1,059 research outputs found
From centralized to decentralized approach for optimal Controller of Discrete Manufacturing Systems
International audienceThis paper deals with a comparison of centralized and decentralized approaches to obtain an optimal controller for discrete manufacturing systems. It is based on a modular modeling of the plant to avoid combinatory explosion found in centralized structure and a synthesis algorithm. From the local Plant Elements, local constraints are defined to build local supervisors. Local constraints restrict the system behavior within a desired specification. Global constraints are added to establish high level supervisors. The resulting automata are translated in a normalized language for implementation in a Programmable Logic Controller
Two Cases of Study for Control Reconfiguration of Discrete Event Systems (DES)
International audienceIn this paper, we propose two cases of study for control reconfiguration of Discrete Event Systems. The main contributions are based on a safe centralized and distributed control synthesis founded on timed properties. In fact, if a sensor fault is detected, the controller of the normal behavior is reconfigured to a timed controller where the timed information replaces the information lost on the faulty sensor. Finally, we apply our contribution to a manufacturing system to illustrate our results and compare between the two frameworks
Comparison of the internalization efficiency of LDL and transferrin receptors on L2C guinea pig lymphocytes
AbstractWe demonstrate that L2C lymphocytes have about 10-times more receptors for transferrin (TO than healthy lymphocytes, as has been shown in the case of LDL receptors. The dissociation constant is the same in the two cell types (about 4 × 10−7 M). In contrast to LDL, Tf enters L2C lymphocytes with very rapid kinetics. It is shown by cross-reaction that each receptor is internalized independently of the other
Checking diagnosability on centralized model of the system
International audienceIn this work, the problem of checking diagnosability on Discrete Event System (DES) is considered especially in centralized architecture. Many approaches in literature deals with diagnosability using one or more intermediate models. In this paper, we present a new model based diagnosability algorithms in the framework of set theory for deciding diagnosability, without any intermediate constructions or models and considering several faults at the same time
CONTRIBUTION A LA COMMANDE DES SYSTEMES A EVENEMENTS DISCRETS TEMPORISES (SEDTS)
International audienceRESUME: Ce papier présente une approche de synthèse de commande sûre de fonctionnement des Systèmes à Evéne-ments Discrets Temporisés (SEDTs), à base de propriétés temporelles. Pour établir cette synthèse, la démarche propo-sée s'appuie sur la modularité des systèmes manufacturiers retrouvée dans les travaux (Qamsane et al., 2014a,b). Un exemple de système automatisé de production vient illustrer nos propos. MOTS-CLES: Systèmes à événements discrets temporisés, théorie de la supervision, commande distribuée, systèmes manufacturiers, modélisation
Conception d'un système de vérification de la diagnosticabilité par model checking à partir du modèle du système
International audienceDans ce papier, nous nous intéressons à la vérification de la diagnosticabilité par model-checking des Systèmes à Evénements Discrets (SED) modélisés à base d'automates à états finis. Nous proposons une méthode basée sur un algorithme permettant l'analyse de la diagnosticabilité du SED à partir de son modèle de base. Celui-ci constitue la donnée d'entrée de notre méthode. Une condition de la diagnosticabilité étant la présence d'un cycle indéterminé dans un système, nous proposons de rechercher l'ensemble des cycles puis de les analyser. Pour cela, notre méthodologie se découpe en 3 phases. Une phase de modélisation et instanciation de modèles, une phase de recherche de cycles et enfin une phase d'analyse de la non-diagnosticabilité. Nous illustrons notre approche autour d'une étude expérimentale
Compared to conventional, ecological intensive management promotes beneficial proteolytic soil microbial communities for agro-ecosystem functioning under climate change-induced rain regimes
Projected climate change and rainfall variability will affect soil microbial communities, biogeochemical cycling and agriculture. Nitrogen (N) is the most limiting nutrient in agroecosystems and its cycling and availability is highly dependent on microbial driven processes. In agroecosystems, hydrolysis of organic nitrogen (N) is an important step in controlling soil N availability. We analyzed the effect of management (ecological intensive vs. conventional intensive) on N-cycling processes and involved microbial communities under climate change-induced rain regimes. Terrestrial model ecosystems originating from agroecosystems across Europe were subjected to four different rain regimes for 263 days. Using structural equation modelling we identified direct impacts of rain regimes on N-cycling processes, whereas N-related microbial communities were more resistant. In addition to rain regimes, management indirectly affected N-cycling processes via modifications of N-related microbial community composition. Ecological intensive management promoted a beneficial N-related microbial community composition involved in N-cycling processes under climate change-induced rain regimes. Exploratory analyses identified phosphorus-associated litter properties as possible drivers for the observed management effects on N-related microbial community composition. This work provides novel insights into mechanisms controlling agro-ecosystem functioning under climate change
Implication of coronin 7 in body weight regulation in humans, mice and flies
Background: Obesity is a growing global concern with strong associations with cardiovascular disease, cancer and type-2 diabetes. Although various genome-wide association studies have identified more than 40 genes associated with obesity, these genes cannot fully explain the heritability of obesity, suggesting there may be other contributing factors, including epigenetic effects. Results: We performed genome wide DNA methylation profiling comparing normal-weight and obese 9-13 year old children to investigate possible epigenetic changes correlated with obesity. Of note, obese children had significantly lower methylation levels at a CpG site located near coronin 7 (CORO7), which encodes a tryptophan-aspartic acid dipeptide (WD)-repeat containing protein most likely involved in Golgi complex morphology and function. Anatomical profiling of coronin 7 (Coro7) mRNA expression in mice revealed that it is highly expressed in appetite and energy balance regulating regions, including the hypothalamus, striatum and locus coeruleus, the main noradrenergic brain site. Interestingly, we found that food deprivation in mice downregulates hypothalamic Coro7 mRNA levels, and injecting ethanol, an appetite stimulant, increased the number of Coro7 expressing cells in the locus coeruleus. Finally, by employing the genetically-tractable Drosophila melanogaster model we were able to demonstrate an evolutionarily conserved metabolic function for the CORO7 homologue pod1. Knocking down the pod1 in the Drosophila adult nervous system increased their resistance to starvation. Furthermore, feeding flies a high-calorie diet significantly increased pod1 expression. Conclusion: We conclude that coronin 7 is involved in the regulation of energy homeostasis and this role stems, to some degree, from the effect on feeding for calories and reward
Land-use intensification differentially affects bacterial, fungal and protist communities and decreases microbiome network complexity
Background: Soil microbial communities are major drivers of cycling of soil nutrients that sustain plant growth and productivity. Yet, a holistic understanding of the impact of land-use intensification on the soil microbiome is still poorly understood. Here, we used a field experiment to investigate the long-term consequences of changes in land-use intensity based on cropping frequency (continuous cropping, alternating cropping with a temporary grassland, perennial grassland) on bacterial, protist and fungal communities as well as on their co-occurrence networks.
Results: We showed that land use has a major impact on the structure and composition of bacterial, protist and fungal communities. Grassland and arable cropping differed markedly with many taxa differentiating between both land use types. The smallest differences in the microbiome were observed between temporary grassland and continuous cropping, which suggests lasting effects of the cropping system preceding the temporary grasslands. Land-use intensity also affected the bacterial co-occurrence networks with increased complexity in the perennial grassland comparing to the other land-use systems. Similarly, co-occurrence networks within microbial groups showed a higher connectivity in the perennial grasslands. Protists, particularly Rhizaria, dominated in soil microbial associations, as they showed a higher number of connections than bacteria and fungi in all land uses.
Conclusions: Our findings provide evidence of legacy effects of prior land use on the composition of the soil microbiome. Whatever the land use, network analyses highlighted the importance of protists as a key element of the soil microbiome that should be considered in future work. Altogether, this work provides a holistic perspective of the differential responses of various microbial groups and of their associations to agricultural intensification
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