Lakhdar SAÏS
Professor in Computer Science
CRIL, CNRS-UMR 8188 rue Jean Souvraz, SP18 F-62307 Lens Cedex T+33 (0)3 21 79 17 77 Bsais@cril.fr www.cril.fr/∼sais
Present Position
Professor in Computer Science CRIL – University of Artois PEDR
Research interests
Propositionnal Satisfiability, Constraint Satisfaction Problems, Quantified Boolean formulae, Knowledge Rep-resentation, Logic and Artificial Intelligence.
Professional activities
2002 – . . . Professor ,UFR des Sciences, University of Artois, Lens.
2001 – 2002 Professor,University of Paul Sabatier, IRIT, Toulouse III.
1994 – 2001 Lecturer,IUT - Lens, University of Artois.
1992 – 1994 Researcher - ATER,University of Provence, Marseille.
Education
2000 French Research Habilitation (HdR) in Computer Science, University of Artois, France, « De la résolution du problème SAT à la résoution de problèmes autour de SAT ».
1993 PhD in Computer Science, University of Provence, Aix-Marseille I, France, « Étude des symétries et de la cardinalité en calcul propositionnel : Application aux algorithmes sémantiques », Supervisor : Pierre Siegel.
Mention : "Très Honorable et Félicitations du jury"
1990 Master Degree (DEA) in Computer Science and Mathematics (Artificial Intelli-gence),University of Aix-Marseille II (Luminy, France), Mention : Bien.
1988 Engineer in Computer Science, National Institute in Computer Science, University of Tizi-Ouzou, Algeria, Mention : Très-Bien.
Research responsibilities
• Head of the CRIL research group on "Inference and Decision Process" (2002 – . . . )
• Co-leader of Animation Structure SA 1.2 (GdR I3) "Algorithms for Inference and Con-straint Satisfaction problems" (1999 – 2006) .
• Member of the Consulting Committee - CRIL research lab (2002 – . . . )
• Member of the Scientific Consulting Committee - University of Artois (1997 – 2000)
• Member of the Consulting Committee - Faculty of Sciences - University of Artois (2002 – 2006)
• Member of the "comité de direction" GdR-I3 (1999–2006), and of the Animation Com-mittee Theme 1 : Fondamental Aritificial Intelligence - GdR-I3 (since january 2007).
•Member of the Management Committee - French Association on Constraint Programming (2004 – 2005)
• Member of the CSE (sections 25-26-27) - University of Artois (2003 – . . . )
• Member of the CSE (section 30) - University of Artois (2002 – 2004)
• Member of the CSE (sections 25-26-27) - University of Artois (1999 – 2001)
•External Member of the CSE (section 27), University of Lille III and University of Valen-ciennes.
• Postgraduate supervisor of 9 PhD theses and two internship at MSR Cambridge
•Program chair of the international CP’08 workshop on Symmetry in Constraint Satisfac-tion (Symcon’08, Sydney Australia), of the internaSatisfac-tional Colloquium on OptimisaSatisfac-tion and Information systems (COSI’07- Algiers and COSI’08 - Oran Algeria), of the First Summer School on Decision Aiding (sponsored by Microsoft Research Cambridge - 9 - 11 june 2007, Oran, Algeria), of the International ECAI’96 workhop on « Advances in Propositional De-duction » (Budapest Hungary) and of the national conference "Journées Nationales sur la résolution pratique de problèmes NP-Complets (JNPC’98, Nantes France).
•Program Committee Member of the international conference : Twenty-Third AAAI Con-ference on Artificial Intelligence (AAAI’08), of the Twentieth International ConCon-ference on Tools with Artificial Intelligence (ICTAI’08), of the International Symmetry Conference (ISC’07,Edinburgh, Scotland), of the IEEE International Conference on Information Reuse and Integration (IEEE-IRI’05-08), of the Eighth International Conference on Theory and Applications of Satisfiability Testing (SAT’05,St Andrews Scotland), of the international Colloquium on Optimisation and Information systems (COSI’05-08), of the CP’06 interna-tional workshop « Integration of SAT and CP Techniques » and of the nainterna-tional conferences : JNPC’99, JNPC’97 et RJCIA’94.
• President of the steering committee of the Summer School on Decision Aiding (Oran) june 2008, of the national conference on Constraint Programming (JFPC’05)
•Reviewer of the international journals « Journal on Operation Research », « Studia Logic », of the international conference on Theory and Applications of Satisfiability Testing (SAT’05, SAT’04), of the International Conference on Tools with Artificial Intelligence (ICTAI’08, IC-TAI’04), of the International Joint Conference on Artificial Intelligence (IJCAI’07, IJCAI’05, IJCAI’03, IJCAI’99 and IJCAI 97), of the International Conference on Constraint Program-ming (CP’07, CP’97), of the European Conference on Artificial Intelligence (ECAI’04, ECAI’98), of the International Symposium on Theoretical Computer Science (STACS’00, STACS’99), of the national journals « Techniques et Sciences Informatique » and « Revue d’Intelligence Artificielle » and of the national conferences «Reconaissance des Formes et Intelligence Artificielle» ( RFIA’04 and RFIA’96).
•Expert at the National Research Agency (ANR) «Evaluation of White and Young Research Program» and at the Ministry of Foreign Affairs «Evaluation of the French and South American Projects
• External Evaluator for the PhD defence of Subbarayan Sathiamoorthy (IT University of Copenhagen), Laurent Verroust (University of Aix-Marselle III), Bing Quan Huang (Univer-sity college of Dublin, Ireland), Mohamed Réda Saïdi (Univer(Univer-sity of Provence, Marseille), Faycal Djerourou (Univ. Paris 13), Hadja Faiza Khellaf-Haned (USTHB, Alger), Ma Jix-uan (Univ. Valenciennes), É. Canaud (Univ. Claude Bernard Lyon I), F. Lardeux (Univ. Angers), M. Butaru (Univ. Metz), L. Keddar (Univ. Aix-Marseille III), and for the "Habil-itation" of Bachir Saadi (Univ. Tizi-Ouzou).
•Jury Member for the "Habilitation HdR" of O. Bailleux (Univ. Bourgogne), L. Henocque (Univ. Provence) and of the PhD defence of Cédric Piette (Univ. Artois), Sébastien Tabary (Univ. Artois), Julien Vion (Univ. Artois), F. Letombe (Univ. Artois), N. Porquet (Univ. Artois), O. Couturier (Univ. Artois), R. Ostrowski (Univ. Artois), D. Ansart (Univ. Artois), G. El Baida (Univ. Artois), B. Jurkowiak (Univ. de Picardie), L. Keddar (Univ. Provence), G. Audemard (Univ. Provence), L. Brisoux(Univ. Artois), B. Mazure (Univ. Artois), Anbulagan (UTC), D. Martinez (ENS Aéronautique de Toulouse).
• Principal Investigator of the Inter-labs project LGI2A-CRIL, Université d’Artois, Math-STIC CNRS project "Heterogeneous Optimization Methods for industrial problem Solving" and of the Cocoa project CPER Nord-Pas-de-Calais.
• Research projects : PAI Ulysses (France-Ireland), PAI PESSOA (French-Portugal), AS STIC "Algorithmic and experimental evaluation for Quantified Boolean Formulas", French-Portugal PAI on "Design of software platform for SAT" and "Solving Pseudo Boolean Formulas", TACT (now TAC CPER Nord/Pas-de-Calais), of the Cocoa project CPER Nord-Pas-de-Calais, of the PRC-IA projects " Boolean: Algorithms and Heuristics for AI" , "Polynomial classes", and "Algorithmic Aspect for Solving Problem expressed with constraints" (RESSA), and of the Ganymède I et II of the "Contrat de plan état/région Nord/Pas-de-Calais".
• Organizer of the Doctoral Fellowship Program JNPC/JFPC (2000-2005).
Scientific Awards
2008 Gold Medal (First Rank), Parallel Track at the SAT Race 2008 - "ManySAT" Solver by Youssef Hamadi, Said Jabbour and Lakhdar Sais (CRIL-MSR Cambridge)
2006 First rank on binary CSP category, at the International Constraint Satisfaction Solver Competition 2006 - "ValCSP" by Assef Chmeiss, Vincent Krawczyk and Lakhdar Sais
2003 First rank (Qualification phase) and second rank (final phase) on handmade category, SAT’2003 International SAT competition - "LSATv2.0" by Richard Ostrowski, Bertrand Mazure and Lakhdar Sais
1998 Best paper award at the 8th international conference on Artificial Intelligence: Methodol-ogy, Systems, and Applications, AIMSA’98
Publications Summary
• 1 French Book on SAT, Hermes Publishing Ltd, London.
• 3 Book chapters
• Editor of 4 conference proceedings
• 8 International Journal papers
•60 referred papers (20 since 2004) at international conference (e.g. IJCAI, ECAI, AAAI, CP, SAT, ICTAI)
•24 referred papers (19 since 2004) at the national conferences (e.g. RFIA, JFPC, JNPC)
Publications (2004–2008)
Articles in international referred journalsG. Audemard, S. Jabbour, and L. Sais. Graph-Based SAT Representation : A New Perspective. In Journal of Algorithms in Logic, Informatics and Cognition, 2008 (to appear)
C. Lecoutre, L. Sais, S. Tabary, and V. Vidal. Recording and Minimizing Nogoods from Restarts.
Journal on Satisfiability, Boolean Modeling and Computation, pages 147-167, 2007.
C. Lecoutre, L. Sais, and J. Vion. Using SAT Encodings to Derive CSP Value Ordering Heuristics.
Journal on Satisfiability, Boolean Modeling and Computation, pages 69-186, 2007.
Editions of Books and Proceedings
L. Saïs. Problème SAT : Progrès et Défis. Hermes Publishing Ltd, London, may , 2008. M. Aider, L. Nourine and L. Saïs, éditeurs. Actes du 5ème Colloque International sur l’optimisation et les systèmes d’information (COSI’2008). Tizi-Ouzou, Algeria, 8-10 june 2008.
L. Nourine and L. Saïs, éditeurs. Actes du 4ème Colloque International sur l’optimisation et les systèmes d’information (COSI’2007). Oran, Algeria, 11 - 13 june 2007.
Book Chapter
O. Dubois et L. Sais. Bilan et Défis. Book chapter, Hermes Publishing Ltd, London, pages 311-318, mai 2008.
Publications in international conferences with selection committee
G. Audemard, L. Bordeaux, Y. Hamadi, S. Jabbour, and L. Sais. A generalized framework for conflict analysis. InProceedings of SAT’08, pages 21–27, Guangzhou, China, 2008.
C. Piette, Y. Hamadi, and L. Sais. Vivifying propositional clausal formulae. InProceedings of ECAI’08, to appear, Patras, Greece, 2008.
A. Chmeiss, V. Krawczyk, and L. Sais. Redundancy in CSPs. InProceedings of ECAI’08, poster to appear, Patras, Greece, 2008.
G. Audemard and L. Sais. Circuit-based Encoding for CNF Formulas. InProceedings of SAT’07, pages 16–21, Lisbon, Portugal, 2007.
O. Fourdrinoy, E. Grégoire, B. Mazure, and L. Saïs. Eliminating Redundant Clauses in SAT Instances. InProceedings of CPAIOR’07, pages 71–83, Bruxelles, Belgium, 2007.
C. Lecoutre, L. Sais, S. Tabary, and V. Vidal. Transposition Tables for Constraint Satisfaction. InProceedings of AAAI’07, pages 243–248, Vancouver, Canada, 2007.
C. Lecoutre, L. Sais, S. Tabary, and V. Vidal. Nogood recording from restarts. InProceedings of IJCAI’07, pages 131–136, Hyderabad, India, 2007.
G. Audemard, S. Jabbour, and L. Sais. Symmetry Breaking in Quantified Boolean Formulae. In
Proceedings of IJCAI’07, pages 2262–2267, Hyderabad, India, 2007.
C. Lecoutre, L. Sais, S. Tabary, and V. Vidal. Last Conflict-based Reasonning. InProceedings of ECAI’06, pages 133–137, Trento, Italy, 2006.
F. Hemery, C. Lecoutre, L. Sais, and F. Boussemart. Extracting MUCs from constraint networks. InProceedings of ECAI’06, pages 113–117, Trento, Italy, 2006.
L. Paris, R. Ostrowski, L. Sais, and P. Siegel. Computing Horn Strong Backdoor Sets Thanks to Local Search. InProceedings of ICTAI’06, pages 139–143, Washington, USA, 2006.
G. Audemard and L. Sais. A Symbolic Search Based Approach for Quantified Boolean Formulas. InProceedings of SAT’05, pages 16–30, St. Andrews, Scotland, 2005.
S. Darras, G. Dequen, L. Devendeville, B. Mazure, R. Ostrowski, and L. Saïs. Using Boolean Constraint Propagation for Sub-clause Deduction. Dans Proceedings of CP’05 (short paper), pages 757–761, Sitges, Espagne, 2005.
O. Fourdrinoy, É. Grégoire, B. Mazure, and L. Saïs. Exploring Hybrid Algorithms for SAT. Dans
Proceedings of LPAR’05 (short paper), pages 33–37, Montego Bay, Jamaïque, 2005.
É Grégoire, R. Ostrowski, B. Mazure, and L. Saïs. Automatic Extraction of Functional Depen-dencies. InProceedings of SAT’04 (Revised Selected Papers), pages 122–132, 2004.
F. Boussemart, F. Hemery, C. Lecoutre, and L. Sais. Boosting systematic search by weighting constraints. InProceedings of ECAI’04, pages 146–150, Valancia, Spain, 2004.
F. Boussemart, F. Hemery, C. Lecoutre, and L. Sais. Support inference for generic filtering. In
Proceedings of CP’04, pages 721–725, Toronto, Canada, 2004.
G. Audemard, B. Mazure, and L. Sais. Dealing with Symmetries in Quantified Boolean Formulas. Inproceedings of SAT’04, pages 257–262, Vancouver, Canada, 2004.
G. Audemard and L. Sais. SAT Based BDD Solver for Quantified Boolean Formulas. In Proceed-ings of ICTAI’04, pages 82–89, Boca Raton, Florida, 2004.
A. Chmeiss and L. Sais. Constraint Satisfaction Problems : Backtrack Search Revisitied. In
Proceedings of ICTAI’04, pages 252-257, Floride, USA, 2004.
Publications in international workshops with selection committee
G. Audemard, S. Jabbour, and L. Sais Efficient Symmetry Breaking Predicates for Quantified Boolean Formulae". InProceedings of the International Workshop on Symmetry and Constraint Satisfaction Problems - Affiliated to CP (SymCon), pages 14–21, september 2007
G. Audemard, S. Jabbour, and L. Sais Using SAT-Graph representation to derive hard instances in
Proceedings of the 14th RCRA International workshop on Experimental Evaluation of Algorithms for Solving Problems with Combinatorial Explosion (RCRA07), july 2007
J.F. Condotta, D. Dalmeida, C. Lecoutre, and L. Sais. From Qualitative to Discrete Constraint Networks. InProceedings of the International Workshop on Qualitative Constraint Calculi held with KI’2006, pages 54–64, Bremen, Germany, 2006.
C. Lecoutre, L. Sais, S. Tabary, and V. Vidal. Nogood Recording from Restarts. InProceedings of SAT/CP workshop held with CP’06, pages 97–111, Nantes, France, 2006.
C. Lecoutre, L. Sais, and J. Vion. Using SAT Encodings to Derive CSP Value Ordering Heuristics. InProceedings of SAT/CP workshop held with CP’06, pages 33–47, Nantes, France, 2006.
G. Audemard, L. Bordeaux, Y. Hamadi, S. Jabbour, and L. Sais. Un cadre général pour l’analyse des conflits. InActes de JFPC’08, pages 267–276, Nantes, France, 2008.
A. Chmeiss, V. Krawczyk, and L. Sais. La redondance dans les CSPs. InActes de JFPC’08, pages 173–180, Nantes, France, 2008.
O. Fourdrinoy, E. Gregoire, B. Mazure, and L. Sais. Réduction d’instances de SAT vers des instances polynomiales. InActes de RFIA’08, pages 388–396, Amiens, France, 2008.
O. Fourdrinoy, E. Grégoire, B. Mazure, and L. Saïs. Suppression des clauses redondantes dans des instances SAT. InActes de JFPC’07, pages 29–38, Rocquencourt, France, 2007.
C. Lecoutre, L. Sais, S. Tabary, and V. Vidal. Tables de transposition pour la satisfaction de contraintes. InActes de JFPC’07, pages 223–230, Rocquencourt, France, 2007.
C. Lecoutre, L. Sais, S. Tabary, and V. Vidal. Recherche dirigée par le dernier conflit. In
Proceedings of JFPC’06, pages 267–276, Nimes, France, 2006.
G. Audemard, S. Jabbour, and L. Sais. Exploitation des symétries dans les formules booléennes quantifiées. InActes de JFPC’06, pages 15–24, Nîmes, France, 2006.
F. Hemery, C. Lecoutre, L. Sais, and F. Boussemart. Extraction de noyaux insatisfiables minimaux de reseaux de contraintes. InProceedings of JFPC’06, pages 209–217, Nimes, France, 2006. L. Paris, R. Ostrowski, L. Saïs and P. Siegel Approximation d’ensembles Horn strong backdoor par recherche locale. InActes de JFPC’06, pages 277–284, Nîmes, France, 2006.
A. Chmeiss and L. Sais. About Look-Ahead Algorithms in Constraint Satisfaction Problems. In
Proceedings of ICTTA’06, Damascus, Syria, 2006
É Grégoire, B. Mazure, R. Ostrowski, and L. Saïs. Dépendances Fonctionnelles Booléennes : Détection et Exploitation. DansActes de COSI’05, pages 263–274, Beijaia, Algérie, 2005. G. Audemard and L. Sais. Une approche symbolique pour les formules booléennes quantifiées. In
Actes de JFPC’05, pages 59–69, Lens, France, 2005.
F. Boussemart, F. Hemery, C. Lecoutre, and L. Sais. Inférence de supports pour les algorithmes de filtrage générique. InActes de JFPC’05, pages 89–98, Lens, France, 2005.
A. Chmeiss and L. Sais. De FC à MAC : un algorithme paramétrable pour la résolution de CSP. InActes de JFPC’05, pages 267-276, Lens, France, 2005.
S. Darras, G. Dequen, L. Devendeville, B. Mazure, R. Ostrowski, and L. Saïs. Utilisation de la Propagation de Contraintes pour la Production de Sous-Clauses. DansActes des JFPC’05, pages 69–78, Lens, France, 2005.
G. Audemard, B. Mazure, and L. Sais. Symétries et formules booléennes quantifiées. InActes de JNPC’04, pages 43–53, 2004.
F. Boussemart, F. Hemery, C. Lecoutre, and L. Sais. Heuristiques de choix de variables dirigees par les conflits. InActes de JNPC’04, pages 91–105, Angers, France, 2004.
É Grégoire, R. Ostrowski, B. Mazure, and L. Saïs. Déduction automatique de dépendances fonctionnelles. DansActes des JNPC’04, pages 171–180, Angers, France, 2004.
R. Ostrowski, B. Mazure, L. Saïs, and É. Grégoire. Élimination des redondances dans les al-gorithmes de résolution de SAT. Dans Actes de RFIA’04, pages 1343–1350, Toulouse, France, 2004.
