Due to their deployment flexibility, Unmanned Aerial Vehicles have been found suitable for many application areas, one of them being air pollution monitoring. In fact, deploying a fleet of Unmanned Aerial Vehicles (UAVs) and using them to take environmental samples is an approach that has the potential to become one of the key enabling technologies to enforce pollution control in industrial or rural areas. In this paper, we propose to use an algorithm called Pollution-driven UAV Control (PdUC) that is based on a chemotaxis metaheuristic and a Particle Swarm Optimization (PSO) scheme that only uses local information. Our approach will be used by a monitoring Unmanned Aerial Vehicle to swiftly cover an area and map the distribution of its aerial pollution. We show that, when using PdUC, an implicit priority is applied in the construction of pollution maps, by focusing on areas where the pollutants' concentration is higher. In this way, accurate maps can be constructed in a faster manner when compared to other strategies. We compare PdUC against various standard mobility models through simulation, showing that our protocol achieves better performances, by finding the most polluted areas with more accuracy, within the time bounds defined by the UAV flight time.
This paper describes a simple and fast way to predict efficiency of DCT-based filtering of images corrupted by signal dependent noise as this often happens for hyperspectral and radar remote sensing. Such prediction allows deciding in automatic way is it worth applying denoising to a given image under condition that parameters of signal-dependent noise are known a priori or pre-estimated with appropriate accuracy. It is shown that denoising efficiency can be predicted not only in terms of traditional quality criteria as output MSE or PSNR but also, with slightly less accuracy, in terms of visual quality metrics and PSNR-HVS-M.
International audience; Marvejols is a small town located in Lozère (France). Traditionally, the region was poor with an agricultural oriented economy. However, by the 1960s a new type of business was launched: the residential care facilities for disabled people, especially in relation to Jacques Blanc, a key person in the organization and development of this business. This economic activity brought jobs and new attractiveness, counterbalancing decline in traditional sectors. Nevertheless, currently, situation is less favourable, and the local players try to find out a new strategy, particularly in relation to diversification. In this study, our main aim was to understand conditions of starting and growing of this business. Moreover, we would like to understand current fragilities and attempts to adapt the economy of the territory. In this way, our students and we have chosen this area in relation to the economic and historical weight of its activity. The organization of field trips and survey was conducted in a comprehensive approach perspective. Therefore, we took account parameters working in this territory, such as strategies, psychologies (individual and collective), networks and identities. Human dimensions are strong, especially in discourses, and our main result is a better understanding of the local situation, with comparisons to close cases (Corrèze, Creuse). Furthermore, the quality of the geographical analysis provides working relations with the stakeholders
International audience; Protected cultivation or Controlled Environment Agriculture (CEA) system has increased tenfold in the last 25 years thanks to tremendous scientific and technical breakthroughs, mainly directed to increasing crop yields and adapting to tough ambient conditions. Currently, greenhouse areas are still spreading and the CEA system is one of the keystones for the agriculture forecasting scenario. However, the environmental acceptability of this very intensive agro-ecosystem is now being questioned. Energy inputs are source of the main economic and environmental weakness, especially for high-tech greenhouses, where IPM is well-established. Pesticides, common in low-cost greenhouses systems, are a major barrier-to IPM. To design and manage more robust CEA systems, both technological and ecological approaches have been chosen. This allowed for increased consideration of IPM issues among global greenhouse engineering innovation and better use of greenhouse system capacities to enhance dedicated IPM high-tech tools and management practices. On the other hand, ecological concepts were used to determine and characterize complex biotic interactions that lead to question the tenant of biological control as soon as IPM is implemented in greenhouses with sub-optimum physical pest control means. More specifically, microclimate at the boundary layer level has been investigated both from a physical and biological point of view in order to determine the best climate preferences of the main pests and beneficials. By the same token, the efficiency of diverse biocontrol plants to provide accurate shelter to natural enemies has been assessed
International audience; Multivalent cation interaction and mineral association play a vital role in organic carbon (OC) stability in tropical soils. However, the retention mechanisms of OC in mineral-cation-OC systems remain largely unclear at the molecular level. Of all OC forms, low molecular weight organic acids (LMWOAs) are readily biodegradable. Given the general acidic conditions and dominance of kaolinite in tropical soils, we investigated the retention mechanisms of malic acid (MA) in kaolinite-Fe(III)-MA systems with various Fe/MA molar ratios at pH similar to 3.5 using Fe K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy. Our results indicated the formed ferrihydrite mainly contributed to the enhanced MA retention through adsorption and/or coprecipitation at high Fe/MA molar ratios in kaolinite-Fe(III)-MA systems relative to kaolinite-MA systems. With the decrease of Fe/MA molar ratios, ternary complexation of MA with kaolinite via a tetrahedral Fe bridge occurred in kaolinite-Fe(III)-MA systems. This study highlighted the significant impact of Fe speciation on MA retention mechanisms in kaolinite-Fe(III)-MA systems under acidic conditions, and clearly showed the impact of ferrihydrite-induced adsorption/coprecipitation and Fe-bridged ternary complexation on MA retention in ternary kaolinite-Fe(III)MA systems, which will enhance our understanding of the dynamics of MA and other LMWOAs in tropical soils.
International audience; Industry includes more and more IoT components to have a better control on production and logistic processes. Unfortunately, growing network openness in a formerly isolated world induces major security risks which are especially critical in an industrial context. These risks are exacerbated by the highly fragmented nature of the industrial IoT market which imposes interoperability management and challenges security. We propose an approach to enable end-to-end data security within a heterogeneous IoT deployment. Interoperability is ensured by a central network powered by oneM2M interacting with various tier protocols. In this paper, we focus on secure communication with ZigBee and discuss how it can be transposed to other protocols, namely Z-Wave and Thread.
International audience; Data fusion is a subject becoming increasingly relevant as scientists try to extract more and more information from remotely sensed data. Archives are growing, as well as the number of space missions devoted to Earth observation. It is generally correct to assume that improvements in terms of classification error probability, rejection rate, and interpretation robustness, can only be achieved at the expenses of additional independent data delivered by more separate sensors. Sensor data fusion allows to formalise the combination of these measurements, as well as to monitor the quality of information in the course of the fusion process. A Special Group of Interest ‘data fusion' has been established jointly within the European Association of the Remote Sensing Laboratories (EARSeL) and the French Society for Electricity and Electronics (SEE). This Group has defined several major tasks to be handled in order to increase our understanding and use of data fusion. One of these tasks is the establishment of terms of reference that are accepted by both the scientific and the industrial communities at least in Europe. A definition of the data fusion is proposed, which allows to set up a conceptual approach to the fusion of Earth observation data by putting an emphasis on the framework and on the fundamentals in remote sensing underlying data fusion. Several other definitions are given which are useful to describe any problem of data fusion.
Publication . Article . Book . Conference object . 2001
Fire blight, caused by Erwinia amylovora, is a major disease of pear (Pyrus communis L.). Different strategies to enhance fire blight resistance of pear through genetic engineering are currently studied in our group. Among them, transformation of pear with a depolymerase gene from a bacteriophage has been investigated. This gene encodes an enzyme that degrades the capsular exopolysaccharide (EPS) of E. amylovora. Mutant strains without bacterial EPS are known to fail to colonize host plants. Pear cv. ‘Passe Crassane’ was transformed with Agrobacterium tumefaciens EHA105pBinAR-dpo carrying the depolymerase gene under the control of the CaMV35S promoter. Sixteen transgenic diploid clones were obtained and analysed by western blot and RT-PCR. In vitro tests for fire blight resistance were performed by inoculation with a virulent strain of E. amylovora. Two transgenic clones showed a slight reduction of fire blight symptoms (about 15 %) in comparison to non-transformed plants. This partial resistance was correlated with a stronger expression of the transgene at transcriptional and traductional levels. Very low depolymerase activity was detected in most transgenic clones (0.006% of total soluble proteins). Greenhouse evaluation of fire blight resistance of the depolymerase clones is under investigation on acclimatized plants.