LIFO - Bâtiment IIIA
Rue Léonard de Vinci
F-45067 ORLEANS Cedex 2
Tel: +33 (0)2 38 41 99 29
Fax: +33 (0)2 38 41 71 37
22/02/2021 : Learning Sparse Penalties for Change-point Detection using Max Margin Interval Regression
Toby Hocking (Northern Arizona University) Résumé
Attention : Débute à 16 h 15.
15/02/2021 : À venir
Cédric Eichler (INSA Centre Val de Loire) Résumé
Attention : Lieu : En ligne
08/02/2021 : A calculus of Branching Processes
Jean Krivine (IRIF) Résumé
Attention : Lieu :
01/02/2021 : Categorifying Non-Idempotent Intersection Types
Federico Olimpieri (LIPN) Résumé
Attention : Lieu : En ligne
18/01/2021 : Toward Safe and Efficient Reconfiguration with Concerto
Simon Robillard et Hélène Coullon (IMT Atlantique) Résumé
Attention : Débute à 13 h 45. Lieu : En ligne
Learning Sparse Penalties for Change-point Detection using Max Margin Interval Regression Toby Hocking, Northern Arizona University
In segmentation models, the number of change-points is typically chosen using a penalized cost function. In this work, we propose to learn the penalty and its constants in databases of signals with weak change-point annotations. We propose a convex relaxation for the resulting interval regression problem, and solve it using accelerated proximal gradient methods. We show that this method achieves state-of-the-art change-point detection in a database of annotated DNA copy number profiles from neuroblastoma tumors.
A calculus of Branching Processes Jean Krivine, IRIF
(joint work with Thomas Ehrhard (CNRS, IRIF) and Ying Jiang (ISCAS, China)
CCS-like calculi can be viewed as an extension of classical automata with communication primitives. In this talk I will show what we obtained when we applied this principle to tree-automata: a calculus of branching processes (termed CBP), where the continuations of communications are allowed to branch according to the arity of the communication channel. I will show that CBP can be “implemented” by a fully compositional LTS semantics. I will argue that CBP offers an interesting tradeoff between calculi with a fixed communication topology à la CCS and calculi with dynamic connectivity such as the π-calculus.
Reference: A Calculus of Branching Processes. Ehrhard, Krivine and Jiang. TCS 807(6) pp 169–184.
Categorifying Non-Idempotent Intersection Types Federico Olimpieri, LIPN
Non-idempotent intersection types can be seen as a syntactic presentation of a well-known denotational semantics for the lambda-calculus, the category of sets and relations. Building on previous work, we present a categorification of this line of thought in the framework of the bang calculus, an untyped version of Levy’s call-by-push-value. We define a bicategorical model for the bang calculus, whose syntactic counterpart is a suitable category of types. In the framework of distributors, we introduce intersection type distributors, a bicategorical proof relevant refinement of relational semantics. Finally, we prove that intersection type distributors characterize normalization at depth 0.
Toward Safe and Efficient Reconfiguration with Concerto Simon Robillard et Hélène Coullon, IMT Atlantique
For large-scale distributed systems that need to adapt to a changing environment, conducting a reconfiguration is a challenging task. In particular, efficient reconfigurations require the coordination of multiple tasks with complex dependencies. We present Concerto, a model used to manage the lifecycle of software components and coordinate their reconfiguration operations. Concerto promotes efficiency with a fine-grained representation of dependencies and parallel execution of reconfiguration actions, both within components and between them. In this paper, the elements of the model are described as well as their formal semantics. In addition, we outline a performance model that can be used to estimate the time required by reconfigurations, and we describe an implementation of the model. The evaluation demonstrates the accuracy of the performance estimations, and illustrates the performance gains provided by the execution model of Concerto compared to state-of-the-art systems. Keywords: reconfiguration, component-based models, coordination, parallelism, distributed software