Information Systems Group

― Knowledge Representation and Reasoning

Despoina Magka

Research Student

Biography

I am a final year doctoral student and member of the Information Systems Group led by Prof. Ian Horrocks. During my DPhil, I worked on knowledge representation and reasoning formalisms modelling non-tree structures, such as complex biochemical objects. Specifically, I built a theoretical and practical logic-based framework for the classification of graph-shaped objects based on their structural properties. In the context of this framework, I researched extensions of datalog rules with existentials in the head and nonmonotonic negation in the body and their application to automatically building taxonomies of manually curated knowledge bases.

Prior to that, I completed an MSc Computer Science degree in the Department of Computer Science, University of Oxford; for my MSc project and under the supervision of Dr. Yevgeny Kazakov and Prof. Ian Horrocks I outlined polynomiality conditions for the lightweight description logic EL when extended with numerical datatypes.

For my first degree, I studied electrical and computer engineering in National Technical University of Athens. In my undergrad project and under the supervision of Dr. Giorgos Stamou, I explored methods for connecting databases and ontological knowledge under the presence of uncertainty. In particular, I developed a java tool to convert database tuples into fuzzy OWL assertions according to user-defined membership functions.

Conference Publications

Despoina Magka, Markus Krötzsch, Ian Horrocks
Computing Stable Models for Nonmonotonic Existential Rules.
In Proceedings of the 23rd International Joint Conference on Artificial Intelligence, (IJCAI 2013), AAAI press, 2013.
[Pdf   |  BibTeX-Entry  |  Abstract  |  Experiments ]

Markus Krötzsch, Despoina Magka, Ian Horrocks
Concrete Results on Abstract Rules.
In Proceedings of the 12th International Conference on Logic Programming and Nonmonotonic Reasoning (LPNMR 2013) , Springer, 2013.
[Pdf   |  BibTeX-Entry  |  Abstract ]

Bernardo Cuenca Grau, Ian Horrocks, Markus Krötzsch, Clemens Kupke, Despoina Magka, Boris Motik and Zhe Wang
Acyclicity Conditions and their Application to Query Answering in Description Logics.
In Proceedings of the 13th International Conference on Principles of Knowledge Representation and Reasoning (KR 2012), AAAI Press, 2012.
[Pdf   |  BibTeX-Entry  |  Abstract ]

Despoina Magka, Boris Motik and Ian Horrocks
Modelling Structured Domains Using Description Graphs and Logic Programming.
In Proceedings of the 9th Extended Semantic Web Conference (ESWC 2012), Vol. 7295, Pages 330-344, Springer, 2012.
[Pdf   |  BibTeX-Entry  |  Abstract  |  Experiments ]

Despoina Magka, Yevgeny Kazakov and Ian Horrocks
Tractable Extensions of the Description Logic EL with Numerical Datatypes.
In Proceedings of the Int. Joint Conf. on Automated Reasoning (IJCAR 2010), Vol. 6173, Pages 61-75, LNAI, 2010.
[Pdf   |  BibTeX-Entry  |  Abstract ]

Journal Publications

Bernardo Cuenca Grau, Ian Horrocks, Markus Krötzsch, Clemens Kupke, Despoina Magka, Boris Motik and Zhe Wang
Acyclicity Notions for Existential Rules and Their Application to Query Answering in Ontologies.
In Journal of Artificial Intelligence Research (JAIR), Vol.47:781-808.
[Pdf   |  BibTeX-Entry  |  Abstract ]

Janna Hastings, Despoina Magka, Colin Batchelor, Lian Duan, Robert Stevens, Marcus Ennis and Christoph Steinbeck
Structure-based classification and ontology in chemistry.
In Journal of Cheminformatics, 4:8, 2012.
[Pdf   |  BibTeX-Entry  |  Abstract  |   Paper at Chemistry Central ]

Despoina Magka, Yevgeny Kazakov and Ian Horrocks
Tractable Extensions of the Description Logic EL with Numerical Datatypes.
In Journal of Automated Reasoning, 47(4):427-450, 2011.
[Pdf   |  BibTeX-Entry  |  Abstract  |  Paper at Springer ]

Workshop Publications

Despoina Magka, Markus Krötzsch, Ian Horrocks
Nonmonotonic Existential Rules for Non-Tree-Shaped Ontological Modelling.
In Proceedings of the The 26th International Workshop on Description Logics (DL 2013) , CEUR, 2013.
[Pdf   |  BibTeX-Entry  |  Abstract  |  Experiments ]

Despoina Magka
Ontology-Based Classification of Molecules: a Logic Programming Approach.
In Proceedings of the 5th International Workshop on Semantic Web Applications and Tools for Life Sciences (SWAT4LS 2012), Best paper prize.
[Pdf   |  BibTeX-Entry  |  Abstract  |  Experiments ]

Despoina Magka, Boris Motik and Ian Horrocks
Modelling Structured Domains Using Description Graphs and Logic Programming.
In Proceedings of the The 25th International Workshop on Description Logics (DL 2012) , Vol. 846, CEUR, 2012.
[Pdf   |  BibTeX-Entry  |  Abstract  |  Experiments ]

Despoina Magka, Boris Motik and Ian Horrocks
Classifying Chemicals Using Description Graphs and Logic Programming.
In Proceedings of the 9th OWL: Experiences and Directions Workshop (OWLED 2012), Vol.849, 2012.
[Pdf   |  BibTeX-Entry  |  Abstract  |  Experiments ]

Despoina Magka, Boris Motik and Ian Horrocks
Chemical Knowledge Representation with Description Graphs and Logic Programming.
In Proceedings of the 4th International Workshop on Semantic Web Applications and Tools for Life Sciences (SWAT4LS 2011), Pages 74-75, ACM, 2011.
Highlight poster .
[Pdf   |  BibTeX-Entry  |  Abstract  |  Experiments ]

Despoina Magka, Yevgeny Kazakov and Ian Horrocks
Tractable Extensions of the Description Logic EL with Numerical Datatypes.
In Proceedings of the 2010 Description Logic Workshop (DL 2010), Vol. 573, Pages 79-90, CEUR, 2010.
[Pdf   |  BibTeX-Entry  |  Abstract ]

Teaching

Class tutor for Knowledge Representation and Reasoning 11/12

Teaching assistant for Reasoning About Information Update 11/12

Teaching assistant for Knowledge Representation and Reasoning 10/11

Teaching assistant and practical demonstrator for Intelligent Systems 10/11

Activities

PC member, 4th International Conference on Biomedical Ontology (ICBO 2013)

PC member, 2nd OWL Reasoner Evaluation Workshop (ORE 2013)

PC member, 2nd International Workshop on Exploiting Large Knowledge Repositories (E-LKR 2012)

Technical Reports

Despoina Magka, Markus Krötzsch, Ian Horrocks
Stable Models for Nonmonotonic Existential Rules.
Technical report, University of Oxford, 2013.
[Pdf   |  BibTeX-Entry  |  Abstract  |  Experiments ]

Despoina Magka
Extending Logic Programming for Life Sciences Applications.
Extended abstract, Oxford University Department of Computer Science Student Conference 2012.
[Pdf   |  BibTeX-Entry ]

Despoina Magka, Boris Motik and Ian Horrocks
Modelling Structured Domains Using Description Graphs and Logic Programming.
Technical report, University of Oxford, 2011.
[Pdf   |  BibTeX-Entry  |  Abstract  |  Experiments ]

Despoina Magka, Yevgeny Kazakov and Ian Horrocks
Tractable Extensions of the Description Logic EL with Numerical Datatypes.
Technical report, University of Oxford, 2010.
[Pdf   |  BibTeX-Entry  |  Abstract ]

Despoina Magka,
Representing Graph-based Structures with Logic.
Transfer report, University of Oxford, 2010.
[Pdf ]

Dissertations

Despoina Magka
Consequence-based Datatype Reasoning in EL: Identifying the Tractable Fragments.
MSc Project, Oxford University Computing Laboratory, September 2009.
[Pdf   |  BibTeX-Entry  |  Abstract ]

Despoina Magka
Database and ontology integration under uncertainty.
Diploma Thesis (in Greek), National Technical University of Athens, July 2008.
[Pdf (6.01M)  |  BibTeX-Entry  |  Abstract ]

Talks and Slides

Computing Stable Models for Nonmonotonic Existential Rules, at International Joint Conference on Artificial Intelligence (IJCAI 2013), Beijing, China, August 2013. [Slides  | Poster ]

Ontology-Based Classification of Molecules: a Logic Programming Approach, at Semantic Web Applications and Tools for Life Sciences workshop (SWAT4LS 2012), Paris, France, November 2012. [Pdf  | Slideshare ]

Extending Logic Programming for Life Sciences Applications, at Oxford University Department of Computer Science Student Conference 2012 , Oxford, UK, November 2012. [Pdf ]

Acyclicity Conditions and their Application to Query Answering in Description Logics, at International Conference on Principles of Knowledge Representation and Reasoning (KR 2012), Rome, Italy, June 2012. [Pdf  | Slideshare ]

Modelling Structured Domains Using Description Graphs and Logic Programming, at International Workshop on Description Logics (DL 2012) , Rome, Italy, June 2012. [Pdf ]

Modelling Structured Domains Using Description Graphs and Logic Programming, at Extended Semantic Web Conference (ESWC 2012) , Hersonissos, Crete, Greece, May 2012. [Pdf  | Slideshare ]

Classifying chemicals Using Description Graphs and Logic Programming, at OWL: Experiences and Directions Workshop (OWLED 2012) , Hersonissos, Crete, Greece, May 2012. [Pdf  | Slideshare ]

Modelling Structured Domains with Logic, at Cakes Talk seminar, Department of Computer Science, University of Oxford, February 2012. [Pdf ]

Chemical Knowledge Representation with Description Graphs and Logic Programming, at Semantic Web Applications and Tools for Life Sciences workshop (SWAT4LS 2011), December 2011. [Pdf ]

Tractable Extensions of the Description Logic EL with Numerical Datatypes,
at Int. Joint Conf. on Automated Reasoning (IJCAR 2010), July 2010. [Pdf   |Slideshare ]

Tractable Extensions of the Description Logic EL with Numerical Datatypes,
at 23rd International Workshop on Description Logics (DL2010), May 2010. [Pdf  ]

Tractable Extensions of the Description Logic EL with Numerical Datatypes,
at Information Systems seminar, Oxford University Computing Laboratory, April 2010. [Pdf  ]

Miscellaneous

My first name is pronounced the-spi-na (like the article) and my surname man-ga (like the cartoon).

Name

Despoina Magka

Posts

Research Student

Contact Information

Room 352, Wolfson Building, Parks Road
Oxford OX1 3QD

News

3 Paper accepted in AAAI'18

Three papers co-authored by the KRR group have been accepted in AAAI'18:
- "Stream Reasoning in Temporal Datalog" by A. Ronca, M. Kaminski, B. Cuenca Grau, B. Motik, and I. Horrocks;
- "Optimised Maintenance of Datalog Materialisations" by P. Hu, B. Motik, and I. Horrocks; and
- "Goal-Driven Query Answering for Existential Rules with Equality" by M. Benedikt, B. Motik, and E. Tsamoura.

Professor Ian Horrocks is a new honorary doctorate at University of Oslo, Faculty of Mathematics and Natural Sciences

Professor Ian Horrocks received an honorary doctorate from the University of Oslo.

Best paper award at IJCAI'17

The paper entitled "Foundations of Declarative Data Analysis Using Limit Datalog Programs" and authored by M. Kaminski, B. Cuenca Grau, B. Motik, E. V. Kostylev, and I. Horrocks received the best paper award at the 26th International Joint Conference on Artificial Intelligence (IJCAI'17).

3 papers accepted in IJCAI'17

Three papers co-authored by the KRR group have been accepted in IJCAI'17:
- "Query Reformulation: Theory and Practice" by M. Benedikt, E. V. Kostylev, F. Mogavero, and E. Tsamoura;
- "Foundations of Declarative Data Analysis Using Limit Datalog Programs" by M. Kaminski, B. Cuenca Grau, B. Motik, E. V. Kostylev, and I. Horrocks; and
- "The Bag Semantics of Ontology-Based Data Access" by C. Nikolaou, E. V. Kostylev, G. Konstantinidis, M. Kaminski, B. Cuenca Grau, and I. Horrocks.

Paper accepted in PODS'17

The paper entitled "Benchmarking the chase" authored by Michael Benedikt, George Konstantinidis, Giansalvatore Mecca, Boris Motik, Paolo Papotti, Donatello Santoro, and Efthymia Tsamoura has been accepted in PODS'17.

Andrew Bate defends his PhD Thesis

Andrew Bate has successfully defended his PhD Thesis on Consequence Based Reasoning. Congratulations to Dr. Andrew Bate!

Best applications paper award at ISWC'16

Our paper entitled "Semantic Technologies for Data Analysis in Health Care" received the Best Applications Paper Award at the International Semantic Web Conference (ISWC 2016).

4 papers accepted in ISWC'16

Four papers authored by the KRR group have been accepted in the International Semantic Web Conference (ISWC 2016).

Best paper award at ICDT'16

Mark Kaminski and Egor Kostylev received the best paper award at ICDT 2016 for their paper entitled "Beyond Well-Designed SPARQL".