contact: teemu.roos at cs.helsinki.fi
NEW: Our fast approximate nearest neighbor algorithm is
available as an optimized C++ package with Python bindings. To my knowledge,
this is the fastest available algorithm for high accuracy queries
(see our forthcoming IEEE Big Data paper below).
C++ library (with Python bindings) | benchmarks
As of 1/2017, I'll be appointed as an Associate Professor (tenure-track) at the Department of Computer Science, University of Helsinki.
The 9th Workshop on Information Theoretic Methods in Science and Engineering (WITMSE) will be held in Helsinki on 19–21 September 2016. web page.
My traveling/conference schedule in 2016:
- HD Big Data Workshop, Cambridge, UK, January 22.
- Martin Luther University, Halle, Germany, April 25–28.
- Finnish Institute in Rome, Italy, May 6–10.
- Purdue, USA, May 15–20.
- WITMSE-2016, Helsinki, September 19–21.
- University of Melbourne, Australia, October 4–18.
- Eindhoven University of Technology, the Netherlands, December 6.
Since November 2013, following Prof Juho Rousu, I am the host of the Helsinki Distinguished Lecture Series on Future Information Technology.
I have been appointed from 4/2013 onwards as an Assistant Professor (tenure-track) at the Department of Computer Science, University of Helsinki.
Recent conference and workshop involvement (program committee or equivalent): AISTATS-2011/2014/2015, ECML/PKDD-2009/2012, ICDM-2014, IJCAI-2013/2015, NIPS-2014/2015/2016, PGM-2008/2012/2014, UAI-2008/2009/2010/2011/2012/2013/2014/2015/2016.
In the academic year 2016–2017, I will teach the following courses:
- Introduction to Machine Learning in period II.
- Introduction to Artificial Intelligence (Johdatus tekoälyyn) in period III (in Finnish)
I am the instructor of the Undergraduate Research Track (tutkijalinja).
I currently supervise:
- Joonas Miettinen (PhD student; 1st year) co-supervised with Dr Janne Pitkäniemi (Finnish Cancer Registry)
- Ville Hyvönen (PhD student, 2nd year)
- Janne Leppä-aho (PhD student, 2nd year)
- Yuan Zou (PhD student, 6th year)
- Elaine Zosa (MSc student)
- Joe Niemi (MSc student)
- Tommi Jalkanen (MSc student) co-supervised with Dr Jutta Jokiranta (Theology)
- Olli Orajärvi (MSc student)
- Teemu Pitkänen (MSc 2016)
- Jussi Määttä (PhD 2016)
- Antti Takalahti (MSc 2016; co-supervised with Prof Edward Haeggström (Physics)
- Risto Tuomainen (MSc 2016)
- Simo Linkola (MSc 2016)
- Kaj Sotala (MSc 2015)
- Quan Nguyen (MSc 2015)
- Peter Hedman (MSc 2015), co-supervised with Prof Jaakko Lehtinen (Aalto/NVIDIA Corp) Acad. Assoc. for Maths and Natural Sciences (MAL) MSc Thesis Award
- Arttu Modig (MSc 2014), co-supervised with Prof Jouko Lampinen (Aalto)
- Janne Leppä-aho (MSc 2014), co-supervised with Prof Jukka Corander
- Henning Lübbers (MSc 2012), co-supervised with Prof Jyrki Kivinen
- Anupam Arohi (MSc 2011)
- Yuan Zou (MSc 2011)
- Teemu Pulkkinen (MSc 2011)
- Toni Merivuori (MSc 2009)
- Lari Latvala (MSc 2009), co-supervised with Prof Jouko Laasasenaho
Students interested in MSc/PhD thesis topics related to information theory, statistical modeling, machine learning, artificial intelligence, and digital humanities are welcome to contact me by e-mail (but see disclaimer below).
Disclaimer: If you currently not enrolled at the University of Helsinki, please do not send me e-mail, but contact the Department of Computer Science for information about the application process. Unfortunately I cannot reply to all e-mail inquiries.
``Your act was unwise,'' I exclaimed ``as you see by the
He solemnly eyed me. ``When choosing the course of my action,''
said he, ``I had not the outcome to guide me.''
I am the leader of the Information, Complexity and Learning (ICL) research group, which is a part of the CoSCo research group led by Prof Petri Myllymäki. I'm also affiliated with the Academy of Finland funded Centre of Excellence COIN.
Topics of my interest include the theory and applications of
- machine learning and big data
- computational statistics
- probabilistic graphical models
- information theory
- digital humanities
Recent and ongoing work:
- J. Leppä-aho, J. Pensar, T. Roos, and J. Corander (2017).
Learning Gaussian graphical models with fractional marginal pseudo-likelihood, to appear in
International Journal of Approximate Reasoning, arXiv:1602.07863
- Y. Zou and T. Roos (2017). On model
selection, Bayesian networks, and the Fisher information integral,
to appear in
New Generation Computing, 35(1) (Special Issue on AMBN 2015), January 2017.
- V. Hyvönen, T. Pitkänen, S. Tasoulis,
E. Jääsaari, R. Tuomainen, L. Wang, J. Corander, and T. Roos.
Fast nearest neighbor search through sparse random projections and voting,
to appear in 2016 IEEE International Conference on Big Data (IEEE Big-Data 2016), Washington DC, Dec. 5–8.
C++ library (with Python bindings) |
- Y. Zou and T. Roos (2016). Sparse logistic regression with logical features,
in J. Bailey, L. Khan, T. Washio, G. Dobbie, J. Z. Huang, and R. Wang (editors), Proc. 20th Pacific Asia Conference on Knowledge Discovery and Data Mining
(PAKDD-2016), Lecture Notes in Artificial Intelligence 9652, Springer, pp. 316–327.
- T. Heikkilä and T. Roos,
Section on Studia Stemmatologica, Digital Scholarship in the
Humanities 31(3):520–522, doi:10.1093/llc/fqw038.
- T. Roos (2016). Minimum Description Length Principle,
in Sammut, C. and Webb G.I. (eds), Encyclopedia of Machine Learning and Data Mining, 2016.
- L. Wang, S. Tasoulis, T. Roos, and J. Kangasharju (2016).
Scalable provision of semantically relevant web content on big data
framework, to appear
in IEEE Transactions on
- Y. Zhao, S. Tasoulis, and T. Roos
(2016). Manifold visualization via short
in E. Bertini, N. Elmqvist, and T. Wishchgoll (editors), Eurographics Conference on Visualization (EuroVis-2016), The Eurographics Association, pp. 85–89,
- J. Määttä and T. Roos (2016). Maximum parsimony and the skewness test: A simulation study of the limits of applicability,
PLOS ONE 11(4):e0152656.
- J. Määttä, D.F. Schmidt, and T. Roos (2016).
Subset selection in linear regression using sequentially normalized least squares: Asymptotic theory,
Scandinavian Journal of Statistics 43(2):382–395.
- J. Määttä and T. Roos
(2016). Robust sequential prediction in
linear regression with Student's t-distribution,
in Proc. 14th International Symposium on Artificial Intelligence
- J. Tehrani, Q. Nguyen, and T. Roos, (2016).
Oral fairy tale or literary fake? Investigating the origins of Little
Red Riding Hood using phylogenetic network analysis,
Digital Scholarship in the Humanities 31(3):611–636.
- K. Watanabe and T. Roos, (2015).
Achievability of asymptotic minimax regret
by horizon-dependent and horizon-independent strategies,
Journal of Machine Learning Research 16(Nov):2357–2375.
- Q. Nguyen and T. Roos, (2015).
Likelihood-based inference of phylogenetic networks from sequence data
by PhyloDAG, in
Proc. 2nd International
Conference on Algorithms for Computational Biology
LNBI 9199, Springer, pp. 126–140.
- A. Barron, T. Roos, and K. Watanabe, (2014).
Bayesian properties of normalized
maximum likelihood and its fast computation,
in Proc. IEEE International Symposium on Information
IEEE Press, pp. 1667–1671.
- M. Sherman, G. Clark, Y. Yang, S. Sugrim, A. Modig, J. Lindqvist,
A. Oulasvirta, and T. Roos, (2014).
User-generated free-form gestures for authentication: security and memorability,
in Proc. 12th International Conference on Mobile Systems, Applications, and Services (MobiSys-2014), ACM Press, pp. 176–189.
- A. Carvalho, T. Roos, A. Oliveira, and
P. Myllymäki, (2011). Discriminative learning of Bayesian
networks via factorized conditional log-likelihood,
- J. Rissanen, T. Roos, and P. Myllymäki, (2010).
Model selection by sequentially normalized least squares,
of Multivariate Analysis 101:4, 839–849.
| R code
- T. Roos and T. Heikkilä, (2009). Evaluating methods for computer-assisted stemmatology using artificial benchmark data sets, Literary and Linguistic Computing, 24:4, 417–433, doi:10.1093/llc/fqp002. abstract | data-sets
Between September 21–November 30, 2015, I was a Visiting Scholar at UC Berkeley, USC and UCSD.
The 8th Workshop on Information Theoretic Methods in Science and Engineering (WITMSE) was held in Copenhagen on 24–26 June 2015; co-chairs Harremoës, Forchhammer, Roos & Myllymäki. web page.
My traveling/conference schedule in 2015:
- Finnish Institute in Rome, December 27, 2014–January 4, 2015.
- E-Philology Lectures, Sorbonne University, Paris, January 12.
- ITA-2015, San Diego, February 1–6.
- COST Training School, Rome, 23–25 March.
- VU Amsterdam, May 13.
- University of Lancaster, University of Cambridge, May 18–22.
- COIN day, Stockholm, Sweden, June 15.
- WITMSE-2015, Copenhagen, June 24–26.
- AlCoB-2015, Mexico City, August 4–6.
- UC Berkeley, USC, UCSD, September 21–November 30.
- IEEE Big Data 2015, Santa Clara, CA, USA, October 29–November 1.
I was a member of the organizing committee of the 11th Conference of the European Society for Textual Scholarship (ESTS-2014). The conference was held in Helsinki on Oct 30-Nov 1, 2014.
We organized the 7th Workshop on Information Theoretic Methods in Science and Engineering (WITMSE) in Hawaii on July 5-8, 2014, right after the ISIT symposium. website
In October–December 2013, I was a Fellow at the Finnish Institute in Rome (Villa Lante).
Associated with our CHI-2013 paper, we are lauching a web server for computing the information capacity from your own motion capture data: infocapacity.hiit.fi. Please ask for a beta testing account.
My traveling/conference schedule in 2014:
- Finnish Institute in Rome, March 28–April 8.
- ISIT-2014 and WITMSE-2014, Hawaii, June 29–July 7.
- ESTS-2014, Helsinki, October 30–November 1.
- Royal Society meeting: Evolutionary analysis beyond the gene, Chicheley Hall, UK, 17–18 November.
I was a co-chair of WITMSE-2013 in Tokyo, Japan, August 26–29.
My traveling/conference schedule in 2013:
- University of Cambridge, UK, January 10–12.
- ITA-2013, San Diego, February 10–15.
- CHI-2013, Paris, April 27–May 2.
- WITMSE-2013, Tokyo, August 26–29.
- Finnish Institute in Rome, October 18–December 28.
Our paper "Information capacity of full-body movements" gets a Best Paper Honorable Mention Award at CHI-2013. If you are planning to attend the conference, please visit our fun interactive Kinect-based demo!
Special issue on selected papers from PGM-2010 in the International Journal of Approximate Reasoning (editors Roos, Myllymäki, Jaakkola): link to editorial and articles.
In January–April 2012, I was a Visiting Fellow at the University of Cambridge.
I was an external evaluator at the PhD thesis defense of Thomas Toftkjær at Aarhus University on January 10, 2012.
My traveling/conference schedule in 2012:
- University of Aarhus, Denmark, January 10.
- University of Cambridge, UK, January 16–April 30.
- ITA-2012, San Diego, February 6–10.
- University of Oxford, UK, March 7–8.
- University of East Anglia, UK, March 22–23.
- Durham University, UK, April 2–5.
- WITMSE 2012, Amsterdam, August 26—30.
- University of Bern, Switzerland, November 22–24.
The Academy of Finland Centre of Excellence COIN starts in 1/2012.
The 5th Brazilian Conference on Statistical Modelling in Insurance and Finance was held in Maresias, Brazil, on April 10–15, 2011. I gave a two-day short course on MDL. lecture notes | slides (day1) | slides (day2)
Tuomas Heikkilä, Petri Myllymäki and I organize a series of stemmatology workshops in Helsinki and elsewhere in 2010–2012. web pages
- Studia Stemmatologica IV, University of Cambridge and Microsoft Research, Cambridge, UK, March 21–26.
- BCSMIF-2011 and University of Sao Paulo, Brazil, April 9–17.
- ICANN-2011, Helsinki, June 14–17.
- ISIT-2011, St. Petersburg, Russia, July 31–August 5.
- WITMSE-2011, Helsinki, August 7–10.
- Studia Stemmatologica V, Rome, October 5–8.
- Nonlinear physics (!), Stockholm, October 18–20.
- ICDM-2011, Vancouver, December 11–14.
4/2011: I was conferred the title Adjunct Professor (in Finnish, dosentti) by the Faculty of Science, and appointed as a senior reseacher at HIIT.
I was invited to the senior program committee of UAI-2011.
The Academy of Finland has graciously decided to fund me under a postdoctoral researcher's project.
Petri Myllymäki, Tommi Jaakkola, and I were the program committee co-chairs of the 5th European Workshop on Probabilistic Graphical Models (PGM-2010) in Helsinki, September 13–15, 2010. web pages
My traveling schedule in 2010:
- MIT, Boston, February 8–April 30.
- Columbia University, New York, February 22–23.
- Yale, New Haven, April 1–2.
- Washington University, St. Louis, April 22–23.
- SCAS, Uppsala, Sweden, June 21–23.
- UCLA & UAI-2010, Los Angeles, July 8–11.
- WITMSE-2010, Tampere, Finland, August 16–18.
- Studia Stemmatologica, Pisa, Italy, November 21–24.
I got the ERCIM (European Research Consortium for Informatics and Mathematics) 2009 Cor Baayen Award.
- ITA-2009, San Diego & HP Labs, Palo Alto, February 8–13.
- ITW-2009, Volos, Greece, June 10–12.
- ISIT-2009, Seoul, Korea, June 28–July 3.
- WITMSE-2009, Tampere, Finland, August 17–19.
- ISTI/CNR & Univ. Pisa, Pisa, Italy, November 5–6.
The Finnish Cultural Foundation has awarded a Science Workshop grant (EUR 200,000) on stemmatology for the years 2009–2010. announcement (w/ fanfares) (in Finnish)
As of August 2008, I have been appointed as post-doctoral researcher at HIIT for three years.
During the Fall term 2007 I lectured the Three Concepts: Information course.
I defended my Ph.D. thesis "Statistical and Information-Theoretic Methods for Data Analysis" on June 9, 2007. The opponent was Prof. Alon Orlitsky (UCSD). Pre-examiners were Prof. Ioan Tabus (Tampere UT) and Prof. Tommi Jaakkola (MIT). electronic version (summary part).
I received a Ph.D. degree (in Computer Science) from the University of Helsinki in 2007. I was supported by HeCSE (Helsinki Graduate School in Computer Science and Engineering). My supervisors were Prof. Henry Tirri (on industrial leave), and Prof. Petri Myllymäki. In addition to computer science I have minors in mathematics and philosophy (see a list of finished courses).
am married to the loveliest girl in the world, the light of my life.
''You are the reason I am. You are all my reasons.''
Since July 31st 2003, the universe revolves around a boy. Since March 1st 2007, we have two boys!
Play a game of Rock, Paper, Scissors: rock beats scissors, paper beats rock, and scissors beat paper. Even such a simple game offers some theoretically interesting problems: Can one predict the other player's choice? What is the best strategy against a good opponent? (Yes, the computer could cheat, but I promise it doesn't.) Such questions were considered by Claude Shannon in the 1950s; see a modern variation of his 'Mind-Reading Machine' based on data-compression (CTW).