cv
Christophe Weibel
Education and Employment
Software Engineer, from 2011
Google Zürich
Project: Shopping Data Quality
Research Associate, from 2010 to 2011
Dartmouth College
Supervisor: Prof. Lisa Fleischer
Postdoctoral Fellow from 2007 to 2010,
McGill University, Montreal, Canada
Supervisor: Prof. Bruce Shepherd
Doctorate of Philosophy in Mathematics, July 2007
Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland
Dissertation: Minkowski sums of polytopes: Combinatorics and Computation
Supervisor: Prof. Thomas M. Liebling and Prof. Komei Fukuda
Jury: Prof. Peter Gritzmann and Prof. Günter M. Ziegler
IT Consultant from 2000 to 2002,
ELCA Informatique, Lausanne, Switzerland
Master in Mathematics, April 2000
Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland
Dissertation: Parallel implementation of a distinct elements simulation of a granular media
Supervisor: Prof. Thomas M. Liebling and Jean-Albert Ferrez
Jury: Didier Müller
Research Interests
- Discrete optimization
- Combinatorial and computational geometry
- Graph theory
Journal papers
Sylvain Lazard, Christophe Weibel, Sue Whitesides, Linqiao Zhang, 2010
A Succinct 3D Visibility Skeleton
Discrete Mathematics, Algorithms and Applications, vol. 2 (2010), pp. 567-589
Komei Fukuda, Christophe Weibel, 2010
Minkowski Sums of polytopes relatively in general position
European Journal of Combinatorics, vol. 31 (2010), pp. 565-573
Efi Fogel, Dan Halperin, Christophe Weibel, 2009
On the exact maximum complexity of Minkowski sums of convex polyhedra
Discrete & Computational Geometry, vol. 42 (2009), pp. 654-669
Komei Fukuda, Christophe Weibel, 2007
f-vectors of Minkowski additions of convex polytopes
Discrete & Computational Geometry vol. 37 (2007), pp. 503-516
Carolina Osorio et al., 2006
Carolina Osorio, Christophe Weibel, Pau Perez, Michel Bierlaire and Philippe Garnerin
Patient flow simulation as a tool for estimating policy impact
Swiss Medical Informatics, vol. 58 (2006), pp. 33-36
Conference proceedings
A. Chakrabarti, L. Fleischer, C. Weibel, 2012
When the Cut Condition is Enough; A Complete Characterization for Multiflow Problems in Series-Parallel Networks
Proceedings of the 44th Symposium on Theory of Computing (STOC 2012)
C. Weibel, L. Zhang, 2011
Minimum Perimeter Convex Hull of Imprecise Points in Convex Regions
Presented at the ACM Symposium on Computational Geometry (SoCG 2011), multimedia session
Erin Chambers et al., 2010
Erin Chambers, Alejandro Erickson, Sandor Fekete, Jon Lenchner, Jeff Sember, Venkatesh Srinivasan, Ulrike Stege, Svetlana Stolpner, Christophe Weibel, Sue Whitesides
Connectivity graphs of uncertainty regions
Presented at the International Symposium on Algorithms and Computation (ISAAC 2010)
Vida Dujmovic, William Evans, Stephen Kobourov, Giuseppe Liotta, Christophe Weibel, Stephen Wismath, 2010
On Graphs Supported by Line Sets
Proc. of the 18th Symposium on Graph Drawing (GD 2010) Konstanz, Germany
Full version submitted to Computational Geometry, Theory and Applications
Linqiao Zhang, Sylvain Lazard, Christophe Weibel, Sue Whitesides, 2010
On the Computation of the 3D Visibility Skeleton
Proceedings of the 16th Annual International Computing and Combinatorics Conference (COCOON 2010) pp. 469-478, Nha Trang, Vietnam
Chandra Chekuri, Bruce Shepherd, Christophe Weibel, 2010
Flow-Cut Gaps for Integer and Fractional Multiflows
Proceedings of the 21st Annual ACM-SIAM Symposium on Discrete Algorithms (SoDA 2010) pp. 1198-1208, Austin, Texas
Full version submitted to the Journal of Combinatorial Geometry, Series B
Christophe Weibel, 2010
Implementation and parallelization of a reverse-search algorithm for Minkowski sums
Proceedings of the 12th Workshop on Algorithm Engineering and Experiments (ALENEX 2010) pp. 34-42, Austin, Texas
Linqiao Zhang, Hazel Everett, Sylvain Lazard, Christophe Weibel, Sue Whitesides, 2008
On the size of the 3D visibility skeleton: experimental results
Proceedings of the 16th Annual European Symposium on Algorithms (ESA 2008), Karlsruhe, 2008
Efi Fogel, Dan Halperin, Christophe Weibel, 2007
On the Exact Maximum Complexity of Minkowski Sums of Convex Polyhedra
Proc. 23rd ACM Symposium on Computational Geometry (SoCG 2010): pp. 319-326, Gyeongju, South Korea, 2007
Komei Fukuda, Christophe Weibel, 2005
Computing faces up to k dimensions of a Minkowski Sum of Polytopes
Proceedings of the 17th Canadian Conference on Computational Geometry (CCCG 05), pages 256-259
Preprint
Christophe Weibel, 2011
Maximal f-vectors of Minkowski sums of large numbers of polytopes
Submitted to Discrete & Computational Geometry
Amit Chakrabarti, Lisa Fleischer, Christophe Weibel, 2011
Characterization of routable multicommodity flows in series-parallel networks
In preparation
Benjamin Matschke, Francisco Santos, Christophe Weibel, 2011
The width of 5-prismatoids and smaller non-Hirsch polytopes
In preparation
Guyslain Naves, Christophe Weibel, 2010
Congestion in planar graphs with demands on faces
Manuscript
Komei Fukuda, Christophe Weibel, 2009
Facet computation for Minkowski sums of polytopes
Manuscript
Software
Computational geometry software in C++ based on an algorithm of Komei Fukuda for the computation of Minkowski sums of polytopes. Sequential and parallel implementations.
Talks
2012
44th ACM Symposium on Theory of Computing (STOC 2012), New York (USA)
2010
16th Annual International Computing and Combinatorics Conference (COCOON 2010), Nha Trang (Vietnam)
Invited talk at the CMS Summer Meeting, Fredericton (Canada)
Invited talk at Dartmouth College, Hanover (USA)
ACM-SIAM Symposium on Discrete Algorithms (SoDA 10), Austin (USA)
SIAM Workshop on Algorithm Engineering & Experiments (ALENEX 10), Austin (USA)
2009
Discrete & Mathematical Optimization Seminar, McGill University, Montréal (Canada)
20th International Symposium for Mathematical Programming (ISMP 09), Chicago (USA)
Canada-Japan Workshop on Discrete and Computational Geometry, Tokyo (Japan)
Invited talk at the Max Planck Institute, Saarbrücken (Germany)
Combinatorial Geometry & Optimization Seminar, EPF Lausannne (Switzerland)
Optimization & Applications Seminar, ETH Zürich (Switzerland)
Invited talk at Victoria University, Victoria (Canada)
2008
Discrete & Mathematical Optimization Seminar, McGill University, Montréal (Canada)
2007
European Workshop on Combinatorial Geometry, Gratz (Austria)
3ème cycle romand de recherche opérationnelle, Zinal (Switzerland)
2006
Joint Operations Research Days, Lausanne (Switzerland)
ADONET Meeting, Lausanne (Switzerland)
3ème cycle romand de recherche opérationnelle, Zinal (Switzerland)
2005
UC Berkeley Combinatorics Seminar, Berkeley (USA)
Canadian Conference on Computational Geoemetry, Windsor (Canada)
Educational Workshop on Geometric Inequalities, Firenze (Italy)
Research Grants
- SNF Postdoctoral Fellowship
- Awarded by the Swiss National Fund
- 40'000 CAD for one year (07-08) in McGill University
- SNF Doctoral Fellowship
- Awarded by the Swiss National Fund
- 150'000 CHF over three years (04-07) in EPFL
- Research Fellowship
- Awarded by the Hospitals of the University of Geneva
- 90'000 CHF over one year and a half (02-04) in EPFL
Invited Research Workshops
- January 2009 & 2010: International INRIA-McGill Workshop on Problems in Computational Geometry, Bellairs Research Institute of McGill University, Barbados, organized by Hazel Everett, Sylvain Lazard and Sue Whitesides
- November 2008: Bonn Workshop on Combinatorial Optimization, Research Institute for Discrete Mathematics, University of Bonn, Germany, organized by William Cook, Bernhard Korte, László Lovász and Jens Vygen
- April 2008: Workshop on Integer Programming, Bellairs Research Institute of McGill University, Barbados, organized by William Cook, Fritz Eisenbrand and Bruce Shepherd
Related Experience
Research
Reviewer
- IEEE Symposium on Foundations of Computer Science
- ACM Symposium on Computational Geometry
- SIAM Journal on Computing
- Discrete & Computational Geometry
- Computational Geometry: Theory and Applications
- Operations Research
- Annals of Combinatorics
- Statistica Sinica
- Computer-Aided Design
Research Assistant, Institute of Mathematics, EPFL, 2002-2004
- Design and implementation of a hospital patient flow simulator
- Statistical analysis of patients surgery and recovery time
Teaching
Student project supervision, McGill University, 2008
- Yang Li: Netflix Prize Competition, supported by an ISM-CRM scolarship
Assistant Lecturer, McGill University, 2007-2008
- Linear Algebra (2009, 60 undergrad students)
- Polyhedral combinatorics for discrete optimization (2008, with Bruce Shepherd, 8 grad students)
- Honour Algorithm Design (2007, 12 undergrad students)
Lecturer, McGill University, 2007-2008
- Linear Algebra (2009, 60 undergrad students)
- Polyhedral combinatorics for discrete optimization (2008, with Bruce Shepherd, 8 grad students)
- Honour Algorithm Design (2007, 12 undergrad students)
Teaching Assistant, weekly exercise sessions and exam redaction, Institute of Mathematics, EPFL, 2002-2007
- Game Theory (2005 & 2007, 20 grad students)
- Decision Models (2004 & 2006, 30 grad students)
- Discrete and algorithmic geometry (2005, 25 grad students)
- Operations Research (2002 - 2004, 40 undergrad students)
- Linear Algebra (2003 - 2004, 200 undergrad students)
Student project supervision, Institute of Mathematics, EPFL, 2002-2007
- Modelisation of the compressive behavior of a fiber lacing (Master Thesis)
- Sudoku Resolution
- Size of production and purchasing lots
- Strategy optimization for Mah-Jong
- Simulator for the Hospitals of the University of Geneva
Private Sector
IT Consultant, ELCA, Lausanne, 2000-2002
- Specification and implementation of components for a banking application
- Implementation of a database application for operational events
Duties
Webmaster, ROSO lab, 2004-2007
Webmaster, Association of Mathematicians from EPFL, 2000-2007
Competitions
- ACM Programming Contest
- EPFL team, Ulm 1997-1999
- Championnat de Jeux Mathématiques et Logiques
- 4th place, Paris 1995
- International Mathematics Olympiad
- Swiss national team, Hong-Kong 1994
Languages
English, French: fluent
German, Japanese: working knowledge