






Thomas Begin
Assistant Professor at
Université Claude Bernard, Lyon 1 (UCBL)
UFR d'Informatique, Bat. Nautibus
43 Bd du 11 novembre 1918
69622 Villeurbanne Cedex  France
Office UCBL (Bât. Nautibus): Room 226
Phone UCBL: +33(0)4 72 44 81 91
EMail Address: firstname.name@univlyon1.fr
Research Team
DANTE / Inria since 2013 (previously
RESO / Inria)
Laboratoire de
l'informatique du parallélisme (LIP) UMR 5668
Ecole Normale Supérieure de
Lyon (ENSL)
46 allée d'Italie
69364 Lyon Cedex 07  France
Office ENS (2nd floor): Room 240
Phone ENS: +33 (0)4 26 23 38 03
Fax ENS: +33 (0)4 72 72 80 80
EMail Address: firstname.name@enslyon.fr





Biography
Since September 2009, I am an Assistant
Professor in the department of Computer Engineering at the
Université Claude Bernard Lyon 1 (UCBL).
I am also a member of the DANTE
team (prior to 2013, I was part of the
RESO team), a joint research team from the LIP
laboratory and from INRIA
located at the ENS Lyon
and hosted by IXXI, where I
do my research work.
I hold an Engineering Degree from Institut
Superieur d'Electronique de Paris (ISEP),
with a major in Telecommunications, along with a M.Sc. in
Computer Networks from University Pierre et Marie Curie (UPMC).
Between 2005 and 2008, I was pursuing a PhD in Computer
Networks in the Networks and Performance Analysis group at the
laboratory LIP6 under the
supervision of Pr.
Serge Fdida and Ass. Pr. Bruno
Baynat. I graduated in December 2008, and then I worked
as a Postdoc at UCSC
where I collaborated actively with Pr. Alexandre
Brandwajn.
During the 20152016 academic year, I was on
research leave at DIVA lab
 University of Ottawa
(uOttawa)  Canada. This leave was funded through a CNRS
grant.
Current and past collaborators with whom I
was privileged to work with:
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Research Interests
My research is in the area of performance
evaluation, queueing theory, stochastic modeling as applied to
networks and computer systems. I am particularly interested in
applying stochastic modeling and queueing theory to practical
problems in computer systems.
Together with Alexandre Brandwajn, we deployed a web
application that produces the solution of certain queueing
systems using our resaerch material (e.g., G/M/clike,
M/G/1like, and M/G/clike queues). Click
here to access the tool.
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Curriculum Vitae
Télécharger mon CV en français
Download my Résumé in English
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Scientific Projects (current and past)

ANR REFLEXION
Scientific leader for ENSL of ANR REsilient and FLEXible
Infrastructure for Open Networking.
 ANR
DISCO
Scientific leader for ENSL of ANR DIStributed SDN
COntrollers for rich and elastic services.

SEMANTIC NETWORKING
Member of the common research lab between INRIA and
AlcatelLucent Bell labs on "selforganising networks".
 ARC MISSION
Member of the ARC MobIle SubStItution Networks (MISSION)
project (20102011, funded by INRIA).
 ANR RESCUE
Member of ANR RESeau Coordonné de sUbstitution mobilE
(RESCUE) project (20102013, funded by ANR  VERSO call).
 FP7 SAIL
Member of Scalable and Adaptive Internet soLutions (SAIL)
project (20102013, funded under 7th FWP).
PhD Students (current and past)
 Marija
Stojanova, "Adaptative solution for multihop wireless
networks" (2016)
 Huu Nghi
Nguyen, "Admission control and controllers allocation
for SDN networks", codirected with Isabelle GuérinLassous
and Anthony Busson (2014)

Thiago Abreu, "Modeling and performance analysis of
IEEE 802.11based chain networks", codirected with Isabelle
GuérinLassous (20112014)
 Shubhabrata Roy, "A Complete
Framework for Modelling Workload Volatility of a VoD System:
a Perspective to Probabilistic Management", codirected with
Paulo Gonçalves (20112014)

Doreid Ammar, "Knowledge plane for semantic
networking", codirected with Isabelle GuérinLassous
(20092012)
Postdoc Students (current and past)
 Guillaume Artero Gallardo,
"Performance modeling of virtual switching
systems"(20152016)
MSc Students (current and past)
 Marija Stojanova, "Modeling
CSMA/CA's capacity sharing in VANETs", codirected with A.
Busson (Feb  Jun 2016).
 Zidong Su,"Performance
Evaluation of Virtual Switch By Polling System", codirected
with B. Baynat (Feb  Jun 2016).
 Omar Dahmani, "Experimental
measurements on multihop wireless networks", codirected
with I. GuérinLassous (Feb  Jun 2015).
 Thibaud Trolliet,
"Implementing a MCMC method for a markovian model to
simulate the dynamic workload a video on demand server",
codirected with P. Gonçalves (Jul  Aug 2013).
 JeanBaptiste Delavoix,
"Implementation and deployment on Grid5k of a markovian mo
del to simulate the dynamic workload a video on demand
server", codirected with P. Gonçalves (Jul  Aug 2012).
 Huu Nghi Nguyen,
"Investigating the numerical behavior of matrix geometric
methods for solving queueing systems" (Apr  Sep 2011).
 Rémi Druihle, "Communications
in parallel applications: the Hadoop study case",
codirected with O. Glück and I. GuérinLassous (Feb  Jun
2010).
 Aurélien Lafranchise,
"Multiclass routing. Differentiated routing for realtime
and elastic traffic", codirected with I. GuérinLassous
(Feb  Jun 2010).
 The Quang Bui, "Failover
wireless network in the crisis context", codirected with P.
Gonçalves (Apr  Nov 2010).
 Van Dan Nguyen,
"Multiconstrained routing: a first step toward a more
realistic evaluation", codirected with I. GuérinLassous
(Apr  Nov 2010).
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Enseignements (Teaching info, sorry available only in
French )
 Réseaux
Avancés (M2 SRIV RA)
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Journals

 Safety Message Generation Rate Adaptation in LTEbased Vehicular Networks. H. Soleimani, T. Begin, A. Boukerche 
Computer Networks, 2017. (new)
 Breaking the dimensionality
curse in multiserver queues. A. Brandwajn, T. Begin 
Computers & Operations Research, Volume 73, 2016.
 Performance analysis of
multihop flows in IEEE 802.11 networks: A flexible and
accurate modeling framework. T. Begin, B. Baynat, I.
GuérinLassous, T. Abreu  Performance Evaluation, Volume
96, 2016.
 Performance Evaluation of
Cloud Computing Centers with General Arrivals and Service.
T.Atmaca, T. Begin, A. Brandwajn, H. CastelTaleb  IEEE
Transactions on Parallel and Distributed Systems, Volume 27,
2016.
 Reduced complexity in M/Ph/c/N
queues. A. Brandwajn, T. Begin  Performance
Evaluation, Volume 78, 2014.
 A recurrent solution of Ph/M/c/Nlike
and Ph/M/clike queues. A. Brandwajn, T. Begin
 Journal of Applied Probability, Volume 49, Issue 1, 2012.
 Dynamic Resource
Management in Clouds: A Probabilistic Approach. P.
Gonçalves, S. Roy, T. Begin, P. Loiseau  IEICE Transactions
on Communications, 2012 (Invited Paper).
 Highlevel Approach to
Modeling of Observed System Behavior. T. Begin, A.
Brandwajn, B. Baynat, B. Wolfinger, S. Fdida  Performance
Evaluation, Volume 67, Issue 5, 2010
 A DFO technique to
Calibrate Queueing Models. T. Begin, B. Baynat, A.
Brandwajn, F. Sourd  Computers & Operations Research,
Volume 37, Issue 2, 2010.
 Higherorder distributional
properties in closed queueing networks. A. Brandwajn,
T. Begin  Performance Evaluation, Volume 66, Issue 11,
2009.

Conferences  Workshops  Misc.

 A new model for
DPDKbased virtual switches. S. Zidong B. Baynat, T.
Begin  IEEE NetSoft 2017  Bologna (Italy). (new)
 Conflict graphbased
Markovian model to estimate throughput in unsaturated IEEE
802.11 networks. M. Stojanova, T. Begin, A. Busson 
IEEE/IFIP WiOpt 2017  Paris (France). (new)
 A Note on the Causes
Degrading Communication between RSUs and Vehicles in
Overloaded Conditions. T. Begin, A. Boukerche  ACM
PEWASUN 2016  Valetta (Malta) (Invited Paper).
 Performance modeling of
virtual switching systems. G. Artero Gallardo, B.
Baynat, T. Begin  IEEE MASCOTS 2016  London (England).
 Evaluation of an EndtoEnd Delay Estimation in the Case of Multiple Flows in SDN Networks. N. Nguyen, T. Begin, A. Busson, I. GuérinLassous  ManSDN/NFV 2016  Montréal (Canada).
 Approximating the
endtoend delay using local measurements: a preliminary
study based on conditional expectation. N. Nguyen,
T.Begin, A. Busson, I. GuérinLassous  IEEE ISNCC 2016 
Hammamet (Tunisia) (Invited Paper).
 Towards a Passive
Measurementbased Estimator for the Standard Deviation of
the EndtoEnd Delay. N. Nguyen, T.Begin, A. Busson,
I. GuérinLassous  IEEE/IFIP NOMS 2016  Istanbul
(Turkey).
 Predicting the System
Performance by Combining Calibrated Performance Models of
its Components  A Preliminary Study. T.Begin, A.
Brandwajn  ICPE 2016  Delft (Netherlands).
 Modeling of IEEE 802.11
Multihop Wireless Chains with Hidden Nodes. T. Abreu,
B. Baynat, T.Begin, I. GuérinLassous, N. Nguyen  ACM MSWIM
2014  Montreal (Canada).
 Hierarchical Modeling of
IEEE 802.11 Multihop Wireless Networks. T. Abreu, B.
Baynat, T.Begin, I. GuérinLassous  ACM MSWIM 2013 
Barcelona (Spain).
 A note on the accuracy of
several existing approximations for M/Ph/m
queues. T.Begin, A. Brandwajn  HSNCE 2013  Kyoto
(Japan).
 Multiconstrained routing
algorithm: a networking evaluation. V. Nguyen,
T.Begin, I. GuérinLassous  HSNCE 2013  Kyoto (Japan).
 An MCMC Procedure for
calibrating a VoD Workload Model. S. Roy, T.Begin, P.
Gonçalves  GRETSI 2013  Brest (France).
 A Complete Framework for
Modelling and Generating Workload Volatility of a VoD
System. S. Roy, T.Begin, P. Gonçalves  IEEE TRAC 2013
 Cagliari (Italy).
 Demonstrating a
Versatile Model for VoD Buzz Workload in a Large Scale
Distributed Network. J.B. Delavoix, S. Roy, T.Begin,
P. Goncalves  IEEE CloudNet12 2012  Paris (France).
 Substitution Networks:
Performance Collapse due to Overhead in Communication
Times. T. Abreu, N. Nguyen, T.Begin, I.
GuérinLassous, B. Baynat  AdhocNets 2012  Paris (France)
(Invited Paper).
 KnowledgeBased
Admission Control: A RealTime Performance Analysis.
D. Ammar, J. Brochet, T. Begin, I. GuérinLassous, L.
Noirie  IEEE LCN 2012  Miami (Florida).
 KBAC: KnowledgeBased
Admission Control. D. Ammar, T. Begin, I.
GuérinLassous, L. Noirie  IEEE LCN 2012  Miami
(Florida).
 A Tool for solving Ph/M/c
and Ph/M/c/N queues.
T. Begin, A. Brandwajn  ACM QEST12  London
(Great Britain).
 An approximate solution for
Ph/Ph/1 and Ph/Ph/1/N queues.A.
Brandwajn, T. Begin  ACM/SPEC ICPE 2012  Boston
(Massachusetts).
 Contrôle d'Admission
Basé sur un Plan de Connaissance. D. Ammar, T. Begin,
I. GuérinLassous, L. Noirie  Algotel 2012  La Grande
Motte (France).
 Promoting Quality of
Service in Substitution Networks with Controlled Mobility.
T. Razafindralambo, T. Begin, M. Dias De Amorim, I.
GuérinLassous, N. Mitton, D. SimplotRym  AdHocNow 2011 
Paderborn (Germany).
 Evaluation and Comparison of
MBAC Solutions. D. Ammar, T. Begin, I.
GuérinLassous, L. Noirie  IEEE LCN 2011  Bonn
(Germany).
 Performance Evaluation of
a Single Node with General Arrivals and Service.
A. Brandwajn, T. Begin  ASMTA 2011  Venice (Italy).
 Une solution approchée
pour les files Ph/Ph/1 et Ph/Ph/1/N.
T. Begin, A. Brandwajn  Algotel 2011  Cap Estérel
(France).
 Contrôles d'admission basés
sur des mesures : Evaluation et comparaison de solutions.
D. Ammar, T. Begin, I. GuérinLassous, L. Noirie  CFIP
2011  Sainte Maxime (France).
 A new tool for
generating realistic Internet traffic in NS3. D.
Ammar, T. Begin, I. GuérinLassous  IEEE SIMUTools 2011 
Barcelona (Spain).
 Note sur la simulation
d'une file M/G/1 selon la distribution du temps de
service. T. Begin, A. Brandwajn  Algotel 2010  Belle
Dune (France).
 Considerations in Workload
Characterization in Parallel Access Volumes.
T. Begin, A. Brandwajn  CMG 2009  Dallas (Texas, US).
 Note sur les performances
de TCP dans un environnement sansfil multisaut. M.
Bezahaf, T. Begin, B. Baynat, S. Fdida  Poster CFIP 2009 
Strasbourg (France).
 On finding the right
balance between fairness and efficiency in WiMAX
scheduling through analytical modeling. S. Doirieux,
B. Baynat, T. Begin  IEEE MASCOTS 2009  London (England).
 Preliminary Results on a
Simple Approach to G/G/clike Queues.
A. Brandwajn, T. Begin  ASMTA 2009  Madrid (Spain).
 A Note on the Effects of
Service Time Distribution in the M/G/1 Queue.
A. Brandwajn, T. Begin  SPEC 2009  Austin (Texas, US).
 Modelisation et
Calibrage Automatiques de Systemes. Thèse de Doctorat
de l'Université Pierre et Marie Curie, Décembre 2008.
 Note sur les temps de
service résiduels. T. Begin, A. Brandwajn  CFIP 2008
 Les Arcs (France).
 Highlevel Approach
to Modeling Observed System Behavior.
T. Begin, A. Brandwajn, B. Baynat, B. Wolfinger, S. Fdida 
Poster at Performance 2007  Cologne (Germany).
 Towards an Automatic
Modeling Tool for Observed System Behavior. T. Begin,
A. Brandwajn, B. Baynat, B. Wolfinger, S. Fdida  EPEW 2007
 Berlin (Germany).
 Génération Automatique de
Modèles Calibrés. T. Begin, B. Baynat, A. Brandwajn,
S. Fdida, S. Kedad, F. Sourd  CFIP 2006  Tozeur (Tunisie).
 Generate calibrated
models in an automatic way.  Master Thesis (2005 
2006).

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Miscellaneous

Member of Technical Program Committees:
 IEEE LCN 2017
 42nd IEEE Conference on Local Computer Networks
 IEEE LCN 2016
 41st IEEE Conference on Local Computer Networks
 IEEE
LCN 2015  40th IEEE Conference on Local Computer
Networks
 PEWASUN
2015  ACM Symposium on Performance Evaluation of
Wireless Ad Hoc, Sensor, and Ubiquitous Networks
 PEWASUN 2014
 ACM Symposium on Performance Evaluation of Wireless Ad
Hoc, Sensor, and Ubiquitous Networks
 PEWASUN 2013
 ACM Symposium on Performance Evaluation of Wireless Ad
Hoc, Sensor, and Ubiquitous Networks
 PEWASUN 2012
 ACM Symposium on Performance Evaluation of Wireless Ad
Hoc, Sensor, and Ubiquitous Networks
 NOTERE /
CFIP 2012  Nouvelles Technologies de la Répartition 
Colloque francophone sur l’ingénierie des protocoles
 IEEE
CIF 2014  IEEE International Workshop on Complex
Information Flows
Reviewer for journals and conferences:
 COR 
Computers & Operations Research
 JPDC
 Journal of Parallel and Distributed Computing
 TMC
 IEEE Transactions on Mobile Computing
 AMM 
Applied Mathematical Modeling
 OR 
Operations Research
 RO 
RAIROOperations Research
 CL 
IEEE Communications Letters
 PERCOM 2010  IEEE
International Conference on Pervasive Computing and
Communications
 IPDPS 2011  IEEE
International Parallel & Distributed Processing
Symposium
Recommanded links (mostly in french):
Personnal interests: Tennis, Travelling, Cooking.
Citations I like about Research:
 "In theory, theory and practice are the same. In
practice, they're different."  Albert Einstein
 "As gold which he cannot spend will make no man
rich, so knowledge which he cannot apply will make no man
wise".  Samuel Johnson
 "Remember that all models are wrong; the practical
question is how wrong do they have to be to not be
useful."  George Box
 "Computer science is no more about computers than
astronomy is about telescopes."  Edsger Wybe
Dijkstra
 "Everything should be made as simple as possible,
but not simpler."  Albert Einstein
 "Faire simple nous a pris beaucoup de temps."
 Voltaire
 "On passe la moitié de son temps à refaire ce que
l'on n'a pas eu le temps de faire correctement". 
Loi de Myers
Funny citations I like about Computer Science:
 "Sometimes it pays to stay in bed on Monday, rather
than spending the rest of the week debugging Monday's
code."  Christopher Thompson
 "Debugging is twice as hard as writing the code in
the first place. Therefore, if you write the code as
cleverly as possible, you are, by definition, not smart
enough to debug it."  Brian W. Kernighan
 Programming today is a race between software
engineers striving to build bigger and better idiotproof
programs, and the universe trying to build bigger and
better idiots. So far, the universe is winning." 
Rick Cook
 "I have always wished for my computer to be as easy
to use as my telephone; my wish has come true because I
can no longer figure out how to use my telephone ." 
Bjarne Stroustrup
 "I think Microsoft named .Net so it wouldn’t show
up in a Unix directory listing."  Oktal
 "Fine, Java MIGHT be a good example of what a
programming language should be like. But Java applications
are good examples of what applications SHOULDN’T be like."
 pixadel
 "Perl – The only language that looks the same
before and after RSA encryption."  Keith Bostic
 "Always code as if the guy who ends up maintaining
your code will be a violent psychopath who knows where you
live."  Martin Golding
 "There are two ways of constructing a software
design. One way is to make it so simple that there are
obviously no deficiencies. And the other way is to make it
so complicated that there are no obvious deficiencies."
 C.A.R. Hoare
 "Be nice to nerds. Chances are you'll end up
working for one."  Bill Gates
 "If you think your teacher is tough, wait until you
get a boss. He doesn't have tenure."  Bill Gates
 "Life is not fair; get used to it."  Bill
Gates
 "Big data is like teenage sex: everyone talks about
it, nobody really knows how to do it, everyone thinks
everyone else is doing it, so everyone claims they are
doing it."  Dan Ariely

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Last
update: November 2016
