Real-time simulation and hardware-in-the-loop approaches for integrating renewable energy sources into smart grids : challenges & actions

The integration of distributed renewable energy sources and the multi-domain behaviours inside the cyber-physical energy system (smart grids) draws up major challenges. Their validation and roll out requires careful assessment, in term of modelling, simulation and testing. The traditional approach focusing on a particular object, actual hardware or a detailed model, while drastically simplifying the remainder of the system under test, is no longer sufficient. Real-time simulation and Hardware-in-the-Loop (HIL) techniques emerge as indispensable tools for validating the behaviour of renewable sources as well as their impact/interaction to with the cyber-physical energy system. This paper aims to provide an overview of the present status-quo of real-time and HIL approaches used for smart grids and their readiness for cyber-physical experiments. We investigate the current limitations of HIL techniques and point out necessary future developments. Subsequently, the paper highlights challenges that need specific attention as well as ongoing actions and further research directions

CALCUL DES PERFORMANCES D'UN LASER CO2 A EXCITATION ÉLECTRIQUE. COMPARAISON AVEC L'EXPÉRIENCE

En utilisant les vitesses d'excitation vibrationnelle calculées à partir de la fonction de distribution des électrons et les équations de relaxation d'un système moléculaire à 3 températures de vibration, on calcule le coefficient d'amplification et l'énergie pouvant être extraite du milieu amplificateur. Quelques résultats expérimentaux obtenus sur un laser à préionisation par faisceau d'électrons sont présentés.Calculation of laser beam amplification and laser output power have been made by resolving the vibrational relaxation equations of a molecular system characterized by three vibrational temperatures. The electron vibrational excitation rates are obtained from numerical calculation of the electron distribution function. Preliminary laser output measurements on an e-beam controlled discharge CO2 laser indicate good agreement between theoretical prediction and experiment

Contact Resistance in Top Gate / Bottom Contact OTFTs.

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Contact resistance and threshold voltage extraction in n -channel organic thin film transistors on plastic substrates

n-channel organic thin film transistors were fabricated on polyethylene naphthalate substrates. The first part of the paper is devoted to a critical analysis of eight methods to extract the threshold voltage from the transfer characteristic in the linear regime. Next, to improve electron injection and reduce contact resistance, self-assembled monolayers (SAMs) were deposited on the gold source and drain electrodes. The subsequent modification on the current-voltage characteristics of the transistors is analyzed by the transfer line method, using a threshold-voltage-corrected gate voltage. The improved performance of the device obtained with some of the SAM treatments is attributed to both a better morphology of the semiconductor film, resulting in an increased channel mobility, and to easier electron injection, which manifests itself through a lowering of the contact resistance. Interestingly, the modulation of the contact resistance exactly follows an opposite behavior to what reported in the case of p -channel devices, which brings further evidence for that charge injection is tuned by the direction and magnitude of the dipole moment of the SAM. © 2009 American Institute of Physics

Vertical Transport in Spin Coated Ultra Thin Polycrystalline Pentacene Organic Stacks

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Vertical Transport in Spin Coated Ultra Thin Polycrystalline Pentacene Organic Stacks

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LABELLED PROOF SYSTEMS FOR INTUITIONISTIC provability

In this paper, we propose new labelled proof systems to analyse the intuitionistic provability in classical and linear logics. An important point is to understand how search in a non-classical logic can be viewed as a perturbation of search in classical logic. Therefore, suitable characterizations of intuitionistic provability and related labelled sequent calculi are defined for linear logic. An alternative approach, based on the notion of proof-net and on the definition of suitable labelled classical proof-nets, allows to directly study the intuitionistic provability by constructing intuitionistic proof-nets for sequents of classical linear logic