Mehun-sur-Yèvre – Le Château

Date de l'opération : 1989 (FP) ; 1986 (SD) ; 1985 (SD) ; 1984 (SU) Inventeur(s) : Delmarre P ; Bon Philippe En 1984, la fouille a porté sur une fosse de plan rectangulaire (1,70 m x 1,80 m), construite en appareil cyclopéen dont le mur nord-est a servi de fondation au mur de la courtine édifié au XIe s., tandis que le mur nord-ouest a été incorporé à la base du donjon édifié au XIIIe s. Dans un premier temps, cette fosse a pu servir de puits, par l'utilisation d'une source résurgente à fleur..

Identifying Alterability States of a Single Track Railway Line Control System

In the context of automation and deployment of computer based control systems, a specific application on French railway line is proposed on low traffic single track railway lines. The issue of updates requires thorough consideration. In the case of low traffic single track railway lines, handling the removal of a shunting track, which role is to allow trains to circulate in both directions of a same line, the issue of timing the update to the control system is particularly critical. Indeed, a wrongly timed update could lead to a deadlock, while one or more trains are expected to travel while respecting safety constraints on the blocked infrastructure. This paper studies the application of works from the field of dynamic software updating, specifically the works of Panzica La Manna et al. [12]. Using their results on a graph based model of a single track rail line, it identifies alterability states that ensure safety constraints are respected at all times without causing deadlocks. These results are then used to discuss the pertinence of using concepts from dynamic software updating in the context of railway systems

URBAN AND PERI URBAN HORTICULTURE AND THE CAPABILITY APPROACH THE CASE OF THE SOUTH-WEST PROVINCE OF CAMEROON

N° ISBN - 978-2-7380-1284-5International audienceThis paper uses the capability approach to analyse the impact of urban and peri urban horticulture on development in Africa. Is horticulture, considered as an innovation, able to improve the capabilities of people? This paper states that it is not the practice of horticulture which increases the capabilities of farmers but the level of capabilities that increases the chances of adopting horticulture. In order to answer the above question we have attempted to understand the context in which the agricultural sector and the farmers evolve in Africa, characterized by the urban transition towards a majority of urban population and the rise of nonfarm incomes. It appeared important to understand the underlying prerequisites for horticultural practices, that is, expensive agrochemical inputs and credit requirements

Endogenous Timing in a Mixed Duopoly with Managerial Delegation: A Quadratic Cost Case

National audienceno abstrac

B Formal Validation of ERTMS/ETCS Railway Operating Rules

The B method is a formal specification method and a means of formal verification and validation of safety-critical systems such as railway systems. In this short paper, we use the B4MSecure tool to transform the UML models, fulfilling requirements of European Railway Traffic Management System (ERTMS) operating rules, into B specifications in order to formally validate them

Modélisation et validation formelle des règles d'exploitation ferroviaires

Le système européen de surveillance du trafic ferroviaire (en anglais, European Rail Traffic Management System, ERTMS) est un système complexe de contrôle/commande et de signalisation ferroviaire mettant en ½uvre des règles européennes d'exploitation ferroviaires. Cet article propose une étude de cas basée sur deux scénarios extraits de ces règles, un scénario nominal d'autorisation de mouvement et un scénario exceptionnel de franchissement d'un arrêt. En effet, on trouve dans ces scénarios des aspects fonctionnels et de sécurité. Ces aspects nécessitent, d'une part, une modélisation fonctionnelle enrichie par des modèles décrivant la politique de sécurité et les autorisations données aux agents agissant sur le système, et d'autre part, une validation formelle. Pour ce faire, nous avons utilisé la plate-forme B4MSecure, fondée sur l'approche IDM (Ingénierie Dirigée par les Modèles), produisant à partir des modèles UML des spécifications formelles B. L'objectif de ces spécifications résultantes est de valider ces scénarios à l'aide d'outils d'animation et de preuve de spécifications B afin de garantir une analyse rigoureuse de la fonctionnalité et de la politique de sécurité

Statistical Automaton for Verifying Temporal Properties and Computing Information on Traces

Verification is decisive for embedded software. The goal of this work is to verify temporal properties on industrial applications, with the help of formal dynamic analysis. The approach presented in this paper is composed of three steps: formalization of temporal properties using an adequate language, generation of execution traces from a given property and verification of this property on execution traces. This paper focuses on the verification step. Use of a new kind of Büchi automaton has been proposed to provide an efficient verification taking into account the industrial needs and constraints. A prototype has been developed and used to carry out experiments on different anonymous real industrial applications

Operation of graphene-on-quartz acoustic cavity at cryogenic temperatures

This paper presents observation of mechanical effects of a graphene monolayer deposited on a quartz substrate designed to operate as an extremely low-loss acoustic cavity standard at liquid-helium temperature. Resonances of this state-of-the-art cavity are used to probe the mechanical loss of the graphene film, assessed to be about $80 \: 10^{-4}$ at 4K. Significant frequency shifts of positive and negative sign have been observed for many overtones of three modes of vibration. These shifts cannot be predicted by the mass-loading model widely used in the Quartz Microbalance community. Although thermo-mechanical stresses are expected in such a graphene-on-quartz composite device at low temperature due to a mismatch of expansion coefficients of both materials, it cannot fully recover the mismatch of the mass loading effect. Based on a force-frequency theory applied to the three thickness modes, to reconcile the experimental results, the mean stresses in the graphene monolayer should be of the order of 140 GPa, likely close to its tensile strength.Comment: Corrected typos. New Fig. Text improve