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International audience; In this paper, we study the effect of smartphone camera exposure on the performance of optical camera communications (OCC) link. The exposure parameters of image sensor sensitivity (ISO), aperture and shutter speed are included. A static OCC link with a 8 × 8 red, green and blue (RGB) LED array employed as the transmitter and a smartphone camera as the receiver is demonstrated to verify the study. Signal-to-noise ratio (SNR) analysis at different ISO values, the effect of aperture and shutter speed on communication link quality is performed. While SNRs of 20.6 dB and 16.9 dB are measured at 1 m and 2 m transmission distance, respectively for a ISO value of 100, they are decreased to 17.4 dB and 13.32 dB for a ISO of 800. The bit error rate (BER) of a 1 m long OCC link with a camera's shutter speed of 1/6000 s is 1.3 × 10 −3 (i.e., below the forward error correction BER limit of 3.8 × 10 −3) and is dropped to 0.0125 at a shutter speed of 1/20 s. This study provides insight of the basic smartphone settings and the exposure adjustment for further complex OCC links.

WEST (Tungsten Environment in Steady-State Tokamak) will be operating by the end of 2016 as a test bed for the ITER divertor components in long pulse operation. In this context, radiative cooling of highly ionized impurities like tungsten (W) sputtered from Plasma Facing Components (PFC) into the plasma core is a critical issue since even small impurity concentrations below 10-4 degrade significantly plasma performances and can lead to radiative collapse. In the plasma core, tungsten emission is dominant in the Soft X-ray (SXR) range 0.1 keV -- 15 keV with complex contributions from line transition, radiative recombination and Bremsstrahlung emission.This paper presents the recent development of a synthetic SXR diagnostic using GEM (Gas Electron Multiplier) detectors. This diagnostic will be used on WEST for W transport studies and will be equipped with two new GEM based poloidal cameras allowing 2D tomographic reconstructions with spectral resolution in energy bands. Thus once GEM response to plasma emissivity is characterized thanks to synthetic diagnostic, it offers new possibilities to disentangle the different SXR contributions in harsh fusion environments like e.g. WEST or ITER with respect to conventional semiconductor diodes working in current mode. Emitted SXR spectrum from the plasma is modelled thanks to ADAS database from given WEST scenario. The synthetic diagnostic includes Lines of Sight (LoS) etendues of the two cameras as well as probability of photoabsorption through filters, photoionization in the detection gas mixture (Ar-CO2), and transport of electron avalanches in the gas through GEM foils as computed with Magboltz. Local SXR emissivity is then retrieved from tomographic inversion using a Minimum Fisher Information (MFI) algorithm. Comment: in 43rd European Physical Society Conference on Plasma Physics, Jul 2016, Leuven, Belgium

The interplay among the effects of dispersion, nonlinearity and gain/loss in optical fibre systems can be efficiently used to shape the pulses and manipulate and control the light dynamics and, hence, lead to different pulse-shaping regimes [1,2]. However, achieving a precise waveform with various prescribed characteristics is a complex issue that requires careful choice of the initial pulse conditions and system parameters. The general problem of optimisation towards a target operational regime in a complex multi-parameter space can be intelligently addressed by implementing machine-learning strategies. In this paper, we discuss a novel approach to the characterisation and optimisation of nonlinear shaping in fibre systems, which combines numerical simulations of the governing equations to identify the relevant parameters and the machine-learning method of neural networks (NNs) to make predictions across a larger range of the data domain. We illustrate this general method through application to two configurations.

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; In this paper, we provide a necessary clarification of the good security properties that can be obtained from parallel implementations of masking schemes. For this purpose, we first argue that (i) the probing model is not straightforward to interpret, since it more naturally captures the intuitions of serial implementations, and (ii) the noisy leakage model is not always convenient, e.g. when combined with formal methods for the verification of cryptographic implementations. Therefore we introduce a new model, the bounded moment model, that formalizes a weaker notion of security order frequently used in the side-channel literature. Interestingly , we prove that probing security for a serial implementation implies bounded moment security for its parallel counterpart. This result therefore enables an accurate understanding of the links between formal security analyses of masking schemes and experimental security evaluations based on the estimation of statistical moments Besides its consolidating nature, our work also brings useful technical contributions. First, we describe and analyze refreshing and multiplication algorithms that are well suited for parallel implementations and improve security against multivariate side-channel attacks. Second, we show that simple refreshing algorithms (with linear complexity) that are not secure in the continuous probing model are secure in the continuous bounded moment model. Eventually, we discuss the independent leakage assumption required for masking to deliver its security promises, and its specificities related to the serial or parallel nature of an implementation.

International audience; The paper reviews mobile government (m-Government) adoption and diffusion factors in developed and developing economies. m-Government is viewed as a class of e-Government applications and refers to any transaction via mobile technologies, such as laptops, phones or personal digital assistants (PDAs). The most significant features of mobile technology include mobility and portability. The ubiquitous dimension of mobile technologies provides means of accessing services anywhere, anytime, and on the move, thanks to advanced wireless interface technologies. The paper examines the literature base in respect of known obstacles to the adoption and diffusion of m-Government, drawing the distinction between technical and non-technical barriers. Furthermore, the paper discusses the economic impacts achieved by e-Government in many countries following the transfer of public services to electronic services; some examples are given from the developed and developing countries.

Part 12: Workshops; International audience; Participatory Design (PD) is a design approach which aims to support users to contribute as partners throughout the entire design process of a product or service intended for their use. PD researchers are interested in employing and/or developing methods and techniques that maximise users’ contributions. By accommodating specific populations, PD proved to offer unique benefits when designing technology for “fringe” groups. However, a lack of understanding of the appropriateness of existing approaches across groups and contexts presents a challenge for the PD community. This workshop will encourage discussion around this challenge. The participants will have the opportunity to exchange and reflect on their experiences with using PD with “fringe” groups. Moreover, we aim to identify, synthesise and collate PD best practices across contexts and participant groups.

International audience; Transformative changes in agriculture at multiple scales are needed to ensure sustainability, i.e. achieving food security while fostering social justice and environmental integrity. These transformations go beyond technological fixes and require fundamental changes in cognitive, relational, structural and functional aspects of agricultural systems. However, research on agricultural transformations fails to engage deeply with underlying social aspects such as differing perceptions of sustainability, uncertainties and ambiguities, politics of knowledge, power imbalances and deficits in democracy. In this paper, we suggest that conflict is one manifestation of such underlying social aspects. We present an original conceptualization and analytical framework, wherein conflict is recognized as an important motor for redistribution of power and leverage for social learning that—if addressed through a conflict transformation process—could potentially create a step-change in agricultural transformation towards greater sustainability. Our analysis, building on an extensive literature review and empirical case studies from around the world, suggests a novel approach to guide future transdisciplinary research that can support agricultural transformations towards sustainability.