Conservatoire national des arts et métiers

About: Conservatoire national des arts et métiers is a education organization based out in Paris, France. It is known for research contribution in the topics: Population & Context (language use). The organization has 3573 authors who have published 7127 publications receiving 141430 citations. The organization is also known as: CNAM & Conservatoire des arts et métiers.

On Liveness in Extended non Self-Controlling Nets

Abstract: For several years, research has been done to establish relations between the liveness of a net and the structure of the underlying graph. This work has resulted in the proposition of polynomial algorithms to check liveness for particular classes of nets. In this paper, we present Extended Non Self-Controlling Nets, a class of nets that includes Extended Free-Choice Nets and Non Self-Controlling Nets. We develop some properties of this new class of nets and we propose polynomial algorithms whose application domain is wider than the domain of the previous algorithms.

Absolute frequency measurement of an I2 stabilized Nd:YAG optical frequency standard

Abstract: The frequency of an I2 stabilized Nd:YAG optical frequency standard, developed at the BNM-INM as a national standard for the `mise en pratique' of the definition of the metre, has been measured with a frequency measurement chain based on a femtosecond laser. A frequency (in-)stability of 2.5×10-13τ-1/2 has been measured in the optical domain against a hydrogen maser. The measured (in-)stability decreases to 1×10-14 without evidence of flicker floor.

Modeling of Fuel Sloshing and its Physical Effects on Flutter

Abstract: The sloshing effects of an internal fluid on the flutter envelope of an aeroelastic system have received little attention in the open literature. This issue is nevertheless relevant for many aircraft, especially high-performance fighter jets carrying stores. This paper addresses some aspects of this problem as well as related modeling and analysis issues. These include the importance or insignificance of accounting for the hydroelastic effect when modeling an internal fluid and its container as well as accounting for that container when modeling the aerodynamics of the overall aeroelastic system. The paper also reports on the findings of four independent sets of flutter analyses performed for a wing–store test configuration and various fuel fill levels in the subsonic, transonic, and early supersonic regimes. Two of these sets of numerica l experiments relied on a computational-fluid-dynamics-based computational technology, and two of them on the doublet-lattice method or a supersonic lifting-surface theo...

Solving the ignoring problem for partial order reduction

Abstract: Partial order reduction limits the state explosion problem that arises in model checking by limiting the exploration of redundant interleavings. A state space search algorithm based on this principle may ignore some interleavings by delaying the execution of some actions provided that an equivalent interleaving is explored. However, if one does not choose postponed actions carefully, some of these may be infinitely delayed. This pathological situation is commonly referred to as the ignoring problem. The prevention of this phenomenon is not mandatory if one wants to verify if the system halts but it must be resolved for more elaborate properties like, for example, safety or liveness properties. We present in this work some solutions to this problem. In order to assess the quality of our propositions, we included them in our model checker Helena. We report the result of some experiments which show that our algorithms yield better reductions than state of the art algorithms like those implemented in the Spin tool.