - Pascal Hitzler A1 - Markus Krötzsch A1 - Bijan Parsia A1 - Peter F. Patel-Schneider A1 - Sebastian Rudolph UR - http://www.w3.org/TR/2009/REC-owl2-primer-20091027 ER - TY - BOOK T1 - Semantic Web Grundlagen Y1 - 2008 A1 - Pascal Hitzler A1 - Markus Krötzsch A1 - Sebastian Rudolph A1 - York Sure PB - Springer textbook ER -