École normale supérieure de Cachan

About: École normale supérieure de Cachan is a education organization based out in Cachan, Île-de-France, France. It is known for research contribution in the topics: Decidability & Finite element method. The organization has 2717 authors who have published 5585 publications receiving 175925 citations.

Rewriting Systems with Data

Abstract: We introduce a uniform framework for reasoning about infinite-state systems with unbounded control structures and unbounded data domains. Our framework is based on constrained rewriting systems on words over an infinite alphabet. We consider several rewriting semantics: factor, prefix, and multiset rewriting. Constraints are expressed in a logic on such words which is parametrized by a first-order theory on the considered data domain. We show that our framework is suitable for reasoning about various classes of systems such as recursive sequential programs, multithreaded programs, parametrized and dynamic networks of processes, etc. Then, we provide generic results (1) for the decidability of the satisfiability problem of the fragment ? * ? * of this logic provided that the underlying logic on data is decidable, and (2) for proving inductive invariance and for carrying out Hoare style reasoning within this fragment. We also show that the reachability problem is decidable for a class of prefix rewriting systems with integer data.

Weak solutions of the initial-boundary value problem for the Vlasov–Poisson system

Abstract: In this paper we show the existence of a weak solution of the boundary value problem for the time dependent Vlasov–Poisson system. First, we regularize the system in order to apply a fixed-point theorem. Then we pass to the limit using an energy estimate.

Structuring new automotive industries, restructuring old automotive industries and the new geopolitics of the global automotive sector

Abstract: The paper considers how the process of structuring new automotive industries in emerging countries and restructuring old automotive industries in the TRIAD is transforming the product policies, productive organisations and employment relationships of global carmakers and redesigning the global and local geography of the design and production of cars. Following the review of the main trends implied by this evolution, it discusses the pertinence of the ‘productive models’ approach developed by the Gerpisa international network to frame and investigate these new issues. In conclusion, it stresses the radical novelty of the double process of global structuring and restructuring new and old automotive industries and proposes an updated set of analytical tools and research questions to fully grasp its multiple and far-reaching implications.