Janvier 2017


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Mardi 3 Janvier
Heure: 14:00 - 17:00
Lieu: Salle B107, bâtiment B, Université de Villetaneuse
Résumé: Combinatorial physics, hypergeometric functions and symmetries of differential equations
Description: Youssef Abelaziz
Mardi 10 Janvier
Heure: 14:00 - 17:00
Lieu: Salle B107, bâtiment B, Université de Villetaneuse
Résumé: Algorithmes efficaces de génération aléatoire contrainte
Description: Philippe Duchon
Heure: 15:00 - 18:00
Lieu: Salle B107, bâtiment B, Université de Villetaneuse
Résumé: Combinatorial physics, hypergeometric functions and symmetries of differential equations
Description: Youssef Abelaziz
Jeudi 12 Janvier
Heure: 13:00 - 14:00
Lieu: Salle B107, bâtiment B, Université de Villetaneuse
Résumé: Harnessing Malware Intelligence for Defense and Attribution
Description: Arun Lakhotia The number of unique malware has been doubling every year for over two decades.
The majority of effort in malware analysis has focused on methods for
preventing malware infection. We view the exponential growth of malware as an
underutilized source of intelligence. Given that the number of malware authors
are not doubling each year, the large volume of malware must contain evidence
that connects them. The challenge is how to extract the connections and do so
in a timely manner to be useful.

This talk will describe Cythereal MAGIC, a cloud-based malware analysis
service, for mining large scale malware repositories. MAGIC, an offshoot of
research conducted under the DARPA Cyber Genome program, uses malware "genome"
to construct features that are resilient to many obfuscations. The correlations
discovered by MAGIC can be used to prevent and detect zero-day malware. The
correlations can also be used to investigate malware attacks for attribution.
Heure: 15:30 - 16:30
Lieu: Salle B107, bâtiment B, Université de Villetaneuse
Résumé: Parametric model checking timed automata under non-Zenoness assumption
Description: Gia Real-time systems often involve hard timing constraints and concurrency, and are notoriously hard to design or verify. Given a model of a real-time system and a property, parametric model-checking aims at synthesizing timing valuations such that the model satisfies the property. However, the counter-example returned by such a procedure may be Zeno (an infinite number of discrete actions in a finite time), which is unrealistic. On the one hand, we show that synthesizing parameter valuations such that at least one counter-example run is non-Zeno is undecidable for Parametric Timed Automata (PTA). On the other hand, we propose a procedure based on a transformation of PTA into Clock Upper Bound PTA to derive such valuations.
Jeudi 19 Janvier
Heure: 15:30 - 16:00
Lieu: Salle B107, bâtiment B, Université de Villetaneuse
Résumé: What’s decidable about parametric timed automata?
Description: Étienne André Parametric timed automata (PTA) are a powerful formalism to reason,
simulate and formally verify critical real-time systems.
After two decades of research on PTA, it is now well-understood that
any non-trivial problem studied is undecidable for general PTA.
We provide here a survey of decision and computation problems for PTA.
On the one hand, bounding time, bounding the number of parameters or
the domain of the parameters does not (in general) lead to any decidability.
On the other hand, restricting the number of clocks, the use of
clocks (compared or not with the parameters), and the use of parameters
(e.g. used only as upper or lower bounds) leads to decidability of some
problems.
Mardi 24 Janvier
Heure: 12:30 - 13:30
Lieu: Salle B107, bâtiment B, Université de Villetaneuse
Résumé: Reformulations for Mixed-Integer Nonlinear Programs: a surprisingly simple one with surprisingly good results in (quite) a few different applications
Description: Antonio Frangioni We describe a quite long line of research about the Perpective Reformulation of certain Mixed-Integer NonLinear Programs, which started with a total serendipity moment motivated by trying to prove wrong a referee who was in fact right but for the wrong reasons. The research was brought forward in part by a series of othe r developments motivated by factors such as the need to finding another application to publish the first paper, the need of fending off competing research teams, and finding a good idea as a by-product of an original one that would never work. All this brought us to a Project-and-Lift approach to certain projected reformulations of the Perspective Reformulation which seems to be one of the few authentic violations of the "no free lunch principle": an easy reformulation of a MIQP with the very same size and structure as the original one but with a substantially stronger bound. Apart from providing an overview on a recent and potentially interesting research field in MINLP, we hope that this talk can motivate the audience to making more errors and looking at them with more interest.
Jeudi 26 Janvier
Heure: 12:15 - 13:30
Lieu: Salle B107, bâtiment B, Université de Villetaneuse
Résumé: Fouille de données déclarative
Description: Benjamin Negrevergne Une grande variété de techniques de fouille de données ne sont disponibles que sous la forme d'algorithmes en programmation impérative. Ces algorithmes sont difficiles à (ré-)utiliser et difficiles à adapter aux besoins de leurs utilisateurs. Une proposition récente vise à utiliser le paradigme de la programmation par contraintes pour obtenir des formulations plus déclaratives de ces techniques. Cette approche offre de nombreux avantages, comme celui de pouvoir incorporer facilement des connaissances métier au sein du processus de fouille.

Dans cette présentation, j'expliquerai comment formuler et résoudre efficacement des problèmes de fouille de données grâce à la programmation par contraintes. Je parlerai également des limites de cette approche pour la formulation de problèmes de fouille de données structurées (fouille de séquences ou graphes) ou par la formulation de critères d'intérêts complexes (combinaisons de contraintes, préférences) ainsi que de mes contributions dans ce domaine.
Mardi 31 Janvier
Heure: 14:00 - 17:00
Lieu: Salle B107, bâtiment B, Université de Villetaneuse
Résumé: Enumerative combinatorics of maps/polyominoes/2-stack-sortable permutations
Description: Veronica Guerrini