News from the LICS Community

Here is some news I just discovered by looking at the web page for LICS 2012.

Highlights and changes for LICS 2012

1. Starting 2012, LICS is jointly organized by ACM and IEEE, and is cosponsored by ACM SIGACT and the IEEE Computer Society's Technical Committee on Mathematical Foundations of Computing.
2. In response to concerns about LICS becoming overly selective with a too-narrow technical focus, the program committee will employ a merit-based selection with no a priori limit on the number of accepted papers.
3. LICS 2012 will continue the tradition of pre-conference tutorials that was initiated in 2011. This year, Jan Willem Klop will give a tutorial on term rewriting systems and Andre Platzer will give a tutorial on logics of dynamical systems.
4. Special Events and Invited Lectures: There will be an invited lecture by Robert J. Aumann, winner of the 2005 Nobel Prize in Economic Sciences, and a plenary session in honor of Alan Turing on the occasion of his centenary, with talks by Robert L. Constable, E. Allen Emerson (co-winner of 2008 A. M. Turing Award), Joan Feigenbaum, and Leonid Levin. 

These are very interesting developments for the LICS community, some of which should be of interest for the TCS community as a whole.

Development A above paves the way to the formation of an ACM Special Interest Group on Logic in CS, say a SIGLOG, about which I have heard reports in private conversations with key players in the LICS community. Such a special interest group would play an important role in the development of volume B TCS research in North America.

Development B is most interesting and might be a watershed event, if it pans out. LICS plays the role of FOCS/STOC for the volume B TCS community and I believe that all of TCS will be interested in observing the outcome of the LICS 2012 experiment. Typically, the quality of an average LICS submission is very high and this new policy might encourage even more submissions to the conference than usual. How will the PC handle these submissions? Will the conference move to parallel sessions? Will this development decrease the value of the "LICS currency"? Will other conferences follow the lead of LICS, if the experiment "succeeds"?

Time will tell. In any event, this is a courageous step taken by the LICS conference and I look forward to seeing how it will affect the conference and the LICS/TCS community.

Last, but not least, items C and D above look exciting. I have heard from several sources that the tutorials at LICS 2011 were a resounding success. (See here, here and here for the slides used by Prakash Panangaden, one of my favourite speakers, in his tutorial on Semantics. Albert Atserias gave a tutorial on Finite Model Theory.)

Standards for promotions

My department is developing its strategy for the next five years. As part of this strategy work, we are working on a "promotion strategy" and we are discussing standards for promotion to associate and full professor positions. Needless to say, there is a wide array of opinions amongst my colleagues on this point. In order to obtain a broad survey of current best practices, let me ask any reader out there:

• What does it typically take to be promoted to associate and full professorships at your institution? 
• What role does teaching performance play in such decisions? And how is it measured?
• What are the incentives to undergo a promotion process, apart from the obvious ones like tenure and possibly higher wages?

Thanks in advance!

Dr. Cimini, I presume

Last Friday, Matteo Cimini successfully defended his PhD thesis entitled Contributions to the Meta-theory of Structural Operational Semantics. Congratulations to Dr. Cimini! I expect that his thesis will be available on line soon, but, for the moment, you can read some of the papers that form the bulk of that tome.

A PhD is not enough, however. I wish Matteo the best of luck for his future career. 

EATCS ballot on the future of the publication of the ICALP proceedings

Today, the European Association for Theoretical Computer Science started a ballot on the future of the publication of the proceedings of ICALP. This is a very important decision for the EATCS, and for the ICALP community in general. As chairman of the publication committee of the EATCS, I urge all the members of the TCS community who have a right to vote as members of the EATCS, to give this matter serious thought and exercise their right to express an opinion on whether future ICALP proceedings should be published with Springer or with LIPIcs. Note that if you attended ICALP 2011, ESA 2011 or MFCS 2011, you have the right to vote since your registration fee probably included a one-year membership of the EATCS.

Note also that the result of the  ballot will only take effect if at least 25 % of the EATCS members participate. Otherwise, the proposal of the EATCS council to recommend to the EATCS membership to go along with Springer for the next four years will take effect automatically.

The ballot on the future of the publication of the ICALP proceedings, as well as all the supporting documentation,  can be found here.  I do hope that you will take time to consider this matter and vote as soon as possible.

Assistant Professor position in Modelling and Analysis of Concurrent Systems at IMT Lucca (deadline October 31st)

Perhaps this announcement will be of interest to some of the readers of this blog. IMT Lucca is an exciting place and there will definitely be some competition for the position. 


Addendum dated 7 October: This video issued by IMT Lucca gives an enticing introduction to that academic institution. Do have a look, if you are interested in applying for this position.

The IMT Institute for Advanced Studies Lucca invites applications for an Assistant Professor position in the areas of foundations and formal specification of concurrent (distributed, mobile, autonomic) systems; quantitative and qualitative modelling and analysis of concurrent systems and design and development of software tools to support their formal analysis; applications to socio economic systems.

IMT Lucca (http://www.imtlucca.it) is a public international Graduate School and Institute of Technology that acts as a research university with the aim of forming human capital in disciplines characterized by their high potential for concrete applications. IMT strives to reach the fusion of theoretical comprehension and practical relevance. 

The Assistant Professor will be a part of the Research Unit "System Modelling and Analysis" (SysMA, http://sysma.lab.imtlucca.it/) in the Computer Science and Applications area of the Institute, and will perform research activities, tutorship and mentoring of Ph.D. students, limited teaching of graduate courses and participation in the development of the research activities of the Institute. 

Appointment compensation packages will depend on the candidates and their records of accomplishment, but are competitive on an international level. Applicants must be able to teach graduate courses in English; knowledge of Italian is not required.

The deadline for application is October 31st, 2011 12:00 pm CET.

Interested candidates must apply before the deadline by filling in the online application form at http://www.imtlucca.it/faculty/positions under "Junior Faculty Recruitment Program". They will also be asked to submit a CV, a research paper (published or working) and the name and contact details of three referees.

For further information about the position, applicants can refer to 

http://www.imtlucca.it/faculty/positions/junior_faculty_recruitment_program.php#modelling_concurrent_systems

or can contact either Rocco De Nicola or Sara Olson: researchers.opening@imtlucca.it.

LICS 2012 Test-of-Time Award

The latest issue of the LICS Newsletter (dated July 29) mentioned the appended information related to the LICS 2012 Test-of-Time Award. 

I strongly encourage the members of the LICS community to send their comments to Andre Scedrov (scedrov@math.upenn.edu), who chairs the award committee. As usual, the committee is faced with a very hard choice and they can do with some input from the community.


LOGIC IN COMPUTER SCIENCE (LICS) - TEST OF TIME AWARD

• The LICS Test-of-Time Award recognizes a small number of papers from the LICS proceedings from 20 years prior that have best met the "test of time".
• The LICS 2012 ToT Award committee consists of
• Martin Grohe,
• Prakash Panangaden,  
• Andre Scedrov (Chair), and  
• Ashish Tiwari.
• The committee will select between 0 to 3 papers  that appeared in LICS 1992 proceedings. All papers are nominated by default, but the  committee welcomes input from our community: please send your comments to  Andre Scedrov (scedrov@math.upenn.edu) which will be shared only among the committee members.  
• LICS 2012 ToT award will be presented during the business meeting at LICS 2012  to be held in Dubrovnik from June 22 to 25, 2012. 
• The list of papers from LICS 1992 is available at  http://www2.informatik.hu-berlin.de/lics/archive/1992/index.html 
• The information about LICS ToT award and the list of past winners is available at  http://www2.informatik.hu-berlin.de/lics/archive/test-of-time-award.html

October 2011 issue of the BEATCS Concurrency Column

I have just submitted the material for the October 2011 issue of the BEATCS Concurrency Column. This instalment of the column consists of a double bill:

• Interval Temporal Logics: a Journey by Dario Della Monica, Valentin Goranko, Angelo Montanari and Guido Sciavicco. [PDF]
• Assertional and Behavioral approaches to concurrency by Uri Abraham. [PDF]

The first piece is a survey  devoted to interval temporal logics. The article presents the main developments in the study of interval temporal logics over the past 10 years (a field of research to which the authors have contributed substantially) and outlines some landmark results on expressiveness and (un)decidability of the satisfiability problem for the family of interval logics. The authors give us a guided tour of this body of work, which, to my mind, deserves to be better known within the concurrency-theory community.

The second contribution is a a piece by Uri Abraham in which he compares two proofs of the mutual-exclusion property for the well known algorithm by Peterson: an assertional proof and a behavioural one. The article outlines a framework within which the behavioural approach can be formalized in a way that retains the intuitive content of the behavioural reasoning.

This is my last issue as editor of the Concurrency Column. I have been editing the column for the last eight years, and I feel that it is time to step down. The column will benefit greatly from a fresh perspective on the world of concurrency theory and I look forward to reading the pieces that will appear in future issues.I thank the contributors to the Concurrency Column over the last eight years and all my readers.

12 PhD positions in Computer Science and Engineering at IMT Lucca

Courtesy of Rocco De Nicola, here is an exciting opportunity for excellent students, which I am happy to advertise.

The institute for advanced studies IMT Lucca (Italy) announces 12 PhD positions in Computer Science and Engineering. The deadline for applications is September 28, 2011.

IMT (http://www.imtlucca.it/) is a research institute located in Lucca (Italy); courses are taught exclusively in English.

The PhD Program (https://www.imtlucca.it/phd_programs/computer_science_engineering/) coordinated by Rocco De Nicola aims at preparing researchers and professionals with broad training in the foundations of informatics as well as in applications to a variety of cutting-edge systems and disciplines.

A number of PhD students will be selected for working within the the two newly founded Research Unit:

SysMA (http://sysma.lab.imtlucca.it/

)
lead by Rocco De Nicola doing research on concurrent (distributed, mobile, autonomic) systems modelling and analysis
and
Dysco (http://dysco.lab.imtlucca.it/)
lead by Alberto Bemporad doing research on control and optimization technologies.

In addition, students will be selected to work on topics related to medical imaging, and imaging for the life sciences
http://users.eecs.northwestern.edu/~stsaft/#Openings

We hope that you may consider applying for and/or signaling these opportunities to colleagues and collaborators.

======= DETAILS ON THE ADVERTISED POSITIONS =======
6 IMT scholarship (12.423 EUR after taxes) plus accommodation and free meals (lunch and dinner).
1 MIUR scholarship (12.423 EUR after taxes) plus free meals (lunch and dinner).
5 positions to be funded with internal projects or third-party scholarships (negotiable salary) that come with a research budget of 3.000 EUR offered by IMT and free meals (lunch and dinner).

For further information please visit
http://www.imtlucca.it/phd_programs/call_for_applications/index.php
and/or contact the sender of this mail.

PhD positions at the University of Camerino, Italy

Emanuela Merelli has asked me to circulate the following announcement of eight PhD positions at the University of Camerino, Italy. The deadline for applications is very close, but perhaps some readers (or some of their students) might want to apply. 

---------------------

We kindly remind you that  the PhD call for applications at University of Camerino is still open. See

http://www.unicam.it/laureati/dottorato/call.asp

There are 8 fellowships available for the Doctoral Study Programme in Information Science and Complex Systems. See

www.cs.unicam.it/merelli/PhD-Informatica.pdf

The deadline is approaching, 26 August 2011.

2011 CNRS Silver Medal to Jean Goubault-Larrecq

Jean Goubault-Larrecq receives the 2011 CNRS Silver Medal. The web site with the list of medal winners states that:

La Médaille d'argent du CNRS distingue un chercheur pour l'originalité, la qualité et l'importance de ses travaux, reconnus sur le plan national et international.

So, Jean is recognized for the originality, the quality and the importance of his research work. Congratulations to Jean for the award, and to LSV as a whole for yet another achievement.

The silver medal for mathematics went to François Loeser.

Accepted papers at ESA 2011 and MFCS 2011; CFP for FSTTCS

The list of accepted papers for ESA 2011 is here. (My colleague Magnús Halldórsson was the PC chair for ESA 2011.) Ditto for MFCS 2011.

The submission deadline for FSTTCS is just two weeks away. The call for papers is here. The list of invited speakers for the event is stellar:

• Susanne Albers (Humboldt-Universität zu Berlin, Germany)
  
• Phokion G. Kolaitis (Univ. of California, Santa Cruz, USA)
  
• John C. Mitchell (Stanford University, USA)
  
• Madhu Sudan (currently at Microsoft Research New England, and on leave from MIT, USA )
  
• Moshe Vardi (Rice University, USA)
  
• Umesh V. Vazirani (Univ. of California, Berkeley, USA) 

Do submit! 

LICS 2011 Test-of-Time Award

The LICS 2011 Test-of-Time award was given yesterday to 

• Patrice Godefroid and Pierre Wolper for their paper A Partial Approach to Model Checking, 
• Dale Miller and Joshua Hodas for their paper Logic Programming in a Fragment of Intuitionistic Linear Logic and 
• Dexter Kozen for his paper A Completeness Theorem for Kleene Algebras and the Algebra of Regular Events.
  

This year's award was given to papers presented at LICS 1991 that have stood the test of time and have had considerable impact since their publication. (Source: Prakash Panangaden)

Congratulations to all the award recipients!

FPSAC 2011

I have received the following short report on FPSAC 2011 from Henning Úlfarsson, which I post with pleasure. Sources within my extended family told me that the conference was very well attended. The lecture hall was packed and it was nearly impossible to get close to the posters. The lure of Iceland as a conference location strikes again :-)

The 23rd International Conference on Formal Power Series and Algebraic Combinatorics, FPSAC 2011, was held in Reykjavik, Iceland on June 13-17, on the premises of the University of Iceland. This year's conference was dedicated to the memory of Philippe Flajolet, who passed away recently, and was very influential in the field of algebraic and analytic combinatorics. (An obituary for Philippe Flajolet may be found here.)

The conference featured 10 invited speakers, 27 talks, 53 poster presentations as well as an afternoon of software demonstrations. The topics ranged from various aspects of combinatorics to applications such as shallow water waves and genome arrangements.

More information can be found on the website http://combinatorics.is/.

Videos of talks by Friedman and Macintyre

There has been a fair amount of discussion recently on the FOM mailing list on whether the consistency of Peano Arithmetic is a legitimate mathematical problem in present day mathematical  culture. This discussion has been sparked by the talk Foundational Concerns and Mathematical Concerns that Angus Macintyre gave at the New Trends in Logic meeting. The video of Angus' talk is here. Perhaps some of the readers of this blog will want to have a look and reach their own conclusions. The person who asks most of the questions to Angus Macintyre is Harvey Friedman, whose own talk at the Vienna meeting can be seen here.

I have to say that Angus Macintyre kept his cool and maintained his thread admirably during his talk.

The videos of all the lectures may be found here, including the one delivered by Thierry Coquand when he received one of the prizes for 2008.

Jan Bergstra turns sixty

Jan Bergstra turns 60 today. Jan is one of the concurrency theorists whose work has had a lot of influence on mine, as well as on that of many others. However, his research interests are much broader and his research so far gives excellent examples of the power of algebraic tools and ideas in TCS.

According to Jan's Wikipedia entry, his main theoretical research programmes are:

• a systematic study of specification methods for abstract data types (starting in 1979, with John V. Tucker);
• the invention, development and application of process algebras, especially ACP (starting in 1984, with Jan Willem Klop, Jos Baeten and others);
• Module Algebra (starting in 1986, together with Paul Klint and Jan Heering);
• Program Algebra (starting in 1998, with Marijke Loots).

This gives a pretty fair reflection of the main thrusts in Jan's research work, and match pretty closely the topics covered by the five papers he has published in the JACM.

Apart from his scientific work, Jan Bergstra has had considerable influence on computer science in the Netherlands via his research and organizational activities. As an example of the impact he has had on CS in the NL, I limit myself to mentioning here that he has supervised over 40 PhD students, many of whom have become academic computer scientists (according to Wikipedia, at least 12 at professorial level).

As a recognition of his work, on May 18 this year, Jan has been inducted into the Royal Netherlands Academy of Arts and Sciences.

I wish Jan many happy returns for his 60th birthday and many more years of seminal scientific activity.

Addendum dated June 23: A special issue of Theoretical Computer Science devoted to the festschrift in honour of Jan Bergstra, edited by I. Bethke, A. Ponse and P.H. Rodenburg, is now available.

Rector Corradini, I Presume

This is not news anymore, but I am happy to report that Flavio Corradini was elected rector of the University of Camerino (Italy) on June 8. To the best of my knowledge, Flavio is now the youngest rector of an Italian university, and the first concurrency theorist to become rector of an Italian university. I wish him the best of luck for his new role, and hope that he will be able to continue doing some (theoretical) computer science.

Jos Baeten new general director of CWI

On June 1, I congratulated Jos Baeten for officially becoming the new chair of IFIP WG 1.8. Now, more congratulations to Jos are in order. Indeed, today the General Board of the Netherlands Organisation for Scientific Research (NWO) confirmed Jos' appointment as the new general director of the Centrum Wiskunde & Informatica (CWI) in Amsterdam. I learned the news from Jos himself, who is here in Reykjavik to attend Discotec 2011 and to deliver an invited talk at PACO.

The appointment of Jos as general director of CWI is excellent news for concurrency theory, and volume B TCS at CWI and in the Netherlands as a whole. In a way, it is also the "return of SEN 2", It is a bit ironic that Jos, who was one of the early directors of the very successful SEN 2 project, which was closed in 2008, returns now as general director of the whole institute. This may be seen as a case of "SEN 2 strikes back."

In any event, congratulations to Jos. I wish him a very successful term as director of CWI, which is one of the hotbeds of TCS research in the world. I look forward to seeing how CWI will develop under his expert leadership.

New Chair for IFIP WG 1.8

Jos Baeten has formally taken over the chairmanship of IFIP WG 1.8 on Concurrency Theory. I say "formally" because Jos has acted as de facto chair of the working group for some time already, since I decided not to run for a second term as chair.

Congratulations to Jos! I wish him the best of luck for his work as chairman of WG 1.8.

Accepted Papers for CONCUR 2011

I noticed that the list of accepted papers for CONCUR 2011 is available here. As usual, there are several interesting papers to look at. I just hope to have the time to do so. As someone said once: "Fermate il mondo! Voglio scendere!" ("Stop the world! I want to get off!")

Hubert Garavel received the Gay-Lussac Humboldt Research Award

These are good days for concurrency theory and computer-aided verification, at least judging by the awards bestowed on members of our community.

Yesterday I mentioned that the Presburger Award 2011will go to Patricia Bouyer. Holger Hermanns has now made me aware of the fact that Hubert Garavel recently received the Gay-Lussac Humboldt Research Award. (Thanks Holger!) Hubert is the fourth French scientist in the field of computer science to be awarded this prize. You can read more about the award to Hubert here. For the few readers who might not know his work, here I just limit myself to mentioning that Hubert is a pioneer in formal methods and verification tools for critical industrial systems. He is perhaps best known for being the prime mover behind the development of CADP, which is a popular toolbox for the design of communication protocols and distributed systems. CADP has been developed now for over twenty years, reflecting the very strong commitment to tool development based on elegant and useful theory that underlies Hubert's work.

Congratulations to Hubert and to Holger, who will be his host in Germany.

I note in passing that the awards to Hubert and Patricia offer further, albeit circumstantial, support on the strength of French TCS research.

Presburger Award 2011 to Patricia Bouyer-Decitre

The Presburger Award 2011 will go to Patricia Bouyer-Decitre.  See here for the details.

Patricia has contributed important results to the theory and applications of timed automata, a fundamental model of real-time systems.  In 2007 she received CNRS Bronze medal, awarded for outstanding achievements by a junior researcher.

I am very happy that this award went to Patricia. I had the pleasure of doing some work together with her at the very beginning of her career, and she has gone from strength to strength.

Congratulations to Patricia!

ERC Advanced Grant to Glynn Winskel

I just saw that Glynn Winskel has been awarded an Advanced Grant from the European Research Council for the period 1/05/2011-30/4/2016. The grant is for the project Events, Causality and Symmetry---the next generation semantics. (Extended Synopsis.)

This grant recognized one of the key players in the theory of concurrency over the last 20 years. Glynn's work on event structures, amongst other things, has had a lot of influence within my research community and it is good to see that this model plays a key role in the funded proposal. Glynn was also the director of BRICS, a research centre that had an enormous influence on TCS research in Europe and beyond.

Congratulations to Glynn!

Accepted papers for CALCO and TARK

The list of accepted paper for CALCO 2011 is here. The list of selected papers for TARK XIII is also available.

Quick reflections on ICALP 2011 (track B), part II: Conferences and long papers

During the review process for ICALP track B, a colleague wrote to me saying that he was planning to submit a paper longer than 70 pages to the conference, but eventually decided not to do so. While he was considering submitting the paper, this colleague was naturally wondering about the implications of submitting such a long paper to a conference with a 12-page limit on submissions. This academic told me that he thought that it would not be unreasonable to reject a very long paper submitted to ICALP  without even reading it. Such a decision could be backed up by a notification notice stating that "the paper is unverifiable given the available time and resources" or even "considering the paper is pointless since only 12 pages will be published."

I can understand very well why this colleague decided not to submit the paper to ICALP. Shrinking a 70+-page paper to 12 pages is a major effort, and one has to wonder whether a conference is the right outlet for such a lengthy piece of work. Indeed, one may argue that our conference publication structure does not lend itself to the publication of (very) long papers. However, I know of at least three exceptions (listed here in chronological order).

1. The ICALP 1990 paper in which Daniel Krob presented his equational axiomatizations of equality of regular expressions was 14 pages long, but the journal paper Complete Systems of B-Rational Identities (solving two problems posed by John Horton Conway in his monograph Regular Algebra and Finite Machines) that appeared in TCS in 1991 was 137 pages long. 
2. The ICALP paper in which Sénizergues introduced the decidability of DPDA equivalence is only 10 pages long, but the journal paper is 166 pages long.
3. The short paper by Martin Grohe at http://www2.informatik.hu-berlin.de/~grohe/pub/gro10.pdf was published in LICS 2010, but the full work takes a book that is still under development. See http://www2.informatik.hu-berlin.de/~grohe/pub/cap/index.html.
   

Now, one might ask what the purpose of those conference papers is. In some sense, my colleague was right in saying that they are "unverifiable" (given the length and time constraints imposed by conferences). I doubt that the conference reviewers went through all the details of the full versions of those papers, when they were available. Even a journal reviewer would probably not do so.

I guess that the answer is simply that the conference versions announce the results and "mark the territory" by saying "I did it". However, IMHO, the results only stand after the interested community has not found any serious errors in the full versions of the papers for a long time.

A separate issue is that of writing a conference paper based on a long full paper, which does justice to the main results and techniques presented by the authors in the full version in all the gory details. IMHO, conference papers reporting  on very long and technical developments are "trailers"  for the full version of the story, which is told elsewhere in all its glory. As a movie trailer, the conference paper serves the purpose of enticing potential readers to check out the full version by motivating the work, putting it in context, stating the achieved results, discussing their importance and giving a high-level sketch of the techniques and of the tools involved in the proof. (I am thinking here, for example, of the above-mentioned paper Grohe published at last year´s LICS, where he did precisely what I wrote above and, to my mind, did it well.) Of course, this is easier said than done..

Quick reflections on ICALP 2011 (track B): French TCS is alive and well

This is the first in what I hope will be a series of posts devoted to some reflections on ICALP 2011 track B. The executive summary is that, for what it is worth, I believe that French TCS is alive and well (at least as far as volume B TCS is concerned).

France was the country with the largest number of track B authors (42), the largest number of submitted papers (21.79) and the largest number of accepted papers (7). Easychair statistics aside, France is home to some research groups in TCS that have amazing strength in depth and breadth. To wit, consider the following three exhibits, with apologies to those that I am unable to mention explicitly here.

• Paris Diderot (aka Paris 7). This university is home to LIAFA and PPS, two large research laboratories hosting an enormous wealth of talent. (In passing, let me mention that PPS is a kind of little Italy, with six Italians holding permanent positions.)
• LSV at ENS Cachan.  The Laboratoire Spécification et Vérification (LSV) is the Computer Science laboratory of ENS de Cachan, and was founded in 1997. I had the pleasure of spending a month there in May 1998 as a visiting professor, but the LSV of today hosts a much larger team of researchers than it did then. The list of members is impressive. When Hubert Comon received a CNRS silver medal in 2008, he said that "I think that this is the best environment in the world to carry out research in computer science, thanks to a unique way of working and to a great scientific homogeneity." (See here, page 34, for the French original.) Of course, one can always debate this kind of statements, but it is hard to question the strength and focus of that group of academics. 
• LaBRI in Bordeaux. This is home to figures such as Bruno Courcelle, Anca Muscholl, Géraud Sénizergues, Igor Walukiewicz  and Pascal Weil, who are all members of the Formal Methods Group, which currently has 55 members.

It seems to me that these research centres are just the tip of a strong research iceberg in TCS. May they continue this way. 

EATCS Award 2011 to Boris (Boaz) Trakhtenbrot

The EATCS Award for 2011 will go to Boris (Boaz) Trakhtenbrot  for "his decisive influence on the developments of algorithms, and, more generally, of computer science as a whole in many ways." You can read a scientific "autobiography" written by Boaz for an LNCS volume devoted to his 85th birthday here (requires access to LNCS). I found the piece a fascinating read.

Congratulation to Boaz.

Here is what the EATCS web site says:

The EATCS Award is awarded annually to honor a scientist with widely recognized contributions to the field of theoretical computer science throughout a distinguished scientific career. The Committee, consisting of Pavlos Spirakis (Chair), Friedhelm Meyer auf der Heide  and Eugenio Moggi in charge of evaluating the nominations to the 2011 EATCS Award has come to the decision to honor Boris (Boaz) Trakhtenbrot with the EATCS Award 2011 for his decisive influence on the developments of algorithms, and, more generally, of computer science as a whole in many ways.The decision has been unanimously approved by the EATCS Council. The Award will be assigned during a ceremony that will take place in Zürich (Switzerland) during ICALP 2011 (July 4-8, 2011).

Best paper awards at ICALP 2011

The best paper awards for the three tracks at ICALP 2011 will go to the following papers:

Track A

• Malte Beecken, Johannes Mittmann and Nitin Saxena. Algebraic Independence and Blackbox Identity Testing.
• Shi Li. A 1.488-approximation algorithm for the uncapacitated facility location problem. (Best student paper)

Track B

• Olivier Carton, Thomas Colcombet and Gabriele Puppis. Regular Languages of Words Over Countable Linear Orderings.
•  Martin Delacourt. Rice's theorem for mu-limit sets of cellular automata. (Best student paper)

Track C

• Martin Hoefer.Local Matching Dynamics in Social Networks.
  
• Shiri Chechik. Fault-Tolerant Compact Routing Schemes for General Graphs. (Best student paper)

Congratulations to all the awardees!

Accepted papers for ICALP 2011 tracks A and C

The lists of accepted papers for ICALP 2011 tracks A and C are now available from the web site for the conference (both with and without abstracts). See here for track A and here for track C. I am no expert, but the lists of accepted papers look very impressive to me. It is also clear that blogging has a positive influence on acceptance of one's papers at ICALP track A :-) Congrats to Andrew, Bill, Lance and Scott, with apologies to other volume A bloggers I might have missed.

Source of a quote by Lazlo Babai

I once read the following quote attributed to Lazlo Babai: "What we need are not more theorems, but more proofs." I think that I originally read it on his Wikipedia entry, but the quote is not there anymore.

Can anyone tell me from where the quote originates, assuming my memory is not playing tricks with me? Thanks in advance!

Accepted papers for ICALP 2011 track B

The notifications and the reviews for ICALP 2011 were posted earlier today. I was the PC chair for track B and I freely admit that, during the electronic PC meeting,  I often felt that the job was too big for me. I owe all of my PC a great debt. I could not have mastered this PC chair job without the support of the members of the PC and without relying on their scientific judgement and professionalism. Indeed, I feel that I have learned a lot from my PC during the meeting.

The overall quality of the submissions to ICALP 2011 track B was unbelievably high. (My co-chairs tell me a similar story for the other two tracks, and this bodes well for the future of ICALP.) I feel that I have never been involved in the PC for a conference where the threshold for acceptance was so high. I wish that we could have selected at least ten more papers, but the number of slots was limited and we had to make some very hard choices. The authors of the many good papers that we could not select have my sympathy. I have no doubt that they will publish their submissions in a top-notch conference and/or journal soon.

There are several interesting topics for discussion that emerge from the field of submissions at this year's ICALP track B. I plan to devote a short series of posts to some of those that I have penned down during the PC meeting. However, this will have to wait until I have caught up with some of the many chores that have piled up on my desk over the last two months. For the moment, the list of accepted papers for track B is here. (See here for the list with abstracts.)

I look forward to a very exciting meeting in Zürich in July.

Student Scholarships at ICALP 2011

If you are a student and you are planning to attend ICALP 2011, read below. 

The EATCS (partly sponsored by MPI-INF) has provided ten 500-Euro student scholarships.  The ten scholarships will be used to support participation of students in ICALP 2011 by covering early registration and possibly some of the local expenses.

To apply for one of these scholarships, please send an email to . The application should be sent by April 19th, 2011, and should contain a motivation for the sponsorship request, one letter of recommendation, the curriculum vitae of the applicant, together with an indication of whether the applicant is an author or co-author of one of the papers selected for the conference.

The applications will be reviewed by the ICALP 2011 conference chairs and the PC chairs. Preference will be given to PhD students from countries where access to funds is limited who will present papers at the conference. Each applicant will receive a notification of acceptance/rejection of her/his application by email by April 30th, 2011.

SOS 2011: Call for Papers

The call for papers for SOS'11 (Structural Operational Semantics 2011) is out. SOS 2011 will be held as an affiliated event of CONCUR 2011 on September 5, 2011, in Aachen, Germany. The important dates are as follows:

• Submission of abstract: Friday 27 May 2011
  
• Submission: Friday 3 June 2011
  
• Notification: Friday 1 July 2011
  
• Final version: Friday 15 July 2011
  
• Workshop: Monday 5 September 2011

SOS is an event that is very close to my heart, so I strongly encourage my readers to submit good papers to the workshop. Let´s start sharpening our pencils now, but not in the sense of Halmos :-)

Accepted papers for LICS 2011

The list of accepted papers for LICS 2011 is out (with abstracts). The programme looks very strong, as usual.

One week to the ICALP deadline

This is to remind any interested reader that the  deadline for submissions to ICALP 2011 is Tuesday, 15 February. The submission server will close at 23:59 CET. The deadline is strict.

See here for information on how to submit.

If you plan to submit to ICALP 2011, as my fellow PC chairs, the organizers and I hope, bear in mind that

1. you are invited to submit an extended abstract of no more than 12 pages in LNCS style;
2. material other than the abstract, references and the first 12 pages may be considered as supplementary and will be read at the committee's discretion.

If you are submitting to track B, I encourage you to place all supplementary material in a clearly marked appendix. As usual, the 12-page extended abstract should really speak for itself.

We look forward to receiving your best papers!

Logic and Computer Science: A Piece for Reykjavik University's Magazine

The following piece will appear in the 2011 issue of Reykjavik University's magazine. I am posting it here in case it may be of interest/use to any of the readers of this blog.

Athens, 330 BC

Dear Plato,

I am writing to you because, as my former mentor and teacher, you will no doubt rejoice at the success of some of the ideas of one of your pupils. I have to warn you that what I am about to recount is a dream I had last night, and may be construed as wishful thinking on my part. However, the dream was so vivid that I believe that what happened in it will come to pass, even though this will take well over 2000 years.

Last night, I had a dream that took me to a year the people around me referred to as 2011 AD. I was standing in front of a large building located in a land that our explorer Pytheas calls Thule. Don't ask me why, but I knew that the building I entered through doors that opened by themselves was a descendant of your Academy and of my Lyceum. Young men and women were obviously there to learn in large numbers. This heritage is already something the two of us should be proud of, but it is not what I wanted to tell you most.

As you know, I consider the development of logic one of my main contributions to human knowledge. I was always a bit miffed by the fact that many people consider logic a very abstract subject with no applications. In my heart, I always felt that logic ought to be the foundation of science, be it basic or applied. I now know that my beliefs will be vindicated within 2300 years and in spectacular fashion.

I know that you will find it hard to believe, but in 2011 humankind will have at its disposal a machine like no other. It is an object they call "computer", which, unlike any other man-made machine, can be told to do many different things by feeding it with appropriate instructions. In 2011, computers will be everywhere. I saw many with my very eyes, but most of them will also be embedded in physical devices, and are therefore invisible to their users. By 2011, this population of "effectively invisible" computers will be in the fabric of our homes, shops, vehicles, farms and some even in our bodies! They will help humankind command, control, communicate, do business, travel and entertain themselves. And you know what? All of this will have to do with logic!

This truly wonderful machine, the computer, will be an engine of logic. Logic, my beloved creation, will be used to construct computers and to breathe life into them. I was told by people in what they call the "School of Computer Science at Reykjavik University" that the design of such a complex machine is only possible because George Boole (a follower of our ideas) invented a simple logic, now called Boolean logic, which deals with the truth and falsity of simple propositions and is the basis of modern digital computer design. Moreover, the languages that future humans will use to communicate with those machines, which they call "programming languages", are themselves special kinds of logical systems. Programming computers will make
logic come alive.

You will no doubt remember my famous syllogism:

All men are mortal.
Socrates is a man.
Therefore Socrates is mortal.

Today, people that call themselves "computer scientists" view syllogisms like the one above as basic steps of computation, which computers carry out at amazing speed and that take place while the computers are doing their job. But this is not all. You might recall that some of my lesser known work dealt with what I called "temporal logic". In a temporal logic, we can express statements like "I am always hungry", or "I will eventually be thirsty", or "I will be hungry until I eat a peach". Well, in 2011 people at this institution of learning in the Thule, like many others throughout the world, will be using this creation of mine to describe properties that computer systems must exhibit, such as "the computer system will never stop working." Another creation of mine, modal logic, lies at the heart of applications of logic to reasoning about possible and necessary behaviour of computing agents. Moreover, computers can be instructed to check whether other computer systems have properties that can be expressed using temporal logic!

There is a lot more I could tell you, but I do not want to bore you more with the contents of this dream of mine. Indeed, I am sure that you will have already realized why this dream has made me proud. In fact, I hope that soon I will have a dream showing me the development of this science in 2050. Even in 2011, computer science will be a young field and its marriage with logic is bound to produce amazing changes to human life and to science as a whole. Indeed, during my visit to that university, I was told that Donald Knuth, a famous computer scientist, said that: "Science is what we understand well enough to explain to a computer. Art is everything else we do." So, science is everything that can be expressed in terms of logic, and in particular the living logic that runs in computers!

Before waking up, I had a glimpse at something they call a "movie", where talking images resembling real life are projected on a screen. In fact, in 2011, computers will also be used to great effect to make movies, games and many other forms of entertainment. I wonder what our playwrights would be able to achieve, if they had access to such a technology.

The movie I watched was entitled "Twins". I did not find it good, but in it an actor by the name of Arnold Schwarzenegger utters the following memorable sentence while talking to a thug: "You have no respect for logic. I have no respect for people who have no respect for logic." He then proceeds to beat up the thug, an act that I abhor. But at that point I woke up, knowing that in 2011 logic will be the most applied branch of mathematics. All this, thanks to the young damsel called computer science.

I hope you are resting well in the world of ideas.

Your former pupil,

Aristotle

Writing papers the hard way

For readers who do not speak Italian, the text roughly reads "Inventing the wheel hasn't been too hard....it´s writing the paper that is back-breaking!"

Faculty position in computer systems at Reykjavik University

In order to implement its strategy in research and teaching, the School of Computer Science at Reykjavik University seeks to hire a faculty member for a new academic position in the field of computer systems, broadly construed. We are interested in an ambitious, highly-qualified academic who, apart from developing her/his research programme, is interested in working with existing faculty, and in bridging between research, in one or more of the research areas within the School, in particular artificial intelligence, software engineering and theoretical computer science (the emphasis is mine). See here for the details regarding the position.

Second call for papers: ICALP 2011

The submission server for ICALP 2011 is now open. See the call for papers and the page with information on how to submit. A wonderful piece of news is that the EATCS (partly sponsored by MPI-INF) has provided ten 500-Euro student scholarships.  The ten scholarships will be used to support participation of students in ICALP 2011 by covering early registration and possibly some of the local expenses.

I trust that you will consider submitting your best work to one of the three tracks of ICALP 2011.  (As PC chair for track B, I am, of course, very keen on seeing many strong submissions to that track of ICALP!) The deadline for submission is February 15, so now is the time to write your paper if you have not already done so.

Concurrency Column of the BEATCS for February 2011

I have just posted the contribution to the Concurrency Column of the Bulletin of the EATCS for February 2011. It is a piece entitled Sessions, from types to programming languages by Vasco Thudichum Vasconcelos.

I hope that the readers of the column will enjoy it.

Feel free to contact me if you would like to contribute a piece to the Concurrency Column. 

Pushdown Automata and Vector Addition Systems

Philippe Schnoebelen just sent me an email announcing the forthcoming event Pushdown Automata and Vector Addition Systems: A New Look At Two Classical Problems, which will be held at LSV in Cachan on January 20, 2011.Quoting from the web page for this one-day event:

This special event focuses on two recent major claims/results:

• a new proof, by P. Jančar, for the decidability of equivalence for deterministic pushdown automata, first established by G. Sénizergues, and
• a new proof, by J. Leroux, for the decidability of accessibility in vector addition systems, or equivalently in Petri nets, first established by E. Mayr (and S. R. Kosaraju).

Our aim here is to provide an exceptional opportunity for Jančar and Leroux to provide an in-depth presentation of their proofs in front of a large audience of expert specialists as well as younger researchers interested in the field. This will be a unique occasion for the kind of interaction and attention to details that is only possible in a 3-hour tutorial format.

This sounds like a very interesting event. If you happen to be in Paris at around that time, do make a point of attending it. For those of us who cannot be there,  Jančar and Leroux have posted write-ups of their results here and here.

Springer's LNCS

Over the last few days, I have been exchanging emails with the chief librarian at my university to find out how much Springer charges us for access to its LNCS proceedings series. My enquiries were prompted by some remarks from a colleague from outside Iceland who told me that her library will likely stop subscribing to LNCS starting in 2011.  

Yesterday, my contact at our library wrote to me saying that LNCS is not part of the Icelandic National Licence to Springer journals, SpringerLINK. Our library used to buy it as a special subscription and we had a deal with Springer for a three year period. This subscription was one of the special subscriptions we had to cancel after the financial crisis. She also told me that the subscription fee for access to LNCS for the year 2009 was the "special price" of  7.566,00 EUROS. (I wonder what the standard price is.) 

I wonder whether your library will continue subscribing to LNCS. (Do post a comment if you have any information on this!) Times are hard for everyone, or so it seems, and perhaps university libraries are becoming more selective in choosing what journals and proceedings series they subscribe to. 

Call for nominations for EATCS awards

The calls for nominations for the EATCS Award, the Presburger Award and the Gödel Prize for 2011 are now out. See here for details. The deadlines are approaching fast, so get your nominations ready now!

Postdoctoral position at Reykjavik University

Processes and Modal Logics

School of Computer Science, Reykjavik University

One postdoctoral position

Applications are invited for one postdoctoral position at the School of Computer Science, Reykjavik University.  The position is part of a research project funded by the Icelandic Fund for Research, under the direction of Anna Ingolfsdottir and Luca Aceto. The general aim of the project is to contribute further advances to the study of the connections between the theory of reactive systems, modal logics and logics of knowledge, amongst others. See the web page of the project at

http://www.ru.is/faculty/luca/PROJECTS/PROMOLO/

for more details on the project.

The successful candidates will benefit from, and contribute to, the research environment at the Icelandic Centre of Excellence in Theoretical Computer Science (ICE-TCS). For information about ICE-TCS and its activities, see

http://www.icetcs.ru.is/.

Qualification requirements

Applicants for the postdoctoral position should have a PhD degree in Computer Science, Mathematics or closely related fields. Previous knowledge of at least one of concurrency theory, modal/epistemic logics and their applications in computer science, and process calculi is highly desirable.

Remuneration

The wage is 330,000 ISK (roughly 2,120 euros at the present exchange rate) per month before taxes. The position is for one year, starting in January 2011 or as soon as possible thereafter, and is renewable for another year, based on good performance and mutual satisfaction.

Application details

Interested applicants should send their CV, including a list of publications, in PDF to the addresses below, together with a statement outlining their suitability for the project and the names of two referees.

Anna Ingolfsdottir
email: annai@ru.is

Luca Aceto
email: luca@ru.is

We will start reviewing applications as soon as they arrive, and will continue to accept applications until the position is filled.

LICS 2011 Test-of-Time Award Nominations

The LICS Test-of-Time Award recognizes a small number of papers from the LICS proceedings from 20 years prior that have best met the "test of time". The LICS 2011 Test-of-Time Award committee is, as usual, stellar and consists of Tom Henzinger, Radha Jagadeesan, Catuscia Palamidessi, and Andy Pitts (Chair). All papers published in the LICS 1991 Proceedings are eligible, see here for the complete list. Any member of the LICS community is welcome to send recommendations to Andy Pitts at Andrew.Pitts@cl.cam.ac.uk.

I already sent in my nomination yesterday, and I encourage my readers to recommend their favourite paper from LICS 1991. This is my fourth nomination this year, and so far I am zero out of three. Let's see whether the author of the paper I recommended will be any luckier.

Call for Papers for FSEN 2011

I have been asked to distribute this call for papers. Consider submitting to FSEN 2011, thereby supporting a young, good-quality conference in formal approaches to software engineering, broadly construed!

########################################
                         CALL FOR PAPERS

                   Fourth International Conference on
               Fundamentals of Software Engineering 2011
                        Theory and Practice
                               (FSEN '11)

                        http://fsen.ir/2011

                            Tehran, Iran
                          April 20-22, 2011

########################################

About FSEN

FSEN is an international conference that aims to bring together
researchers, engineers, developers, and practitioners from the academia
and the industry, who work in every area of formal methods. This
conference seeks to facilitate the transfer of experience, adaptation of
methods, and where possible, foster collaboration among different groups.
The topics of interest cover all aspects of formal methods, especially
those related to advancing the application of formal methods in the
software industry and promoting their integration with practical
engineering techniques. Following the success of the previous FSEN events
in 2005, 2007 and 2009, the next event in the FSEN series will take place
in Tehran, Iran, April 20-22, 2011.
---------------------------------------------------------------------

In cooperation with

ACM SIGSOFT
IFIP WG2.2
---------------------------------------------------------------------

Important Dates

Abstract Submission:   October 18 , 2010
Paper Submission:      October 25 , 2010
Notification:          December 13, 2010
Camera Ready:          January 10 , 2011
Conference:            April 20-22, 2011
---------------------------------------------------------------------

Keynote Speakers

Carlo Ghezzi, Politecnico di Milano, Italy
Joost-Pieter Katoen, RWTH Aachen University, Germany

(Third speaker to be announced)
---------------------------------------------------------------------

Topics of Interest

The topics of this symposium include, but are not restricted to, the
following:

* Models of programs and systems
* Software specification, validation and verification
* Software architectures and their description languages
* Object and multi-agent systems
* Coordination and feature interaction
* Integration of formal and informal methods
* Integration of different formal methods
* Component-based development
* Service-oriented development
* Model checking and theorem proving
* Software and hardware verification
* CASE tools and tool integration
* Application to industrial cases

The length of each paper including figures and references must not exceed
15 pages and should conform to the Springer LNCS style. All papers must be
submitted in PDF or postscript format. Submissions should explicitly state
their contribution and their relevance to the theme of the conference.
Other criteria for selection will be originality, significance,
correctness, and clarity. Simultaneous or similar submissions to other
conferences or journals are not allowed.
----------------------------------------------------------------------

Proceeding and Special Issues

The post-proceedings of FSEN11 will be published by Springer Verlag in the
LNCS series.  There will also be a pre-proceeding for the accepted papers,
which is printed locally by IPM. This pre-proceeding will be made
available at the conference.

The proceedings of FSEN07 and FSEN09 were published in the LNCS series. A
special issue of Science of Computer Programming is being published,
containing the extended versions of a selection of papers of FSEN09. A
special issue of Fundamenta Informaticae was published, containing the
extended versions of a selection of papers of FSEN07. The proceedings of
FSEN05 was published in the ENTCS series: ENTCS 159 (2006). Two special
issues were published containing the extended versions of a selection of
papers of FSEN05 in Fundamenta Informaticae (FI, vol. 82, 2008) and  in
Journal of Universal Computing (J.UCS, 13(13), 2007).

----------------------------------------------------------------------
General Chair

Hamid Sarbazi-azad - IPM, Iran; Sharif University of Technology, Iran

Program Chairs

Farhad Arbab - CWI, Netherlands; Leiden University, Netherlands
Marjan Sirjani - Reykjavik University, Iceland; University of Tehran, Iran

Steering Committee

Farhad Arbab - CWI, Netherlands; Leiden University, Netherlands
Christel Baier - University of Dresden, Germany
Frank de Boer - CWI, Netherlands; Leiden University, Netherlands
Ali Movaghar - IPM, Iran; Sharif University of Technology, Iran
Hamid Sarbazi-azad - IPM, Iran; Sharif University of Technology, Iran
Marjan Sirjani - Reykjavik University, Iceland; University of Tehran, Iran
Jan Rutten - CWI, Netherlands; Vrije University Amsterdam, Netherlands

Program Committee

Luca Aceto - Reykjavik University, Reykjavik, Iceland
Gul Agha - University of Illinois at Urbana - Champaign, USA
Farhad Arbab - CWI, Netherlands; Leiden University, Netherlands
Jos Baeten - Eindhoven University of Technology, Netherlands
Christel Baier - University of Dresden, Germany
Frank de Boer - CWI, Netherlands; Leiden University, Netherlands
Marcello Bonsangue - Leiden University, Netherlands
Mario Bravetti - University of Bologna
James C. Browne - University of Texas at Austin, USA
Einar Broch Johnsen - University of Oslo, Norway
Michael Butler - University of Southampton, UK
David Clarke - CWI, Netherlands; K.U.Leuven, Belgium
Wan Fokkink - Vrije Universiteit Amsterdam, Netherlands
Masahiro Fujita - University of Tokyo, Japan
Maurizio Gabbrielli - University of Bologna, Italy
Radu Grosu - State University of New York at Stony Brook, USA
Jan Friso Groote - Technical University of Eindhoven, Netherlands
Joost Kok - Leiden University, Netherlands
Ramtin Khosravi - University of Tehran, Iran
Kim Larsen - Aalborg University, Denmark
Zhiming Liu - United Nations University, Macao, China
Seyyed Hassan Mirian - Sharif University of Technology, Iran
Sun Meng - Peking University, China
Ugo Montanari - University of Pisa, Italy
Peter Mosses - Swansea University, UK
Mohammad Reza Mousavi - Technical University of Eindhoven, Netherlands
Ali Movaghar - IPM, Iran; Sharif University of Technology, Iran
Andrea Omicini - University of Bologna, Italy
Saeed Parsa - Iran University of Science & Technology, Iran
Hiren Patel - University of Waterloo, Canada
Jan Rutten - CWI, Netherlands; Vrije University Amsterdam, Netherlands
Davide Sangiorgi - University of Bologna, Italy
Marjan Sirjani - Reykjavik University, Iceland; University of Tehran, Iran
Carolyn Talcott - SRI International, USA

CNRS Bronze Medal to Thomas Colcombet

Thomas Colcombet of LIAFA, Université Paris Diderot - Paris 7, has been awarded a CNRS bronze medal. See here for the full list of awardees. As you can see, Thomas is the only recipient of the award in the field of computer science. It is good for TCS at large to see one of its researchers receive such a prestigious national award.

This has been quite a year for researchers working on the classic theory of automata, logic and their applications. Earlier in 2010, one of Thomas' collaborators, viz. Mikolaj Bojanczyk, received the first Presburger Award and Anca Muscholl was awarded a CNRS silver medal.

Congrats to all of them!

SOS 2010

On August 30, Pawel Sobocinski and I co-chaired SOS 2010, an affiliated workshop of CONCUR 2010. The workshop programme was interesting and we had 18 participants. (It was hard to compete with EXPRESS 2010, which had 35 registered participants.) The proceedings for the workshop are available as an EPTCS volume.

Apart from five contributed talks touching on a fairly wide variety of topics, the workshop featured two invited presentations. MohammadReza Mousavi kicked off the workshop in style with a talk entitled How to cook a security-enabled semantics. In his talk, which was partly based on this paper, Mohammad introduced notions such as restricted revocable delegation and studied their consequences in language-based security. Listening to Mohammad speak I felt, not for the first time, that language-based security is one of the (alas, many) topics that I should make an effort to understand better.

The second invited talk was joint with EXPRESS, and was delivered by Catuscia Palamidessi. Catuscia had a very large audience for a workshop, and fortunately we had decided to move to a lecture hall that could hold about 100 people before her talk :-). Catsucia's talk, which was entitled Compositionality of Secure Information Flow, dealt with ways in which one can quantify the amount of leakage of confidential information through public outputs in computer systems. Catuscia discussed a proposal for measuring the amount of leakage that is based on the Bayes risk, namely (the converse of) the probability of guessing the right value of the secret, once we have observed the output. In her talk, Catuscia presented a process calculus for the specification of systems composed by concurrent and probabilistic processes, and investigated "safe constructs", namely constructs which do not increase the leakage.

Overall, I like to think that SOS 2010 was a successful workshop. However, I would like to see this workshop series be more visible and receive more submissions. I hope that future chairs will be more successful than I have been in achieving these goals.

A Selection of Papers from CONCUR 2010

As I have already mentioned in earlier posts, I enjoyed a lot of talks in the programme for CONCUR 2010. Here are just a few highlights, with apologies to all the speakers whose talks/papers I do not mention in this post. Overall, the conference programme was of very high quality. This bodes well for the future of CONCUR.

• Lutz Schröder and Yde Venema. Flat Coalgebraic Fixed Point Logic. Lutz presented the paper and gave a very clear introduction to the coalgebraic approach to the study of modal logics. Technically, this paper presents a unified co-algebraic treatment  of flat fixed-point logics. (Fixed-point logics, such as the mu-calculus, are widely used in computer science, in particular in artificial intelligence and concurrency.) The main results in the paper are the completeness of the Kozen-Park axiomatization and a general  EXPTIME upper bound for flat fixed-point logics.
• Fides Aarts and Frits Vaandrager. Learning I/O Automata. The talk was delivered by Frits, who addressed the general question of learning models of reactive systems automatically, e.g., for model-based testing or software engineering.In this work, Fides and Frits establish links between three widely used modelling frameworks for reactive systems: the ioco theory of Tretmans, the interface automata of De Alfaro and Henzinger, and Mealy machines. It is shown that, by exploiting these links, any tool for active learning of Mealy machines can be used for learning I/O automata that are deterministic and output determined. The approach presented in the paper has been implemented on top of the LearnLib tool and has been applied successfully to three case studies, including learning a model of Fides' biometric passport. 
• Pawel Sobocinski. Representations of Petri net interactions. . Pawel, who was my co-chair for SOS 2010, presented a novel compositional algebra of Petri nets. The algebra contains two binary operators (tensor product and sequential composition) and twelve constants! He also introduced a stateful extension of the calculus of connectors and showed that .these two formalisms have the same expressive power.
• Pavol Cerny, Thomas Henzinger and Arjun Radhakrishna. Simulation Distances.  The simulation preorder is often used to establish the correctness of an implementation I with respect to a specification S as follows: I correctly implements S if S can simulate the behaviour of I. In other words, this happens if everything the implementation I does is allowed by the specification S. The result of such a verification is boolean and cannot be used to assess how far I is from implementing the behaviour allowed by  S. This paper extends the simulation preorder to the quantitative setting by  defining three different simulation distances. The correctness distance measures how much the specification must be changed in order to be satisfied by the implementation. The coverage distance measures how much the implementation restricts the degrees of freedom offered by the specification. The robustness distance measures how much a system can deviate from the implementation description without violating the specification. The paper develops a comprehensive theory for those notions of simulation distances. 

Reading the papers from CONCUR 2010 will keep me busy for some time. 

Milner Session at CONCUR 2010

During CONCUR 2010, the concurrency-theory community paid a small tribute to Robin Milner by dedicating a session of its flagship conference to him. The so-called Milner Session was held on Wednesday, 1 September, from 2pm till 4pm. It consisted of a talk by Jos Baeten and of three presentations of papers that were selected for the conference by the PC.

Jos kicked off the session with a talk devoted to Milner's contributions to concurrency theory. He focused on his seminal Calculus of Communicating Systems, providing an overview of its syntax, of some of the design decisions Milner made in that calculus and of its semantics. The presentation by Jos was followed by a short discussion, with remarks from Ugo Montanari, Kohei Honda and myself, amongst others.

My two readers might be interested in reading a short note  by Samson Ambramsky entitled Robin Milner's Work on Concurrency that was published yesterday in the Proceedings of MFPS 2010. According to Samson,

Robin’s ideas have become part of the air we breathe in our scientific community.....

CCS was not just a new calculus, but a new paradigm — that has played a central role in the subsequent development of our subject. It opened up the world of compositional behavioural modelling.

I have always found that one of the red threads in Milner's work was the, I believe novel, emphasis on behavioural semantics and on his standpoint that a process is an equivalence class of process descriptions (be they terms in a process algebra/calculus or states in a labelled transition system/automaton) modulo some notion of behavioural equivalence. Milner himself reiterated this point in several of his writings/talks, and I am glad to see this mentioned in Samson's piece.

We knew what functions were already! But what are processes? CCS established the fundamental methodological point of studying them through their observational behaviour (defined in terms of labelled transition systems via SOS).

This led inexorably in turn to notions of observational equivalence.

Thanks to Jos and Samson for their tributes to Milner's work.

Amongst the contributed talks in the Milner Session, let me mention the excellent talk by Edsko de Vries, who presented joint work with Vasileios Koutavas and Matthew Hennessy on Communicating Transactions. Communicating transactions are obtained by dropping the isolation requirement from standard transactions and can be used to model automatic error recovery in distributed systems. Edsko presented a behavioural theory for a version of CCS with communicating transactions that  is sound and complete with respect to the may-testing preorder. The technical work looked really impressive.

I really enjoyed Silvia Crafa's talk entitled A Logic for True Concurrency, which presented joint work with Paolo Baldan. Perhaps, I was biased since Silvia's talk brought me back in time some twenty years, when a different version of myself was working on topics related to true concurrency. However, I was not the only one to be impressed by that paper, which proposes a logic for true concurrency whose formulae describe events in computations and their causal dependencies. The induced logical equivalence is hereditary history preserving bisimilarity. The authors also identify fragments of the logic that capture other truly concurrent behavioural equivalences in the literature: step, pomset and history preserving bisimilarity. After Silvia's talk, I felt that her paper with Paolo should have been written long ago. 

A Thought Experiment

Suppose that a top-class conference to which you usually submit your papers decide to publish its proceedings in an electronic open-access outlet instead of using a commercial publisher, like STACS and FST-TCS have done over the last few years. Would that decision have any effect on whether you submit your papers to that conference? Would you encourage your students to submit to that conference in order to further their future career? Do you think that a prestigious conference has anything to lose in publishing its proceedings in an electronic open-access outlet?

CONCUR 2010

From August 30 till the very early hours of September 3, I was in Paris to co-chair SOS 2010 and attend CONCUR 2010. It is always a pleasure to have the chance to attend CONCUR, which is the flagship conference for the concurrency-theory community, and the lure of Paris made this conference even more attractive than usual.

CONCUR 2010 was perfectly organized by Paul Gastin (LSV, ENS Cachan, France), François Laroussinie (LIAFA, Université Denis Diderot - Paris 7, France) and their support team (see the bottom of this page for the details), and was held at Université Denis Diderot - Paris 7.

According to the program chairs, there were 160 people registered for the main conference and 215 people were registered for the conference or one of the eight affiliated events. I am not a CONCUR historian, but I believe that this makes this edition of CONCUR one of the best attended on record, together with the one held in Bologna last year. I do not find this level of attendance particularly surprising----after all, Paris is an attractive city and it is one of the hotbeds of research in concurrency theory. However, it is a great credit to the organizational effort that everything went smoothly and that the atmosphere at the conference was relaxed and conducive to both scientific and social exchanges.

On behalf of the CONCUR community, I'd like to say thanks to François, Paul and their support team for organizing a great conference. We had many excellent talks on a variety of exciting topics, a session devoted to Robin Milner (chaired by Matthew Hennessy and featuring a talk by Jos Baeten), varied and tasty lunches served next to the conference room, and yet another edition of the CONCUR football match (which saw about 20 participants kick a ball around for about one hour before the conference dinner).

I hope to devote another post to the main conference and to SOS 2010. Here I will just limit myself to a few brief remarks on the invited talks that I could attend. (Unfortunately, I had to leave at an ungodly early hour on Friday, 3 September, and therefore I missed  Holger Hermann's invited presentation and the last day of the conference. Knowing Holger's communication skills, I am sure that I missed a great talk. I hope that Holger will make a recording of his talk available from his web page.)

The conference was given the best possible start by Vladimiro Sassone, who delivered a very clear talk entitled Trust in Anonymity Networks.  In his presentation, after having introduced the basic setting of anonymity protocols, Vladimiro presented an analysis of the privacy guarantees of the Crowds anonymity protocol, with and without onion forwarding, for standard and adaptive attacks against the trust level of honest users.

I had the great honour of chairing the session featuring the second invited talks, which was delivered by Maurice Herlihy. After-lunch sessions are always challenging, especially when the conference is held in France, but Maurice's talk, entitled Applications of Shellable Complexes to Distributed Computing, was the perfect digestive after an excellent lunch. In his talk, Maurice reviewed some of the ideas behind his award-winning application of tools from algebraic topology to distributed computing and then discussed some very recent results that will be presented at DISC 2010 in the paper Concurrent Computing and Shellable Complexes co-authored with Sergio Rajsbaum.

In her talk Taming Distributed Asynchronous Systems, Anca Muscholl delivered a good overview of many results and open problems related to  analysis techniques for distributed, asynchronous systems with two kinds of synchronization, namely shared variables and fifo channels. Anca has just received the prestigious CNRS silver medal for 2010 for computer science. Congrats to her!


The last invited talk I was able to attend was delivered by Frank S. de Boer, who gave a presentation entitled Dating Concurrent Objects: Real-Time Modeling and Schedulability Analysis. After giving the audience an overview of the CREDO project, Frank introduced a real-time extension of the concurrent object-oriented language Creol, and showed us how to analyze schedulability of an abstraction of real-time concurrent objects in terms of timed automata. He concluded the talk by telling the audience about techniques for testing the conformance between these behavioral abstractions and the executable semantics of Real-Time Creol in Real-Time Maude. I enjoyed the talk, and I think that Frank was successful in keeping his audience away from their laptops and in making the attendees resist the temptation of checking their email during his talk, which was one of his stated aims!

Addendum.  Holger Hermann's invited presentation is now available (in flash) from here. Enjoy!

One year of Electronic Proceedings in Theoretical Computer Science (EPTCS)

Electronic Proceedings in Theoretical Computer Science (EPTCS) was launched by Rob van Glabbeek in 2009, as an initiative to have proceedings of all worthy workshops in Theoretical Computer Science freely available on-line. The papers in the proceedings are simply entries in the CoRR repository. DOI numbers are assigned to EPTCS publications, and they are indexed in CrossRef and in the Directory of Open Access Journals.  There is no charge for authors or workshops/conferences.

The idea caught on like wildfire, and since EPTCS was launched over 30 proceedings were published, and 22 more have been accepted for publication.

Perhaps one of the reasons is that the procedure for submitting a proposal is very simple, and our response time to a proposal is very fast, usually less than 10 days. Additionally, thanks to efficient workflow, proceedings usually appear within 10 days after all the constituents have been delivered.

We find that it is very important to properly record workshop proceedings in one, easily searchable place. Also, we want to contribute in this way to the growing acceptance of the view that all scientific publications should be freely available on-line.

We hope that researchers working in Theoretical Computer Science will follow the example of the many others in accord with the originators of this idea.  Please see http://published.eptcs.org/ for the list of published workshops.

The editors,

Rob van Glabbeek (NICTA, Sydney, Australia)
   Editor in Chief
Luca Aceto (Reykjavik University)
Rajeev Alur (University of Pennsylvania)
Krzysztof R. Apt (CWI and University of Amsterdam)
Lars Arge (Aarhus University)
Ran Canetti (Tel Aviv University)
Luca Cardelli (Microsoft Research)
Rocco De Nicola (Universita di Firenze)
Jose Luiz Fiadeiro (University of Leicester)
Wan Fokkink  (Vrije Universiteit Amsterdam)
Lane A. Hemaspaandra (University of Rochester)
Matthew Hennessy (Trinity College Dublin)
Bartek Klin (Warsaw University, University of Cambridge)
Evangelos Kranakis (Carleton University)
Shay Kutten (Technion)
Nancy Lynch (Massachusetts Institute of Technology)
Aart Middeldorp (University of Innsbruck)
Benjamin Pierce (University of Pennsylvania)
Gordon Plotkin (University of Edinburgh)
Vladimiro Sassone (University of Southampton)
Robert H. Sloan (University of Illinois at Chicago)
Wolfgang Thomas (RWTH Aachen University)
Irek Ulidowski (University of Leicester)
Dorothea Wagner (Universitaet Karlsruhe (TH))
Martin Wirsing (LMU Munich)
Moti Yung (Google Inc. and Columbia University)

Rolf Nevanlinna Prize to Daniel Spielman

Daniel Spielman  has been chosen for the 2010 Rolf Nevanlinna Prize for smoothed analysis of Linear Programming, algorithms for graph-based codes and applications of graph theory to Numerical Computing. The full details are here.


Congrats to Daniel for landing another prize after the Goedel prize 2008, which he received in Reykjavik during ICALP 2008.

Details about the other prize winners are here.

An interesting publication experiment in the logic-programming community

Krzysztof Apt has alerted me of the changes that have taken place in the Logic Programming community. The Association for Logic Programming (ALP) recently left the Springer LNCS series and embraced a new publication model for the proceedings of their flagship conference (the International Conference on Logic Programming (ICLP)) that tries to upgrade the papers directly to journal papers. Here is how the co-chairs of the 2010 edition of the conference describe the new publication model and its rationale.

The Logic Programming (LP) community, through the Association for Logic Programming (ALP) and its Executive Committee, decided to introduce for 2010 important changes in the way the main yearly results in LP and related areas are published. Whereas such results have appeared to date in standalone volumes of proceedings of the yearly International Conferences on Logic Programming (ICLP), and this method – fully in the tradition of Computer Science (CS) – has served the community well, it was felt that an effort needed to be made to achieve a higher level of compatibility with the publishing mechanisms of other fields outside CS.

In order to achieve this goal without giving up the traditional CS conference format a different model has been adopted starting in 2010 in which the yearly ICLP call for submissions takes the form of a joint call for a) full papers to be considered for publication in a special issue of the journal, and b) shorter technical communications to be considered for publication in a separate, standalone volume, with both kinds of papers being presented by their authors at the conference. Together, the journal special issue and the volume of short technical communications constitute the proceedings of ICLP.

The special issue of the journal  Theory and Practice of Logic Programming (TPLP) devoted to the 26th International Conference on Logic Programming Special is the first of a series of yearly special issues of that journal putting this new model into practice. It contains the papers accepted from those submitted as full papers (i.e., for TPLP) in the joint ICLP call for 2010. The collection of technical communications for 2010 will appear in turn as Volume 7 of the Leibniz International Proceedings in Informatics (LIPIcs) series, published on line through the Dagstuhl Research Online Publication Server (DROPS). Both sets of papers will be presented by their authors at the 26th ICLP.

This seems a very interesting way of dealing with some of the concerns that have been aired by some pundits about the publication culture within CS, while preserving the crucial role that conferences play in CS. I think that it is certainly worth a thought.

Call for papers: ICALP 2011

The first call for papers for ICALP 2011, which is presently being distributed at ICALP 2010, is here.

I hope that you will make plans to submit excellent papers to ICALP 2011.