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International audience; The corrosion process (oxidation and hydriding) of the zirconium alloy cladding is one of the limiting factors on the fuel rod lifetime, in particular for the Zircaloy-4 alloy. The corrosion rate of this alloy shows indeed a great acceleration at high burn-up in Light Water Reactors. Understanding the corrosion behavior under irradiation for this alloy is an important technological issue for the safety and efficiency of LWRs. In particular, understanding the effect of irradiation on the metal and the oxide layers is a key parameter in the study of corrosion behavior of zirconium alloys. Zircaloy-4 samples have undergone helium and proton ion-irradiation up to 0.3 dpa forming a uniform defect distribution up to 1 µm deep. Both as-received and pre-corroded samples have been irradiated in order to compare the effect of metal irradiation to that of oxide layer irradiation. After irradiation, samples have been corroded in order to study the impact of irradiation defects in the metal and in pre-existing oxide layers on the formation of new oxide layers. Synchrotron X-ray micro-diffraction and micro-fluorescence are used to follow the evolution of oxide crystallographic phases, texture and stoichiometry both in the metal and in the oxide in cross-section. In particular, the tetragonal oxide phase fraction, which has been known to have an important role on corrosion behavior, is mapped in both unirradiated and irradiated metal at the sub-micron scale and appears to be significantly affected by irradiation. These observations, complemented with electron microscopy analyses on samples in carefully chosen areas of interest are combined in order to fully characterize changes due to irradiation in metal and oxide phases of both alloys.

International audience; Orchestras of Digital Musical Instruments (DMIs) enable new musical collaboration possibilities, extending those of acoustic and electric orchestras. However the creation and development of these orchestras remain constrained. In fact, each new musical collaboration system or orchestra piece relies on a fixed number of musicians, a fixed set of instruments (often only one), and a fixed subset of possible modes of collaboration. In this paper, we describe a unified framework that enables the design of Digital Orchestras with potentially different DMIs and an expand-able set of collaboration modes. It relies on research done on analysis and classification of traditional and digital orchestras, on research in Collaborative Virtual Environments, and on interviews of musicians and composers. The BOEUF framework consists of a classification of modes of collaboration and a set of components for modelling digital orchestras. Integrating this framework into DMIs will enable advanced musical collaboration modes to be used in any digital orchestra, including spontaneous jam sessions.

International audience; This chapter introduces several state of the art techniques that could help to make deep underwater archaeological photogrammetric surveys easier, faster, more accurate, and to provide more visually appealing representations in 2D and 3D for both experts and public. We detail how the 3D captured data is analysed and then represented using ontologies, and how this facilitates interdisciplinary interpretation and cooperation. Towards more automation, we present a new method that adopts a deep learning approach for the detection and the recognition of objects of interest, amphorae for example. In order to provide more readable, direct and clearer illustrations, we describe several techniques that generate different styles of sketches out of orthophotos developed using neural networks. In the same direction, we present the Non-Photorealistic Rendering (NPR) technique, which converts a 3D model into a more readable 2D representation that is more useful to communicate and simplifies the identification of objects of interest. Regarding public dissemination, we demonstrate how recent advances in virtual reality to provide an accurate, high resolution, amusing and appropriate visualization tool that offers the public the possibility to ‘visit’ an unreachable archaeological site. Finally, we conclude by introducing the plenoptic approach, a new promising technology that can change the future of the photogrammetry by making it easier and less time consuming and that allows a user to create a 3D model using only one camera shot. Here, we introduce the concepts, the developing process, and some results, which we obtained with underwater imaging.

International audience; The relative efficiency of auctions and negotiations is still a puzzle in the literature. While auctions are the prescribed procedures and the most used ones for public procurement, in the private sector, where buyers are free to choose their purchasing method, competitive tendering is far from being their preferred option (Bajari et al. 2009). In addition, recent empirical studies (Estache et al. 2009, Bajari et al. 2009) highlight some failures of auction procedures and identify conditions under which negotiation is more efficient. In particular, they show that auctions perform poorly when projects are complex. In this paper, our aim is to contribute to this debate by providing an empirical analysis of how awarding mechanisms are chosen in public procurement in France. To this end, we examine a comprehensive database of 76,188 observations corresponding to the entire set of public procurement work contracts awarded between 2005 and 2007 in the construction sector. We find empirical regularities regarding the choice of awarding procedures by public buyers. However, most of these regularities do not coincide with what the theoretical literature considers as transaction-cost minimizing behaviours. In particular, the size of the construction projects as well as the length of contracts do not appear as key determinants of the choice of awarding procedures, which translates into costly renegotiations.

International audience; Toxoplasma gondii is a highly successful parasite that is thought to infect nearly one third of the world's population. Molecular epidemiology studies have illuminated the population structure of T. gondii strains world-wide and enabled insights into how the parasite is transmitted and the frequency of genetic exchange. Toxoplasma population genetics studies have shown that in North America and Europe, three genotypes have predominated whereas other diverse genotypes have propagated in other parts of the world, particularly in Central and South America. This chapter summarizes the techniques used to understand the population structure of T. gondii and how these techniques have also been helpful in understanding outbreaks of toxoplasmosis. As technology has advanced, more in-depth studies have facilitated our understanding of how differing genotypes can be linked to biological phenotypes including human disease.

National audience; This chapter focuses on the economic mechanisms at work in recent models of advertising finance in media markets developed around the concept of two-sided markets. The objective is to highlight new and original insights from this approach, and to clarify the conceptual aspects. The chapter first develops a canonical model of two-sided markets for advertising, where platforms deliver content to consumers and resell their “attention” to advertisers. A key distinction is drawn between free media and pay media, where the former result from the combination of valuable consumer attention and low ad-nuisance cost. The first part discusses various conceptual issues such as equilibrium concepts and the nature of inefficiencies in advertising markets, and concrete issues such as congestion and second-degree discrimination. The second part is devoted to recent contributions on issues arising when consumers patronize multiple platforms. In this case, platforms can only charge incremental values to advertisers, which reduce their market power and affect their price strategies and advertising levels. The last part discusses the implications of the two-sided nature of the media markets for the choice of content and diversity.

International audience; The threat of quantum computers has sparked the development of a new kind of cryptography to resist their attacks. Isogenies between elliptic curves are one of the tools used for such cryptosystems. They are championed by SIKE (Supersingular isogeny key encapsulation), an "alternate candidate" of the third round of the NIST Post-Quantum Cryptography Standardization Process. While all candidates are believed to be mathematically secure, their implementations may be vulnerable to hardware attacks. In this work we investigate for the first time whether Ti's 2017 theoretical fault injection attack is exploitable in practice. We also examine suitable countermeasures. We manage to recover the secret thanks to electromagnetic fault injection on an ARM Cortex A53 using a correct and an altered public key generation. Moreover we propose a suitable countermeasure to detect faults that has a low overhead as it takes advantage of a redundancy already present in SIKE implementations.

International audience; The study area mainly includes the continental shelves of two European states (France and Spain), three North African countries (Algeria, Morocco and Tunisia), and Gibraltar and Monaco. Overall, the total shelf area in the western Mediterranean down to the 150 m isobath is 208,000 km2 within a total basin area of 1,343,620 km2. There is a major difference in the degree of available information from EU member states and North African countries.