Prof. Bernard Ries

Professor, head of group

T: +41 26 300 83 33

Address: Bd de Pérolles 90, 1700 Fribourg

Office: C 324

Email

 


 

Main research activities

  • Structural and algorithmic graph theory
  • Combinatorial optimization
  • Computational complexity

 


 

Teaching activities

 


 

Publications

Accepted

  • Upper domination: towards a dichotomy through boundary properties
    H. AbouEisha, S. Hussain, V. Lozin, J. Monot, B. Ries, V. Zamaraev 
    to appear in Algorithmica
  • On split B1-EPG graphs
    Z. Deniz, S. Nivelle, B. Ries, D. Schindl
    to appear in Lecture Notes in Computer Science (LATIN 2018)
  • Characterising chordal contact B0-VPG graphs

    F. Bonomo, M. P. Mazzoleni, M. L. Rean, B. Ries, 
    to appear in Lecture Notes in Computer Science (ISCO 2018)
  • Contraction and Deletion Blockers for Perfect Graphs and H-free Graphs

    O.Y. Diner, D. Paulusma, C. Picouleau, B. Ries
    to appear in Theoretical Computer Science

Recently published

  • Graphs vertex-partitionable into strong cliques
    A. Hujdurovic, M. Milanic, B. Ries
    Discrete Mathematics 341(5) 1392--1405 (2018).
  • Dominating induced matchings in graphs containing no long claw
    A. Hertz, V. Lozin, B. Ries, V. Zamaraev, D. de Werra
    Journal of Graph Theory 88(1) 18--39 (2018)
  • On the bend number of circular-arc graphs as edge intersection graphs of paths on a grid
    L. Alcon, F. Bonomo, G. Duran, M. Gutierrez, M. P. Mazzoleni, B. Ries, M. Valencia-Pabon
    Discrete Applied Mathematics 234 12--21 (2018)
  • Complexity and algorithms for finding a perfect phylogeny from mixed tumor samples

    A. Hujdurovic, U. Kacar, M. Milanic, B. Ries, A.I. Tomescu
    IEEE IEEE/ACM Transactions on Computational Biology and Bioinformatics 15(1) 96--108 (2018)

  • Blocking Independent Sets for H-free graphs via Edge Contractions and Vertex Deletions
    D. Paulusma, C. Picouleau, B. Ries
    Lecture Notes in Computer Science 10185, TAMC 2017, 470--483 (2017)
  • On star and biclique edge-colorings
    S. Dantas, M. Groshaus, A. Guedes, R.C.S. Machado, B. Ries, D. Sasaki
    International Transactions In Operational Research 24, 339--346 (2017)
  • A boundary property for upper domination
    H. Aboueisha, S. Hussain, V. Lozin, J. Monnot, B. Ries, V. Zamaraev
    Lecture Notes in Computer Science 9843, IWOCA 2016, 229--240 (2016)
  • Reducing the clique and chromatic number via edge contractions and vertex deletions
    D. Paulusma, C. Picouleau, B. Ries
  • Lecture Notes In Computer Science 9849, ISCO 2016, 38--49 (2016)
    On the ratio between maximum weight perfect matchings and maximum weight matchings in grids
    G. D. da Fonseca, D. Sasaki, B. Ries
    Discrete Applied Mathematics 207, 45--55 (2016)
  • On the Minimum and Maximum Selective Graph Coloring Problems in some Graph Classes
    M. Demange, T. Ekim, B. Ries
    Discrete Applied Mathematics 204, 77--89 (2016)
  • Vote par approbation pour les élections à vainqueurs multiples : une famille générale de règles
    N. Barrot, J. Lang, B. Ries
    Revue d'Intelligence Artificielle 29 (3-4), 265--291 (2015)
  • On the maximum independent set problem in subclasses of subcubic graphs
    V. Lozin, J. Monnot, B. Ries
    Journal of Discrete Algorithms 31, 104--112 (2015)
  • Blockers for the stability number and the chromatic number
    C. Bazgan, C. Bentz, C. Picouleau, B. Ries
    Graphs and Combinatorics 31(1) 73--90 (2015)
  • Finding a perfect phylogeny from mixed tumor samples
    A. Hujdurovic, U. Kacar, M. Milanic, B. Ries, A.I. Tomescu
    Lecture Notes in Bioinformatics 9289 80--92 (2015)
    15th International Workshop on Algorithms in Bioinformatics 2015 (WABI 2015) (2015)
  • Coloring graphs characterized by a forbidden subgraph
    D. Paulusma, P. A. Golovach, B. Ries
    Discrete Applied Mathematics 189 101--110 (2015)
  • On Some Applications Of The Selective Graph Coloring Problem
    M. Demange, T. Ekim, B. Ries, C. Tanasescu
    European Journal of Operations Research 240(2) 307--314 (2015)
  • Contraction Blockers for Graphs with Forbidden Induced Paths
    O.Y. Diner, D. Paulusma, C. Picouleau, B. Ries
    Lecture Notes in Computer Science 9079 194--207 (2015)
    9th International Conference on Algorithms and Complexity (CIAC 2015)
  • Multiple referenda and multiwinner elections using Hamming distances: complexity and manipulability
    Y. Amanatidis, N. Barrot, J. Lang, V. Markakis, B. Ries
    Proceedings of the 14th International Conference on Autonomous Agents & Multiagent Systems (AAMAS 2015)
    Bordini, Elkind, Weiss, Yolum (eds) 715--723 (2015)

A comprehensive list of my publications is available on my futura page.

 


 

PhD students

  • Nathanael Barrot: 2012 - 2015
    (co-supervisor: Jérôme Lang (Université Paris Dauphine))
  • Esther Galby: 2015 -
  • Vera Fischer: 2018 -

Postdocs

  • Diana Sasaki: 2014 - 2015
  • Andrea Munaro: 2018 (3 months)

 


 

Research Grants

  • 2015 : PHC Proteus grant; Structural and Algorithmic Aspects of Graph Classes Defined by Cliques and Stable Sets
    in collaboration with Slovenian researchers; role: coordinator
  • 2014 : MATH-AmSud grant; Discrete mathematics: graph partition problems
    in collaboration with Brazilian researchers; role: coordinator
  • 2013 : MATH-AmSud grant; Algorithmic, Algebraic and Structural issues on coloring and matching theory of graphs
    in collaboration with Argentinian and Chilean researchers; role: member
  • 2012 : GdR - Recherche Opérationnelle grant; Décoloration: d-bloqueur minimum pour le nombre chromatique d'un graphe
    in collaboration with French researchers; role: member
  • 2012 : PHC Bosphore grant; The selective graph coloring problem
    in collaboration with Turkish researchers; role: coordinator
  • 2012 : GdR - Recherche Opérationnelle grant; Problèmes de coloration avec sélection
    in collaboration with French researchers; role: coordinator
  • 2008 : FNR (Luxembourg) grant for postdoctoral research at Columbia University