356 research outputs found

    Effect of Nonuniform Partial Shading on the Performance of Photovoltaic Systems

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    This paper deals with the influence of the shading problem on the electrical production of a photovoltaic generator based on the analysis of the I-V and P-V characteristics of the PV generator for different operating scenarios. The shading problem not only causes energy losses but also increases the non-linearity of the I-V and P-V characteristics of photovoltaic systems. The choice of the model is an essential step to allow analysis and evaluation of the performance of photovoltaic generators. The single diode model was presented in the MATLAB / SIMULINK software. The study began with the presentation of the characteristics of a module, a comparison was made between the values of the obtained electrical parameters and those supplied by the manufacturer. To show the effect of shading on photovoltaic systems another comparative study was presented between a group of series-connected modules and another connected in parallel, both exposed to nonuniform partial shading. The obtained simulation results show that the influence of shading on a set of modules connected in series is greater than that of a set of modules connected in parallel under the same operating conditions

    État des lieux des exigences et des mĂ©thodes de laboratoire pour la mise en oeuvre d'une pratique de mĂ©decine rĂ©gĂ©nĂ©rative en contexte hospitalier, clinique privĂ©e ou cabinet privĂ©

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    L’objectif de ce travail de masters est de fournir un document de rĂ©fĂ©rence concis dans le domaine des thĂ©rapies cellulaires afin qu’elles puissent ĂȘtre implĂ©mentĂ©es au sein des hĂŽpitaux, cliniques et cabinets privĂ©s en pleine conformitĂ©. Il a aussi pour objectif de prĂ©ciser lesquelles de ces techniques sont utilisables dans chaque structure de soin (hĂŽpitaux, cliniques et cabinets privĂ©s). Du point de vue de sa structure, ce document est divisĂ© en deux parties : I. Partie rĂ©glementaire; II. Partie applications courantes. La premiĂšre partie prĂ©sente les diffĂ©rents rĂšglements Ă©mis par les autoritĂ©s sanitaires Suisse et EuropĂ©ennes applicables aux traitements de mĂ©decine rĂ©gĂ©nĂ©rative les plus courantes, notamment le lipofilling, la rĂ©gĂ©nĂ©ration du cartilage et la rĂ©gĂ©nĂ©ration de la peau. La deuxiĂšme partie prĂ©sente pour les applications les plus courantes, application par application, du moins rĂ©glementĂ© au plus rĂ©glementĂ©, les textes applicables ainsi que les acteurs sanitaires qui ont le droit de le mettre en oeuvre

    Fake face detection based on a multi discriminator deep CNN architecture (MDD-CNN)

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    Due to the robustness of the deep learning tools used to design these applications, fakes are becoming increasingly common as these applications become more widely available and accessible to the general public. These fakes are typically fake faces or even fake people, which are difficult to distinguish from real individuals. Therefore, we need more efficient applications for fraud detection. In this work, we propose a new multi-discriminator architecture to distinguish fake faces from real ones. The architecture consists of three deep networks (discriminators) competing with each other, each trained differently. The final decision is made by voting based on the decisions of the three discriminators. The core element of our architecture is the proposed new adversarial deep network discriminator (NDGAN), which is trained in three different ways, resulting in three distinct discriminators. Discriminator 1 undergoes adversarial training, discriminator 2 is trained using transfer learning, and the third discriminator undergoes supervised training with a standard CNN using examples and counterexamples. Training and testing were performed on 70 000 real faces from the Flickr-Face-HQ (FFHQ) dataset, while 70 000 fake faces were generated using Nvidia’s StyleGAN. The tests conducted on the three networks produced significant results, with accuracy ranging from 79 % to 98 % for fake faces, and from 80 % to 98 % for real faces. The reliability of the discriminators contributes significantly to the overall performance of the multi-discriminator system, achieving an accuracy of 96 % for fake faces and 98 % for real faces

    Effect of Environmental Conditions and Training Algorithms on the Efficiency of a NARX Based Approach to Predict PV Panel Power Output

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    Photovoltaic energy is volatile in nature since it depends on weather conditions. It is important to have an idea about the reliability and the economic feasibility of any new project to decide whether it is right to proceed with the installation of such a project. Hence, it is becoming fundamental to know renewable energy state and production that can be combined with other less variable and more predictable sources to justify the choice of regions for the new photovoltaic projects installation. The current research investigates the forecasting abilities of a NARX based approach. The influence of the meteorological data, such as irradiance, ambient temperature, and wind speed, and the impact of training algorithms on the performance of the NARX-based forecaster is studied. For this purpose, four models are discussed, each model is trained based on three training algorithms. The NARX model using a Bayesian Regularization algorithm, trained by the three meteorological data as inputs and the converted power output as output, outperforms the other models. It consists of a simple architecture with one input layer, a hidden layer containing 1O neurons, and an output layer, with a mean square error of 0.0085 W2 for the training phase and 0.0043 W2 testing phase, and the overall regression of 95.48%. This simplified architecture and low values of the mean square error and the regression coefficient suggest that they are promising photovoltaic output prediction tools, particularly in locations where few meteorological parameters are monitored

    Direct cleavage of ROCK II by granzyme B induces target cell membrane blebbing in a caspase-independent manner

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    Caspase activation in target cells is a major function of granzyme B (grB) during cytotoxic lymphocyte granule-induced apoptosis. grB-mediated cell death can occur in the absence of active caspases, and the molecular targets responsible for this additional pathway remain poorly defined. Apoptotic plasma membrane blebbing is caspase independent during granule exocytosis–mediated cell death, whereas in other instances, this event is a consequence of the cleavage by caspases of the Rho effector, Rho-associated coiled coil–containing protein kinase (ROCK) I. We show here that grB directly cleaves ROCK II, a ROCK family member encoded by a separate gene and closely related to ROCK I, and this causes constitutive kinase activity and bleb formation. For the first time, two proteins of the same family are found to be specifically cleaved by either a caspase or grB, thus defining two independent pathways with similar phenotypic consequences in the cells. During granule-induced cell death, ROCK II cleavage by grB would overcome, for this apoptotic feature, the consequences of deficient caspase activation that may occur in virus-infected or malignant target cells

    OPTIMIZING THE USE OF GREEN ENERGIES, AN APPLICATION TO CROP IRRIGATION

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    This paper assesses the optimal farmland that can be irrigated by a predetermined renewable energy system. The optimal irrigated surface from an agriculture area, cultivated by potatoes and tomatoes and powered by a PV system is studied. Two scenarios are discussed: the constraints applied to the first scenario is the limited surface of the agricultural area. While in the second scenario, the surface cultivated with tomatoes must be at least Πthe surface cultivated with potatoes. Linear programming based on the Simplex algorithm is used to solve the optimization problem. The obtained results show that for the specified cultivating area, and for 10 panels at hand, an optimal surface of about 5.6 ha and 4.7 ha for the first scenario and the second scenario, respectively can be satisfied

    ROCK1 and LIMK2 Interact in Spread but Not Blebbing Cancer Cells

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    Cancer cells migrating within a 3D microenvironment are able to adopt either a mesenchymal or amoeboid mode of migration. Amoeboid migration is characterised by membrane blebbing that is dependent on the Rho effectors, ROCK1/2. We identify LIMK2 as the preferred substrate for ROCK1 but find that LIMK2 did not induce membrane blebbing, suggesting that a LIMK2 pathway is not involved in amoeboid-mode migration. In support of this hypothesis, novel FRET data demonstrate a direct interaction between ROCK1 and LIMK2 in polarised but not blebbing cells. Our results point to a specific role for the ROCK1:LIMK2 pathway in mesenchymal-mode migration

    Rho-associated kinase (ROCK) function is essential for cell cycle progression, senescence and tumorigenesis

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    Rho-associated kinases 1 and 2 (ROCK1/2) are Rho-GTPase effectors that control key aspects of the actin cytoskeleton, but their role in proliferation and cancer initiation or progression is not known. Here, we provide evidence that ROCK1 and ROCK2 act redundantly to maintain actomyosin contractility and cell proliferation and that their loss leads to cell-cycle arrest and cellular senescence. This phenotype arises from down-regulation of the essential cell-cycle proteins CyclinA, CKS1 and CDK1. Accordingly, while the loss of either Rock1 or Rock2 had no negative impact on tumorigenesis in mouse models of non-small cell lung cancer and melanoma, loss of both blocked tumor formation, as no tumors arise in which both Rock1 and Rock2 have been genetically deleted. Our results reveal an indispensable role for ROCK, yet redundant role for isoforms 1 and 2, in cell cycle progression and tumorigenesis, possibly through the maintenance of cellular contractility
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