Section: Partnerships and Cooperations

International Initiatives

Inria International Partners

IIP TuMuLT

• Title: Trustworthy Modeling using Logical Time

• International Partner (Institution - Laboratory - Researcher):

  • E.C.N.U. (Shanghai, China) - Departement of Software Engineering and Computer Science - Zhang Min

  • Duration: 2018 - 2022

  • See also: https://team.inria.fr/tumult/

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  Modeling the Uncertain Environments of Cyber-Physical Systems: Logical Time is one of the main scientific foundation of the KAIROS Team. From the background in theory of concurrency, we are used to consider mainly discrete control systems that can guarantee a functional determinism independently of any implementation-specific timing variation. Addressing Cyber-Physical Systems and the Internet of Things means widening those assumptions to consider the external environment, typically involving uncertainty, as part of the design. This task explores the definition of sound extensions to logical time to capture both the physical continuous behavior and make an abstract characterization as a statistical approximation.

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  SMT For Logical Time: While synchronous systems usually focus on finite state-based control systems, our abstraction of logical time relies on both Boolean algebra (for synchronous operations) and integer arithmetic (for synchronizing mechanisms), In that context, SMT is a promising solution to solve systems that combine several theories. We had first results on this aspect [SCP’17] but we still need to increase the subset of constraints that can be addressed efficiently as well as the performances of the solving tools.

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  Spatio-Temporal Specification for Trustworthy Intelligent Transportation Systems: Focusing on Intelligent Transportation Systems as a subset of Cyber-Physical Systems, we encounter specific problems. This task would focus on extensions of our framework for a spatio-temporal logics based on logical time. This means a description of the location of infrastructures as well as the ability to build constraints that depend both on time (logic or physical) and locations (logical or physical).

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  Symbolic approaches for models and analysis of Open systems: Methods for analyzing and guaranteeing the properties of critical and complex systems, including their data and time depend aspects, have strongly evolved with the emergence of efficient SAT and SMT engines. We are working on novel methods combining classical verification paradigms with SMT approaches to create symbolic and compositional verification methods and tool platforms [22], [27].

  Collaboration will come in the form of scientific short or middle term visits, student exchanges (master and PhD), and organization of events (workshops and conferences).

Informal International Partners

• Luigi Liquori has a steady collaboration with researchers from University of Udine and Turin, Italy.

• We keep close informal relations with the Universities of Kiel and Bamberg Germany, in the context of the Synchronous Reactive academic community. We all attended the yearly Synchron seminar, held this year in Aussois (together with researchers from Verimag and the Parkas and Spades Inria teams).

• Frédéric Mallet has a collaboration with Peter Olvecsky from University of Oslo. He was funded in 2019 by a program of the French Embassy in Norway called Asgard.

Participation in Other International Programs

• PHC Cai Yuan Pei: The partnership is a joint funding from Campus France and Chinese Scholarship Council (CSC) to fund short exchanges of permanent staffs and long exchanges of PhD students. A 2-week visit was carried out by Frédéric Mallet in 2019, while Xiaohong Chen is visiting France during 3 months starting in mid-November. The program is funded for three years and a PhD student (Zhang Juan) will visit our team during 16 months in 2020.