Verification of Real-Time Systems using Linear Relation Analysis

Linear Relation Analysis [11] is an abstract interpretation devoted to the automatic discovery of invariant linear inequalities among numerical variables of a program. In this paper, we apply such an analysis to the verification of quantitative time properties of two kinds of systems: synchronous programs and linear hybrid systems.     

Effects of Grit Blasting and Annealing on the High-Temperature Oxidation Behavior of Austenitic and Ferritic Fe-Cr Alloys

Grit blasting (corundum) of an austenitic AISI 304 stainless steel (18Cr-8Ni) and of a low-alloy SA213 T22 ferritic steel (2.25Cr-1Mo) followed by annealing in argon resulted in enhanced outward diffusion of Cr, Mn, and Fe. Whereas 3 bar of blasting pressure allowed to grow more Cr₂O₃ and Mn _x Cr_3?x O₄ spinel-rich scales, higher pressures gave rise to Fe₂O₃-enriched layers and were therefore disregarded. The effect of annealing pre-oxidation treatment on the isothermal oxidation resistance was subsequently evaluated for 48 h for both steels and the results were compared with their polished counterparts. The change of oxidation kinetics of the pre-oxidized 18Cr-8Ni samples at 850 °C was ascribed to the growth of a duplex Cr₂O₃/Mn _x Cr_3?x O₄ scale that remained adherent to the substrate. Such a positive effect was less marked when considering the oxidation kinetics of the 2.25Cr-1Mo steel but a more compact and thinner Fe _x Cr_3?x O₄ subscale grew at 650 °C compared to that of the polished samples. It appeared that the beneficial effect is very sensitive to the experimental blasting conditions. The input of Raman micro-spectroscopy was shown to be of ground importance in the precise identification of multiple oxide phases grown under the different conditions investigated in this study.     

Marsokhod: Autonomous navigation tests on a Mars-like terrain

This paper describes the Russian rover Marsokhod, designed by Babakin Center for Mars exploration and the navigation sub-system based on stereovision developed by the French Space Agency C.N.E.S. to provide the rover with autonomous motion ability, improving thus its exploration range on the surface of Mars. Tests of the complete vehicle, including autonomous locomotion, has been recently fulfilled on a Mars-like area build in C.N.E.S. for this purpose by a joined Russian-French team; the main results and conclusions of these test are related.