%0 Conference Proceedings %B Proceedings of the AAAI 2020 Spring Symposium on Combining Machine Learning and Knowledge Engineering in Practice %D 2020 %T Completion Reasoning Emulation for the Description Logic EL+ %A Aaron Eberhart %A Monireh Ebrahimi %A Lu Zhou %A Cogan Shimizu %A Pascal Hitzler %K Deep Learning %K Description Logic %K EL+ %K LSTM %K NeSy %K Reasoning %X

We present a new approach to integrating deep learning with knowledge-based systems that we believe shows promise. Our approach seeks to emulate reasoning structure, which can be inspected part-way through, rather than simply learning reasoner answers, which is typical in many of the black-box systems currently in use. We demonstrate that this idea is feasible by training a long short-term memory (LSTM) artificial neural network to learn EL+ reasoning patterns with two different data sets. We also show that this trained system is resistant to noise by corrupting a percentage of the test data and comparing the reasoner's and LSTM's predictions on corrupt data with correct answers.

%B Proceedings of the AAAI 2020 Spring Symposium on Combining Machine Learning and Knowledge Engineering in Practice %I CEUR-WS.org %C Stanford University, Palo Alto, California, USA %V 2600 %8 03/2020 %G eng %U http://ceur-ws.org/Vol-2600/paper5.pdf %0 Conference Paper %B The Semantic Web: ESWC 2018 Satellite Events - ESWC 2018 Satellite Events, Heraklion, Crete, Greece, June 3-7, 2018, Revised Selected Papers %D 2018 %T Pseudo-Random ALC Syntax Generation %A Aaron Eberhart %A Michelle Cheatham %A Pascal Hitzler %K ALC %K Description Logic %K DL %K random generation %K synthetic data %X We discuss a tool capable of rapidly generating pseudo-random syntactically valid ALC expression trees. The program is meant to allow a researcher to create large sets of independently valid expressions with a minimum of personal bias for experimentation. %B The Semantic Web: ESWC 2018 Satellite Events - ESWC 2018 Satellite Events, Heraklion, Crete, Greece, June 3-7, 2018, Revised Selected Papers %I Springer %C Heraklion, Crete, Greece %V 11155 %P 19–22 %@ 978-3-319-98191-8 %G eng %U https://doi.org/10.1007/978-3-319-98192-5\_4 %R 10.1007/978-3-319-98192-5\_4 %0 Thesis %B Computer Science and Engineering %D 2017 %T Efficient Reasoning Algorithms for Fragments of Horn Description Logics %A David Carral %K Description Logic %K Knowledge representation %K Reasoning %X We characterize two fragments of Horn Description Logics and we define two specialized reasoning algorithms that effectively solve the standard reasoning tasks over each of such fragments. We believe our work to be of general interest since (1) a rather large proportion of real-world Horn ontologies belong to some of these two fragments and (2) the implementations based on our reasoning approach significantly outperform state-of-the-art reasoners. Claims (1) and (2) are extensively proven via empirically evaluation. %B Computer Science and Engineering %I Wright State University %C Dayton %V Doctor of Philosophy (PhD) %P 70 %G eng %U http://rave.ohiolink.edu/etdc/view?acc_num=wright1491317096530938 %0 Journal Article %J Semantic Web %D 2013 %T Paraconsistent OWL and Related Logics %A Frederick Maier %A Yue Ma %A Pascal Hitzler %K Automated Deduction %K Complexity %K Description Logic %K OWL %K Paraconsistency %K Semantic Web %K Web Ontology Language %X The Web Ontology Language OWL is currently the most prominent formalism for representing ontologies in Semantic Web applications. OWL is based on description logics, and automated reasoners are used to infer knowledge implicitly present in OWL ontologies. However, because typical description logics obey the classical principle of explosion, reasoning over inconsistent ontologies is impossible in OWL. This is so despite the fact that inconsistencies are bound to occur in many realistic cases, e.g., when multiple ontologies are merged or when ontologies are created by machine learning or data mining tools. In this paper, we present four-valued paraconsistent description logics which can reason over inconsistencies. We focus on logics corresponding to OWL DL and its profiles. We present the logic SROIQ4, showing that it is both sound relative to classical SROIQ and that its embedding into SROIQ is consequence preserving. We also examine paraconsistent varieties of EL++, DL-Lite, and Horn-DLs. The general framework described here has the distinct advantage of allowing classical reasoners to draw sound but nontrivial conclusions from even inconsistent knowledge bases. Truth-value gaps and gluts can also be selectively eliminated from models (by inserting additional axioms into knowledge bases). If gaps but not gluts are eliminated, additional classical conclusions can be drawn without affecting paraconsistency. %B Semantic Web %V 4 %P 395–427 %G eng %U http://dx.doi.org/10.3233/SW-2012-0066 %R 10.3233/SW-2012-0066 %0 Conference Paper %B Proceedings of the 20th International Conference on World Wide Web, WWW 2011, Hyderabad, India, March 28 - April 1, 2011 %D 2011 %T A Better Uncle for OWL: Nominal Schemas for Integrating Rules and Ontologies %A Markus Krötzsch %A Frederick Maier %A Adila Krisnadhi %A Pascal Hitzler %E Sadagopan Srinivasan %E Krithi Ramamritham %E Arun Kumar %E M. P. Ravindra %E Elisa Bertino %E Ravi Kumar %K datalog %K Description Logic %K Semantic Web Rule Language %K SROIQ %K tractability %K Web Ontology Language %X We propose a description-logic style extension of OWL 2 with nominal schemas which can be used like "variable nominal classes" within axioms. This feature allows ontology languages to express arbitrary DL-safe rules (as expressible in SWRL or RIF) in their native syntax. We show that adding nominal schemas to OWL 2 does not increase the worst-case reasoning complexity, and we identify a novel tractable language SROELV3(\cap, x) that is versatile enough to capture the lightweight languages OWL EL and OWL RL. %B Proceedings of the 20th International Conference on World Wide Web, WWW 2011, Hyderabad, India, March 28 - April 1, 2011 %I ACM %P 645-654 %8 03/2011 %@ 978-1-4503-0632-4 %G eng %U http://doi.acm.org/10.1145/1963405.1963496 %R 10.1145/1963405.1963496 %0 Journal Article %J Artificial Intelligence %D 2011 %T Local Closed World Reasoning with Description Logics under the Well-Founded Semantics %A Matthias Knorr %A José Júlio Alferes %A Pascal Hitzler %K Description Logic %K Knowledge representation %K Logic Programming %K Non-monotonic reasoning %K Ontologies %K Semantic Web %X

An important question for the upcoming Semantic Web is how to best combine open world ontology languages, such as the OWL-based ones, with closed world rule-based languages. One of the most mature proposals for this combination is known as hybrid MKNF knowledge bases [52], and it is based on an adaptation of the Stable Model Semantics to knowledge bases consisting of ontology axioms and rules. In this paper we propose a well-founded semantics for nondisjunctive hybrid MKNF knowledge bases that promises to provide better efficiency of reasoning, and that is compatible with both the OWL-based semantics and the traditional Well-Founded Semantics for logic programs. Moreover, our proposal allows for the detection of inconsistencies, possibly occurring in tightly integrated ontology axioms and rules, with only little additional effort. We also identify tractable fragments of the resulting language.

%B Artificial Intelligence %V 175 %P 1528–1554 %G eng %U http://dx.doi.org/10.1016/j.artint.2011.01.007 %N 9-10 %R 10.1016/j.artint.2011.01.007 %0 Conference Paper %B Proceedings of the 24th International Workshop on Description Logics (DL 2011), Barcelona, Spain, July 13-16, 2011 %D 2011 %T Local Closed World Semantics: Keep it simple, stupid! %A Adila Krisnadhi %A Kunal Sengupta %A Pascal Hitzler %E Riccardo Rosati %E Sebastian Rudolph %E Michael Zakharyaschev %K circumscription %K closed world %K decidability %K Description Logic %X 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. %B Proceedings of the 24th International Workshop on Description Logics (DL 2011), Barcelona, Spain, July 13-16, 2011 %I CEUR-WS.org %V 745 %8 07/2011 %G eng %U http://ceur-ws.org/Vol-745/paper_12.pdf