Homepage of Magdalena Ortiz

Magdalena Ortiz
(M.Sc. Maria Magdalena Ortiz de la Fuente)

Knowledge Based Systems Group 184/3
Institute for Information Systems
Vienna University of Technology
Favoritenstrasse 9-11
A-1040 Vienna, Austria

Phone: (+43)1 58801 18462
Email: ortiz (at) kr (dot) tuwien (dot) ac (dot) at


I'm interested in Computational Logic in general, and particuarly in the context of Knowledge Representation and Reasoning.

I'm a member of the Knowledge Based Systems Group since September 2006 , where I'm doing my Ph.D. research under the supervision of Thomas Eiter.
Currently I'm working on Complexity of Querying Expressive Knowledge Bases, in collaboration with Diego Calvanese.

I was born in Puebla, Mexico.
I studied Computer Science at the
Universidad de las Americas, Puebla where I obtained  a B.Sc. degree in 2003 and a M.Sc. in 2004.
I was a member of the research group on Answer Set Programming lead by Mauricio Osorio.

I also obtained a European Masters in Computational Logic in 2006, after studying at the Free University of Bolzano and in the Vienna University of Technology.

More details can be found in my CV (pdf).

In the last year, I have recevied these awards and scholarpships (it seems it was my lucky year!):
  • The OeCG Foerderpreis 2007 awarded by the Austrian Computer Society to the best Computer Science thesis presented last year in an Austrian University.
    For the time being, there is a press release (in German) with a photo here and here.
  • The OeGAI Preis 2006 from the Austrian Society for Artificial Intelligence, also for the best master thesis of the year, but within fields of Artificial Intelligence.
  • The consotium of the European Masters in Computational Logic also awarded me the Best Thesis Award of the first generation of graduates.
  • I was awarded the Google Europe Anita Borg Memorial Scholarship 2007, given to female students in CS and related fields on the basis of their academic performance and community commitment. There is also a small press release (in German) with a picture here.

My most recent work is on query answering in expressive description logics.

In the last publication, we presented an algorithm using automata on infinite trees:

  • Diego Calvanese, Thomas Eiter, and Magdalena Ortiz.
    Answering regular path queries in expressive description logics: An automata-theoretic approach.
    In Proc. of the 22nd Nat. Conf. on Artificial Intelligence (AAAI 2007), 2007. pp. 391-396. AAAI Press. USA, July 2007.
Before that, we were using tableaux-techniques and we obtained some data complexity results:
  • Magdalena Ortiz, Diego Calvanese, and Thomas Eiter.
    Characterizing Data Complexity for Conjunctive Query Answering in Expressive Description Logics.
    In Proceedings of the Twenty-First National Conference on Artificial Intelligence (AAAI'06). AAAI Press, July 2006.
  • Magdalena Ortiz, Diego Calvanese, and Thomas Eiter.
    Data Complexity of Answering Unions of Conjunctive Queries in SHIQ
    In Bijan Parsi, Ulrike Sattler, and David Toman, editors, Proc. 2006 International Workshop on Description Logics (DL'06), volume 189 of CEUR Workshop Proceedings, Lake District, UK, June 2006.
    (pdf)     (Full proceedings available here)
I also wrote my Master Thesis on this topic.
The results of my thesis, with some later corrections and improvements, can be found in this Technical Report.

An article on my previous work with Mauricio Osorio appeared recently. It's about strong negation in Answer Set Programming:

A bit independently of my main line of research, with the help of Carlos Areces, I proposed last year a sequent calculus for Categorial Logics with hybrid operators.
  • Magdalena Ortiz.
    A Fully Internalized Sequent Calculus for Hybrid Categorial Logics.
    In Janneke Huitink and Sophia Katrenko, editors, Proceedings of the Student Session of the 18th European Summer School of Logic, Language and Information (ESSLLI'06), Malaga, Spain, August 2006.
    (pdf)     (Full proceedings available here)
Most of my older publications are related to Answer Set Programming.
Some of them can be found on the DBLP server, but the list is not complete. My full list of publications is here (pdf) (bib).
If you are interested in any of my work and you don't find it here, please mail me.