Dominique de Werra
Dominique de Werra was born in Switzerland in 1942. He graduated in physical engineering at EPFL in 1965, and in 1969, a doctorate in technical sciences. From 1969 to 1971 he was professor at Waterloo University (Canada) in the Management Sciences department. He has been a visiting professor in various European and American High Schools. In 1971 he became professor of Operations Research in Mathematics at EPFL. In 1990, he was appointed Vice President of EPFL and in addition, he became Director of training in autumn 1993. His research focuses on discrete mathematics (combinatorial optimization, graph theory, algorithms, etc.) and their applications to industrial and informatics technology. He has participated and directed several interdisciplinary projects in production, distribution, energy and scheduling. His work leads in particular to the time management problem and specifically to calendar management for important projects (sports, education, etc.). In 1987-1988, he chaired the EURO association which encompasses the Operational Research in Europe. He is Dr. h.c. of Paris University and Ecole Polytechnique in Poznan, and he was the winner of the European gold medal (EURO) of Operational Research in 1995. In March 2000 he was appointed Dean of International Affairs.
2025
Conference Papers
Minimizing breaks in incomplete round-robin tournaments
2025. 13 Latin American Algorithms, Graphs, and Optimization Symposium (LAGOS 2025), Buenos Aires, Argentina, 2025-11-10 - 2025-11-14. p. 94 - 101. DOI : 10.1016/j.procs.2025.10.285.Book Chapters
Metaheuristics for Problems in Sports Scheduling
Handbook of Heuristics; Cham: Springer Nature Switzerland, 2025. p. 1 - 30.2023
Journal Articles
A tutorial on graph models for scheduling round-robin sports tournaments
International Transactions In Operational Research. 2023. DOI : 10.1111/itor.13290.Books
Combinatorial Models for Scheduling Sports Tournaments
Cham: Springer International Publishing, 2023.Book Chapters
Leagues, Tournaments, and Schedules
Combinatorial Models for Scheduling Sports Tournaments; Cham: Springer Nature, 2023. p. 1 - 20.Metaheuristics and Local Search
Combinatorial Models for Scheduling Sports Tournaments; Cham: Springer Nature, 2023. p. 57 - 98.Combinatorial Structures
Combinatorial Models for Scheduling Sports Tournaments; Cham: Springer Nature, 2023. p. 21 - 56.Integer Programming Approaches
Combinatorial Models for Scheduling Sports Tournaments; Cham: Springer Nature, 2023. p. 99 - 115.2022
Journal Articles
The micro-world of cographs
Discrete Applied Mathematics. 2022. DOI : 10.1016/j.dam.2021.11.004.2021
Journal Articles
Recoloring subgraphs of K-2n for sports scheduling
Theoretical Computer Science. 2021. DOI : 10.1016/j.tcs.2021.03.029.2020
Journal Articles
Letter graphs and geometric grid classes of permutations: Characterization and recognition
Discrete Applied Mathematics. 2020. DOI : 10.1016/j.dam.2020.01.038.Minimal graphs for 2-factor extension
Discrete Applied Mathematics. 2020. DOI : 10.1016/j.dam.2019.11.022.Conference Papers
The Micro-world of Cographs
2020. 31st International Workshop on Combinatorial Algorithms (IWOCA 2020), Bordeaux, France, 2020-06-08 - 2020-06-10. p. 30 - 42. DOI : 10.1007/978-3-030-48966-3_3.Book Chapters
Les expériences de l’EPFL dans l’international
The Many Facets of International Education of Engineers = Les Multiples Facettes de la Formation Internationale des Ingénieurs : Proceedings of the International Conference SEFI 2000, Paris, France, 6-8 September 2000 / edited by Jean Michel.; CRC Press, 2020.2018
Conference Papers
Letter Graphs and Geometric Grid Classes of Permutations: Characterization and Recognition
2018. 28th International Workshop on Combinational Algorithms (IWOCA), Newcastle, AUSTRALIA, Jul 17-21, 2017. p. 195 - 205. DOI : 10.1007/978-3-319-78825-8_16.2016
Conference Papers
Minimal reinforcement of edges: a problem of reliability in graphs
2016. 42nd International Workshop on Graph-Theoretic Concepts in Computer Science (WG 2016), Bogazici University, Istanbul, Turkey, 2016-06.Reviews
Edge coloring: A natural model for sports scheduling
European Journal of Operational Research. 2016. DOI : 10.1016/j.ejor.2016.03.038.2015
Journal Articles
Combinatorics and Algorithms for Augmenting Graphs
Graphs and Combinatorics. 2015. DOI : 10.1007/s00373-015-1660-0.Conference Papers
Minimal graphs for matching extensions: an optimisation problem in a reliability context
2015. Kwansei Branch of Japanese O. R. Society (invited seminar), Kwansei Gaku in University, Osaka, 2015-07.Sports Scheduling: a challenging playground
2015. International Scheduling Symposium, Kobe, Japan, 2015-07.Books
Operations Research and Enterprise Systems: 4th International Conference, ICORES 2015, Lisbon, Portugal, January 10-12, 2015, Revised Selected Papers
Cham: Springer International Publishing, 2015.Book Chapters
Chromatic scheduling
Topics in Chromatic Graph Theory; Cambridge University Press, 2015. p. 255 - 276.2014
Journal Articles
Combinatorial Optimization [Preface]
DISCRETE APPLIED MATHEMATICS. 2014. DOI : 10.1016/j.dam.2013.11.011.Conference Papers
Transform to simplify
2014. Congress Graphsand Decisions, Luxembourg, 2014-10.Des jeux discrets qui finissent en des salons particuliers
2014. Conférence Université Libre de Bruxelles, Bruxelles, 2014-03.Book Chapters
Graph Coloring Problems
Paradigms of Combinatorial Optimization: Problems and New Approaches; Wiley Blackwell, 2014. p. 265 - 310.2013
Conference Papers
Matching Expansion: a problem of reliability
2013. Seminar Universitätder Bundeswehr München, München, 2013-12.Grouping processors in open shop scheduling
2013. Seminar ESSEC (2013), Paris, 2013-04.Graph coloring and sports scheduling: keynote address
2013. MathSportInternational, Leuven, 2013-06.Book Chapters
Graph Coloring Problems
Paradigms of Combinatorial Optimization: Problems and New Approaches; John Wiley and Sons, 2013. p. 265 - 310.2012
Journal Articles
A note on chromatic properties of threshold graphs
Discrete Mathematics. 2012. DOI : 10.1016/j.disc.2012.01.036.Conference Papers
(p,q) - Choosability of Grid Graphs
2012. Annual International Conference on Computational Mathematics, Computational Geometry & Statistics (2012(, 2012. DOI : 10.5176/2251-1911_cmcgs57.Some combinatorial optimization problems in a conflict situation
2012. 33th Annual Conference of the Sociedad de Estadistica e Investigacion Operativa (SEIO), Madrid, 2012-04.Some basic models for multiprocessor scheduling
2012. CLAIO-SBPO meeting 2012, Rio de Janeiro, 2012-09.Literature with constraints: an exercise of composition following the French OULIPO
2012. GO VIII Conference 2012, Leukerbad, Switzerland, 2012-08.Some graph problems arising in elementary robotics
2012. ICORES, First International Conference on Operations Researchand Enterprise Systems, Vilamoura (Portugal, 2012-02.Optimization problems related to blockers and transversals in graphs
2012. ORSC Annual Meeting 2012, Shenyang (Mandchuria), 2012-10.On some chromatic properties of threshold graphs and signed graphs
2012. Mathematics Institute of Shanghai Jiaotong University (2012), Jiaotong, 2012-10.Some combinatorial problems in multiprocessor scheduling
2012. Academy of Mathematicsand Systems Science (2012), Beijing, 2012-10.Book Chapters
Swiss Operations Research Society (Schweizerische Vereinigung Für Operations Research/Association Suisse Pour La Recherche Operationelle/Associazione Svizzera Di Ricerca Operativa)
Wiley Encyclopedia of Operations Research and Management Science; Wiley, 2012.2011
Journal Articles
Minimum d-Transversals of Maximum-Weight Stable Sets in Trees
Electronic Notes in Discrete Mathematics. 2011. DOI : 10.1016/j.endm.2011.09.022.Minimum d-blockers and d-transversals in graphs
Journal Of Combinatorial Optimization. 2011. DOI : 10.1007/s10878-010-9334-6.The mathematics of Peter L. Hammer (1936-2006): graphs, optimization, and Boolean models
Annals Of Operations Research. 2011. DOI : 10.1007/s10479-011-0913-4.Conference Papers
An introduction to Chromatic Scheduling
2011. COPIOS, 3rd Peruvian Congress on Operations Researchand Systems, Lima, 2011-11.On some problems of optimization in graphs
2011. COPIOS, 3rd Peruvian Congress on Operations Researchand Systems, Lima, 2011-11.On three rather simple questions related to graphs
2011. Conférence Université Fédérale de Rio de Janeiro (2011), Rio de Janeiro, Brésil, 2011-04.Une brève méditation sur St Sébastien, St Laurent et certains graphes
2011. ROADEF 2011, St Etienne, France, 2011-03.Une introduction molle à la peinture de graphes avec des applications répétées
2011. Séminaire Université de Fribourg (2011), Fribourg, 2011-02.A few questions related to colorings in threshold and in grid graphs
2011. Colloquium on Discrete mathematics (2011), Université de Graz, Autriche, 2011-09.Variations on blockers and transversals
2011. LAGOS 2011, Bariloche, Argentine, 2011-04.2010
Journal Articles
Split-critical and uniquely split-colorable graphs
Discrete Mathematics And Theoretical Computer Science. 2010. DOI : 10.46298/dmtcs.484.Blockers and transversals in some subclasses of bipartite graphs: When caterpillars are dancing on a grid
Discrete Mathematics. 2010. DOI : 10.1016/j.disc.2009.08.009.A projective algorithm for preemptive open shop scheduling with two multiprocessor groups
Operations Research Letters. 2010. DOI : 10.1016/j.orl.2009.10.007.On the use of graphs in discrete tomography
Annals Of Operations Research. 2010. DOI : 10.1007/s10479-009-0649-6.Conference Papers
Blocking and hitting problems in Chromatic Scheduling
2010. New Challenges in Scheduling (2010), Fréjus, 2010-09.On graph transformations preserving the stability number
2010. Séminaire Technical University Poznan (2010), Pologne, 2010-04.Book Chapters
Les mathématiques appliquées à l'École polytechnique de Lausanne
math.ch/100 Schweizerische Mathematische Gesellschaft – Société Mathématique Suisse – Swiss Mathematical Society 1910 - 2010; Zurich: European Mathematical Society, 2010. p. 241 - 245.Weighted Edge Coloring
Combinatorial Optimization and Theoretical Computer Science: Interfaces and Perspectives: 30th Anniversary of the LAMSADE; Wiley-ISTE, 2010. p. 291 - 317.Complexity and Approximation Results for the Min Weighted Node Coloring Problem
Combinatorial Optimization and Theoretical Computer Science: Interfaces and Perspectives: 30th Anniversary of the LAMSADE; Wiley-ISTE, 2010. p. 259 - 289.2009
Journal Articles
A Magnetic Procedure for the Stability Number
Graphs And Combinatorics. 2009. DOI : 10.1007/s00373-010-0886-0.Graph coloring with cardinality constraints on the neighborhoods
Discrete Optimization. 2009. DOI : 10.1016/j.disopt.2009.04.005.Degree-constrained edge partitioning in graphs arising from discrete tomography
Journal of Graph Algorithms and Applications. 2009. DOI : 10.7155/jgaa.00178.Conference Papers
A magnetic algorithm for a maximum stable set in a graph
2009. INOC 2009, Pisa, Italia, 2009-04.2008
Journal Articles
Preemptive open shop scheduling with multiprocessors: polynomial cases and applications
Journal Of Scheduling. 2008. DOI : 10.1007/s10951-007-0050-8.A tutorial on the use of graphs in discrete tomography
4OR. 2008. DOI : 10.1007/s10288-008-0077-5.Addendum to "Bicolored matchings in some classes of graphs"
Graphs and Combinatorics. 2008. DOI : 10.1007/s00373-008-0771-2.Construction of balanced sports schedules using partitions into subleagues
Operations Research Letters. 2008. DOI : 10.1016/j.orl.2007.09.007.Polar cographs
Discrete Applied Mathematics. 2008. DOI : 10.1016/j.dam.2007.08.025.On two coloring problems in mixed graphs
European Journal of Combinatorics. 2008. DOI : 10.1016/j.ejc.2007.03.006.On a graph coloring problem arising from discrete tomography
Networks. 2008. DOI : 10.1002/net.20218.Conference Papers
Réductions de graphes d’inspiration pseudobooléenne
2008. Séminaire au GERAD, Ecole Polytechnique de Montréal (2008), Canada, 2008-09.Timetabling and discrete tomography
2008. Congrès ECCO XXI (2008), Dubrovnik, Croatie, 2008-05.Graph transformations and pseudo-Boolean operations
2008. Congrès IFORS 2008, Johannesburg, Afrique du Sud, 2008-07.Sur quelques problèmes de tomographie discrète
2008. Séminaire Ecole doctorale - Ecole Polytechnique Fédérale de Lausanne, EPFL (2008), Lausanne, 2008-04.Transformations of graphs and pseudo-Boolean optimization
2008. Séminaire invité au Memorial University, St John’s - Département des Mathématiques (2008), Canada, 2008-09.On the image reconstrution problem in discrete tomography
2008. New Challenges in Scheduling Theory (CIRM 2008), Marseille-Luminy, 2008-05.Polarity of chordal graphs
2008. 5th International Conference on Graphs and Optimization, Leukerbad, SWITZERLAND, Aug, 2006. p. 2469 - 2479. DOI : 10.1016/j.dam.2008.01.026.Finding Hamiltonian circuits in quasi-adjoint graphs
2008. 5th International Conference on Graphs and Optimization, Leukerbad, SWITZERLAND, Aug, 2006. p. 2573 - 2580. DOI : 10.1016/j.dam.2008.03.014.Theses
Some coloring and walking problems in graphs
Lausanne, EPFL, 2008. DOI : 10.5075/epfl-thesis-4090.2007
Journal Articles
Weighted stability number of graphs and weighted satisfiability: the two facets of pseudo-Boolean optimization
Annals of Operations Research. 2007. DOI : 10.1007/s10479-006-0101-0.Time slot scheduling of compatible jobs
Journal of Scheduling. 2007. DOI : 10.1007/s10951-006-0003-7.Bicolored matchings in some classes of graphs
Graphs and Combinatorics. 2007. DOI : 10.1007/s00373-006-0686-8.Conference Papers
Mixed graph coloring
2007. LAGOS 2007 Graphs & Optimizati on Symposium, Chili, 2007-11.Some Eulerian-looking problems
2007. GO VI Graphs and Optimization (2007), Cademario, Tessin, 2007-08.A DOT in the SPOT or how is Discrete Oriented Tomography related to Specific Packing and Optimization Techniques
2007. Congrès ECCO XX (2007) - Session plénière, Limassol, Chypre, 2007-05.Robotics and chromatic scheduling
2007. MISTA conference (2007), Paris, 2007-08.Some variations on colorings of graphs
2007. Technische Universität Graz (2007), Graz (Austria), 2007-01.Variations sur divers problèmes de tomographie discrète
2007. Congrès FRANCORO-ROADEF (2007), Grenoble, 2007-02.Beyond chromatic scheduling and discrete tomography
2007. Séminaire Universität der Bundeswehr (2007), Munich, 2007-06.Theses
Variations of coloring problems related to scheduling and discrete tomography
Lausanne, EPFL, 2007. DOI : 10.5075/epfl-thesis-3968.Book Chapters
Problèmes de coloration dans les graphes
Optimisation Combinatoire; Paris: Hermès Science, 2007. p. 95 - 141.2006
Journal Articles
Three is easy, two is hard: open shop sum-batch scheduling problem refined
Operations Research Letters. 2006. DOI : 10.1016/j.orl.2005.07.006.Construction of sports schedules with multiple venues
Discrete Applied Mathematics. 2006. DOI : 10.1016/j.dam.2005.03.011.On the approximation of Min Split-coloring and Min Cocoloring
Journal of Graph Algorithms and Applications. 2006.Good and nice colorings of balanced hypergraphs
Discrete Mathematics. 2006. DOI : 10.1016/j.disc.2005.12.044.Locally Restricted Colorings
Discrete Applied Mathematics. 2006. DOI : 10.1016/j.dam.2005.05.012.Some simple optimization techniques for self-organized public key management in mobile ad hoc networks
Discrete Applied Mathematics. 2006. DOI : 10.1016/j.dam.2005.12.002.Using graphs for some discrete tomography problems
Discrete Applied Mathematics. 2006. DOI : 10.1016/j.dam.2005.07.003.Conference Papers
Chromatic scheduling and discrete tomography
2006. Scheduling in New Emerging Applications (2006), Marseille-Luminy, France, 2006-06.IFORS Distinguished Lecture 2006: Variations and extensions of coloring
2006. Federation of Asia-Pacific Operations Research Societies APORS 2006 Conference, Manila (Philippines), 2006-01.Theses
Generalized vertex coloring problems using split graphs
Lausanne, EPFL, 2006. DOI : 10.5075/epfl-thesis-3629.Reports
Variations of split-coloring in permutation graphs
20062005
Journal Articles
Bicolored matchings in some classes of graphs
Electronic Notes in Discrete Mathematics. 2005. DOI : 10.1016/j.endm.2005.06.033.A hypocoloring model for batch scheduling
Discrete Applied Mathematics. 2005. DOI : 10.1016/j.dam.2004.06.016.A solvable case of image reconstruction in discrete tomography
Discrete Applied Mathematics. 2005. DOI : 10.1016/j.dam.2005.03.006.Partitioning cographs into cliques and stable sets
Discrete Optimization. 2005. DOI : 10.1016/j.disopt.2005.03.003.Path colorings in bipartite multigraphs
European Journal of Operational Research. 2005. DOI : 10.1016/j.ejor.2003.05.007.Variations on the Roy-Gallai Theorem
4OR. 2005.On split-coloring problems
Journal of Combinatorial Optimization. 2005. DOI : 10.1007/s10878-005-4103-7.(p,k)-coloring problems in line graphs
Theoretical Computer Science. 2005. DOI : 10.1016/j.tcs.2005.09.037.Conference Papers
From Ali HamOR to the Duke of DensmORe: a guided tour of combinatorial literature
2005. 30th anniversary of EURO - Plenary session, Brussels, 2005-01.Methods for assigning players to stadiums with patterns
2005. MAPSP 2005, 7th Workshop on Modelsand Algorithmsfor Planning & Scheduling Problems, Siena (Italia), 2005-06.Mauro Picone Lecture: Generalized colorings and chromatic scheduling
2005. Istituto per le Applicazioni del Calcolo, Consiglio Nazionale delle Ricerche (2004-2005), Rome, 2004-2005.Theses
Suboptimal colorings and solution of large chromatic scheduling problems
Lausanne, EPFL, 2005. DOI : 10.5075/epfl-thesis-3363.Book Chapters
Hypergraph coloring by bichromatic exchanges
Graph Theory and Combinatorial Optimization; Springer Verlag, 2005. p. 255 - 264.Reports
Polar cographs
20052004
Journal Articles
On Some Properties of Suboptimal Colorings of Graphs
Networks. 2004. DOI : 10.1002/net.10107.Conference Papers
Quelques idées simples pour des problèmes qui le sont moins
2004. 2004 Conférence francophone de R.O. FRANCORO 4e, Fribourg, 2004-08.Some combinatorial problems of authentication in mobile ad hoc networks
2004. Dagstuhl Seminar on “Scheduling in Computer and Manufacturing Systems” (2004), Dagstuhl, 2004-06.Weighted coloring: on planar bipartite and split graphs: complexity and improved approximation
2004. 15th International Symposium, ISAAC 2004, Hong Kong, China, December 20-22, 2004. p. 896 - 907. DOI : 10.1007/978-3-540-30551-4_76.L’authentification est-elle garantie dans un réseau ad hoc ? Tintin !
2004. Journées franciliennnes de R.O., CNAM (2004), Paris, 2004-03.The hypocoloring problem: complexity and approximability results when the chromatic number is small
2004. 30th International Workshop, WG 2004, Bad Honnef, Germany, June 21-23, 2004. p. 377 - 388. DOI : 10.1007/978-3-540-30559-0_32.Theses
Some combinatorial optimization problems in graphs with applications in telecommunications and tomography
Lausanne, EPFL, 2004. DOI : 10.5075/epfl-thesis-3082.Book Chapters
Applications to timetabling
Handbook of Graph Theory; CRC Press London, 2004. p. 445 - 474.Tabu search
Local Search in Combinatorial Optimization; Princeton University Press, 2004. p. 121 - 136.Colorings and Related Topics
Handbook of Graph Theory; CRC Press, 2004. p. 340 - 483.Reports
Preemptive open shop scheduling with multiprocessors: polynomial cases and applications
2004Color-blind Graphs and Suboptimal Colorings
20042003
Journal Articles
Partitioning the edge set of a bipartite graph into chain packings: complexity of some variations
Linear Algebra and its Applications. 2003. DOI : 10.1016/S0024-3795(02)00691-2.Struction revisited
Discrete Applied Mathematics. 2003. DOI : 10.1016/S0166-218X(03)00388-3.Using stable sets to bound the chromatic number
Information Processing Letters. 2003. DOI : 10.1016/S0020-0190(03)00266-7.Colorations de graphes: fondements et applications
RAIRO Operations Research. 2003. DOI : 10.1051/ro:2003013.Variations on the theorem of Birkhoff-von Neumann and extensions
Graphs and Combinatorics. 2003. DOI : 10.1007/s00373-002-0496-6.Conference Papers
Special issue on stability in graphs and related topics
2003. Stability in Graphs and Related Topics (2002), Switzerland, 2002-07-01 - 2002-07-01. p. 1 - 2. DOI : 10.1016/S0166-218X(03)00385-8.Colorations de chemins dans les graphes bipartis
2003. Séminaire du CNAM (2003), Paris, 2003-06.Book Chapters
Constraints of availability in timetabling and scheduling
Practice and Theory of Automated Timetabling IV; Springer Verlag, 2003. p. 3 - 23.2002
Journal Articles
A generalized class-teacher model for timetabling problems
European Journal of Operational Research. 2002. DOI : 10.1016/S0377-2217(01)00342-3.Complexity of some special types of timetabling problems
Journal of Scheduling. 2002. DOI : 10.1002/jos.97.Circular-arc graph coloring: on chords and circuits in the meeting graph
European Journal of Operational Research. 2002. DOI : 10.1016/S0377-2217(01)00058-3.Conference Papers
Tomography: Exploring the Analogies for Timetabling Optimisation
2002. Congress ECCO XV (2002), Lugano, 2002-05.Nouvelles bornes du nombre chromatique
2002. Séminaire du DEA en Optimisation Combinatoire, Université de Paris 6 (2002), Paris, 2002-03.Scheduling and weighted colorings
2002. Congrès international de Programmation Mathématique (2002), Université de Shanghai (Chine), 2002-12.Chromatic properties of balanced (0, +1,-1)-matrices
2002. Séminaire Combinatorial Optimization, Math. Forschungsinstitut (2002), Oberwolfach, Allemagne, 2002-11.Some scheduling models for school timetabling and multiprocessor scheduling
2002. Congrès CO2002, CNAM, Paris, 2002-04.Une propriété chromatique des matrices à coefficients 0 1+|-1 équilibrées
2002. Séminaire du LAMSADE - Université de Paris-Dauphine (2002), Paris-Dauphine, 2002-03.Weighted colorings and batch scheduling
2002. Dagstuhl Seminar on Scheduling in Computerand Manufacturing Systems (2002), Dagstuhl, Allemagne, 2002-06.Contraintes de parité dans les décompositions eulériennes de graphes orientés
2002. Journée scientifique en l’honneur de Claude Benzaken, INPG, Grenoble, 2002-09.Où l’on en verra de toutes les couleurs... et avec des arguments de poids !
2002. Journées franciliennes de recherche opérationnelle. Session plénière d’ouverture (2002), Paris, 2002-10.CATS and RATS : (Constraints of Availability in Timetabling and Scheduling and Reconstruction of Arrays in Tomographic Scanning)
2002. Congrès PATAT (2002), Gent, Belgique, 2002-08.Quelques problèmes d’optimisation chromatique
2002. 4e Congrès ROADEF (2002), Paris, 2002-02.Quelques extensions et variations sur le théorème de Birkhoff-vonNeumann
2002. Séminaire du DEA en Optimisation Combinatoire, Université de Paris 6 (2002), Paris, 2002-04.Weighted node coloring: when stable sets are expensive
2002. 28th International Workshop, WG 2002, Český Krumlov, Czech Republic, June 13–15, 2002. p. 113 - 125. DOI : 10.1007/3-540-36379-3_11.Book Chapters
Connectivity, transitivity and chromaticity: the pioneering work of Bernard Roy in Graph Theory
Aiding Decisions with Multiple Criteria; Kluwer Academic Publishers, 2002. p. 23 - 42.2001
Conference Papers
Some graph-theoretical models for open shop problems with mutliprocessors
2001. Perspectives en ordonnancement pour les systèmes parallèles et distribués, Université de Marseille-Luminy (France), 2001-10.Quelques variations chromatiques sur des sommets colorés
2001. 3e Congrès FRANCORO: Colloque international francophone de recherche opérationnelle (2001), Québec (Can da), 2001-05.Combinatorial models for time slot scheduling problems
2001. Séminaire à l’Université de Bonn (2001), Bonn, Allemagne, 2001-11.Une suite de variations chromatiques
2001. INRIA 2001, Rocquencourt (France), 2001-02.Colorations et orientations
2001. Séminaire du LAMSADE, Université de Paris Dauphine (2001), Paris, 2001-02.Some bounds on the chromatic number
2001. ECCO Conference on Combinatorial Optimization (2001), Université de Bonn (Allemagne), 2001-05 - 2001-06.Modèles de graphes et d’hypergraphes pour des problèmes d’emploi du temps
2001. Séminaire de Mathématiques discrètes et sciences sociales du Centre d’Analyse et de Mathématiques Sociales à Paris (2001), Paris, 2001-01.Chromatic optimization problems: some models for scheduling and timetabling
2001. ORP3 Meeting (2001) - EURO Université de Paris-Dauphine (France), Paris-Dauphine, 2001-09.Colorations, orientations et chaînes panchromatiques dans les graphes
2001. GERAD, Ecole des HEC, Montréal, Québec (Canada), 2001-05.A quoi peuvent bien servir les modèles de coloration dans les graphes ?
2001. Sémainaire dans le cadre du Colloque "Optimisation, Jeux et Applications" de l’Equipe Combinatoire - Université de Paris 6, Paris, 2001-02.2000
Journal Articles
Variations on the theorem of Birkhoff-von Neumann and extensions
Electronic Notes in Discrete Mathematics. 2000. DOI : 10.1016/S1571-0653(05)80135-0.Feasible edge colorings of trees with cardinality constraints
Discrete Mathematics. 2000. DOI : 10.1016/S0012-365X(00)00006-6.Conference Papers
Variations on the theorem of Birkhoff-von Neumann
2000. Colloque intenational de Théorie des Graphes (2000), Marseille-Luminy (France), 2000-08.Modèles de graphes et d’hypergraphes pour des problèmes d’emploi du temps et d’ordonnancement
2000. Séminaire au GERAD Ecole des HEC, Montréal, Montréal (Canada), 2000-10.Some Models for Timetabling problems
2000. GO IV Graphs and Optimization (2000), Leukerbad (Suisse), 2000-08.Some extensions of graph-theoretical models for timetabling problems
2000. Séminaire avec le Prof. Bruno Simeone de l’Université de Rome (2000), Rome, Italie, 2000-10.1999
Journal Articles
On perfectness of sums of graphs
Discrete Mathematics. 1999. DOI : 10.1016/S0012-365X(98)00168-X.On some properties of DNA graphs
Discrete Applied Mathematics. 1999. DOI : 10.1016/S0166-218X(99)00109-2.Restricted graph coloring: some mathematical programming models
CRM Processings & Lectures Notes. 1999.On a graph-theoretical model for cyclic register allocation
Discrete Applied Mathematics. 1999. DOI : 10.1016/S0166-218X(99)00105-5.On a multiconstrained model for chromatic scheduling
Discrete Applied Mathematics. 1999. DOI : 10.1016/S0166-218X(99)00019-0.Book Chapters
Restricted graph coloring: some mathematical programming models
CRM Processings & Lecture Notes; 1999. p. 135 - 148.1998
Conference Papers
Une vie sans contraintes serait peu colorée
1998. 1er Congrès de la Société Française de Recherche Opérationnelle (1998), Paris (France), 1998-01.Locally and globally constr ained coloring problems
1998. ECCO XI (11ème Conférence annuelle du EURO Chapter on Combinatorial Optimizaton), Copenhague (Danemark), 1998-05.1997
Journal Articles
What is my objective function?
European Journal of Operational Research. 1997. DOI : 10.1016/s0377-2217(96)00393-1.The combinatorics of timetabling
European Journal of Operational Research. 1997. DOI : 10.1016/S0377-2217(96)00111-7.Mixed graphs colorings
Mathematical Methods of Operations Research. 1997. DOI : 10.1007/BF01194253.Preassignment requirements in chromatic scheduling
Discrete Applied Mathematics. 1997. DOI : 10.1016/S0166-218X(97)82776-X.Restricted colorings models for timetabling
Discrete Mathematics. 1997. DOI : 10.1016/S0012-365X(96)00208-7.Conference Papers
Sur les colorations de graphes orientés
1997. Séminaire au Laboratoire d'Informatique de Marseille (1997), Marseille (France), 1997-05.Mathematical programming models for various extensions of colorings
1997. Séminaire Université de Pisa (1997), Pisa, Italia, 1997-04.Optimizing compilers via graph coloring models
1997. Colloque "Graph Coloringand Applications" Centre de Recherches Mathématique, Université de Montréal (1997), Montréal (Canada), 1997-05.Circular arc graph coloring and compilers
1997. Séminaire Université de Pisa (1997), Pisa, Italia, 1997-04.Some Combinatorial Problems Occurring in the Optimization of Compilers
1997. Séminaire Université de Cologne (1997), Cologne (Allemagne), 1997-12.Some models for optimizing compilers
1997. Séminaire Université de Bologna (1997), Bologne, Italia, 1997-04.Some coloring models for optimizing compilers
1997. Conférence EURO 15- INFORMS 34, Barcelone (Espagne), 1997-07.Multiconstrained chromatic scheduling problem
1997. Mathematische Optimierung (1997), Oberwolfach (Allemagne), 1997-01.Restricted coloring models
1997. Séminaire Université de Bologna (1997), Bologne, Italia, 1997-04.Nesticity
1997. DIMACS Workshop, November 13-15, 1996. p. 225 - 232. DOI : 10.1090/dimacs/037/14.Reviews
Lectures on mathematical programming ismp97. Preface
Mathematical Programming. 1997. DOI : 10.1007/bf02614307.Book Chapters
Tabu Search
Local search in combinatorial optimization; N.Y.: John Wiley & Sons Ltd, 1997. p. 121 - 136.1996
Journal Articles
Restrictions and pre-assignments in preemptive open shop scheduling
Discrete Applied Mathematics. 1996. DOI : 10.1016/0166-218X(95)00055-V.Open shop scheduling with some additional constraints
Graphs and Combinatorics. 1996. DOI : 10.1007/BF01858447.Deadline scheduling of multiprocessor tasks
Discrete Applied Mathematics. 1996. DOI : 10.1016/0166-218X(95)00020-R.Conference Papers
Modèles chromatiques pour l'ordonnancement en robotique et en horairique
1996. Séminaire Université de Paris Dauphine (1996), Paris, 1996-01.Chromatic scheduling with disjunctive and precedence constraints
1996. Séminaire Université Libre de Bruxelles (1996), Bruxelles (Belgique), 1996-11.Book Chapters
Some combinatorial models for course scheduling
Practice and Theory of Automated Timetabling. PATAT 1995; Springer Verlag, 1996. p. 296 - 308.1995
Journal Articles
A chromatic scheduling model with costs
IISE Transactions. 1995. DOI : 10.1080/07408179508936730.Conference Papers
Some remarks about OR
1995. 10th EURO Gold Medal, EURO XIV, Jerusalem, Israel, 1995-07.Some combinatorial models for course scheduling
1995. 1st International Conference on the Practice and Theory of Automated Timetabling (1995), Edinburgh, Scotland, 1995-08.Some list coloring problems with a scheduling flavour
1995. 5th International Symposium on Graph Theory and Combinatorics, Marseille-Luminy, France, 1995-09.0,1-programming, systems of distinct representatives and graph coloring
1995. Mathematische Optimierung (1995), Oberwolfach, Germany, 1995-01.Mathematical Programming and Chromatic Scheduling
1995. Séminaire Université de Bonn (1995), Bonn, Allemagne, 1995-12.A tutorial on Tabu Search
1995. AIRO '95 Annual Conference , Operational Research Society of Italy, Ancone, Italia, 1995-09.Theses
Heuristiken für kombinatorische Optimierung und semantische Bildinhaltserkennung mit Techniken der künstlichen Intelligenz
Lausanne, EPFL, 1995. DOI : 10.5075/epfl-thesis-1333.Méthodes d'optimisation combinatoire pour des problèmes de graphes
Lausanne, EPFL, 1995. DOI : 10.5075/epfl-thesis-1315.Book Chapters
Some graph coloring models for cyclic scheduling
Scheduling Theory and its Applications; N.Y.: John Wiley & Sons Ltd, 1995. p. 227 - 239.1994
Journal Articles
Scheduling Periodic Jobs Compactly Within A Fixed Time Period In Open Shops
INFOR: Information Systems and Operational Research. 1994. DOI : 10.1080/03155986.1994.11732242.Scheduling periodic jobs compacly within a fixed time period in open shops
INFOR: Information Systems and Operational Research. 1994.Extensions of colorings models for scheduling purposes
European Journal of Operational Research. 1994. DOI : 10.1016/0377-2217(96)00013-6.A discrete model for studying existence and uniqueness of solution sin non linear resistive circuits
Discrete Applied Mathematics. 1994. DOI : 10.1016/0166-218X(92)00152-C.A review of combinatorial problems arising in feed forward neural network design
Discrete Applied Mathematics. 1994. DOI : 10.1016/0166-218X(92)00184-N.Chordless paths, odd holes and kernels in graphs without m-obstructions
Journal of Algorithms. 1994. DOI : 10.1006/jagm.1994.1031.A sufficient condition to equitable edge colorings of simple graphs
Discrete Mathematics. 1994. DOI : 10.1016/0012-365X(94)90112-0.Non preemptive open shop with restricted processing times
Zeitschrift für Operations Research. 1994. DOI : 10.1007/BF01415583.Chromatic scheduling and frequency assignment
Discrete Applied Mathematics. 1994. DOI : 10.1016/0166-218X(94)90207-0.Scheduling independent multi processor tasks on a uniform k-processor system
Parallel computing. 1994. DOI : 10.1016/0167-8191(94)90110-4.On an optimization problem occurring in FMMs: a hypergraph theoretical formulation
Discrete Applied Mathematics. 1994. DOI : 10.1016/0166-218X(94)90002-7.Conference Papers
Chromatic Scheduling
1994. 5 lectures given at Università di Pisa (1994), Pisa, Italia, 1994-01.Mathematical Programming Aspects of Chromatic Scheduling
1994. ECCO VII, Milan (Italy), 1994-02.Production Scheduling and Timetabling: a model-oriented tutorial
1994. EURO XIII- Semi-Plenary Session (1994), Glasgow (Scotland), 1994-07.Colorings with preassignments
1994. Graphs & Optimization II, Leukerbad (Switzerland), 1994-08.Preassignments in Chromatic Scheduling
1994. 18th Symposium on Operations Research (1993), Cologne, 1993-09-01 - 1993-09-03. p. 526 - 528. DOI : 10.1007/978-3-642-46955-8_134.Theses
From finding maximum feasible subsystems of linear systems to feedforward neural network design
Lausanne, EPFL, 1994. DOI : 10.5075/epfl-thesis-1282.1993
Journal Articles
Graph endpoint coloring and distributed processing: A scheduling problem in distributed processing
Networks. 1993. DOI : 10.1002/net.3230230203.Addendum: some preemptive open shop scheduling problems with a renewable or a non renewable resource
Discrete Applied Mathematics. 1993. DOI : 10.1016/0166-218X(93)90172-K.Some graph-theoretical models for scheduling in automated production systems
Networks. 1993. DOI : 10.1002/net.3230230803.The cyclic compact open-shop scheduling problem
Discrete Mathematics. 1993. DOI : 10.1016/0012-365X(93)90171-O.On the stability number of AH-free graphs
Journal of Graph Theory. 1993. DOI : 10.1002/jgt.3190170107.The burrow system of the fossorial form of the water vole (arvicola Terrestris L.)
Mammalia. 1993. DOI : 10.1515/mamm.1993.57.3.423.Edge-chromatic scheduling with simultaneity constraints
SIAM Journal on Discrete Mathematics. 1993. DOI : 10.1137/0406048.EPCOT : an Efficient Procedure for Coloring Optimally with Tabu search
Computers & Mathematics with Applications. 1993. DOI : 10.1016/0898-1221(93)90279-5.Conference Papers
Coloring mixed graphs
1993. 18. Symposiumüber Operations Research, Cologne (Allemagne), 1993-09.Open shop scheduling and some variations on simultaneity requirements
1993. ECCO VI Meeting, Bruxelles (Belgique), 1993-04.Models and Algorithms for Planning and Scheduling Problem
1993. 1er Colloque international sur l'ordonnancement (1993), Villa Vigoni (Italy), 1993-06.Optimisation combinatoire, productique, transport
1993. AFCET 93. Tutoriel, Versailles (France), 1993-06.Problèmes d'ordonnancement chromatique: les limites des colorations
1993. Séminaire au LAMSADE (1993), Paris (France), 1993-11.Flows and Chromatic Scheduling
1993. Netflow 93, San Miniato (Italy), 1993-10.Theses
Recherches itératives dirigées parallèles
Lausanne, EPFL, 1993. DOI : 10.5075/epfl-thesis-1153.Feedforward boolean neural networks with discrete weights : computational power and training
Lausanne, EPFL, 1993. DOI : 10.5075/epfl-thesis-1157.Elaboration de tournées de véhicules sous contraintes d'accessibilité
Lausanne, EPFL, 1993. DOI : 10.5075/epfl-thesis-1163.1992
Journal Articles
Discrete Applied Mathematics Volume 35, Issue 3, 6 March 1992, Pages 175-176. Foreword
Discrete Applied Mathematics. 1992. DOI : 10.1016/0166-218x(92)90242-3.Cylindrical open shop scheduling: some solvable cases
Vishwa International Journal of Graph Theory. 1992.Basic ideas of Tabu search with an application to traveling salesman and quadratic assignment
Ricerca Operativa. 1992.Some preemptive open shop scheduling problems with a renewable or a nonrenewable resource
Discrete Applied Mathematics. 1992. DOI : 10.1016/0166-218X(92)90245-6.Conference Papers
Operations Research and Engineering
1992. Ecole Polytechnique de Poznan (1992). Remise d'un doctorat h.c., Poznan, Pologne, 1992-12.Some modelling principles for automated production systems
1992. EURO XI I, TIMS XXXI. Tutorial, Helsinki (Finland), 1992-07.Generalized Colorings for Scheduling
1992. Symposium on Combinatorial Optimization (1992), Maastricht (Pays-Bas), 1992-02.Chromatic scheduling
1992. Mathematische Optimierung (1992), Oberwolfach, Germany, 1992-01.Chromatic Scheduling
1992. ECCO V, Graz (Austria), 1992-04.La Recherche Opérationnelle, une science très humaine au carrefour de bien des techniques
1992. Université de Paris-Dauphine. Remise d'un doctorat h.c., Paris (France), 1992-06.Ordonnancement chromatique
1992. Séminaire au Laboratoire d'Automatique et d'Analyse de Systèmes, CNRS (1992), Toulouse (France), 1992-09.Anwendungen der Graphentheorie in Ablauf- und Terminplanung
1992. Seminar Hochschule St-Gallen (1992), St-Gallen, 1992-01.Reviews
Greenberg, H. J., Glover, E: Annals of OR, Vol 21: "Linkages with Artificial Intelligence" (Basel: J. C. Baltzer 1989). [Buchbesprechung]
Operations-Research-Spektrum. 1992. DOI : 10.1007/bf01783520.1991
Journal Articles
A convoy scheduling problem
Discrete Applied Mathematics. 1991. DOI : 10.1016/0166-218X(91)90009-L.A preemptive open shop scheduling problem with one resource
Operations Research Letters. 1991. DOI : 10.1016/0167-6377(91)90080-9.On the use of augmenting chains in chain packings
Discrete Applied Mathematics. 1991. DOI : 10.1016/0166-218X(91)90039-Y.Compact cylindrical chromatic scheduling
SIAM Journal on Discrete Mathmematics. 1991. DOI : 10.1137/0404046.Idendifying mythological scenes with artificial intelligence
Science and Archeology. 1991.Loading problems with tool management in flexible manufacturing systems: a few integer programming models
International Journal of Flexible Manufacturing Systems. 1991. DOI : 10.1007/BF00167526.Conference Papers
Les problèmes de coloration de graphes et leur application en gestion
1991. 700th Birthday of Swiss Confederation - University Laval, Quebec (Canada), Laval (Canada), 1991-03.Quelques modèles pour des problèmes de transport
1991. University of Montreal. Centre de Recherches sur les Transports (1991), Montréal (Canada), 1991-03.Some graph-theoretical models for scheduling
1991. Institute of Applied Mathematics, Academia Sinica (1991), Beijing (China), 1991-08.Graph coloring problems for high technology
1991. Annual Meeting of Italian O.R. Society (1991), Riva del Garda (Italy), 1991-09.Combinatorial Optimisation Problems in Neural Networks
1991. EURO XI Optimisation Combinatoire et Production, Aachen (Germany), 1991-07.Graph-theoretical models in scheduling
1991. Conference on Graph Labellings, Northeastern University (1991), Boston (USA), 1991-03.Some Graph-theoretical models for open shop problems
1991. EURO XI Optimisation Combinatoire et Production, Aachen (Germany), 1991-07.Some variations on open shop scheduling
1991. Seminar at the Prague University (1991), Prague (Tchécoslovaquia), 1991-06.Recent results in chromatic scheduling
1991. APORS 91 - Conference of the Association of Asian-Pacific Operational Research Societies (1991), Beijing (China), 1991-08.Learning problems in neural networks: some optimization techniques
1991. Séminaire de neuroinformatique ETHZ (1991), Zürich (Switzerland), 1991-02.Coloring models for scheduling production systems
1991. Seminar at the Beijing Institute of Technology (1991), Beijing (China), 1991-08.Quelques problèmes de gestion de production
1991. Séminaire de productique. Université de Grenoble (1991), Grenoble (France), 1991-01.Flexible Manufacturing Systems: new problems, new techniques
1991. Seminar at Department Systems Engineering, Shanghai Institute of Mechanical Engineering (1991), Shanghai (China), 1991-09.Open shop scheduling
1991. Seminar "Combinatorial Optimization" (Oberwolfach 1991), Oberwolfach, Germany, 1991-01.Open shop scheduling
1991. Northeastern University (1991), Boston (USA), 1991-03.Modèles de gestion de production
1991. Cours Experts Polytechniques Internationaux (1991), Bulle (Switzerland), 1991-01.Ordonnancement chromatique
1991. Rencontres franco-suisses de R.O. (1991), Paris (France), 1991-09.Resource-constrained open shop scheduling
1991. Seminar at the Beijing Institute of Technology (1991), Beijing (China), 1991-08.Gestion de production et modèles mathématiques
1991. 700th Birthday of Swiss Confederation - University of Montreal (Canada), Montréal (Canada), 1991-02.Theses
Nouvelles approches mathématiques des problèmes de conception et de pilotage des ateliers flexibles
Lausanne, EPFL, 1991. DOI : 10.5075/epfl-thesis-975.Book Chapters
Graph coloring models for scheduling in automated production systems
Proceedings of the second conference of the Association of Asian-Pacific Operational Research Societies APORS; Peking University Press, 1991. p. 26 - 34.1990
Journal Articles
Recognition of a class of unimodular functions
Discrete Applied Mathematics. 1990. DOI : 10.1016/0166-218X(90)90147-5.A note on SS/TDMA, satellite communication
Linear Algebra and its Applications. 1990. DOI : 10.1016/0024-3795(90)90116-T.Scheduling independent two-processor tasks on a uniform duo-processor system
Discrete Applied Mathematics. 1990. DOI : 10.1016/0166-218X(90)90090-Y.The Tabu search metaheuristic: how we used it
Annals of Mathematics and Artificial Intelligence. 1990. DOI : 10.1007/BF01531073.Almost nonpreemptive schedules
Annals of Operations Research. 1990. DOI : 10.1007/BF02248592.TABARIS: an exact algorithm based on Tabu search for finding a maximum independent set in a graph
Computers and Operations Research. 1990. DOI : 10.1016/0305-0548(90)90048-C.A constrained sports scheduling problem
Discrete Applied Mathematics. 1990. DOI : 10.1016/0166-218X(90)90019-9.Conference Papers
Some graph-theoretical models for distributed processing problems
1990. 3rd Meeting of ECCO (EURO Chapter on Combinatorial Optimisation), Barcelona, Spain, 1990-05.Problèmes d'optimisation dans les ateliers flexibles
1990. Journées du Laboratoire d'Informatique de Paris-Nord, L.I.P.N. (1990), Villetaneuse, France, 1990-09.Problèmes d'ordonnancement cyclique
1990. Séminaire au Laboratoire d'Automatique et d'Analyse de Aystèmes LAAS, Toulouse (1990), Toulouse, France, 1990-05.Management and Cyclic Scheduling in Flexible Manufacturing
1990. Systems Research Institute of Academy of Sciences in Warsaw (1990), Warsaw. Poland, 1990-10.Chromatic Scheduling
1990. Colloque "Mathematische Optimierung" (1990), Oberwolfach, R.F.A, 1990-01.Artificial Neural Networks: some discrete optimization problems
1990. Seminar at the University in Bonn. Institute of Discrete Mathematics (1990), Bonn, Allemagne, 1990-12.Problèmes combinatoires en productique et en distributique
1990. Colloque "Les Mathématiques discrètes au service de l'ingénieur" - Association Royale des Ingénieurs sortis de l'U.L.B., Brussels, 1990-05.Some combinatorial problems in manufacturing systems
1990. Seminar at the University of Osnabrück (1990), Osnabrück, 1990-12.Graph-theoretical Models for Restricted Preemptive Scheduling
1990. Colloque "Viewpoints on Optimization" (1990), Grimentz, 1990-09.A scheduling problem in computer networks
1990. Operations Research Conference (1990), Vienna, 1990-08.Cyclic Interval Edge Coloring and Scheduling
1990. Colloque International de Théorie des Graphes et de Combinatoire (1990), Marseille, 1990-07.Restricted preemptive open shop scheduling
1990. Seminar at the Ecole Polytechnique de Poznan (Pologne). Institute of Computer Science (1990), Poznan, 1990-10.Tabu Search and Exact Methods
1990. IFORS Conference. Section Heuristics (1990), Athens, 1990-06.Reviews
A. Gibbons and W. Rytter "Efficient parallel algorithms" (Cambridge University Press, Cambridge, 1988)
European Journal of Operational Research. 1990. DOI : 10.1016/0377-2217(90)90254-9.Theses
Modèles mathématiques pour une gestion efficace des ateliers flexibles
Lausanne, EPFL, 1990. DOI : 10.5075/epfl-thesis-839.Sur quelques problèmes combinatoires relatifs à l'ordonnancement
Lausanne, EPFL, 1990. DOI : 10.5075/epfl-thesis-897.1989
Journal Articles
Tabu search techniques - A tutorial and an application to neural networks
OR Spektrum. 1989. DOI : 10.1007/BF01720782.Generalized edge packings
Mathematical Programming. 1989. DOI : 10.1007/BF01587091.Paths, chains and antipaths
Networks. 1989. DOI : 10.1002/net.3230190109.Discrete Mathematics Volume 74, Issues 1–2, 1989. Foreword
Discrete Mathematics. 1989. DOI : 10.1016/0012-365x(89)90192-1.Connected sequential colorings
Discrete Mathematics. 1989. DOI : 10.1016/0012-365X(89)90197-0.Tabu search: a tutorial and an application to neural networks
OR Spektrum. 1989.Preemptive scheduling with staircase and piecewise linear resource availability
Zeitschrift für Operations Research. 1989. DOI : 10.1007/BF01416077.Odd path packings
European Journal of Operational Research. 1989. DOI : 10.1016/S0195-6698(89)80075-7.An interactive system for constructing timetables on a PC
European Journal of Operational Research. 1989. DOI : 10.1016/0377-2217(89)90269-5.STABULUS: a technique for finding stable sets in large graphs with tabu search
Computing. 1989. DOI : 10.1007/BF02243141.Conference Papers
Somes uses of Tabu Search
1989. Meeting of contact group on O.R. of the FNRB (1989), Brussels, 1989-10.Introduction à la Méthode Tabou
1989. Séminaire à l'Institut de Physique Théorique. Université de Genève (1989), Genève, 1989-04.Operations Research, Engineering and Artificial Intelligence
1989. 20th anniversary of V.U.B., Brussels, 1989-10.Cylindrical Scheduling
1989. Symposium über Operations Research (1989), Ulm (RFA), 1989-09.Graph Coloring and Frequency Assignment
1989. EURO X, Belgrade (Yugoslavia), 1989-06.A wiring problem
1989. Seminar on Functions, Propositional Logic and AI Techniques, Forschungsinstitutfüranwendungsorientierte Wissensverarbeitung (FAW), Universität Ulm (RFA), 1989-09.On the use of augmenting chains in chain packings
1989. Seminar of Combinatorial Optimization, University of Waterloo (1989), Waterloo, Canada, 1989-05.Finding large Independant sets in graphs with the Tabu Search
1989. Colloque "Computational Aspects of Combinatorial Optimization" (1989), Oberwolfach, RFA, 1989-01.Cyclic chromatic scheduling
1989. Académie des Sciences, Belgrade. Institut de Mathématiques (1989), Belgrade (Yugoslavia), 1989-06.La méthode tabou
1989. Groupe Enseignement de la R.O., AFCET (1989), Paris, 1989-12.Variations on matchings
1989. 17th DGOR Annual Meeting, Berlin, 1988-09-13 - 1988-09-16. DOI : 10.1007/978-3-642-74862-2_50.Some combinatorial problems in Production Systems
1989. Optimization Days, Ecole Polytechnique de Montréal, University of Montreal (1989), Montréal (Canada), 1989-05.Combinatorial problems in Flexible Manufacturing Systems
1989. EURO Working Group on Combinatorial Optimization. Universita di Venezia (1989), Venezia, 1989-03.The Future of O.R.
1989. 125ème anniversaire de la Société Suisse de Statistique, Fribourg, 1989-04.Theses
La coloration des sommets d'un graphe et son application à la confection d'horaires
Lausanne, EPFL, 1989. DOI : 10.5075/epfl-thesis-785.Book Chapters
Packing independent sets and transversals
Combinatorics and graph theory; Warsaw: Banach Center Publications, 1989. p. 233 - 240.Graph-theoretical models for preemptive scheduling
Advances in Project Scheduling; Amsterdam: Elsevier, 1989. p. 171 - 185.Heuristics for graph coloring
Computational graph theory; Springer Verlag NY, 1989. p. 171 - 185.Apprentissage dans les réseaux de Hopfield
Comptes rendus des journées d'électronique; Presses Polytechniques Romandes, 1989. p. 77 - 85.1988
Journal Articles
Consecutive colorings of graphs
Zeitschrift für Operations Research. 1988. DOI : 10.1007/BF01920567.From linear separability to unimodality: a hierarchy of pseudo-boolean functions
SIAM Journal on Discrete Mathematics. 1988. DOI : 10.1137/0401019.Some models of graphs for scheduling sports competitions
Discrete Applied Mathematics. 1988. DOI : 10.1016/0166-218X(88)90033-9.On the two-phase method for preemptive scheduling
European Journal of Operational Research. 1988. DOI : 10.1016/0377-2217(88)90332-3.On randomized stopping points and perfect graphs
Journal of Combinatorial Theory, Series B. 1988. DOI : 10.1016/0095-8956(88)90076-7.Perfectly orderable graphs are quasi-parity graphs
Discrete Mathematics. 1988. DOI : 10.1016/0012-365X(88)90047-7.Conference Papers
Some graph-theoretical models for scheduling
1988. RUTCOR, Rutgers University (1988), New Brunswick, USA, 1988-05.Production systems and O.R.
1988. Lectures at the Institute für Höhere Studien, Wien (1988), Wien, Austria, 1988-03.Modèles de graphes pour des problèmes d'ordonnancement
1988. Séminaire à l'Université de Grenoble (1988), Grenoble, France, 1988-03.Flexible Manufacturing Systems: some scheduling models
1988. International Institute for Advanced Systems Analysis (IIASA), Laxenburg (1988), Laxenburg, Austria, 1988-03.Tabu Search for the Convoy Scheduling Problem
1988. 13e Symposium International de Programmation Mathématique, Tokyo, 1988-09.Generalized Colorings and production scheduling
1988. AT & T Laboratories, Holmdel, N.J. (1988), Holmdel, NJ, USA, 1988-05.Les ateliers flexibles: une mine de problèmes pour la Recherche Opérationnelle
1988. Séminaire d'Informatique. Université de Fribourg (1988), Fribourg, Switzerland, 1988-06.Preemptive scheduling in production
1988. EURO IX - TIMS XXVIII, Université Dauphine, Paris, 1988-07.A tutorial on preemptive scheduling
1988. EURO IX - TIMS XXVIII, Université Dauphine, Paris, 1988-07.Almost non preemptive schedules
1988. Advanced Research Institute on Discrete Applied Mathematics, Rutgers University (1988), New Brunswick, USA, 1988-05.Recuit simulé et méthode tabou
1988. Journée du Groupe Combinatoire de l'AFCET (1988), Paris, 1988-12.Generalized Chain Packings
1988. Session annuelle de la Deutsche Gesellschaft für Operations Research (1988), Berlin, 1988-09.1987
Journal Articles
Some experiments with simulated annealing
European Journal of Operational Research. 1987. DOI : 10.1016/S0377-2217(87)80148-0.Partitions into odd chains
Mathematical Programming. 1987. DOI : 10.1007/BF02591682.Design and operation of flexible manufacturing systems : the kingdom of heuristic methods
RAIRO - Operations Research. 1987. DOI : 10.1051/ro/1987210403651.Design and operation of flexible manufacturing systems: the kingdom of heuristics
Revue française d'Automatique, d'Informatique et de Recherche Opérationnelle. 1987.Four classes of perfectly orderable graphs
Journal of Graph Theory. 1987. DOI : 10.1002/jgt.3190110405.Using tabu search techniques for graph coloring
Computing. 1987. DOI : 10.1007/BF02239976.Network simplex method applied to AC load-flow calculation
IEEE Transactions on Power Systems. 1987. DOI : 10.1109/TPWRS.1987.4335100.Conference Papers
Heuristics for the Control of FMS
1987. Cours Computer Integrated Manufacturing, Fondation Industrie-Université (1987), Bruxelles, 1987-03.Operations Research and Artificial Intelligence for Production and for Flexible Manufacturing Systems
1987. SVOR-OeGOR Conference 1987 - Swiss-Autrian O.R. Meeting, Graz, Austria, 1987-07.Graphs and Scheduling
1987. Lectures presented at Laboratory of Control Engineering, Beijing Institute of Technology, Beijing (1987), Beijing, China, 1987-03.Coloring Large graphs and Connected Colorings and Interval Colorings
1987. S. Banach International Mathematical Institute, Warsaw (1987), Warsaw, Poland, 1987-09.Quelques méthodes de coloration de graphes
1987. Séminaire à l'Université de Grenoble (1987), Grenoble, 1987-01.Tabu Method in Combinatorial Optimization and Scheduling and Timetabling
1987. Lectures given at Department of Applied Mathematics, Xi'an Jiaotong University (1987), Xi'an, China, 1987-04.The future of O.R.
1987. 3rd EURO Mini Conference "O.R. Techniques for Traffic and Transportation", Herceg Novi, Yugoslavia, 1987-06.Tabu Method vs Simulated Annealing in Group Technology
1987. Seminar at the Institute of Control Engineering, Politechnika Poznanska, Poznan (1987), Poznan, Pologne, 1987-09.Combinatorial Optimization
1987. Lectures presented at the Institute of Applied Mathematics, Academia-Sinica, Beijing (1987), Beijing, China, 1987-03.Coloring Large graphs
1987. ICIAM Conference , International Conference on Applied Mathematics (1987), Paris, 1987-06.Reviews
S.K. Bhatnagar "Network analysis techniques" (Wiley, New Delhi, 1986)
European Journal of Operational Research. 1987. DOI : 10.1016/0377-2217(87)90286-4.Theses
Optimisation convexe dans les réseaux avec applications au trafic routier et à l'énergie électrique
Lausanne, EPFL, 1987. DOI : 10.5075/epfl-thesis-669.1986
Journal Articles
Variations on the integral decomposition property
Mathematical Programming Study. 1986.Timetabling problems : should they be canonical ?
INFOR: Information Systems and Operational Research. 1986.Node covering with odd chains
Journal of Graph Theory. 1986. DOI : 10.1002/jgt.3190100206.A note on superbrittle graphs
Discrete Mathematics. 1986. DOI : 10.1016/0012-365X(86)90097-X.Generalized neighbourhoods and a class of perfectly orderable graphs
Discrete Applied Mathematics. 1986. DOI : 10.1016/0166-218X(86)90043-0.Conference Papers
Optimization of Pseudo-Boolean functions
1986. EURO VIII, Libson, Portugal, 1986-09.Modèles de R.O. pour les systèmes flexibles de production
1986. Atelier de printemps de l'Association Suisse de R.O., Grimentz, Switzerland, 1986-03.Some experiments in graph coloring
1986. Politecnico di Milano (1986), Milano, 1986-02.Pseudo-Boolean Optimization and Graphs
1986. International Symposium on Mathematical Programming (1986), Leibnitz, Austria, 1986-05.Ordonnancement sur des processeurs parallèles
1986. Université de Paris-Dauphine (1986), Paris, 1986-03.Paths, chains and antipaths
1986. Colloque International "Théorie des Graphes et Combinatoire" (1986), Marseille-Luminy, 1986-06.Some models for preemptive scheduling
1986. C.O.R.E., Université Catholique de Louvain, Louvain-La-Neuve, Belgique, 1986-04.Some experiments in Graph Coloring
1986. Application of Combinatorial Optimization (1986), Oberwolfach, RFA, 1986-12.Some extensions of matchings
1986. Colloque "20e Anniversaire du Groupe Combinatoire de l'AFCET", Paris, 1986-12.Flexible Manufacturing Systems: a challenge for O.R.
1986. Journée annuelle de l'ASRO, Zürich (1986), Zurich, Switzerland, 1986-10.Heuristics for Flexible Manufacturing Systems
1986. Cours Computer Integrated Manufacturing, Fondation Industrie-Université (1986), Bruxelles, 1986-04.Flexible Manufacturing Systems: a challenge for O.R .
1986. Politecnico di Milano (1986), Milano, 1986-01.Reviews
J. Koene "Minimal cost flow in processing networks: A primal approach" : CWI Tract 4 (Amsterdam, 1983)
European Journal of Operational Research. 1986. DOI : 10.1016/0377-2217(86)90075-5.Alan Gibbons: Algorithmic graph theory
European Journal of Operational Research. 1986. DOI : 10.1016/0377-2217(86)90177-3.1985
Journal Articles
The struction of a graph: Application toCN-free graphs
Combinatorica. 1985. DOI : 10.1007/bf02579377.Graphs, hypergraphs and timetabling
Methods Operational Research (Verlag A. Hain, Königstein). 1985.An introduction to timetabling
European Journal of Operational Research. 1985. DOI : 10.1016/0377-2217(85)90167-5.Stability in CAN-free graphs
Journal of Combinatorial Theory. 1985. DOI : 10.1016/0095-8956(85)90089-9.The struction of a graph : application to CN-free graphs, N.V. R. Mahadev
Combinatorica. 1985.Some uses of hypergraphs in timetabling
Asia-Pacific Journal of Operational Research. 1985.Threshold characterization of graphs with Dilworth number two
Journal of Graph Theory. 1985. DOI : 10.1002/jgt.3190090207.On split graphs of Dilworth number 2
Discrete Mathematics. 1985. DOI : 10.1016/0012-365X(85)90040-8.A note on strong perfectness of graphs
Mathematical Programming. 1985. DOI : 10.1007/BF02591953.On the multiplication of divisions
Networks. 1985. DOI : 10.1002/net.3230150110.Conference Papers
Optimization in distribution networks
1985. Congress on Optimization (1985), Marianske Lazne, Tchecoslovaquia, 1985-11.Heuristics for Flexible Manufacturing Systems
1985. Cours de la Fondation Industrie-Université (1985), Bruxelles, 1985-05.Odd chain packings
1985. Mathematical Programming Seminar (1985), Oberwolfach, RFA, 1985-01.Preemptive scheduling
1985. FNRS (1985), Brussels, 1985-12.Graphs, Networks and Applications
1985. British O.R. Society Annual Conference (1985), University of Durham, Durham, G.B., 1985-09.Optimization
1985. EURO VII, Bologna, Italy, 1985-06.General survey of graph theory
1985. FNRS (1985), Brussels, 1985-11.Some models for preemptive scheduling
1985. British O.R. Society Annual Conference (1985), University of Durham, Durham, G.B., 1985-09.Book Chapters
Graphs, hypergraphs and timetabling
Methods Operational Research; Königstein: Verlag A. Hain, 1985. p. 201 - 215.Graphs, networks and applications
Further developments in operational research; Pergamon Press Oxford, 1985. p. 76 - 95.1984
Journal Articles
Variation on a theorem of König
Discrete Mathematics. 1984. DOI : 10.1016/0012-365X(84)90015-3.Balanced optimisation problems
Operations Research Letters. 1984. DOI : 10.1016/0167-6377(84)90061-0.On some properties of the struction of a graph
SIAM Journal on Algebraic and Discrete Methods. 1984. DOI : 10.1137/0605025.Preemptive scheduling, linear programming and network flows
SIAM Journal on Algebraic and Discrete Methods. 1984. DOI : 10.1137/0605003.A decomposition property of polyhedra
Mathematical Programming. 1984. DOI : 10.1007/BF02591932.Conference Papers
Some Optimization Problems in Bipartite Graphs
1984. Colloquium on Combinatorics (1985), University of Bielefeld, RFA, 1984-11.Simple Algorithms for some classes of perfect graphs
1984. V. Workshop on Combinatorial Optimization (1984), Bonn, RFA, 1984-06.Struction, Stability and Matching Number
1984. University of Bonn (1984), Bonn, RFA, 1984-11.Stability number and struction
1984. Workshop on Combinatorial Optimization (1984), St.-Gallen, 1984-09.A Tutorial on Timetabling
1984. 9th Symposium on Operations Research (SOR), Osnabrück, RFA, 1984-08.Pseudo-Boolean functions and stability of graphs
1984. Symposium on Algebraic Structures in Operational Research (1982), Bad Honnef, RFA, 1982-04. DOI : 10.1016/S0304-0208(08)72955-4.Timetabling: Models based on Graphs
1984. Institute of Applied Mathematics of C.N.R. S. (1984), Rome, 1984-10.Perfect Graphs and Greedy Algorithms
1984. University of Bonn (1984), Bonn, RFA, 1984-10.Theses
Elaboration de systèmes informatisés pour l'organisation de tournées de distribution
Lausanne, EPFL, 1984. DOI : 10.5075/epfl-thesis-539.Book Chapters
Some min-max formulations for partitioning problems in graphs and hypergraphs
Graphs and hypergraphs, DGOR Operations Research Proceedings; Springer Verlag, 1984. p. 269 - 273.1983
Conference Papers
Optimisation dans les problèmes d'ordonnancement et de transport
1983. EPFL février 1983, Lausanne, 1983-02.Chromatic optimisation: a survey
1983. 2nd SIAM Meeting on the applications of discrete Mathematics, MIT, Boston, 1983-06.Chromatic scheduling
1983. 1983 Meeting of the Canadian Applied Mathematical Society, Toronto, 1983-06.Basic features of heuristic methods
1983. University of Waterloo. Department of Management Science (1983), Waterloo, Canada, 1983-06.Pseudo-Boolean functions and hypergraphs
1983. EURO VI - 6th European Congress on Operational Research, Vienne, Autriche, 1983-07.Some chromatic characterization of perfect graphs
1983. Symposium über Mathematische Optimierung (1983), Oberwolfach, RFA, 1983-01.Polyhedra and scheduling
1983. EURO VI - 6th European Congress on Operational Research, Vienne, Autriche, 1983-07.Netword flows and scheduling
1983. Université de Montréal. Département d'I.R.O (1983), Montréal (Canada), 1983-03.Some min-max formulations of partitioning problems for graphs and hypergraphs
1983. Congress of the Deutsche Gesellschaft für O.R. (1983), Mannheim, RFA, 1983-09.Introduction aux hypergraphes: principes de décomposition
1983. Crans mars 1983, Crans, Switzerland, 1983-03.Hiérarchie de classes de fonctions pseudo-booléennes
1983. Université de Grenoble (1983), Grenoble, 1983-11.Matchings and stable sets
1983. University of Toronto. Depatment of Computer Science (1983), Toronto, 1983-05.Variation on a decomposition property of polyhedra
1983. Congress Netflow 83, Pisa, Italia, 1983-03.On the use of bichromatic interchanges
1983. International Colloquium on Graph Theory and Combinatorics, Marseille–Luminy, 1981-06. p. 639 - 646. DOI : 10.1016/S0304-0208(08)73444-3.Book Chapters
On the fuzzy faces of the COP domain
Methods operational research; Hain, Hastein: Althenäum, 1983. p. 213 - 216.1982
Journal Articles
Chromatic optimisation : limitations, objectives, uses, references
European Journal of Operational Research. 1982. DOI : 10.1016/S0377-2217(82)80002-7.Some experiments with a timetabling system
OR Spektrum. 1982.Obstructions for regular colorings
Journal of Combinatorial Theory B. 1982. DOI : 10.1016/0095-8956(82)90008-9.Minimizing irregularities in sports schedules using graph theory
Discrete Applied Mathematics. 1982. DOI : 10.1016/0166-218X(82)90042-7.Conference Papers
Scheduling on unrelated parallel processors and hypergraphs
1982. XI International Symposium on Math. Programming, University of Bonn, RFA, 1982-08.On the fuzzy faces of the COP domain
1982. VII Symposium on Operational Research, University of St-Gallen, 1982-08.Confection automatique de calendriers sportifs
1982. Séminaire d'Informatique de l'ACM (1982), Montreux, Switzerland, 1982-05.Modélisation de problèmes d'ordonnancement à l'aide de graphes
1982. Colloque FNRS, Faculté Polytechnique de Mons (1982), Belgique, 1982-02.Reviews
D. Klingman and J.M. Mulvey (Eds.) "Network models and associated applications" (Vol. 15 in: Mathematical Programming Studies. - North-Holland, Amsterdam, 1981)
European Journal of Operational Research. 1982. DOI : 10.1016/0377-2217(82)90233-8.J.L. Kennington and R.V. Helgason "Algorithms for network programming" (Wiley, New York, 1980)
European Journal of Operational Research. 1982. DOI : 10.1016/0377-2217(82)90081-9.1981
Journal Articles
Remarks on the requirement matrix of school timetable problems and regular embeddings of graphs
European Journal of Operational Research. 1981. DOI : 10.1016/0377-2217(81)90233-2.Remarks on the requirement matrix of school timetable problems
European Journal of Operational Research. 1981. DOI : 10.1016/0377-2217(81)90247-2.On some characterisations of totally unimodular matrices
Mathematical Programming. 1981. DOI : 10.1007/BF01589329.On the existence of generalized good and equitable colorings
Journal of Graph Theory. 1981. DOI : 10.1002/jgt.3190050306.Conference Papers
Threshold signed graphs
1981. Internatioanl Colloquium on Graph Theory and Combinatorics (1981), Marseille-Luminy, 1981-06.On the multiplication of divisions
1981. V. Math. Programming Seminar, Bad Honnef, RFA, 1981-04.Obstructions for regular colorings
1981. University of Bonn (1981), RFA, 1981-11.Graphs and scheduling
1981. Polytechnical School of Poznan (1981), Poznan, Poland, 1981-10.Book Chapters
Scheduling in Sports
Studies on graphs and integer programming; North Holland: Annals of Discrete Mathematics, 1981. p. 381 - 395.1980
Journal Articles
Geography, games and graphs
Discrete Applied Mathematics. 1980. DOI : 10.1016/0166-218X(80)90028-1.A tutorial on heuristic methods
European Journal of Operational Research. 1980. DOI : 10.1016/0377-2217(80)90084-3.Conference Papers
The design of heuristic procedures - a survey
1980. EURO IV, Cambridge, U.K, 1980-07.Chromatic scheduling
1980. University of Copenhagen. Institute of Datalogy, Course 1980, Copenhagen, 1980-03.Some experiments with a timetabling system
1980. Instituto Politecnico di Milano (1980), Milano, 1980-03.A beautiful coloring device for edges of finite graphs
1980. BUDAPS 1980, Internatioanl Seminar on Discrete Optimization, Vizegrad, Hungary, 1980-05.Some combinatorial aspects of sports
1980. EURO IV, Cambridge, U.K, 1980-07.Partitioning problems for graphs and hypergraphs
1980. V. Symposium on Operational Research, Cologne, 1980-08.Fantaisies chromatiques sur diverses partitions
1980. Colloque "Regards sur la théorie des graphes", Cerisy-la-Salle, Normandie, 1980-06.Reviews
Schrijver, A. (Ed.): Packing and Covering in Combinatorics (Amsterdam: Mathematisch Centrum 1979)
Operations-Research-Spektrum. 1980. DOI : 10.1007/bf01719342.Book Chapters
Optimisation in edge-chromatic scheduling
Survey of Mathematical Programming; Budapest: Akademiai Kiado, 1980. p. 379 - 382.Some partitioning problems for graphs and hypergraphs
Proceedings V Symposium on Operations Research; 1980. p. 291 - 293.Network flows and chromatic scheduling
Proceedings of DAPS; Uni of Copenhagen, 1980. p. 429 - 438.Fantaisies chromatiques sur diverses partitions
Regards sur la théorie des graphes; Presses Polytechniques Romandes, 1980. p. 217 - 226.1979
Journal Articles
Regular and canonical colorings
Discrete Mathematics. 1979. DOI : 10.1016/0012-365X(79)90165-1.On the use of alternating chains and hypergraphs in edge colorings
Journal of Graph Theory. 1979. DOI : 10.1002/jgt.3190030208.Partial compactness in chromatic scheduling
Op. Res. Verfahren. 1979.Conference Papers
Oriented colorings and applications
1979. Workshop on Applications of Graph Theory, Combinatorics and Management - European Institute for Advanced Studies in Management (1979), Bruxelles, 1979-03.Graphes et emploi du temps
1979. Institut d'Economie Scientifique et de Gestion. Université de Lille (1979), Lille, 1979-03.Some characterizations of totally unimodular and balanced matrices
1979. X. Symposium on Math. Progr. (1979), Montréal (Canada), 1979-08.Partitions régulières et canoniques des hypergraphes
1979. Séminaire d'algèbre et de combinatoire. Université de Grenoble (1979), Grenoble, 1979-03.The oriented chromatic index of a graph
1979. P.O.P.C.O.R.N. Festival - Stiching Math. Centrum Amsterdam 1979, Amsterdam, 1979-04.Scheduling in sports
1979. EURO III - 3rd European Conference on Operational Research, Amsterdam, 1979-04.A tutorial on chromatic scheduling
1979. 2nd Danish-Polish Conference on Math. Programming, Copenhagen, 1979-05.A survey of recent results in applied graph theory
1979. Séminaire à l'Université de Waterloo (1979), Waterloo, Canada, 1979-08.Book Chapters
On a class of hypergraphs occurring in chromatic scheduling
Cahiers du C.E.R.O.; 1979. p. 239 - 245.1978
Journal Articles
On line perfect graphs
Mathematical Programming. 1978. DOI : 10.1007/BF01609025.Color-feasible sequences of multigraphs
Networks. 1978. DOI : 10.1002/net.3230080105.Some comments on a note about timetabling
INFOR: Information Systems and Operational Research. 1978.Conference Papers
Timetabling problems
1978. Summer School on Combinatorial Optimization - SOGESTA (1978), Urbino, Italy, 1978-07.Chromatic scheduling and timetabling
1978. III. Symposium on Operations Research, Mannhein, 1978-09.Book Chapters
Color-feasible sequences in almost bipartite graphs
Problèmes combinatoires et théorie des graphes; Paris: Orsay - Editions CNRS, 1978. p. 427 - 429.1977
Journal Articles
Multigraphs with quasi-weak odd cycles
Journal of Combinatorial Theory, Series B. 1977. DOI : 10.1016/0095-8956(77)90058-2.Uniqueness of colorings
Archiv der Mathematik. 1977.Conference Papers
Réseaux et heuristiques - survol
1977. Assemblée de l'ASRO (1977), Fribourg, 1977-03.Balancing in chromatic scheduling
1977. Center for Operational Research and Econometrics. Université de Louvain (1977), Louvain, 1977-03.Problèmes d'ordonnancement - aspects théoriques
1977. Cours ASSPA (1977), Genève, 1977-12.Book Chapters
On a multi-period assignment problem
Advances in operations research; North Holland, Amsterdam: Physica-Verlag, Würzburg, 1977. p. 129 - 134.Some coloring techniques
Studies in Integer Programming; 1977. p. 179 - 184.Teaching & PhD
Past EPFL PhD Students
Andreas Rogger, David Schindl, Ivo Blöchliger, Tinaz Ekim, Bernard Ries, Benjamin Leroy-Beaulieu