Biography

Biography: In 2007, I received my PhD in mathematics from Ecole Polytechnique Fédérale de Lausanne(CH). From 2008 to 2009, I was a Postdoctoral Research Fellow at Columbia University (US) in the Department of Industrial Engineering and Operations Research. In 2009-2010, I was appointed as Assistant Professor at the University of Warwick (UK) in the Center for Discrete Mathematics and its Applications (DIMAP) and the Warwick Business School (WBS). From September 2010 to July 2015, I was an Associate Professor at the Université Paris Dauphine (F) in the Computer Science and Mathematics Department. Currently I am a Professor at the University of Fribourg (CH), where I am heading the Decision Support & Operations Research Group together with Marino Widmer in the Department of Informatics. In 2022, I joined the Smart Living Lab project with some members of my team.

My main research interests are:

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

Phd Students:

• Nathanael Barrot: 2012 - 2015 (currently postdoc at RIKEN Research Center in Japan)
  (co-supervisor: Jérôme Lang (Université Paris Dauphine))
• Esther Galby: 2015 - 2020 (currently Assistant professor at Chalmers University of Technology, Sweden)
• Vera Fischer: 2018 - 2023 (co-supervision with Meritxell Pacheco, now at La Poste)
• Felix Mann: 2019 - 2024 (now at soobr - smart cleaning)
• Felicia Lucke: 2020 - 2024 (now postdoc at ENS Lyon)
• Narmina Baghirova: 2020 - 2025 (co-supervision with David Schindl, now postdoc at CHUV Lausanne)
• Elise Bangerter: 2023 - (co-supervision with Meritxell Pacheco)
• Henri Ortmüller: 2025 - (co-supervision with Clément Dallard)

Visiting PhD students:

• Mariano Rean (2016, University of Buenos Aires (Argentina)) 
• Zakir Deniz (2017, Duzce University (Turkey))
• Pierre Hauweele (2018, Université de Mons (Belgium))
• Paloma Thomé de Lima (2018, University of Bergen (Norway))
• Carolina Goncalvez (20021, 2022, University of Buenos Aires (Argentina))

Member of PhD committees:

• Grégoire Cotté, Conservatoire National des Arts et Métiers, Paris, France (2016)
• Vasileios Papapanagiotu, Università della Svizzera Italiana, Lugano, Switzerland (2018)
• Gauvain Devillez, Université de Mons, Belgium (2022)
• Nikolaos Melissinos, Université Paris Dauphine PSL, France (2022)
• Valentin Bouquet, Conservatoire National des Arts et Métiers, Paris, France (2022)

Postdocs:

• Diana Sasaki: 2014 - 2015 (now Professor at Universidade do Estado do Rio de Janeiro (Brazil))
• Maria Pia Mazzoleni: August 2017 (now Docencia at Universidad Nacional La Plata (Argentina))
• Andrea Munaro: February - June 2018 (now Assistant Professor at University of Parma (Italy))
• Zakir Deniz: September - December 2019
• Meritxell Pacheco: January 2021 - August 2021 (now Senior Researcher and Lecturer at University of Fribourg (CH))
• Jérôme De Boeck: March 2022 - August 2023 (now Assistant Professor at HEC Liège, Belgium)
• Nour Elhouda Tellache: 2024 - 

Research and publications

• Publications
  196 publications

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  Matching Cuts in Graphs of High Girth and H-Free Graphs
  Carl Feghali, Felicia Lucke, Daniël Paulusma, Bernard Ries, Algorithmica (2025) | Journal article

  Explainable Graph-theoretical Machine Learning: with Application to Alzheimer's Disease Prediction
  Narmina Baghirova and Duy-Thanh Vũ and Duy-Cat Can and Christelle Schneuwly Diaz and Julien Bodlet and Guillaume Blanc and Georgi Hrusanov and Bernard Ries and Oliver Y. Chén, (2025) | Preprint

  Finding k-community structures in special graph classes
  Narmina Baghirova, Clément Dallard, Bernard Ries, David Schindl, Discrete Applied Mathematics (2024) | Journal article

  Dichotomies for Maximum Matching Cut: H-freeness, bounded diameter, bounded radius
  Felicia Lucke, Daniël Paulusma, Bernard Ries, Theoretical Computer Science (2024) | Journal article

  On blockers and transversals of maximum independent sets in co-comparability graphs
  Felicia Lucke, Bernard Ries, Discrete Applied Mathematics (2024) | Journal article

  Blocking Graph Parameters , in Encyclopedia of Optimization
  Felix Mann and Bernard Ries (2024) | Book chapter

  Maximizing Matching Cuts , in Encyclopedia of Optimization
  Van Bang Le and Felicia Lucke and Daniël Paulusma and Bernard Ries (2024) | Book chapter

  Dichotomies for Maximum Matching Cut H-Freeness, Bounded Diameter, Bounded Radius1
  Bernard Ries and Felicia Lucke and Daniël Paulusma, (2024) | Preprint

  Maximizing Matching Cuts
  Van Bang Le and Felicia Lucke and Daniël Paulusma and Bernard Ries, (2023) | Preprint

  On Blockers and Transversals of Maximum Independent Sets in Co-Comparability Graphs
  Felicia Lucke and Bernard Ries, (2023) | Preprint

  Finding Matching Cuts in H-Free Graphs
  Felicia Lucke and Daniël Paulusma and Bernard Ries, Algorithmica (2023) | Journal article

  Finding k-community structures in special graph classes
  Narmina Baghirova and Clément Dallard and Bernard Ries and David Schindl, (2023) | Preprint

  Dichotomies for Maximum Matching Cut: H-Freeness, Bounded Diameter, Bounded Radius
  Lucke, F. and Paulusma, D. and Ries, B. , arXiv (2023) | Other

  Preface
  Paulusma, D. and Ries, B. (Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2023) | Book

  Dichotomies for Maximum Matching Cut: H-Freeness, Bounded Diameter, Bounded Radius
  Lucke, F. and Paulusma, D. and Ries, B. , arXiv (2023) | Other

  Matching Cuts in Graphs of High Girth and H-Free Graphs
  Feghali, Carl and Lucke, Felicia and Paulusma, Daniël and Ries, Bernard, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2023) | Conference

  Graph-Theoretic Concepts in Computer Science
  Daniël Paulusma and Bernard Ries (Lecture Notes in Computer Science, 2023) | Book

  Using edge contractions to reduce the semitotal domination number
  Esther Galby and Paloma T. Lima and Felix Mann and Bernard Ries, Theoretical Computer Science (2023) | Journal article

  Dichotomies for Maximum Matching Cut: $H$-Freeness, Bounded Diameter, Bounded Radius
  Felicia Lucke and Daniël Paulusma and Bernard Ries and Jérôme Leroux and Sylvain Lombardy and David Peleg, (2023) | Preprint

  Matching Cuts in Graphs of High Girth and H-Free Graphs
  Carl Feghali and Felicia Lucke and Daniel Paulusma and Bernard Ries, (2022) | Preprint

  On the complexity of matching cut for graphs of bounded radius and H-free graphs
  Felicia Lucke and Daniël Paulusma and Bernard Ries, Theoretical Computer Science (2022) | Journal article

  Finding Matching Cuts in $H$-Free Graphs
  Felicia Lucke and Daniël Paulusma and Bernard Ries, (2022) | Preprint

  Finding $k$-community structures in special graph classes
  Narmina Baghirova and Clément Dallard and Bernard Ries and David Schindl, (2022) | Preprint

  On The Complexity of Matching Cut for Graphs of Bounded Radius and $H$-Free Graphs
  Felicia Lucke and Daniël Paulusma and Bernard Ries, (2022) | Preprint

  On some special classes of contact B0-VPG graphs
  Flavia Bonomo-Braberman and María Pía Mazzoleni and Mariano Leonardo Rean and Bernard Ries, Discrete Applied Mathematics (2022) | Journal article

  On The Complexity of Matching Cut for Graphs of Bounded Radius and H-Free Graphs
  Lucke, F. and Paulusma, D. and Ries, B. , arXiv (2022) | Other

  LOCALLY CHECKABLE PROBLEMS PARAMETERIZED BY CLIQUE-WIDTH
  Baghirova, N. and Gonzalez, C.L. and Ries, B. and Schindl, D. , arXiv (2022) | Other

  Finding Matching Cuts in H-Free Graphs
  Lucke, F. and Paulusma, D. and Ries, B., Leibniz International Proceedings in Informatics, LIPIcs: (2022) | Conference

  Matching Cuts in Graphs of High Girth and H-Free Graphs
  Feghali, C. and Lucke, F. and Paulusma, D. and Ries, B. , arXiv (2022) | Other

  Locally Checkable Problems Parameterized by Clique-Width
  Narmina Baghirova and Carolina Lucía Gonzalez and Bernard Ries and David Schindl and Sang Won Bae and Heejin Park, (2022) | Preprint

  Reducing the domination number of (P3+kP2)-free graphs via one edge contraction
  Esther Galby and Felix Mann and Bernard Ries, Discrete Applied Mathematics (2021) | Journal article

  Using edge contractions to reduce the semitotal domination number
  Esther Galby and Paloma T. Lima and Felix Mann and Bernard Ries, (2021) | Preprint

  Using edge contractions to reduce the semitotal domination number.
  Esther Galby and Paloma T. Lima and Felix Mann and Bernard Ries, (2021) | Preprint

  Blocking total dominating sets via edge contractions
  Esther Galby and Felix Mann and Bernard Ries, Theoretical Computer Science (2021) | Journal article

  Graph colouring variations , in Topics in Algorithmic Graph Theory
  Alain Hertz and Bernard Ries (2021) | Book chapter

  CPG graphs: Some structural and hardness results
  Nicolas Champseix and Esther Galby and Andrea Munaro and Bernard Ries, Discrete Applied Mathematics (2021) | Journal article

  New progress in combinatorial optimization
  Bo Chen and Silvano Martello and Bernard Ries, Discrete Applied Mathematics (2021) | Journal article

  Using edge contractions to reduce the semitotal domination number
  Galby, E. and Lima, P.T. and Mann, F. and Ries, B. , arXiv (2021) | Other

  Reducing the domination number of graphs via edge contractions and vertex deletions
  Esther Galby and Paloma T. Lima and Bernard Ries, Discrete Mathematics (2021) | Journal article

  LATIN - On Some Subclasses of Split \(B_1\)-EPG Graphs , in Lecture Notes in Computer Science
  Zakir Deniz and Simon Nivelle and Bernard Ries and David Schindl (2020) | Book chapter

  Reducing the domination number of $P_3+kP_2$-free graphs via one edge contraction
  Esther Galby and Felix Mann and Bernard Ries, (2020) | Preprint

  Reducing the domination number of $P_3+kP_2$-free graphs via one edge\n contraction
  Esther Galby and Felix Mann and Bernard Ries, (2020) | Preprint

  Blocking total dominating sets via edge contractions
  Esther Galby and Felix Mann and Bernard Ries, (2020) | Preprint

  Semitotal Domination: New hardness results and a polynomial-time algorithm for graphs of bounded mim-width
  Esther Galby and Andrea Munaro and Bernard Ries, Theoretical Computer Science (2020) | Journal article

  Blocking total dominating sets via edge contractions
  Galby, E. and Mann, F. and Ries, B. , arXiv (2020) | Other

  Blocking total dominating sets via edge contractions
  Galby, E. and Mann, F. and Ries, B. , arXiv (2020) | Other

  Maximum eccentric connectivity index for graphs with given diameter
  Pierre Hauweele and Alain Hertz and Hadrien Mélot and Bernard Ries and Gauvain Devillez, Discrete Applied Mathematics (2019) | Journal article

  Detecting strong cliques
  Ademir Hujdurović and Martin Milanič and Bernard Ries, Discrete Mathematics (2019) | Journal article

  Blocking dominating sets for $H$-free graphs via edge contractions
  Esther Galby and Paloma T. Lima and Bernard Ries, (2019) | Preprint

  Classifying k-edge colouring for H-free graphs
  Esther Galby and Paloma T. Lima and Daniël Paulusma and Bernard Ries, Information Processing Letters (2019) | Journal article

  Proper circular arc graphs as intersection graphs of pathson a grid
  Esther Galby and María Pía Mazzoleni and Bernard Ries, Discrete Applied Mathematics (2019) | Journal article

  Preface: Tenth International Colloquium on Graphs and Optimization (GO X), 2016
  Yves Crama and Bernard Gendron and Bernard Ries, Discrete Applied Mathematics (2019) | Journal article

  Graph colouring variations
  Alain Hertz and Bernard Ries (2019) | Other

  CPG graphs: Some structural and hardness results
  Nicolas Champseix and Esther Galby and Andrea Munaro and Bernard Ries, (2019) | Preprint

  Reducing the domination number of graphs via edge contractions
  Esther Galby and Paloma T. Lima and Bernard Ries, (2019) | Preprint

  Critical vertices and edges in H-free graphs
  Daniël Paulusma and Christophe Picouleau and Bernard Ries, Discrete Applied Mathematics (2019) | Journal article

  On the Parameterized Complexity of k-Edge Colouring.
  Esther Galby and Paloma T. Lima and Daniël Paulusma and Bernard Ries, (2019) | Preprint

  Blocking dominating sets for H-free graphs via edge contractions
  Galby, E. and Lima, P.T. and Ries, B. , arXiv (2019) | Other

  Reducing the domination number of graphs via edge contractions
  Galby, E. and Paloma, T.L. and Ries, B. , arXiv (2019) | Other

  CPG graphs: Some structural and hardness results
  Champseix, N. and Galby, E. and Munaro, A. and Ries, B. , arXiv (2019) | Other

  On the parameterized complexity of k-edge colouring
  Galby, E. and Lima, P.T. and Paulusma, D. and Ries, B. , arXiv (2019) | Other

  Blocking dominating sets for H-free graphs via edge contractions
  Galby, E. and Lima, P.T. and Ries, B. , arXiv (2019) | Other

  CPG graphs: Some structural and hardness results
  Champseix, N. and Galby, E. and Munaro, A. and Ries, B. , arXiv (2019) | Other

  Reducing the domination number of graphs via edge contractions
  Galby, E. and Paloma, T.L. and Ries, B. , arXiv (2019) | Other

  On the parameterized complexity of k-edge colouring
  Galby, E. and Lima, P.T. and Paulusma, D. and Ries, B. , arXiv (2019) | Other

  Graph Drawing - On contact graphs of paths on a grid , in Lecture Notes in Computer Science
  Zakir Deniz and Esther Galby and Andrea Munaro and Bernard Ries (2018) | Book chapter

  Planar CPG graphs
  Nicolas Champseix and Esther Galby and Bernard Ries, (2018) | Preprint

  Planar CPG graphs
  Nicolas Champseix and Esther Galby and Bernard Ries, (2018) | Preprint

  Semitotal Domination: New hardness results and a polynomial-time algorithm for graphs of bounded mim-width.
  Esther Galby and Andrea Munaro and Bernard Ries, (2018) | Preprint

  Semitotal Domination: New hardness results and a polynomial-time\n algorithm for graphs of bounded mim-width
  Esther Galby and Andrea Munaro and Bernard Ries, (2018) | Preprint

  Classifying k-Edge Colouring for H-free Graphs
  Esther Galby and Paloma T. Lima and Daniël Paulusma and Bernard Ries, (2018) | Preprint

  Contraction and deletion blockers for perfect graphs and H-free graphs
  Öznur Yaşar Diner and Daniël Paulusma and Christophe Picouleau and Bernard Ries, Theoretical Computer Science (2018) | Journal article

  Maximum Eccentric Connectivity Index for Graphs with Given Diameter
  Pierre Hauweele and Alain Hertz and Hadrien Mélot and Bernard Ries and Gauvain Devillez, (2018) | Preprint

  Proper circular arc graphs as intersection graphs of paths on a grid
  Esther Galby and María Pía Mazzoleni and Bernard Ries, (2018) | Preprint

  Detecting strong cliques
  Ademir Hujdurović and Martin Milanič and Bernard Ries, (2018) | Preprint

  Maximum eccentric connectivity index for graphs with given diameter
  Pierre Hauweele and Alain Hertz and Hadrien Mélot and Bernard Ries and Gauvain Devillez (2018) | Other

  On some special classes of contact $B_0$-VPG graphs
  Flavia Bonomo-Braberman and María Pía Mazzoleni and Mariano Leonardo Rean and Bernard Ries, (2018) | Preprint

  ISCO - Characterising Chordal Contact $$B_0$$-VPG Graphs
  Flavia Bonomo and María Pía Mazzoleni and Mariano Leonardo Rean and Bernard Ries (Lecture Notes in Computer Science, 2018) | Book

  Graphs vertex-partitionable into strong cliques
  Ademir Hujdurović and Martin Milanič and Bernard Ries, Discrete Mathematics (2018) | Journal article

  LATIN - On Split $$B_1$$-EPG Graphs , in Lecture Notes in Computer Science
  Zakir Deniz and Simon Nivelle and Bernard Ries and David Schindl (2018) | Book chapter

  On contact graphs of paths on a grid
  Zakir Deniz and Esther Galby and Bernard Ries, (2018) | Preprint

  Planar CPG graphs
  Champseix, N. and Galby, E. and Ries, B. , arXiv (2018) | Other

  Semitotal Domination: New hardness results and a polynomial-Time algorithm for graphs of bounded mim-width
  Galby, E. and Munaro, A. and Ries, B. , arXiv (2018) | Other

  Classifying k-edge colouring for H-free graphs
  Galby, E. and Lima, P.T. and Paulusma, D. and Ries, B. , arXiv (2018) | Other

  Proper circular arc graphs as intersection graphs of paths on a grid
  Galby, E. and Mazzoleni, M.P. and Ries, B. , arXiv (2018) | Other

  Detecting strong cliques
  Hujdurovi?, A. and Milani?, M. and Ries, B. , arXiv (2018) | Other

  On some special classes of contact B₀-VPG graphs
  Bonomo, F. and Mazzoleni, M.P. and Rean, M.L. and Ries, B. , arXiv (2018) | Other

  On contact graphs of paths on a Grid
  Deniz, Z. and Galby, E. and Munaro, A. and Ries, B. , arXiv (2018) | Other

  On some special classes of contact B₀-VPG graphs
  Bonomo-Braberman, F. and Mazzoleni, M.P. and Rean, M.L. and Ries, B. , arXiv (2018) | Other

  Proper circular arc graphs as intersection graphs of paths on a grid
  Galby, E. and Mazzoleni, M.P. and Ries, B. , arXiv (2018) | Other

  Classifying k-edge colouring for H-free graphs
  Galby, E. and Lima, P.T. and Paulusma, D. and Ries, B. , arXiv (2018) | Other

  Detecting strong cliques
  Hujdurovi?, A. and Milani?, M. and Ries, B. , arXiv (2018) | Other

  On contact graphs of paths on a Grid
  Deniz, Z. and Galby, E. and Munaro, A. and Ries, B. , arXiv (2018) | Other

  On the bend number of circular-arc graphs as edge intersection graphs of paths on a grid
  Liliana Alcón and Flavia Bonomo and Guillermo Durán and Marisa Gutierrez and María Pía Mazzoleni and Bernard Ries and Mario Valencia-Pabon, Discrete Applied Mathematics (2018) | Journal article

  Reducing the Chromatic Number by Vertex or Edge Deletions
  Christophe Picouleau and Daniël Paulusma and Bernard Ries, Electronic Notes in Discrete Mathematics (2017) | Journal article

  Dominating induced matchings in graphs containing no long claw
  Alain Hertz and Vadim V. Lozin and Bernard Ries and Victor Zamaraev and D. de Werra, Journal of Graph Theory (2017) | Journal article

  Upper Domination: Towards a Dichotomy Through Boundary Properties
  Hassan AbouEisha and Shahid Hussain and Vadim V. Lozin and Jérôme Monnot and Bernard Ries and Victor Zamaraev, Algorithmica (2017) | Journal article

  Critical Vertices and Edges in $H$-free Graphs
  Daniël Paulusma and Christophe Picouleau and Bernard Ries, (2017) | Preprint

  Contraction and Deletion Blockers for Perfect Graphs and $H$-free Graphs
  Öznur Yaşar Diner and Daniël Paulusma and Christophe Picouleau and Bernard Ries, (2017) | Preprint

  TAMC - Blocking Independent Sets for H-Free Graphs via Edge Contractions and Vertex Deletions , in Lecture Notes in Computer Science
  Daniël Paulusma and Christophe Picouleau and Bernard Ries (2017) | Book chapter

  Contraction and deletion blockers for perfect graphs and h-free graphs?
  Diner, O.Y. and Paulusma, D. and Picouleau, C. and Ries, B. , arXiv (2017) | Other

  Critical Vertices and Edges in H-free Graphs^?
  Paulusma, D. and Picouleau, C. and Ries, B. , arXiv (2017) | Other

  Contraction and deletion blockers for perfect graphs and h-free graphs?
  Diner, O.Y. and Paulusma, D. and Picouleau, C. and Ries, B. , arXiv (2017) | Other

  Critical Vertices and Edges in H-free Graphs^?
  Paulusma, D. and Picouleau, C. and Ries, B. , arXiv (2017) | Other

  Complexity and Algorithms for Finding a Perfect Phylogeny from Mixed Tumor Samples
  Ademir Hujdurović and Urša Kačar and Martin Milanič and Bernard Ries and Alexandru I. Tomescu, IEEE/ACM transactions on computational biology and bioinformatics (2016) | Journal article

  Graphs vertex-partitionable into strong cliques
  Ademir Hujdurović and Martin Milanič and Bernard Ries, (2016) | Preprint

  ISCO - Reducing the Clique and Chromatic Number via Edge Contractions and Vertex Deletions , in Lecture Notes in Computer Science
  Daniël Paulusma and Christophe Picouleau and Bernard Ries (2016) | Book chapter

  Upper Domination: towards a dichotomy through boundary properties
  Hassan AbouEisha and Shahid Hussain and Vadim V. Lozin and Jérôme Monnot and Bernard Ries and Victor Zamaraev, (2016) | Preprint

  IWOCA - A Boundary Property for Upper Domination , in Lecture Notes in Computer Science
  Hassan AbouEisha and Shahid Hussain and Vadim V. Lozin and Jérôme Monnot and Bernard Ries and Victor Zamaraev (2016) | Book chapter

  On the ratio between maximum weight perfect matchings and maximum weight matchings in grids
  Guilherme D. da Fonseca and Bernard Ries and Diana Sasaki, Discrete Applied Mathematics (2016) | Journal article

  On star and biclique edge-colorings
  Simone Dantas and Marina Groshaus and André Luiz Pires Guedes and Raphael C. S. Machado and Bernard Ries and Diana Sasaki, International Transactions in Operational Research (2016) | Journal article

  On the minimum and maximum selective graph coloring problems in some graph classes
  Marc Demange and Tınaz Ekim and Bernard Ries, Discrete Applied Mathematics (2016) | Journal article

  On the bend number of circular-arc graphs as edge intersection graphs of paths on a grid
  Liliana Alcón and Flavia Bonomo and Guillermo Durán and Marisa Gutierrez and María Pía Mazzoleni and Bernard Ries and Mario Valencia-Pabon, Electronic Notes in Discrete Mathematics (2015) | Journal article

  Advances in Combinatorial Optimization
  Silvano Martello and Bernard Ries, Discrete Applied Mathematics (2015) | Journal article

  Vote par approbation pour les élections à vainqueurs multiples. Une famille générale de règles, leur complexité algorithmique et leur manipulabilité
  Nathanaël Barrot and Jérôme Lang and Bernard Ries, Revue d’intelligence artificielle (2015) | Journal article

  WABI - Finding a Perfect Phylogeny from Mixed Tumor Samples , in Lecture Notes in Computer Science
  Ademir Hujdurović and Urša Kačar and Martin Milanič and Bernard Ries and Alexandru I. Tomescu (2015) | Book chapter

  On the bend number of circular-arc graphs as edge intersection graphs of paths on a grid
  Liliana Alcón and Flavia Bonomo and Guillermo Durán and Marisa Gutierrez and María Pía Mazzoleni and Bernard Ries and Mario Valencia-Pabon, (2015) | Preprint

  Finding a perfect phylogeny from mixed tumor samples
  Ademir Hujdurović and Urša Kačar and Martin Milanič and Bernard Ries and Alexandru I. Tomescu, (2015) | Preprint

  Complexity and algorithms for finding a perfect phylogeny from mixed\n tumor samples
  Ademir Hujdurović and Urša Kačar and Martin Milanič and Bernard Ries and Alexandru I. Tomescu, (2015) | Preprint

  Complexity and algorithms for finding a perfect phylogeny from mixed tumor samples
  Ademir Hujdurović and Urša Kačar and Martin Milanič and Bernard Ries and Alexandru I. Tomescu, (2015) | Preprint

  CIAC - Contraction Blockers for Graphs with Forbidden Induced Paths , in Lecture Notes in Computer Science
  Öznur Yaşar Diner and Daniël Paulusma and Christophe Picouleau and Bernard Ries (2015) | Book chapter

  Dominating induced matchings in graphs containing no long claw
  Alain Hertz and Vadim V. Lozin and Bernard Ries and Victor Zamaraev and D. de Werra, (2015) | Preprint

  AAMAS - Multiple Referenda and Multiwinner Elections Using Hamming Distances: Complexity and Manipulability
  Georgios Amanatidis, Nathanaël Barrot, Jérôme Lang, Evangelos Markakis, Bernard Ries, (4.5.2015) | Conference

  Multiple Referenda and Multiwinner Elections Using Hamming Distances: Complexity and Manipulability
  Georgios Amanatidis and Nathanaël Barrot and Jérôme Lang and Evangelos Markakis and Bernard Ries, International Joint Conference on Autonomous Agents and Multiagent Systems: (4.5.2015) | Conference

  On the maximum independent set problem in subclasses of subcubic graphs
  Vadim V. Lozin and Jérôme Monnot and Bernard Ries, Journal of Discrete Algorithms (2015) | Journal article

  Multiple referenda and multiwinner elections using Hamming distances: Complexity and manipulability
  Amanatidis, G. and Barrot, N. and Lang, J. and Markakis, E. and Ries, B., Proceedings of the International Joint Conference on Autonomous Agents and Multiagent Systems, AAMAS: (2015) | Conference

  On some applications of the selective graph coloring problem
  Marc Demange and Tınaz Ekim and Bernard Ries and Cerasela Tanasescu, European Journal of Operational Research (2015) | Journal article

  ICORES - Analyzing the Performance of Greedy Maximal Scheduling via Local Pooling and Graph Theory.
  Bernard Ries (2015) | Book

  CTW - On the Minimum and Maximum Selective Graph Coloring Problems.
  Marc Demange, Tınaz Ekim, Bernard Ries, (2015) | Conference

  Coloring graphs characterized by a forbidden subgraph
  Petr A. Golovach and Daniël Paulusma and Bernard Ries, Discrete Applied Mathematics (2015) | Journal article

  Characterizations of cographs as intersection graphs of paths on a grid
  Elad Cohen and Martin Charles Golumbic and Bernard Ries, Discrete Applied Mathematics (2014) | Journal article

  COCOA - A Dichotomy for Upper Domination in Monogenic Classes , in Lecture Notes in Computer Science
  Hassan AbouEisha and Shahid Hussain and Vadim V. Lozin and Jérôme Monnot and Bernard Ries (2014) | Book chapter

  Approval Voting for Committee Elections : a General Family of Rules
  Nathanaël Barrot and Jérôme Lang and Bernard Ries (2014) | Other

  On the complexity of the selective graph coloring problem in some special classes of graphs
  Marc Demange and Jérôme Monnot and Petrica C. Pop and Bernard Ries, Theoretical Computer Science (2014) | Journal article

  A note on r-equitable k-colorings of trees
  Alain Hertz and Bernard Ries, Yugoslav Journal of Operations Research (2014) | Journal article

  Blockers for the Stability Number and the Chromatic Number
  Cristina Bazgan and Cédric Bentz and Christophe Picouleau and Bernard Ries, Graphs and Combinatorics (2013) | Journal article

  Perfectness of clustered graphs
  Flavia Bonomo and Denis Cornaz and Tınaz Ekim and Bernard Ries, Discrete Optimization (2013) | Journal article

  A Note on \(r\)-Equitable \(k\)-Colorings of Trees
  Alain Hertz and Bernard Ries (2013) | Other

  Packing and covering with linear programming: A survey
  Cédric Bentz and Denis Cornaz and Bernard Ries, European Journal of Operational Research (2013) | Journal article

  The firefighter problem with more than one firefighter on trees
  Cristina Bazgan and Morgan Chopin and Bernard Ries, Discrete Applied Mathematics (2013) | Journal article

  Optimal edge-coloring with edge rate constraints
  Dariusz Dereniowski and Wieslaw Kubiak and Bernard Ries and Yori Zwols, Networks (2013) | Journal article

  Editorial: GO VII Meeting, Ovronnaz (CH), June 13-17, 2010
  Marc Demange and Vadim Lozin and Christophe Picouleau and Bernard Ries, Discrete Applied Mathematics (2013) | Journal article

  Possible winners in approval voting
  Barrot, N. and Gourvès, L. and Lang, J. and Monnot, J. and Ries, B. (Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2013) | Book

  ADT - Possible Winners in Approval Voting , in Lecture Notes in Computer Science
  Nathanaël Barrot and Laurent Gourvès and Jérôme Lang and Jérôme Monnot and Bernard Ries (2013) | Book chapter

  IWOCA - On the Maximum Independent Set Problem in Subclasses of Subcubic Graphs , in Lecture Notes in Computer Science
  Vadim V. Lozin and Jérôme Monnot and Bernard Ries (2013) | Book chapter

  d-Transversals of stable sets and vertex covers in weighted bipartite graphs
  Cédric Bentz and Marie-Christine Costa and Christophe Picouleau and Bernard Ries and D. de Werra, Journal of Discrete Algorithms (2012) | Journal article

  A note on chromatic properties of threshold graphs
  Bernard Ries and D. de Werra and Rico Zenklusen, Discrete Mathematics (2012) | Journal article

  Colouring vertices of triangle-free graphs without forests
  Konrad K. Dabrowski and Vadim V. Lozin and Rajiv Raman and Bernard Ries, Discrete Mathematics (2012) | Journal article

  Analyzing the performance of greedy maximal scheduling via local pooling and graph theory
  Berk Birand and Maria Chudnovsky and Bernard Ries and Paul Seymour and Gil Zussman and Yori Zwols, IEEE/ACM Transactions on Networking (2012) | Journal article

  On the Intersection Graphs of Orthogonal Line Segments in the Plane: Characterizations of Some Subclasses of Chordal Graphs
  Martin Charles Golumbic and Bernard Ries, Graphs and Combinatorics (2012) | Journal article

  MFCS - Coloring graphs characterized by a forbidden subgraph , in Lecture Notes in Computer Science
  Petr A. Golovach and Daniël Paulusma and Bernard Ries (2012) | Book chapter

  Some properties of edge intersection graphs of single-bend paths on a grid
  Andrei Asinowski and Bernard Ries, Discrete Mathematics (2012) | Journal article

  ISCO - Selective graph coloring in some special classes of graphs
  Marc Demange and Jérôme Monnot and Petrica C. Pop and Bernard Ries (Lecture Notes in Computer Science, 2012) | Book

  Minimum d-Transversals of Maximum-Weight Stable Sets in Trees
  Cédric Bentz and Marie-Christine Costa and D. de Werra and Christophe Picouleau and Bernard Ries, Electronic Notes in Discrete Mathematics (2011) | Journal article

  Weighted Transversals and Blockers for Some Optimization Problems in Graphs
  Marie-Christine Costa and D. de Werra and Christophe Picouleau and Bernard Ries and Cédric Bentz (2011) | Other

  The firefighter problem with more than one firefighter on trees
  Cristina Bazgan and Morgan Chopin and Bernard Ries, (2011) | Preprint

  Claw-free graphs with strongly perfect complements. Fractional and integral version, Part II: Nontrivial strip-structures
  Maria Chudnovsky and Bernard Ries and Yori Zwols, Discrete Applied Mathematics (2011) | Journal article

  Claw-free graphs with strongly perfect complements. Fractional and integral version. Part I. Basic graphs
  Maria Chudnovsky and Bernard Ries and Yori Zwols, Discrete Applied Mathematics (2011) | Journal article

  A 2-approximation for the maximum satisfying bisection problem
  Bernard Ries and Rico Zenklusen, European Journal of Operational Research (2011) | Journal article

  Solution Methods for a Scheduling Problem with Incompatibility and Precedence Constraints
  François-Xavier Meuwly and Bernard Ries and Nicolas Zufferey, Algorithmic Operations Research (2010) | Journal article

  S3@MobiCom - Analyzing the performance of greedy maximal scheduling via local pooling and graph theory
  Berk Birand and Maria Chudnovsky and Bernard Ries and Paul Seymour and Gil Zussman and Yori Zwols (Proceedings of the 2010 ACM workshop on Wireless of the students, by the students, for the students, 2010) | Book

  INFOCOM - Analyzing the Performance of Greedy Maximal Scheduling via Local Pooling and Graph Theory
  Berk Birand, Maria Chudnovsky, Bernard Ries, Paul Seymour, Gil Zussman, Yori Zwols, (14.3.2010) | Conference

  Complexity of two coloring problems in cubic planar bipartite mixed graphs
  Bernard Ries, Discrete Applied Mathematics (2010) | Journal article

  Analyzing the Performance of Greedy Maximal Scheduling via Local Pooling and Graph Theory
  Berk Birand and Maria Chudnovsky and Bernard Ries and Paul Seymour and Gil Zussman and Yori Zwols, 2010 Proceedings IEEE INFOCOM: (3.2010) | Conference

  Split-critical and uniquely split-colorable graphs
  Ekim, T. and Ries, B. and De Werra, D., Discrete Mathematics and Theoretical Computer Science (2010) | Journal article

  WG - Colouring vertices of triangle-free graphs , in Lecture Notes in Computer Science
  Konrad K. Dabrowski and Vadim V. Lozin and Rajiv Raman and Bernard Ries (2010) | Book chapter

  Split-critical and uniquely split-colorable graphs
  Tınaz Ekim and Bernard Ries and D. de Werra, Discrete Mathematics & Theoretical Computer Science (2010) | Journal article

  Blockers and transversals in some subclasses of bipartite graphs: When caterpillars are dancing on a grid
  Bernard Ries and Cédric Bentz and Christophe Picouleau and D. de Werra and Marie-Christine Costa and Rico Zenklusen, Discrete Mathematics (2010) | Journal article

  Split-critical and uniquely split-colorable graphs
  Tınaz Ekim and Bernard Ries and Dominique De Werra, Discrete Mathematics & Theoretical Computer Science (2010) | Journal article

  Blockers and transversalsnext term in some previous termsubclasses of bipartite graphs: When caterpillars are dancing on a gridnext term
  Cédric Bentz and Marie-Christine Costa and Bernard Ries and D. de Werra and Christophe Picouleau and Rico Zenklusen (2010) | Other

  On the use of graphs in discrete tomography
  D. de Werra and Marie-Christine Costa and Christophe Picouleau and Bernard Ries, Annals of Operations Research (2009) | Journal article

  Graph coloring with cardinality constraints on the neighborhoods
  Marie-Christine Costa and D. de Werra and Christophe Picouleau and Bernard Ries, Discrete Optimization (2009) | Journal article

  Some properties of edge intersection graphs of single bend paths on a grid
  Bernard Ries, Electronic Notes in Discrete Mathematics (2009) | Journal article

  Blockers and transversals
  Rico Zenklusen and Bernard Ries and Christophe Picouleau and D. de Werra and Marie-Christine Costa and Cédric Bentz, Discrete Mathematics (2009) | Journal article

  Mixed graph edge coloring
  Hanna Furmańczyk and Adrian Kosowski and Bernard Ries and Paweł Żyliński, Discrete Mathematics (2009) | Journal article

  d-bloqueurs et d-transversaux
  Cédric Bentz and Marie-Christine Costa and D. de Werra and Christophe Picouleau and Bernard Ries and Rico Zenklusen (2009) | Other

  Degree-constrained edge partitioning in graphs arising from discrete tomography
  Bentz, C. and Costa, M.-C. and Picouleau, C. and Ries, B. and de Werra, D., Journal of Graph Algorithms and Applications (2009) | Journal article

  Degree-constrained edge partitioning in graphs arising from discrete tomography
  Cédric Bentz and Marie-Christine Costa and Christophe Picouleau and Bernard Ries and D. de Werra, Journal of Graph Algorithms and Applications (2009) | Journal article

  Addendum to “Bicolored Matchings in Some Classes of Graphs”
  Marie-Christine Costa and D. de Werra and Christophe Picouleau and Bernard Ries, Graphs and Combinatorics (2008) | Journal article

  On the use of graphs in discrete tomography
  D. de Werra and Marie-Christine Costa and Christophe Picouleau and Bernard Ries, 4OR (2008) | Journal article

  On two coloring problems in mixed graphs
  Bernard Ries and D. de Werra, European Journal of Combinatorics (2008) | Journal article

  On a graph coloring problem arising from discrete tomography
  Bentz, C. and Costa, M.C. and De Werra, D. and Picouleau, C. and Ries, B., Networks (2008) | Journal article

  Complexity of mixed graph coloring
  Bernard Ries, Theoretical Computer Science (2008) | Journal article

  Reconstruction d'une coloration des arêtes dun graphe à partir des séquences de degrés
  Cédric Bentz and Marie-Christine Costa and D. de Werra and Christophe Picouleau and Bernard Ries (2007) | Other

  Bicolored Matchings in Some Classes of Graphs
  Marie-Christine Costa and D. de Werra and Christophe Picouleau and Bernard Ries, Graphs and Combinatorics (2007) | Journal article

  Reconstruction de la coloration dun graphe à partir des projections des voisinages
  Marie-Christine Costa and D. de Werra and Christophe Picouleau and Bernard Ries (2007) | Other

  Reconstruction de la coloration d'un graphe à partir des projections des voisinages
  Marie-Christine Costa and D. de Werra and Christophe Picouleau and Bernard Ries (2007) | Other

  Coloring some classes of mixed graphs
  Bernard Ries, Discrete Applied Mathematics (2007) | Journal article

  Bicolored matchings in some classes of graphs
  Marie-Christine Costa and D. de Werra and Christophe Picouleau and Bernard Ries, AKCE International Journal of Graphs and Combinatorics (2007) | Journal article

  Reconstruction de la coloration dun graphe à partir de projections de chaînes
  Cédric Bentz and Marie-Christine Costa and Christophe Picouleau and Bernard Ries and D. de Werra (2006) | Other

  Discrete tomography and graph coloring
  Cédric Bentz and Marie-Christine Costa and D. de Werra and Christophe Picouleau and Bernard Ries (2006) | Other

  Graph colouring with vertex neighbourhoods constraints
  Marie-Christine Costa and D. de Werra and Christophe Picouleau and Bernard Ries (2006) | Other

  Bicolored matchings in some classes of graphs
  Marie-Christine Costa and D. de Werra and Christophe Picouleau and Bernard Ries, Electronic Notes in Discrete Mathematics (2005) | Journal article

  ISAAC - Blocking dominating sets for $H$-free graphs via edge contractions
  Esther Galby, Paloma T. Lima, Bernard Ries, | Conference

  MFCS - Reducing the Domination Number of Graphs via Edge Contractions
  Esther Galby, Paloma T. Lima, Bernard Ries, | Conference

  Variations of coloring problems related to scheduling and discrete tomography
  Bernard Ries | Other

• Research projects

  WG 2023
  Status: Completed

  Start	01.05.2023
  End	31.07.2023
  Funding	SNSF  Open project sheet
  WG conferences (Workshop on Graph-Theoretic Concepts in Computer Science) aim to connect theory and applications by demonstrating how graph-theoretic concepts can be applied in various areas of computer science. Organised in a different place each year, their goal is to present the strongest recent results and to identify and explore directions for future research. The Program Committee, composed of international experts in the field of theoretical computer science, decides on the accepted papers taking into account the reviews received for each submitted paper. A special issue of Springer's Lecture Notes in Computer Science will be published containing the accepted papers. The 49th edition of the International Workshop on Graph-Theoretic Concepts in Computer Science (WG 2023) will be held at the University of Fribourg from June 28 to 30, 2023. It will be organised by the applicant together with Prof. Daniel Paulusma from Durham University (UK). Both will also chair the Program Committee. There will be three internationally-reknowned invited speakers: Prof. Flavia Bonomo, Dr. Eunjung Kim and Dr. Nicolas Trotignon.

  Efficient and sustainable waste collection
  Status: Completed

  Start	01.09.2019
  End	31.08.2022
  Funding	Innovation
  In Swiss municipalities, a curbside system is often used to collect the non-recoverable solid waste. In principle, the trucks stop at every household for the collection. Due to the many stops of the heavy trucks, this classic strategy causes high fuel consumption, emissions and noise. The objective of this project is to improve the municipal solid waste collection process by designing efficient and sustainable waste collection strategies targeted to the needs of the municipalities. This objective is pursued through the following three components. First, new waste collection concepts are proposed using modern physical waste collection elements, such as electric vehicles and containers with compressors. For example, small, agile vehicles may bring the garbage bags to larger containers in intermediate depots and large vehicles may then regularly discharge these containers. Second, mathematical models and optimization algorithms are developed for deciding how to design a waste collection concept for a given municipality in the best possible way. Typical decisions are about the locations of the waste collection points, the types of vehicles used to collect the waste at all collection points and the routing of each vehicle. Third, an interactive decision support tool is developed. It enables to specify the inputs, such as the street network and the waste quantities, and to display the results of the optimization algorithms for all alternatives. This tool will help the decision-makers to choose the best waste collection concept for their municipality.

Teaching and courses

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