1,644 research outputs found

    Another Multidimensional Synchronous Dataflow: Simulating Array-OL in Ptolemy II

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    Computation intensive multidimensional applications appear in many application domains such as video processing or detection systems. We present here the Array-OL specification model to handle such multidimensional applications. This model is compared to the Multidimensional Synchronous Dataflow proposition by Lee et al. We also detail in this a new domain in the Ptolemy simulation environment dedicated to Array-OL specification simulation

    Mass transfer coefficients of styrene into water/silicone oil mixtures: New interpretation using the "equivalent absorption capacity" concept.

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    International audienceThe physical absorption of styrene into water/silicone oil systems at a constant flow rate for mixtures of different compositions (silicone oil volume fraction Ď• = 0%, 1%, 2%, 3%, 4%, 5%, 6%, 8%, and 10%) was investigated in laboratory-scale bubble reactors using a dynamic absorption method. Experimental results previously analyzed assuming no contact between gas and silicone oil [10] were reconsidered by applying the "equivalent absorption capacity" concept characterized by the value of the styrene partition coefficient between air and the mixture (Hmix). The results indicate that silicone oil addition slightly hinders the styrene mass transfer rate compared to the air/water system. Moreover, a dramatic decrease in KLa values due to silicone oil addition is observed. In comparison with similar measurements available in the literature, it is noted that this decrease in KLa value could be related to the change in the partition coefficient ratio mR = Hwater/Hoil. Two explanations concerning the relationship between the change in a hydrodynamic parameter (KLa) and that in a thermodynamic parameter (mR) are proposed. Finally, it appears questionable to study the change in KLa in terms of silicone oil addition

    La solitude chez les jeunes : recension des écrits

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    Contrairement à la croyance populaire qui veut que la solitude soit avant tout un problème vécu par les adultes, notamment par les personnes âgées, ce sentiment peut se manifester tôt dans la vie. Un nombre croissant d'études révèlent qu'un pourcentage important d'adolescents vivent un épisode intense de solitude. Cette recension des écrits trace un portrait de l'expérience de la solitude chez les jeunes. Il sera question de l'importance du problème, de la description du phénomène, des sentiments reliés à cette expérience, des facteurs qui prédisposent les jeunes à une telle expérience, des facteurs susceptibles de déclencher le phénomène et des stratégies d'ajustement déployées pour faire face à une situation d'isolement.Contrary to the popular belief that loneliness is typically associated with adults, and especially with older persons, this state can occur early in life. In fact, an increasing number of studies indicate that an important proportion of adolescents experience an intense episode of loneliness. This literature review describes loneliness among younger persons. We discuss the ampleness of the problem, the definition of the phenomenon, the feeling associated with loneliness, precipitating and predisposating factors and, finally, coping strategies to deal with this experience

    Metrics for the violation of detailed balance in microwave circuits: theory and experiment

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    We propose a new approach to detailed balance violation in electrical circuits by relying on the scattering matrix formalism commonly used in microwave electronics. This allows to include retardation effects which are paramount at high frequencies. We define the spectral densities of phase space angular momentum, heat transfer and cross power, which can serve as criteria for detailed balance violation. We confirm our theory with measurements in the 4-8 GHz frequency range on several two port circuits of varying symmetries, in space and time. This validates our approach, which will allow to treat quantum circuits at ultra-low temperature

    Fault Injection and Safe-Error Attack for Extraction of Embedded Neural Network Models

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    Model extraction emerges as a critical security threat with attack vectors exploiting both algorithmic and implementation-based approaches. The main goal of an attacker is to steal as much information as possible about a protected victim model, so that he can mimic it with a substitute model, even with a limited access to similar training data. Recently, physical attacks such as fault injection have shown worrying efficiency against the integrity and confidentiality of embedded models. We focus on embedded deep neural network models on 32-bit microcontrollers, a widespread family of hardware platforms in IoT, and the use of a standard fault injection strategy - Safe Error Attack (SEA) - to perform a model extraction attack with an adversary having a limited access to training data. Since the attack strongly depends on the input queries, we propose a black-box approach to craft a successful attack set. For a classical convolutional neural network, we successfully recover at least 90% of the most significant bits with about 1500 crafted inputs. These information enable to efficiently train a substitute model, with only 8% of the training dataset, that reaches high fidelity and near identical accuracy level than the victim model.Comment: Accepted at SECAI Workshop, ESORICS 202
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