Guillaume Ducoffe – Postdoctoral Candidate

Guillaume
Ducoffe
Postdoctoral Candidate
Inria Sophia Antipolis Méditerranée,
2004 route des Lucioles, 06902 Sophia Antipolis
France
H +33 (0) 637 794 319
+33 (0) 492 387 599
B [email protected]
Í www-sop.inria.fr/members/Guillaume.Ducoffe/
Research Interests
Computation in Large Graphs, Information-propagation in real-life graphs, Online targeting detection,
Graph Theory, Combinatorics.
PHD thesis
(Sep. 2014 – Dec. 2016)
title On the metric properties of large graphs
supervisors David Coudert
description Graph algorithms are the cornerstone of various problems in telecommunications, social networks, bioinformatics and economics, to name a few.
However, most textbook algorithms do not scale to real-life graphs with
tens of thousands of nodes and billions of edges. A main objective of the
thesis is to establish a finer-grained complexity of the computation of
some graph properties and graph primitives on large graphs. It has an
emphasis on the computation of hyperbolicity, and other distance-related
graph parameters, that all found applications in the study of geometrical
routing schemes in networks.
Education
2012–2013 Parisian Master of Research in Computer Science, École Normale
Supérieure de Cachan, Cachan.
top of my class
2010–2013 Master’s Degree in Engineering — Cryptography, System, Security & Networks, École Polytechnique Universitaire de Nice - Sophia
Antipolis, Sophia Antipolis.
top of my class
Research Experience
Dec. 2015 Research Visit, Universidad Adolfo Ibáñez / Universidad de Chile, Santiago de Chile.
hosted by Karol Suchan.
Design and implementation of graph algorithms in order to improve the transportation network in Santiago.
Nov.– Dec. 2014 Research Visit, Universidad Adolfo Ibáñez / Universidad de Chile, Santiago de Chile.
hosted by Karol Suchan.
Study on new relations between the structure of a graph and its metric properties
(properties of its distance distribution).
1/5
Mar–Jul 2014 Research Internship: Security and Information Sharing in Social
Networks, Columbia University, New York.
supervised by Augustin Chaintreau and Roxana Geambasu.
Design and theoretical limitations of learning algorithms for the problem of
Online Targeting.
Oct–Mar 2014 Research Internship: Algorithmic Applications of the Metric Structure of a Graph, Inria Sophia Antipolis Méditerranée, Nice.
supervised by David Coudert
Study on relations between the diameter of a graph and other metric parameters
such as hyperbolicity.
Mar–Aug 2013 Research Internship: Approximation Algorithms for computing in
large graphs, Inria Sophia Antipolis Méditerranée, Nice.
supervised by David Coudert
Feasible computation of hyperbolicity on large graphs (a parameter related to
the stretch of geometrical routing schemes).
Jun–Sep 2012 Research Internship: Dynamics in Social Networks, Columbia University, New York.
supervised by Augustin Chaintreau and Dorian Mazauric
Proofs of the existence of equilibria, and bounds on the time of convergence to
one, in a game-theoretic model for social communities.
Jun–Aug 2011 Research Internship: Eulerian and Hamiltonian Directed Hypergraphs, Inria Sophia Antipolis Méditerranée, Nice.
supervised by Jean-Claude Bermond and Julio Araujo
Generalization of known results about Eulerian and Hamiltonian digraphs to the
directed hypergraphs.
Teaching Experience
Co-supervision of internships 2 PFE (End of Study Project, one month each); 1 research internship
(six months) co-supervised with Frédéric Giroire.
Algorithmic courses recursive programming, dichotomy, sorting algorithms, basics on Hoare
logic, etc . . . (L2 level, ∼ 30 h., École Polytechnique Universitaire de
Nice Sophia-Antipolis)
Programming courses Java (L2 level, ∼ 30 h., École Polytechnique Universitaire de Nice SophiaAntipolis) and Python (L1 level, ∼ 20 h., École Polytechnique Universitaire de Nice Sophia-Antipolis)
Web courses basics of HTML, CSS and client/server paradigm (L2 level, ∼ 30 h.,
École Polytechnique Universitaire de Nice Sophia-Antipolis)
Awards and Distinctions
Best Student Paper Award [9], 15èmes Rencontres Francophones des Aspects Algorithmiques des
Télécommunications
3rd Heidelberg Laureate Forum selected as a participant by an international scientific panel
Selected Projects
Feb.–May 2012 OpenCV software for translating Sign language from a WebCam (supervised by Frédéric Precioso)
Jan. 2012 Web developers toolkit based on the XSLT language (supervised by Paul
Franchi)
2/5
Feb.–May 2011 DEVINT Project: Java game for visually deficient people (supervised by
J.-P. Stromboni)
Languages
French
English
Italian
Romanian
mother tongue
full professional working proficiency
professional working proficiency
beginner
TOEIC score 900/990
B1 level
Computer skills
Graph Theory Algorithms on Large Graphs, Fine-grained lower-bounds on graph problems, graph decompositions, metric graph invariants
Theoretical Computer Science Algorithms, Complexity, Distributed Complexity, Learning Theory, Computability, Combinatorics, Graphs and Networks, Formal Languages,
Game Theory
Programming Languages Java, C++, C#, C POSIX, Python, Assembly Language ARM, SQL,
Scheme, Caml, Shell, Matlab, Scilab, Maple
Web Standards X(HT)ML, XSD/DTD, XSLT, XUL, CSS, JavaScript, Action Script
Operating Systems Linux (Ubuntu,Fedora) and Windows
Softwares Astah, Cosmos, Dreamweaver, Eclipse, Editix, ESC/java, Essential Modeler, JProbe, Lex/Yacc, Microsoft SQL Server, Microsoft Visual Studio,
NetBeans, Open Office, Understand, Valgrind
References
Former supervisors
{
{
{
{
{
{
David Coudert
J.-C. Bermond
Augustin Chaintreau
Roxana Geambasu
Dorian Mazauric
Julio Araujo
Former teachers
{ Jean Goubault
{ Paul Franchi
{ Ioan Bond
(more upon requests)
3/5
Publications
Journal papers
[1] D. Coudert and G. Ducoffe. “Data Center interconnection networks are not hyperbolic”. In: Journal
of Theoretical Computer Science 639.1 (2016), pp. 72–90.
[2] D. Coudert and G. Ducoffe. “On the hyperbolicity of bipartite graphs and intersection graphs”. In:
Discrete Applied Mathematics (2016). To appear.
[3] D. Coudert, G. Ducoffe, and N. Nisse. “To approximate treewidth, use treelength!” In: SIAM Journal
of Discrete Mathematics 30.3 (2016), p. 13.
[4] J. Araujo, J-C. Bermond, and G. Ducoffe. “Eulerian and Hamiltonian dicyles in directed hypergraphs”.
In: Discrete Mathematics, Algorithms and Applications 6 (2014).
[5] D. Coudert and G. Ducoffe. “Recognition of C4 -free and 1/2-hyperbolic graphs”. In: SIAM Journal
of Discrete Mathematics 28.3 (2014), pp. 1601–1617.
[6] G. Ducoffe. “Hamiltonicity of large generalized de Bruijn cycles”. In: Discrete Applied Mathematics
161 (2013), pp. 2200–2204.
Conference papers
[1] D. Coudert and G. Ducoffe. “Liens entre symétries et étirements de routages dans les réseaux
d’interconnexion de centres de données”. In: ALGOTEL 2016 – 18èmes Rencontres Francophones
sur les Aspects Algorithmiques des Télécommunications. 2016.
[2] G. Ducoffe. “The parallel complexity of coloring games”. In: SAGT 2016 – 9th International Symposium
on Algorithmic Game Theory. 2016.
[3] G. Ducoffe, N. Legay, and N. Nisse. “On the complexity of computing treebreadth”. In: IWOCA 2016
– 27th International Workshop on Combinatorial Algorithms. 2016.
[4] A. Chaintreau et al. “Vers une plus grande transparence du Web”. In: ALGOTEL 2015 – 17èmes
Rencontres Francophones sur les Aspects Algorithmiques des Télécommunications. 2015.
[5] D. Coudert, G. Ducoffe, and N. Nisse. “Structure vs. métrique dans les graphes”. In: ALGOTEL 2015
– 17èmes Rencontres Francophones sur les Aspects Algorithmiques des Télécommunications. 2015.
[6] G. Ducoffe et al. “Web’s Transparency for Complex Targeting: Algorithms, Limits and Tradeoffs”.
In: SIGMETRICS ’15 Proceedings of the 2015 ACM SIGMETRICS International Conference on
Measurement and Modeling of Computer Systems. 2015.
[7] M. Lécuyer et al. “XRay: Enhancing the Web’s Transparency with Differential Correlation”. In:
USENIX Security Symposium. 2014.
[8] G. Ducoffe, D. Mazauric, and A. Chaintreau. “Can Selfish Groups be Self-Enforcing?” In: Workshop
on Social Computing and User Generated Content at EC’13. 2013.
[9] G. Ducoffe, D. Mazauric, and A. Chaintreau. “De la difficulté de garder ses amis (quand on a des
ennemis)!” In: ALGOTEL 2013 – 15èmes Rencontres Francophones sur les Aspects Algorithmiques
des Télécommunications. 2013.
Unpublished papers
[1] J. Araujo et al. “Instantaneous cycle convexity”. In preparation.
[2] A. Chaintreau and G. Ducoffe. “A theory for ad targeting identification”. In preparation.
[3] A. Chaintreau and G. Ducoffe. “On Web’s Transparency and an economics of online discrimination”.
In preparation.
4/5
[4] D. Coudert et al. “Existence of a distance-preserving ordering is hard to decide”. In preparation.
[5] G. Ducoffe and D. Coudert. “Clique-decomposition revisited”. Submitted.
[6] G. Ducoffe, D. Mazauric, and A. Chaintreau. “The Complexity of Hedonic Coalitions under Bounded
Cooperation”. Submitted.
[7] G. Ducoffe, M. Tucker, and A. Chaintreau. “Can Web’s Transparency Tools Cope with Complex
Targeting?” In preparation.
[8] Cohen N. et al. “Applying clique-decomposition for computing Gromov hyperbolicity”. In preparation.
Theses
[1] G. Ducoffe. “Outils Théoriques pour le Calcul Pratique de l’Hyperbolicité dans les Grands Graphes”.
MA thesis. MPRI – ENS Cachan, 2013.
5/5