COALA : COntraintes, ALgorithmes et Applications

Keys Words

IArtificial Intelligence, Constraint Programming, Problem Solving, Real-Life Applications, Design and Implementation of Solvers, Propositional Calculus, SAT, CSP, Constrained Optimization, Algorithmics, Complexity Theory, Graph Algorithms, Automated Planning, Packing

 

Head

Philippe JEGOU

 

Permanent Members

GONZALES ChristopheProfesseur des Universités
Courriel : christophe.gonzales@lis-lab.fr
GRANDCOLAS StéphaneMaitre de Conférences
Courriel : stephane.grandcolas@lis-lab.fr
Telephone : 0491288325
Page personnelle : https://pageperso.lis-lab.fr/stephane.grandcolas/
HABET DjamalProfesseur des Universités
Courriel : djamal.habet@lis-lab.fr
Telephone : 0491288321
Page personnelle : https://pageperso.lis-lab.fr/djamal.habet/
HENOCQUE LaurentMaitre de Conférences
Courriel : laurent.henocque@lis-lab.fr
Telephone : 0491282740
JEGOU PhilippeProfesseur des Universités
Courriel : philippe.jegou@lis-lab.fr
Telephone : 0491288937
OSTROWSKI RichardMaitre de Conférences
Courriel : richard.ostrowski@lis-lab.fr
Telephone : 0491288367
Page personnelle : https://pageperso.lis-lab.fr/richard.ostrowski/
OXUSOFF LaurentMaitre de Conférences
Courriel : laurent.oxusoff@lis-lab.fr
PAIN-BARRE CyrilMaitre de Conférences
Courriel : cyril.pain-barre@lis-lab.fr
Telephone : 0442939031
PARIS LionelMaitre de Conférences
Courriel : lionel.paris@lis-lab.fr
Telephone : 0491288367
PRCOVIC NicolasMaitre de Conférences
Courriel : nicolas.prcovic@lis-lab.fr
Telephone : 0491288951
TERRIOUX CyrilMaitre de Conférences
Courriel : cyril.terrioux@lis-lab.fr
Telephone : 0491288991
Page personnelle : https://pageperso.lis-lab.fr/cyril.terrioux/

 

Phd Studients

ADRAR NabilDoctorant
Courriel : nabil.adrar@lis-lab.fr
CHERIF Mohamed SamiDoctorant
Courriel : mohamedsami.cherif@lis-lab.fr
PY MatthieuDoctorant
Courriel : matthieu.py@lis-lab.fr
VARET AdrienDoctorant
Courriel : adrien.varet@lis-lab.fr

 

Other staff members

 
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Research interests

The researchs of the COALA team are located at the heart of the foundations of Artificial Intelligence and Constraint Programming.

Our work aims to equip Artificial Intelligence reasoning systems with effective resolution tools, both in theory and in practice, and they can also have strong repercussions in many practical applications.

Our research focuses mainly on the algorithmic associated with solving the satisfiability problem in propositional logic (SAT problem), satisfaction of problem-solving constraints (CSP) and their extensions (eg. optimization).

This work consists of developing theoretical tools and methods for solving combinatorial problems, highlighting tractable classes (polynomial fragments), designing efficient solvers and applying them to real-life problems.

The theoretical foundations are based on graph theory and complexity theory.
We develop 3 major axes:

development of theoretical tools and solving methods for SAT, CSP and their extensions to optimization
related issues and transfer to industrial applications
conception and realization of solvers

We coordinate the national ANR Demograph project since 2017 (http://www.lsis.org/demograph/).

The team publishes in the main journals specialized in Artificial Intelligence and Constraint Programming (Artificial Intelligence Jal, Constraints, Annals of Mathematics and Artificial Intelligence and SAT Journal) as well as in the major conferences of these domains (IJCAI, AAAI, CP and ECAI ). .

As an illustration, the ahmaxsat solver who won 3 gold medals at the 2014 Max-SAT World Competition and an multi-objective optimal maritime route (industrial application).

Legende 1. Performance of the ahmaxsat solver developed by COALA. This solver won 3 gold medals at the Max-SAT World Cup at FloC 2014 in Vienna. (FloC 2014 is to date the most important scientific event organized around logic, including mathematics and computer science)

Legende 2. Plot of an optimal trajectory (weather and fuel consumption) between Le Havre and New York obtained by a system developed with the team in the perspective of an industrial collaboration for the routing of cargo ships.

 

Scientific publications



57 documents

Article dans une revue

  • Victor Chepoi, Arnaud Labourel, Sébastien Ratel. On density of subgraphs of halved cubes. European Journal of Combinatorics, Elsevier, 2019, 80, pp.57-70. ⟨10.1016/j.ejc.2018.02.039⟩. ⟨hal-02268756⟩
  • Kolja Knauer, Petru Valicov. Cuts in matchings of 3-connected cubic graphs. European Journal of Combinatorics, Elsevier, 2019, 76, pp.27-36. ⟨10.1016/j.ejc.2018.09.004⟩. ⟨hal-02068863⟩
  • Jérémie Chalopin, Victor Chepoi. 1-Safe Petri nets and special cube complexes: equivalence and applications. ACM Transactions on Computational Logic, Association for Computing Machinery, 2019, 20 (3), pp.17:1-17:49. ⟨10.1145/3322095⟩. ⟨hal-01863455v2⟩
  • Kolja Knauer, Torsten Ueckerdt. Decomposing 4-connected planar triangulations into two trees and one path. Journal of Combinatorial Theory, Series B, Elsevier, 2019, 134, pp.88-109. ⟨10.1016/j.jctb.2018.05.006⟩. ⟨hal-02068864⟩
  • François Brucker, Pascal Prea, Célia Châtel. Totally Balanced Dissimilarities. Journal of Classification, Springer Verlag, 2019, ⟨10.1007/s00357-019-09320-w⟩. ⟨hal-02269391⟩
  • Victor Chepoi, Feodor Dragan, Michel Habib, Yann Vaxès, Hend Alrasheed. Fast approximation of eccentricities and distances in hyperbolic graphs. Journal of Graph Algorithms and Applications (JGAA), Brown University, 2019, 23 (2), pp.393-433. ⟨10.7155/jgaa.00496⟩. ⟨hal-02268468⟩
  • Jérémie Chalopin, Victor Chepoi, Feodor Dragan, Guillaume Ducoffe, Abdulhakeem Mohammed, et al.. Fast Approximation and Exact Computation of Negative Curvature Parameters of Graphs. Discrete and Computational Geometry, Springer Verlag, In press, ⟨10.1007/s00454-019-00107-9⟩. ⟨hal-02149991⟩
  • Kolja Knauer, Leonardo Martínez-Sandoval, Jorge Luis Ramírez Alfonsín. On Lattice Path Matroid Polytopes: Integer Points and Ehrhart Polynomial. Discrete and Computational Geometry, Springer Verlag, 2018, 60 (3), pp.698-719. ⟨10.1007/s00454-018-9965-4⟩. ⟨hal-02068868⟩
  • Hans-Jürgen Bandelt, Victor Chepoi, Kolja Knauer. COMs: Complexes of oriented matroids. Journal of Combinatorial Theory, Series A, Elsevier, 2018, 156, pp.195-237. ⟨10.1016/j.jcta.2018.01.002⟩. ⟨hal-02268709⟩
  • Victor Chepoi, Arnaud Labourel, Sébastien Ratel. On density of subgraphs of halved cubes. European Journal of Combinatorics, Elsevier, 2018. ⟨hal-01959093⟩
  • Jérémie Chalopin, Victor Chepoi, Hirai Hiroshi, Damian Osajda. Weakly modular graphs and nonpositive curvature. Memoirs of the American Mathematical Society, American Mathematical Society, In press. ⟨hal-01787197⟩
  • Victor Chepoi. Distance-Preserving Subgraphs of Johnson Graphs. Combinatorica, Springer Verlag, 2017, 37 (6), pp.1039-1055. ⟨10.1007/s00493-016-3421-y⟩. ⟨hal-02268710⟩
  • Victor Chepoi, Bertrand Estellon, Guyslain Naves. Packing and Covering with Balls on Busemann Surfaces. Discrete and Computational Geometry, Springer Verlag, 2017, 57 (4), pp.985-1011. ⟨10.1007/s00454-017-9872-0⟩. ⟨hal-02268712⟩
  • Nicolas Catusse, Victor Chepoi, Karim Nouioua, Yann Vaxès. Bidirected minimum Manhattan network problem. Networks, Wiley, 2017, 69 (2), pp.167-178. ⟨10.1002/net.21719⟩. ⟨hal-02268714⟩
  • Boris Albar, Daniel Gonçalves, Kolja Knauer. Orienting Triangulations. Journal of Graph Theory, Wiley, 2016, 83 (4), pp.392-405. ⟨10.1002/jgt.22005⟩. ⟨hal-01457782⟩
  • Ignacio García-Marco, Kolja Knauer. Drawing graphs with vertices and edges in convex position. Computational Geometry, Elsevier, 2016, 58, pp.25-33. ⟨10.1016/j.comgeo.2016.06.002⟩. ⟨hal-01457727⟩
  • Ian Gambini, Laurent Vuillon. Tiling the Space by Polycube Analogues of Fedorov’s Polyhedra. Fundamenta Informaticae, Polskie Towarzystwo Matematyczne, 2016, 146 (2), pp.197-209. ⟨10.3233/FI-2016-1381⟩. ⟨hal-02269399⟩
  • Stefan Felsner, Kolja Knauer, George Mertzios, Torsten Ueckerdt. Intersection Graphs of L-Shapes and Segments in the Plane. Discrete Applied Mathematics, Elsevier, 2016, 206, pp.48-55. ⟨10.1016/j.dam.2016.01.028⟩. ⟨hal-01457800⟩
  • Marie Albenque, Kolja Knauer. Convexity in partial cubes: the hull number. Discrete Mathematics, Elsevier, 2016, 339 (2), pp.866-876. ⟨10.1016/j.disc.2015.10.032⟩. ⟨hal-01457877⟩
  • Kolja Knauer, Leonardo Martínez-Sandoval, Jorge Luis Ramírez Alfonsín. A Tutte polynomial inequality for lattice path matroids. Advances in Applied Mathematics, Elsevier, 2016, 94, pp.23-38. ⟨10.1016/j.aam.2016.11.008⟩. ⟨hal-01457675⟩
  • Kolja Knauer, Ulrich Knauer. On planar right groups. Semigroup Forum, Springer Verlag, 2016, 92, pp.142 - 157. ⟨10.1007/s00233-015-9688-2⟩. ⟨hal-01457892⟩
  • Kolja Knauer, Torsten Ueckerdt. Three ways to cover a graph. Discrete Mathematics, Elsevier, 2016, 339, pp.745 - 758. ⟨10.1016/j.disc.2015.10.023⟩. ⟨hal-01457977⟩
  • Bartłomiej Bosek, Stefan Felsner, Kolja Knauer, Grzegorz Matecki. On the Duality of Semiantichains and Unichain Coverings. Order, Springer Verlag, 2016. ⟨hal-01457982⟩
  • Hans-Jürgen Bandelt, Victor Chepoi, David Eppstein. Ramified Rectilinear Polygons: Coordinatization by Dendrons. Discrete and Computational Geometry, Springer Verlag, 2015, 54 (4), pp.771-797. ⟨10.1007/s00454-015-9743-5⟩. ⟨hal-02268742⟩
  • Jérémie Chalopin, Victor Chepoi, Damian Osajda. On two conjectures of Maurer concerning basis graphs of matroids. Journal of Combinatorial Theory, Series B, Elsevier, 2015, 114, pp.1-32. ⟨10.1016/j.jctb.2015.03.004⟩. ⟨hal-02065778⟩
  • Jérémie Chalopin, Victor Chepoi, Guyslain Naves. Isometric Embedding of Busemann Surfaces into $L_1$. Discrete and Computational Geometry, Springer Verlag, 2015, 53 (1), pp.16-37. ⟨10.1007/s00454-014-9643-0⟩. ⟨hal-02268738⟩
  • L Lücken, J Pade, K Knauer. Classification of Coupled Dynamical Systems with Multiple Delays: Finding the Minimal Number of Delays. SIAM Journal on Applied Dynamical Systems, Society for Industrial and Applied Mathematics, 2015, 14 (1), pp.286-304. ⟨10.1137/14097183X⟩. ⟨hal-01457962⟩
  • Victor Chepoi, Damian Osajda. Dismantlability of weakly systolic complexes and applications. Transactions of the American Mathematical Society, American Mathematical Society, 2015, 367, pp.1247-1272. ⟨hal-01199906⟩
  • Kolja Knauer, Piotr Micek, Bartosz Walczak. Outerplanar graph drawings with few slopes ✩. Computational Geometry: Theory and Applications Computational Geometry @ ScienceDirect, 2014. ⟨hal-01457974⟩
  • Daniel Heldt, Kolja Knauer, Torsten Ueckerdt. Edge-intersection graphs of grid paths: The bend-number. Discrete Applied Mathematics, Elsevier, 2014, 167, pp.144 - 162. ⟨10.1016/j.dam.2013.10.035⟩. ⟨hal-01457989⟩
  • Daniel Heldt, Kolja Knauer, Torsten Ueckerdt. On the bend-number of planar and outerplanar graphs. Discrete Applied Mathematics, Elsevier, 2014. ⟨hal-01457986⟩
  • Jean Cardinal, Kolja Knauer, Piotr Micek, Torsten Ueckerdt. Making Octants Colorful and Related Covering Decomposition Problems. Siam Journal on Discrete Mathematics, Society for Industrial and Applied Mathematics, 2014. ⟨hal-01457899⟩
  • Maria Axenovich, Kolja Knauer, Judith Stumpp, Torsten Ueckerdt. Online and size anti-Ramsey numbers. Journal of Combinatorics, International Press, 2014, 5, pp.87 - 114. ⟨10.4310/JOC.2014.v5.n1.a4⟩. ⟨hal-01457849⟩
  • Kolja Knauer, Juan Montellano-Ballesteros, Ricardo Strausz. A graph-theoretical axiomatization of oriented matroids. European Journal of Combinatorics, Elsevier, 2014. ⟨hal-01457945⟩

Communication dans un congrès

  • Jérémie Chalopin, Victor Chepoi, Shay Moran, Manfred Warmuth. Unlabeled Sample Compression Schemes and Corner Peelings for Ample and Maximum Classes. 46th International Colloquium on Automata, Languages, and Programming (ICALP 2019), 2019, Patras, Greece. pp.34:1--34:15, ⟨10.4230/LIPIcs.ICALP.2019.34⟩. ⟨hal-02269141⟩
  • Victor Chepoi, Arnaud Labourel, Sébastien Ratel. Distance and routing labeling schemes for cube-free median graphs. 44th International Symposium on Mathematical Foundations of Computer Science (MFCS 2019), 2019, Aachen, Germany. pp.15:1--15:14, ⟨10.4230/LIPIcs.MFCS.2019.15⟩. ⟨hal-02268771⟩
  • Victor Chepoi, Feodor Dragan, Michel Habib, Yann Vaxès, Hend Alrasheed. Fast Approximation of Centrality and Distances in Hyperbolic Graphs. COCOA 2018 - 12th Annual International Conference on Combinatorial Optimization and Applications, Dec 2018, Atlanta, United States. pp.1-23. ⟨hal-01955263⟩
  • Jérémie Chalopin, Victor Chepoi, Feodor Dragan, Guillaume Ducoffe, Abdulhakeem Mohammed, et al.. Fast Approximation and Exact Computation of Negative Curvature Parameters of Graphs. 34th International Symposium on Computational Geometry (SoCG 2018), Jun 2018, Budapest, Hungary. pp.22, ⟨10.4230/LIPIcs.SoCG.2018.22⟩. ⟨hal-01836063⟩
  • Jérémie Chalopin, Victor Chepoi. A Counterexample to Thiagarajan's Conjecture on Regular Event Structures. ICALP 2017, 2017, Warsaw, Poland. ⟨10.4230/LIPIcs.ICALP.2017.101⟩. ⟨hal-01787205⟩
  • Victor Chepoi, Feodor Dragan, Yann Vaxès. Core congestion is inherent in hyperbolic networks. Proceedings of the Twenty-Eighth Annual ACM-SIAM Symposium on Discrete Algorithms, 2017, Barcelona, Spain. pp.2264-2279. ⟨hal-02268729⟩
  • Kolja Knauer, Bartosz Walczak. Graph Drawings with One Bend and Few Slopes. LATIN 2016, Apr 2016, Ensenada, Mexico. pp.549 - 561, ⟨10.1007/978-3-662-49529-2_41⟩. ⟨hal-01457778⟩
  • Ignacio García-Marco, Kolja Knauer. Drawing graphs with vertices and edges in convex position. Graph Drawing 2015, Sep 2015, Los Angeles, United States. ⟨hal-01457773⟩
  • Stefan Felsner, Kolja Knauer, George Mertzios, Torsten Ueckerdt. Intersection Graphs of L-Shapes and Segments in the Plane. MFCS 2014, Aug 2014, Budapest, Hungary. ⟨hal-01457818⟩
  • Marie Albenque, Kolja Knauer. Convexity in partial cubes: the hull number. LATIN 2014, Mar 2014, Montevideo, Uruguay. ⟨hal-01457880⟩
  • Jean Cardinal, Kolja Knauer, Piotr Micek, Torsten Ueckerdt. Making Octants Colorful and Related Covering Decomposition Problems. SODA 2014, Jan 2014, Portland, United States. ⟨hal-01457914⟩

Pré-publication, Document de travail

  • Victor Chepoi, Kolja Knauer, Manon Philibert. Two-dimensional partial cubes. 2019. ⟨hal-02268768⟩
  • Ignacio García-Marco, Kolja Knauer, Luis Pedro Montejano. Chomp on generalized Kneser graphs and others. 2019. ⟨hal-02068632⟩
  • Kolja Knauer, Piotr Micek, Torsten Ueckerdt. The Queue-Number of Posets of Bounded Width or Height. 2019. ⟨hal-02068620⟩
  • Guillaume Guegan, Kolja Knauer, Jonathan Rollin, Torsten Ueckerdt. The interval number of a planar graph is at most three. 2019. ⟨hal-02068628⟩
  • Oswin Aichholzer, Jean Cardinal, Tony Huynh, Kolja Knauer, Torsten Mütze, et al.. Flip distances between graph orientations. 2019. ⟨hal-02068615⟩
  • Victor Chepoi, Kolja Knauer, Tilen Marc. Partial cubes without $Q_3^-$ minors. 2019. ⟨hal-02065775⟩
  • Jérémie Chalopin, Victor Chepoi, Shay Moran, Manfred K. Warmuth. Unlabeled sample compression schemes and corner peelings for ample and maximum classes. 2019. ⟨hal-02065772⟩
  • Jérémie Chalopin, Victor Chepoi, Feodor F. Dragan, Guillaume Ducoffe, Abdulhakeem Mohammed, et al.. Fast approximation and exact computation of negative curvature parameters of graphs. 2018. ⟨hal-01737445⟩
  • Victor Chepoi, Kolja Knauer, Marc Tilen. Partial cubes without Q − 3 minors. 2017. ⟨hal-01457191⟩
  • Rémi Desgranges, Kolja Knauer. A correction of a characterization of planar partial cubes. 2017. ⟨hal-01457179⟩
  • Hans-Jürgen Bandelt, Victor Chepoi, Kolja Knauer. COMs: Complexes of Oriented Matroids. 2017. ⟨hal-01457780⟩
  • Kolja Knauer, Leonardo Martínez-Sandoval, Jorge Luis Ramírez Alfonsín. On lattice path matroid polytopes: integer points and Ehrhart polynomial. 2017. ⟨hal-01457185⟩