127 research outputs found

    Wave Energy Harvesting System Using Piezocomposite Materials

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    Marine energies are a strategic channel for renewable energies to diversify and complement the global energy mix. From this perspective, several researches have seen the light in order to allow the maximum exploitation possible of the energy estimated at 80,000 TWh/year, presenting multiple vacant possibilities concerning energy not yet exploited on a large scale. The purpose of this paper is the use of ocean vibratory energy coupling with a smart composite material in order to harvest the maximum power. This study will be devoted to the design, modeling, and simulation of a floating harvester energy system that combines the mechanical strength and flexibility of polymer with the high piezo and pyroelectric activities of ceramic. The harvester system is composed of a mass-spring system used to transfer wave movements to mechanical vibrations, and two piezoelectric lever devices will be used to amplify and convert the harvested mechanical vibration into electrical power. With this flexible device, the maximum power harvested is 56.45 μW/mm², using PU/PZT composite with the optimal resistance of 108 MΩ. Considering these results, this system can be used in very different ways in marine applications

    Combining Haar Wavelet and Karhunen Loeve Transforms for Medical Images Watermarking

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    International audienceThis paper presents a novel watermarking method, applied to the medical imaging domain, used to embed the patient's data into the corresponding image or set of images used for the diagnosis. The main objective behind the proposed technique is to perform the watermarking of the medical images in such a way that the three main attributes of the hidden information (i.e. imperceptibility, robustness, and integration rate) can be jointly ameliorated as much as possible. These attributes determine the effectiveness of the watermark, resistance to external attacks and increase the integration rate. In order to improve the robustness, a combination of the characteristics of Discrete Wavelet and Karhunen Loeve Transforms is proposed. The Karhunen Loeve Transform is applied on the sub-blocks (sized 8x8) of the different wavelet coefficients (in the HL2, LH2 and HH2 subbands). In this manner, the watermark will be adapted according to the energy values of each of the Karhunen Loeve components, with the aim of ensuring a better watermark extraction under various types of attacks. For the correct identification of inserted data, the use of an Errors Correcting Code (ECC) mechanism is required for the check and, if possible, the correction of errors introduced into the inserted data. Concerning the enhancement of the imperceptibility factor, the main goal is to determine the optimal value of the visibility factor, which depends on several parameters of the DWT and the KLT transforms. As a first step, a Fuzzy Inference System (FIS) has been set up and then applied to determine an initial visibility factor value. Several features extracted from the Co-Occurrence matrix are used as an input to the FIS and used to determine an initial visibility factor for each block; these values are subsequently re-weighted in function of the eigenvalues extracted from each sub-block. Regarding the integration rate, the previous works insert one bit per coefficient. In our proposal, the integration of the data to be hidden is 3 bits per coefficient so that we increase the integration rate by a factor of magnitude 3

    Les universités d'élite au top des palmarês universitaires

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    Les classements internationaux des universités suscitent un intérêt croissant parmi l'opinion public, les universités et les nations, ce qui est évident dans une économie mondiale du savoir, améliorer la compétitivité et la réputation des universités devient une fin en soi même. Leur caractêre public attire l'attention sur les préoccupations pour l'excellence dans l'enseignement supérieur et semble produire un esprit de compétitivité parmi les universités et les encourage à  mieux performer. Les palmarês universitaires montrent de plus en plus la suprématie des universités d'élite  qui sont toujours au top et qui maintiennent leur réputation. Le présent article met l'accent sur les caractéristiques globales prédominantes qui déterminent la qualité et la compétitivité des universités d'élite et propose quelques stratégies que les universités peuvent adopter pour améliorer leur compétitivité en s'inspirant des différents indicateurs retenus par les différents classements des universités

    Future Internet of Things: Connecting the Unconnected World and Things Based on 5/6G Networks and Embedded Technologies

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    Undeniably, the Internet of Things (IoT) ecosystem keeps on advancing at a fast speed, far above all predictions for growth and ubiquity. From sensor to cloud, this massive network continues to break technical limits in a variety of ways, and wireless sensor nodes are likely to become more prevalent as the number of Internet of Things devices increases into the trillions to connect the world and unconnected objects. However, their future in the IoT ecosystem remains uncertain, as various difficulties as with device connectivity, edge artificial intelligence (AI), security and privacy concerns, increased energy demands, the right technologies to use, and continue to attract opposite forces. This chapter provides a brief, forward-looking overview of recent trends, difficulties, and cutting-edge solutions for low-end IoT devices that use reconfigurable computing technologies like FPGA SoC and next-generation 5/6G networks. Tomorrow’s IoT devices will play a critical role. At the end of this chapter, an edge FPGA SoC computing-based IoT application is proposed, to be a novel edge computing for IoT solution with low power consumption and accelerated processing capability in data exchange

    La formation continue des professeurs universitaires

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    Les changements de paradigmes dans la formation des professionnels de l'enseignement supérieur connus au cours de ces derniêres décennies apporteront nécessairement une conception différente de l'enseignement et des rôles des professeurs dans le processus d'enseignement et d'apprentissage. Une formation pédagogique adaptée pour les enseignants est aussi une condition essentielle pour la qualité de l'université, l'objectif explicite de toutes les réformes de l'éducation. Grâce aux données d'un questionnaire adressé aux professeurs de l'Université Abdelmalek Essaâdi, le présent article analyse la perception de ces derniers sur la nécessité de la formation continue du personnel enseignant, leur volonté et leur disponibilité pour s'impliquer et comment ces formations doivent être planifiées

    Network Slicing for Industrial IoT and Industrial Wireless Sensor Network: Deep Federated Learning Approach and Its Implementation Challenges

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    5G networks are envisioned to support heterogeneous Industrial IoT (IIoT) and Industrial Wireless Sensor Network (IWSN) applications with a multitude Quality of Service (QoS) requirements. Network slicing is being recognized as a beacon technology that enables multi-service IIoT networks. Motivated by the growing computational capacity of the IIoT and the challenges of meeting QoS, federated reinforcement learning (RL) has become a propitious technique that gives out data collection and computation tasks to distributed network agents. This chapter discuss the new federated learning paradigm and then proposes a Deep Federated RL (DFRL) scheme to provide a federated network resource management for future IIoT networks. Toward this goal, the DFRL learns from Multi-Agent local models and provides them the ability to find optimal action decisions on LoRa parameters that satisfy QoS to IIoT virtual slice. Simulation results prove the effectiveness of the proposed framework compared to the early tools

    Consanguinité, Isonymie et Age Précoce au Mariage dans les deux Provinces de Tétouan et M’diq-fnideq (Maroc)

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    The purpose of this work is to contribute to the description of marital practices in Northern Morocco, to follow the evolution of these practices, and to determine the motives for marriages between relatives. Thus our results show a highly significant positive correlation between the age of the two spouses (r = 0.619, p <0.001), with the mean age of the mothers being 49.03 ± 6.56 years, while for the fathers it is 56,02 ± 6,16 years with a difference of 7 years between the two spouses in the current generation. For consanguineous marriages, we identified 51 relatives, namely a frequency of 25.4% for the generation of studied couples GCE, 13.3% for the generation of paternal grandparents GGPP, and 17.5% for the generation of maternal grandparents GGPM. The intergenerational comparison reveals a highly significant increase in the percentage of consanguinity, ranging from the generation of grandparents (15.4%) to that of the studied couples (25.4%), with a difference of 10% (p˂0.001). These results also show that there is a strong association between the prevalence of consanguineous marriages and the group of women under 19 years old (p = 0.002), whereas for husbands it is noted that There is no association between marital status and age at marriage. The coefficient of consanguinity estimated by isonymy is almost twice as large as the coefficient of inbreeding estimated by genealogy
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