116 research outputs found

    Robust control strategy for a conduction-convection system based on the scenario optimization

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    International audienceThis paper deals with the robust control of an uncertain conduction-convection system in the framework of probabilistic control design based both on the geometric control and the scenario optimization approach. Thus, a robust control strategy that copes with parameter uncertainties is proposed for a heated rod taken as an application example of a conduction-convection system. The design approach consists in two steps. In the first step, assuming a nominal model, a state feedback that yields a stable linear lumped parameter system, of first order, in closed loop is designed by means of geometric control theory. The stability of the resulting closed loop system is demonstrated based on the perturbation theorem from semigroup theory. The second step consists in defining the input reference of the designed state feedback by a structured robust controller. The parameter tuning of the structured controller is formulated as a semi-infinite (or robust) optimization problem which is, then, relaxed using the scenario approach leading to a standard finite optimization problem. The solution of this scenario optimization problem is achieved using a genetic algorithm. The proposed control strategy is adopted to cope with parameter uncertainties in the problem of heating a steel rod. The effectiveness of the proposed robust control strategy is demonstrated by simulation

    Robust Control Strategy for a Conduction–Convection System Based on the Scenario Optimization

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    International audienceThis paper deals with the robust control of an uncertain conduction–convection system in the framework of probabilistic control design based on both the geometric control and the scenario optimization approach. Thus, a robust control strategy that copes with parameter uncertainties is proposed for a heated rod taken as an application example of a conduction–convection system. The design approach consists in two steps. In the first step, assuming a nominal model, a state feedback that yields a stable linear lumped parameter system, of first order, in closed loop is designed by means of geometric control theory. The stability of the resulting closed-loop system is demonstrated based on the perturbation theorem from semigroup theory. The second step consists in defining the input reference of the designed state feedback by a structured robust controller. The parameter tuning of the structured controller is formulated as a semi-infinite (or robust) optimization problem which is, then, relaxed using the scenario approach leading to a standard finite optimization problem. The solution of this scenario optimization problem is achieved using a genetic algorithm. The proposed control strategy is adopted to cope with parameter uncertainties in the problem of heating a steel rod. The effectiveness of the proposed robust control strategy is demonstrated by simulation

    Reinforcement Learning-Based Dynamic Power Management of a Battery-Powered System Supplying Multiple Active Modes

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    Abstract-This paper addresses the problem of extending battery service lifetime in a portable electronic system while maintaining an acceptable performance degradation level. The proposed dynamic power management (DPM) framework is based on model-free reinforcement learning (RL) technique. In this DPM framework, the Power Manager (PM) adapts the system operating mode to the actual battery state of charge. It uses RL technique to accurately define the optimal battery voltage threshold value and use it to specify the system active mode. In addition, the PM automatically adjusts the power management policy by learning the optimal timeout value. Moreover, the SoC and latency tradeoffs can be precisely controlled based on a userdefined parameter. Experiments show that the proposed method outperforms existing methods by 35% in terms of saving battery service lifetime. Keywords-Dynamic power management; reinforcement learning, extending battery lifetime; battery-powered system design

    Microstructure and chemical composition of camel and cow milk powders’ surface

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    This study aimed at investigating the chemical composition and microstructure of spray dried camel and cowmilk powders' surfaces with two different milk-fat contents (1 and 20g 100 g−1). The SEM (Scanning ElectronMicroscopy) micrographs showed that spherical particles with a ‘brain’-type surface for both milk powders wereproduced. The surface roughness (Ra) of whole (WDMP) and skimmed (SDMP) camel milk powders(Ra=7.6 ± 0.4 nm and 5.6 ± 0.7 nm, respectively) were significantly lower as compared with the partiallyskimmed (PSCMP) and skimmed (SCMP) cow milk powders. The XPS (X-ray Photoelectron Spectroscopy)analysis highlighted that the surface of skimmed camel milk powders contained twice the lactose amount(17.7 ± 0.8%) as compared to cow milk powders (8.7 ± 0.4%). Furthermore, both milk powders showed theoverexposure of proteins and fats at their surfaces regardless of the fat content. The CLSM (Confocal LaserScattering Microscopy) micrographs highlighted that most of the camel milk fat globules were encapsulated bythe proteins near the powder surface. Camel milk fat behavior during particle formation was attributed to theirlower size distribution and their higher crystallization temperature

    The Effect of a 12-Week Moderate Intensity Interval Training Program on the Antioxidant Defense Capability and Lipid Profile in Men Smoking Cigarettes or Hookah: A Cohort Study

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    Aim. To examine the impact of interval training program on the antioxidant defense capability and lipid profile in men smoking cigarettes or hookah unable or unwilling to quit smoking. Methods. Thirty-five participants performed an interval training (2 : 1 work : rest ratio) 3 times a week for 12 weeks at an intensity of 70% of VO 2 max. All subjects were subjected to a biochemical test session before and after the training program. Results. The increase of total antioxidant status (TAS), glutathione peroxidase (GPx), and -tocopherol, is significant only for cigarette smokers (CS) and hookah smokers (HS) groups. The decrease of malondialdehyde (MDA) and the increase of glutathione reductase (GR) are more pronounced in smokers groups compared to those of nonsmokers (NS). Superoxide dismutase (SOD) increases in NS, CS, and HS groups by 10.1%, 19.5%, and 13.3%, respectively ( < 0.001). Likewise, a significant improvement of high-density lipoprotein cholesterol (HDL-C) and TC/HDL-C ratio was observed in CS and HS groups ( < 0.05). Conclusion. Although the interval training program does not have a significant effect on blood lipid levels, it seems to be very beneficial in the defense and prevention programs of oxidative stress

    The Effect of a 12-Week Moderate Intensity Interval Training Program on the Antioxidant Defense Capability and Lipid Profile in Men Smoking Cigarettes or Hookah: A Cohort Study

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    Aim. To examine the impact of interval training program on the antioxidant defense capability and lipid profile in men smoking cigarettes or hookah unable or unwilling to quit smoking. Methods. Thirty-five participants performed an interval training (2 : 1 work : rest ratio) 3 times a week for 12 weeks at an intensity of 70% of VO2max. All subjects were subjected to a biochemical test session before and after the training program. Results. The increase of total antioxidant status (TAS), glutathione peroxidase (GPx), and α-tocopherol, is significant only for cigarette smokers (CS) and hookah smokers (HS) groups. The decrease of malondialdehyde (MDA) and the increase of glutathione reductase (GR) are more pronounced in smokers groups compared to those of nonsmokers (NS). Superoxide dismutase (SOD) increases in NS, CS, and HS groups by 10.1%, 19.5%, and 13.3%, respectively (P<0.001). Likewise, a significant improvement of high-density lipoprotein cholesterol (HDL-C) and TC/HDL-C ratio was observed in CS and HS groups (P<0.05). Conclusion. Although the interval training program does not have a significant effect on blood lipid levels, it seems to be very beneficial in the defense and prevention programs of oxidative stress

    First experimental demonstration of real-time orchestration in a Multi-head metro network

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    International audienceWe present for the first time the experimental demonstration of a Real-Time control-plane on the Multi-hEad sub-wavElength swiTching (MEET), Metro architecture. The key control assets are calculated and provided to the edge nodes in a form of grant files. These grant files eliminate the contention possibility at source nodes and destinations, thus they offer a lossless passive optical grooming and multiplexing/demultiplexing at the intermediate nodes. The experimental results validate the control plane structure designed based on a deterministic operating system well scalable for a regional metro network

    Effect of low- intensity continuous training on lung function and cardiorespiratory fitness in both cigarette and hookah smokers.

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    Background: The decline in cardiorespiratory fitness and lung function was higher in smokers. Training method could mitigate some of the negative consequences of smoking among smokers unable or unwilling to quit. Objective: To examine the effects of continuous training on lungs functional capability and cardiorespiratory fitness in smokers. Methods: Fifteen cigarette smokers, 14 hookah smokers, and 14 nonsmokers were assigned to low-intensity continuous training (20-30 minutes of running at 40% of maximum oxygen uptake (O2max)). Lung function and cardiorespiratory fitness parameters were determined using respectively spirometer and treadmill maximal exercise test. Results: Continuous training improved forced expiratory volume in one second (FEV1) and forced expiratory flow at 50% of FVC (FEF50 %) in all participants, smokers and nonsmokers (p &lt; 0.05). In contrast, forced vital capacity (FVC) improvement was significant only among cigarette smokers (CS) (+1.7\ub12.21%, p &lt; 0.01) and hookah smokers (HS) (+1.3\ub11.7 %, p &lt; 0.05). Likewise, an improvement in cardiorespiratory fitness in both smokers groups without significant changes in diastolic blood pressure (DBP) for CS group and in velocity at maximum oxygen uptake (vO2max) for HS group. Conclusion: The low-intensity continuous training improves cardiorespiratory fitness and reduces lung function decline in both cigarette and hookah smokers. It seems to be beneficial in the prevention programs of hypertension. It could have important implications in prevention and treatment programs in smokers unable or unwilling to quit

    MycoBank gearing up for new horizons.

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    MycoBank, a registration system for fungi established in 2004 to capture all taxonomic novelties, acts as a coordination hub between repositories such as Index Fungorum and Fungal Names. Since January 2013, registration of fungal names is a mandatory requirement for valid publication under the International Code of Nomenclature for algae, fungi and plants (ICN). This review explains the database innovations that have been implemented over the past few years, and discusses new features such as advanced queries, registration of typification events (MBT numbers for lecto, epi- and neotypes), the multi-lingual database interface, the nomenclature discussion forum, annotation system, and web services with links to third parties. MycoBank has also introduced novel identification services, linking DNA sequence data to numerous related databases to enable intelligent search queries. Although MycoBank fills an important void for taxon registration, challenges for the future remain to improve links between taxonomic names and DNA data, and to also introduce a formal system for naming fungi known from DNA sequence data only. To further improve the quality of MycoBank data, remote access will now allow registered mycologists to act as MycoBank curators, using Citrix software
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