Research interests
My main interest has always been in languages for querying data: their design, computational complexity and optimisation. My PhD was about Queries on Graphs, a topic which has seen renewed interest with the advent of the semantic web and social networks. Other areas I have worked in include XML querying, active rule languages (similar to database triggers), deductive rule languages (e.g. Datalog), compression techniques for XML, and algorithms for combining recommendations from recommender systems.
Research students
- Mirko Michele Dimartino (co-supervised with Andrea Calì and Alex Poulovassilis), working on integration and querying of linked data, completed his PhD in 2020
- Riccardo Frosini (co-supervised with Andrea Calì and Alex Poulovassilis), working on flexible querying, completed his PhD in 2017
- Petra Selmer (co-supervised with Alex Poulovassilis), working on flexible querying, completed her PhD in 2017
- Khaled Alyoubi (co-supervised with Sven Helmer), working on query optimisation, completed his PhD in 2016
- Mohammad Jaber (co-supervised with Panos Papapetrou and Sven Helmer), working on interaction networks, completed his PhD in 2015
- Manizheh Montazerian, working on optimising XML queries, completed her PhD in 2014
Recent publications
See also the list of publications from the DBLP Bibliography Server.
- M.M. Dimartino, P. T. Wood, A. Poulovassilis and A. Calì: Efficient Ontology-Mediated Query Answering: Extending DL-liteR and Linear ELH, J. Artificial Intelligence Research, Vol. 82 (February 2025), 851-899.
- Kaitlin Conway-Moore, Darius Tetsa Tata, Peter Wood, Val Katerinchuk, D M Dinesh Yadav, Little Flower Augustine, Manne Munikumar, Assana Diop, Fassiatou Tairou, Modou Lamin Jobarteh, Babacar Faye, Paul Haggarty and Claire Heffernan: Developing a data repository to support interdisciplinary research into childhood stunting: a UKRI GCRF Action Against Stunting Hub protocol paper, BMJ Paediatrics Open, Vol. 8 (June 2024), 5pp.
- S. Helmer, P. T. Wood and M. Stuefer: Optimism and Pessimism in Database Query Optimisation, in Proc.\ 18th IEEE International Conference on Semantic Computing, (Laguna Hills, CA, USA), 2024, pp. 269-276.
- A. Ballatore, V. Katerinchuk, A. Poulovassilis, P. T. Wood: Tracking Museums' online responses to the Covid-19 pandemic: a study in museum analytics, ACM J. Comput. Cult. Herit., Vol. 17, Issue 1, Article 2 (January 2024), 29 pages.
- R. Frosini, A. Poulovassilis, P.T. Wood and A. Calì: Optimisation Techniques for Flexible SPARQL Queries. ACM Trans. Web 16(4): 16:1-16:44 (2022)
- G.H.L. Fletcher, A. Poulovassilis, P. Selmer, P.T. Wood: Approximate Querying for the Property Graph Language Cypher. IEEE BigData 2019: 617-622
- M.M. Dimartino, A. Calì, A. Poulovassilis, P.T. Wood: Efficient Ontological Query Answering by Rewriting into Graph Queries. FQAS 2019: 75-84
- C. Gutierrez, J. Hidders, P.T. Wood: Graph Data Models. Encyclopedia of Big Data Technologies 2019
- R. Frosini, A. Calì, A. Poulovassilis and P.T. Wood, ``Flexible Query Processing for SPARQL,'' Semantic Web - Interoperability, Usability, Applicability, Vol. 8, No. 4, 2017, pp. 533-563.
- M. Jaber, P.T. Wood, P. Papapetrou and A. González-Marcos, ``A Multi-granularity Pattern-based Sequence Classification Framework for Educational Data,'' in Proc. 3rd IEEE Int. Conf. on Data Science and Advanced Analytics (DSAA) (Oct. 17-19, Montreal, Canada), 2016, pp. 370-378.
- A. Poulovassilis, P. Selmer and P.T. Wood, ``Approximation and Relaxation of Semantic Web Path Queries,'' Journal of Web Semantics, Vol. 40, October 2016, pp. 1-21.
- M.M. Dimartino, A. Calì, A. Poulovassilis, P.T. Wood, ``Query Rewriting under Linear EL Knowledge Bases,'' in 10th Int. Conf. on Web Reasoning and Rule Systems (RR) (September 9-11, Aberdeen, UK), 2016, pp. 61-76.
- K.H. Alyoubi, S. Helmer and P.T. Wood, ``Ordering Selection Operators Under Partial Ignorance,'' in Proc. 24th ACM Int. on Conf. on Information and Knowledge Management (CIKM) (Oct. 19-23, Melbourne, VIC, Australia,), 2015, pp. 1521-1530.
- M. Xie, L.V.S. Lakshmanan and P.T. Wood, ``Generating Top-k Packages via Preference Elicitation,'' in Proc. 41st Int. Conf. on Very Large Data Bases (VLDB) (August 31-September 4, Hawaii, USA), 2015, and PVLDB, Vol. 7, No. 14, 2014, pp. 1941-1952.
- M.M. Dimartino, A. Calì, A. Poulovassilis, P.T. Wood, ``Implementing Peer-to-Peer Semantic Integration of Linked Data,'' in 30th British Int. Conf. on Databases (BICOD) (July 6-8, Edinburgh, UK), 2015, pp. 41-45.
- M. Jaber, P. Papapetrou, A. González-Marcos and P.T. Wood, ``Analysing Online Education-based Asynchronous Communication Tools to Detect Students' Roles,'' in Proc. 7th Int. Conf. on Computer Supported Education (CSEDU) (May 23-25, Lisbon, Portugal), 2015, pp. 416-424.
- M.M. Dimartino, A. Calì, A. Poulovassilis, P.T. Wood, ``Peer-to-Peer Semantic Integration of Linked Data,'' in Fifth Int. Workshop on Linked Web Data Management (LWDM) (March 27, Brussels, Belgium), 2015, pp. 213-220.
- P. Selmer, A. Poulovassilis and P.T. Wood, ``Implementing Flexible Operators for Regular Path Queries,'' in Fourth Int. Workshop on Querying Graph Structured Data (GraphQ) (March 27, Brussels, Belgium), 2015, pp. 149-156.
- A. Calì, R. Frosini, A. Poulovassilis, P.T. Wood, ``Flexible Querying for SPARQL,'' in Proc. 13th Int. Conf. on Ontologies, DataBases, and Applications of Semantics (ODBASE) (October 27-31, Amantea, Italy), 2014, pp. 473-490.
- M. Jaber, P. Papapetrou, S. Helmer and P.T. Wood, ``Using Time-Sensitive Rooted PageRank to Detect Hierarchical Social Relationships,'' to appear in Proc. 13th Int. Symp. on Intelligent Data Analysis (IDA) (October 30-November 1, Leuven, Belgium), LNCS 8819, 2014, pp. 143-154.
- M. Jaber, P.T. Wood, P. Papapetrou and S. Helmer, ``Inferring Offline Hierarchical Ties from Online Social Networks,'' in Workshop on Connecting Online and Offline Life (COOL) (April 8), Seoul, South Korea), WWW (Companion Volume), 2014, pp. 1261-1266.
- M. Xie, L.V.S. Lakshmanan and P.T. Wood, ``IPS: An Interactive Package Configuration System for Trip Planning,'' demo paper in Proc. 39th Int. Conf. on Very Large Data Bases (VLDB) (August 26-30, Trento, Italy), 2013, pp. 1362-1365.
- M. Xie, L.V.S. Lakshmanan and P.T. Wood, ``Efficient Top-k Query Answering using Cached Views,'' in Proc. 16th Int. Conf. on Extending Database Technology (EDBT) (March 18-22, Genoa, Italy), 2013, pp. 489-500.
- P. Barceló, L. Libkin, A.W. Lin and P.T. Wood, ``Expressive Languages for Path Queries over Graph-Structured Data,'' in ACM Trans. on Database Systems, Vol. 37, No. 4, 2012, Article No. 31.
- M. Xie, L.V.S. Lakshmanan and P.T. Wood, ``Composite Recommendations: From Items to Packages,'' in Frontiers of Computer Science, Vol. 6, No. 3, 2012, pp. 264-277.
- P.T. Wood, ``Query Languages for Graph Databases,'' in SIGMOD RECORD, Vol. 41, No. 1 (March), 2012, pp. 50-60.
- A. Poulovassilis, P. Selmer and P.T. Wood, ``Flexible Querying of Lifelong Learner Metadata,'' in IEEE Trans. on Learning Technologies, Vol. 5, No. 2, 2012, pp. 117-129.
- M. Montazerian and P.T. Wood, ``Chasing One's Tail: XPath Containment Under Cyclic DTDs,'' in Proc. 13th International Symposium on Database Programming Languages (August 29, Seattle, Washington), 2011.
- M. Xie, L.V.S. Lakshmanan and P.T. Wood, ``Efficient Rank Join with Aggregation Constraints,'' in Proc. 37th Int. Conf. on Very Large Data Bases (Aug. 29-Sept. 3, Seattle, Washington), PVLDB, Vol. 4, No. 11, 2011, pp. 1201-1212.
- M. San Martín, C. Gutierrez and P.T. Wood, ``SNQL: A Social Network Query and Transformation Language,'' in Proc. 5th Alberto Mendelzon Workshop on Foundations of Data Management (May 9-12, Santiago, Chile), 2011.
- M. Xie, L.V.S. Lakshmanan and P.T. Wood, ``CompRec-Trip: a Composite Recommendation System for Travel Planning,'' demo paper in Proc. 27th IEEE Int. Conf. on Data Engineering (Hannover, Germany, Apr. 11-16), 2011, pp. 1352-1355.
- G. Papamarkos, A. Poulovassilis and P.T. Wood, ``Performance Modelling of Event-Condition-Action Rules in P2P networks,'' in Journal of Computer and System Sciences, DOI: doi:10.1016/j.jcss.2010.02.004, Vol. 77, Elsevier, 2011, pp. 621-636.
- A. Poulovassilis and P.T. Wood, ``Combining Approximation and Relaxation in Semantic Web Path Queries,'' in Proc. 9th International Semantic Web Conference (Shanghai, China, Nov. 7-11), 2010, pp. 631-646.
- M. Xie, L.V.S. Lakshmanan and P.T. Wood, ``Breaking out of the Box of Recommendations: From Items to Packages,'' in Proc. 4th ACM Conf. on Recommender Systems (Barcelona, Spain, Sept. 26-30), 2010, pp. 151-158.
- P. Barceló, C.A. Hurtado, L. Libkin and P.T. Wood, ``Expressive Languages for Path Queries over Graph-Structured Data,'' in Proc. 29th ACM Symposium on Principles of Database Systems (Indianapolis, Indiana, June 6-10), 2010, pp. 3-14.
- P.T. Wood, ``Graph Database,'' in Encyclopedia of Database Systems, Editors-in-chief: M. Tamer Ozsu and Ling Liu, Springer, 2009, pp. 1263-1266.
- C.A. Hurtado, A. Poulovassilis and P.T. Wood, ``Finding Top-k Approximate Answers to Path Queries,'' to appear in Proc. 8th Int. Conf. on Flexible Query Answering Systems (Roskilde, Denmark, Oct. 26-28), 2009.
- C.A. Hurtado, A. Poulovassilis and P.T. Wood, ``Ranking Approximate Answers to Semantic Web Queries,'' in Proc. 6th European Semantic Web Conference (Heraklion, Crete, May 31-June 4), LNCS 5554, Springer-Verlag, 2009, pp. 263-277.
- K. Keenoy, V. Christophides, G. Papamarkos, A. Poulovassilis, D. Kotzinos, P. Rigaux, N. Spyratos, and P.T. Wood, ``Personalisation Services for Self e-Learning Networks,'' in The Learning Grid Handbook: Concepts, Technologies and Applications, S. Salerno, M. Gaeta, P. Ritrovato, N. Capuano, F. Orciouli, S. Miranda and A. Pierri (Editors), IOS Press, February 2008.
- C.A. Hurtado, A. Poulovassilis and P.T. Wood, ``Query Relaxation in RDF,'' Journal on Data Semantics X, LNCS 4900, Springer-Verlag, 2008, pp. 31-61.
- M. Montazerian, P.T. Wood and S.R. Mousavi, ``XPath Query Satisfiability is in PTIME for Real-World DTDs,'' in Proc. Fifth Int. XML Database Symposium (Vienna, Austria, Sept. 23-24), LNCS 4704, Springer-Verlag, 2007, pp. 17-30.
- C.A. Hurtado, A. Poulovassilis and P.T. Wood, ``A Relaxed Approach to RDF Querying,'' in Proc. 5th Int. Semantic Web Conference (Athens, Georgia, Nov. 5-9), LNCS 4273, Springer-Verlag, 2006, pp. 314-328.
- W. Ng, W.-Y. Lam, P.T. Wood and M. Levene, ``XCQ: A Queriable XML Compression System,'' in Knowledge and Information Systems, Vol. 10, No. 4 (November), Springer-Verlag, 2006, pp. 421-452.
- G. Papamarkos, A. Poulovassilis and P.T. Wood, ``Event-Condition-Action Rules on RDF Metadata in P2P Environments,'' in Computer Networks, 50, 10 (July), Elsevier, 2006, pp. 1513-1532.
- A. Poulovassilis, G. Papamarkos and P.T. Wood, ``Event-Condition-Action Rule Languages for the Semantic Web,'' in EDBT Workshops, Reactivity on the Web (Munich, Germany, Mar. 26-31), LNCS 4254, Springer-Verlag, 2006, pp. 855-864.
Teaching
- Advances in Data Management (an MSc module)
- Internet and Web Technologies (an MSc module)
Short biography
I obtained my BSc and MSc in Computer Science from the University of Cape Town (UCT). I then worked for the Institute for Applied Computer Science at the University of Stellenbosch for 18 months, before leaving for the University of Toronto where I obtained a PhD in Computer Science in 1989. I subsequently spent 9 years as a member of the Department of Computer Science at UCT, before joining the Department of Computer Science at King's College London in 1998. I moved to the School of Computer Science and Information Systems (now Department) at Birkbeck in 2001. I was Head of School from September 2006 until July 2009.