Décembre 2020

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Jeudi 3 Décembre
Heure: 10:30 - 11:30
Lieu: Salle B107, bâtiment B, Université de Villetaneuse
Résumé: Geometric Set Cover via Randomized LP Rounding
Description: Mustafa Nabil Geometric set-cover/hitting-set problems arise naturally in several basic settings, and therefore the problem of computing small set covers (and hitting sets) has been studied extensively. A common first step in solving such optimization problems is to formulate and solve the corresponding covering/packing LP to get a fractional solution. Then the task reduces to constructing an integer solution from this fractional solution. In this talk, I will present a new simple iterative randomized rounding scheme that gives optimal approximation bounds, within constant factors, for many well-studied geometric systems.
Lundi 7 Décembre
Heure: 12:30 - 13:30
Lieu: Salle B107, bâtiment B, Université de Villetaneuse
Résumé: wikiSERA: Domain independent evaluation of automatic summaries using relevance analysis on Wikipedia
Description: Jorge Garcia Flores Text summarization has been the subject of increasing research efforts in the last years. However, automatic summary evaluation is as crucial as the summarization task itself. For more than 15 years, the dominant approach for evaluating this task has been ROUGE [Lin, 2004], a machine translation inspired lexical comparison between a candidate machine summary and a set of human gold standard summaries. Lexical comparison might be a suitable evaluation approach for extractive summarization systems. However, the methodological leap of Deep Learning brought increasing research efforts on abstractive summarization, which raised some questions about the pertinence of an all-lexical evaluation perspective. In this work we present wikiSERA, an open source improvement of the SERA evaluation method [Cohan et al., 2018], based on a semantic comparison of information extraction vectors from a document base. We adapted the method to generic domain summarization and provide to the community a Wikipedia based implementation that shows robust correlation with human evaluations.


Après le séminaire on va saluer Jorge qui nous quitte pour quelques mois, avec un apéro de "résistance" (contre la Covid, la LPR, etc..)
Jeudi 17 Décembre
Heure: 10:30 - 11:30
Lieu: Salle B107, bâtiment B, Université de Villetaneuse
Résumé: Combinatorial Optimization problems in telecommunication networksitre bientôt disponible
Description: Sébastien Martin The telecommunication network area provides lot of interesting optimization problems. Furthermore, the arrival of 5G technology modifies the traditional combinatorial optimization problems by adding some specificities. We quickly present some case studies done by the "network optimization" team from "Datacom" department. For instance, we present the "network slicing technology" ensuring isolation in resource sharing among users. We also describe the "Deterministic Networking" to guarantee bounded jitter and latency constraints. Finally, we show how to consider network calculus in optimization problems to ensure latency guarantees.
We finish by the presentation of future telecommunication network topics from an optimization point of view.

Joint work with Nicolas Huin, Jérémie Leguay, Youcef Magnouche, Paolo Medagliani