Find all the recent news concerning the Decision Support & Operations Research group here!

  • Several papers accepted!

    Several papers involving members of our group got recently accepted. Congratulations to everyone involved!

    • Treewidth versus clique number. III. Tree-independence number of graphs with a forbidden structure by C. Dallard, M. Milanič, and K. Štorgel, accepted in Journal of Combinatorial Theory, Series B,
    • Detecting K_{2,3} as an induced minor, by C. Dallard, M. Dumas, C. Hilaire, M. Milanič, A. Perez, and N. Trotignon, accepted at IWOCA 2024
    • Computing Tree Decompositions with Small Independence Number, by C. Dallard, F. V. Fomin, P. A. Golovach, T. Korhonen, and M. Milanič, accepted at ICALP 2024
    • Graphs with at most two moplexes, by C. Dallard, R. Ganian, M. Hatzel, M. Krnc, and M. Milanic, accepted in Journal of Graph Theory
    • Finding d-Cuts in Graphs of Bounded Diameter, Graphs of Bounded Radius and H-Free Graphs, by Felicia Lucke, Ali Momeni, Daniel Paulusma, Siani Smith, accepted at WG 2024
    • Blockers and Transversals of Maximum Independent Sets in Co-Comparability Graphs, Felicia Lucke, Bernard Ries, accepted in Discrete Applied Mathematics


  • Clément Dallard joins the group!

    From February 2024 on, Clément Dallard will join our group as senior researcher and lecturer! He is specialized in algorithmic and structural graph theory. In AS he will be teaching the graph theory course. Welcome Clément!

  • Paper accepted in Discrete Applied Mathematics!

    The paper On $d$-stable locally checkable problems parameterized by mim-width by Carolina Gonzalez and Felix Mann has been accepted for publication in the journal Discrete Applied Mathematics! Congratulations to all authors!

  • First comic related to the use of mathematics in real life!

    Together with Philippe Baumann (aka debhume), Florian Cuennet, Fabian Page, Ismaïl Ceylan and Laurent Dubois, our group created a first comic story explaining the notion of algorithm through the waste collection problem.



  • Paper accepted in EJOR!

    The paper A capacitated multi-vehicle covering tout problem on a road network and its application to waste collection by Fischer V., Paneque M.P., Legrain A., Bürgy R. has been accepted for publication in the European Journal of Operations Research! Congratulations to all authors!

  • Best Paper Award at ISAAC 2023!

    Our paper Matching Cuts in Graphs of High Girth and H-free Graphs by Carl Feghali, Felicia Lucke, Daniel Paulusma and Bernard Ries has been accepted for presentation at ISAAC 2023! In addition, we will be awarded the Best Paper Award at the conference! Congratulations to all authors!

  • Paper accepted in Computers and Operations Research!

    Vera Fischer's paper A logic-based Benders decomposition solution approach for two covering problems that consider the underlying transportation with Sanne Wøhlk has been accepted for publication in the journal Computers and Operations Research! The paper can be found here.

  • Two papers accepted in Algorithmica!

    Two papers from our group got accepted in the journal Algorithmica:


    • Reducing Graph Parameters by Contractions and Deletions, F. Lucke, F. Mann
    • Finding Matching Cuts in H-Free Graphs, F. Lucke, D. Paulusma, B. Ries
  • Vera Fischer -> Dr. Vera Fischer

    Congratulations to Vera Fischer who successfully defended her PhD thesis on April 26, 2023!

  • DS&OR organises the WG 2023 conference!

    From June 28 till June 30, 2023, our group organizes the 49th Interbnational Workshop on Graph Theoretical Apsects in Computer Science (WG 2023). For more information, click here!

  • Jérôme De Boeck gets a position at HEC Liège (Belgium)!

    Congratulations to Jérôme De Boeck! He will start a professor position at HEC Liège (Belgium) from Spetember 2023 on in the area of Computational Methods in Management.

  • DS&OR joins the Smart Living Lab!

    From July 2022 on, our group is also involved in the activities of the Smart Living Lab at bluefactory in Fribourg. Find out more about this exciting project and our involvement  here!

  • Jérôme De Boeck gets innovation booster grant!
    DS&OR will start a new project on plant health and food production in partnership with Vivent SA ( in March 2023, funded by Innovation Booster ( Vivent is a world leader in monitoring plant health through its electrical internal activity. The interpretation of electrical signals is a complex task currently performed through empirical observations which are mainly interpreted through artifical inteliigence. Our project aims at modelling the internal communication system of a plant through graph theory for a better understanding of the electrical activity in a plant and its interpretation.
  • 2 papers accepted at ISAAC 2022 in Seoul (South Korea)

    Two papers got accepted at the ISAAC 2022 conference which will take place in Seoul (South Korea) in December 2022. Congratulations to all the co-authors of the two papers!


    • Finding Matching Cuts in H-Free Graphs, F. Lucke, D. Paulusma, B. Ries, accepted at ISAAC 2022 (available on arxiv)
    • Locally checkable problems parameterized by clique-width, N. Baghirova, C. Gonzalez, B. Ries, D. Schindl, accepted at ISAAC 2022 (available on arxiv)
  • Interview on Operations Research

    Through an initiative of the Faculty of Management, Economics and Social Sciences, Prof. Bernard Ries was interviewed on what exactly OR is, where it can be used and applied. Check out the video here!

  • Jérôme De Boeck joins our group for 1 year!

    Jérôme De Boeck will join our team from March 2022 on for one year. He will work as a senior researcher on our project funded by the SBB Research Fund. Welcome Jérôme!

  • Project funded by SBB Research Fund

    Our project Train crew assignment to activity segments got accepted for a one-year-funding period by the SBB Research Fund! David Schindl will take the lead of this project!

  • Carolina Lucia Gonzalez @DS&OR with UNIFR grant!

    In February 2022, Carolina will join the team again for 5 onths with a grant from UNIFR! Looking forward to having you again among us Carolina!

  • Manuel Barroso joins our group for 3 months!

    Manuel Barroso will join our team as junior researcher from January 2022 on for 3 months to work on our Innosuisse project! Welcome Manuel!

  • August 21: Paper accepted in Discrete Applied Mathematics

    Our paper "Reducing the domination number of P3 + kP2-free graphs via one edge contraction" E. Galby, F. Mann, B. Ries, has been accepted in Discrete Applied Mathematics!

  • Elise Bangerter joins our group for 6 months!

    On July 1st, 2021 Elise Bangerter joins our group for 6 months as a "sous-assistante"! Welcome Elise!

  • Carolina Lucia Gonzalez @DS&OR as visiting researcher!

    Carolina Lucia Gonzalez from the University of Buenos Aires is visiting our group during two months (May, June 2021)! Welcome Carolina!

  • Meritxell Pacheco Paneque joins DS&OR in January 2021 as Senior Researcher

    On January 2021, Dr. Meritxell Pacheco Paneque joins our group as Senior Researcher to work on our Innosuisse project on efficient and sustainable waste collection. Meritxell recently finished her PhD at EPFL's Transport and Mobility Laboratory. We are looking forward to welcoming here soon here in Fribourg!

  • September 20: Paper accepted in Discrete Mathematics

    Our paper "Reducing the domination number of graphs via edge contractions and vertex deletions" E. Galby, P. T. Lima, B. Ries, has been accepted in Discrete Mathematics and is available via Open Access here!

  • July 20: Paper accepted in Discrete Applied Mathematics

    Our paper "Semitotal Domination: New hardness results and a polynomial-time algorithm for graphs of bounded mim-width", E. Galby, A. Munaro, B. Ries, has been accepted in Discrete Applied Mathematics. This work has been done mainly while Andrea Munaro was a postdoctoral research fellow in our group!

  • Esther Galby defended her PhD thesis successfully!

    Latest publications

    Congratulations to Esther who defended her PhD tehsis successfully on June 29, 2020. The jury was impressed by her work and her presentation. Well done Esther!

  • Felicia Lucke and Narmina Baghirova will join our group in September 2020!

    Felicia Lucke, currently doing her Master thesis at the University of Ulm (Germany), and Narmina Baghirova, currently doing her Master thesis at the University of Primorska (Slovenia), will both join our group as PhD students in September 2020. We are looking forward to welcoming them!

  • Jan 2020: Paper accepted in Theoretical Computer Science!

    Our paper "CPG graphs: some structural and hardness results", E. Galby, A. Munaro, B. Ries, has been accepted in Theoretical Computer Science. This work has been done mainly while Andrea Munaro was a postdoctoral research fellow in our group!

  • Maria Grazia Speranza: Docteure Honoris Causa of the University of Fribourg

    During the Dies Academicus 2019, Maria Grazia Speranza was given the title of Docteure Honoris Causa from the Faculty of Management, Economics and Social Sciences. An interview (in italian) as well as some pictures from teh ceremony can be found here.

  • Sept 2019: Felix Mann joins our group

    On Sept 1st, 2019, Felix Mann joined our group as PhD student.  Welcome Felix!

  • Aug 2019: Zakir Deniz joins DS&OR

    Zakir Deniz joins our group as a postdoc for 4 months! Welcome Zakir!

  • June 2019: Paper accepted at MFCS 2019!

    Our paper "Reducing the domination number of graphs via edge contractionsE. Galby, P.T. Lima, B. Ries" has been accepted at the MFCS conference 2019! These results were obtained while Paloma de Lima was visiting our University.

  • June 2019: Paper accepted in Discrete Mathematics!

    Our paper "Detecting strong cliques, A. Hujdurovic, M. Milanic, B. Ries" has been accepted for publication in Discrete Mathematics! These results were obtained while B. Ries was visiting M. Milanic and A. Hujdurovic in Koper (Slovenia).

  • Feb 2019: Paper accepted in Information processing Letters!

    Our paper "Classifying k-edge colouring for H-free graphs, E. Galby, P. T. Lima, D. Paulusma, B. Ries" just appeared in Information Processing Letters! These results were obtained while Paloma Lima and Daniel Paulusma were visiting our group in 2018!

  • Feb 2019: David Schindl joins DS&OR for five years!

    David Schindl, maître d'enseignement at HEG Geneva, will join our group on February 1st, 2019 for five years. He will be working at 40% as a maître assistant and collaborate with us on several projects. Furthermore, he will be giving the lecture Graph Theory & Applications from 2019 on. Welcome David!