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How An Automated Gesture Imitation Game Can Improve Social Interactions With Teenagers With ASD
No full textInternational audienceWith the outlook of improving communication and social abilities of people with ASD, we propose to extend the paradigm of robot-based imitation games to ASD teenagers. In this paper, we present an interaction scenario adapted to ASD teenagers, propose a computational architecture using the latest machine learning algorithm Openpose for human pose detection, and present the results of our basic testing of the scenario with human caregivers. These results are preliminary due to the number of session (1) and participants (4). They include a technical assessment of the performance of Openpose, as well as a preliminary user study to confirm our game scenario could elicit the expected response from subjects
Evidence of charge density wave transverse pinning by x-ray microdiffraction
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Two-Color Soft X-Ray Lasing in a High-Density Nickel-like Krypton Plasma
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Guaranteed cosimulation of Cyber-Physical Systems
No full textIn this paper, we tackle the problem of guaranteed simulation of Cyber-Physical Systems (CPS), an important model for current engineering systems. Their always increasing complexity leads to models of higher and higher dimensions, yet typically involve multiple subsystems or even multiple physics. Given this modularity, we more precisely explore cosimulation of such dynamical systems, with the aim of reaching higher dimensions of the simulated systems. In this paper, we present a guaranteed interval based approach for cosimulation of continuous time systems. We propose an algorithm which first proves the existence, and returns an enclosure of global solutions, using only local computations. This mitigates the curse of dimensionality faced by global (guaranteed) integration methods. Local computations are then realized with a safe estimate of the other subsystems until the next macro step. We increase the accuracy of the approach by using an interval extrapolation of the state of the other subsystems. We finally propose some possible further improvements including adaptive macro step size. Our method is fully guaranteed , taking into account all possible sources of error. It is implemented in a C++ prototype relying on the DynIbex library, and we illustrate our approach on multiple examples of the literature
Multi-channel EEG epileptic spike detection by a new method of tensor decomposition
No full textInternational audienceObjective. Epilepsy is one of the most common brain disorders. For epilepsy diagnosis or treatment, the neurologist needs to observe epileptic spikes from electroencephalography (EEG) data. Since multi-channel EEG records can be naturally represented by multi-way tensors, it is of interest to see whether tensor decomposition is able to analyze EEG epileptic spikes. Approach. In this paper, we first proposed the problem of simultaneous multilinear low-rank approximation of tensors (SMLRAT) and proved that SMLRAT can obtain local optimum solutions by using two well-known tensor decomposition algorithms (HOSVD and Tucker-ALS). Second, we presented a new system for automatic epileptic spike detection based on SMLRAT. Main results. We propose to formulate the problem of feature extraction from a set of EEG segments, represented by tensors, as the SMLRAT problem. Efficient EEG features were obtained, based on estimating the 'eigenspikes' derived from nonnegative GSMLRAT. We compared the proposed tensor analysis method with other common tensor methods in analyzing EEG signal and compared the proposed feature extraction method with the state-of-the-art methods. Experimental results indicated that our proposed method is able to detect epileptic spikes with high accuracy. Significance. Our method, for the first time, makes a step forward for automatic detection EEG epileptic spikes based on tensor decomposition. The method can provide a practical solution to distinguish epileptic spikes from artifacts in real-life EEG datasets
Perfect Brewster transmission through ultrathin perforated films
No full textInternational audienceWe address the perfect transmission of a plane acoustic wave at oblique incidence on a perforated, sound penetrable or rigid, film in two-dimensions. It is shown that the Brewster incidence θ * realizing so-called extraordinary transmission due to matched impedances varies significantly when the thickness e of the film decreases. For thick films, i.e. ke ≫ 1 with k the incident wavenumber, the classical effective medium model provides an accurate prediction of the Brewster angle independent of e (this Brewster angle is denoted θ B). However, for thinner films with ke < 1, θ * becomes dependent of e and it deviates from θ B. To properly describe this shift, an interface model is used (Marigo et al., 2017) which accurately reproduces the spectra of ultrathin to relatively thick perforated films. Depending on the contrasts in the material properties of the film and of the surrounding matrix, decreasing the film thickness can produce an increase or a decrease of θ * ; it can also produce the disappearance of a perfect transmission or to the contrary its appearance
ARCH-COMP20 Category Report: Continuous and Hybrid Systems with Nonlinear Dynamics
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Chemo-Hydro-Mechanical analysis of Bituminized Waste swelling due to water uptake: Experimental and model comparisons
No full textInternational audienceThis paper presents a numerical model developed to reproduce the behaviour of French simplified Bituminized Waste Products (BWP) during a leaching test. The model is calibrated on experimental data sets. BWP were mainly produced during industrial reprocessing of nuclear spent fuel and are classified as low or intermediate activity long lived radioactive waste. Geological disposal is the reference solution for intermediate level long-lived BWP. Under geological disposal facility conditions, and after a long period of time, BWP will undergo water re-saturation from the host rock. A chemo-hydro-mechanical numerical model has been implemented with a finite element scheme to model BWP behaviour under such conditions. The constitutive model takes into account the impact of dissolution, permeation, diffusion and osmosis. Original evolution laws of diffusion coefficient and permeability as a function of the porosity are proposed. Specific mechanical model is proposed including Mori-Tanaka homogenization law. To simulate the hydration of the material, an original and simple method is proposed, avoiding costly two-phase flow resolution and complex calibration of the related parameters. This model was mainly used to reproduce the evolution of the amount of both water absorbed and salt leached by the sample during unconfined water up-taking tests. The calibration is based on experimental data obtained on French simplified BWP containing one highly soluble salt. Water uptake could generate swelling mainly due to osmosis
Hatred of the Earth, Climate Change, and the Dreams of Post-Planetary Culture
No full textInternational audienceThis text examines the effects of climate change on cultural ideas regarding the colonization of space. More specifically, this paper explores the ways which the looming danger of climate catastrophe has fueled the growth of post-planetary culture: a culture that dreams of a human destiny beyond the Earth. It takes as its object both science fiction texts and non-fiction futurological pronouncements by scientists and entrepreneurs. What emerges from this study is the observation that unlike climate skeptics, post-planetarists believe that climate change is real. Yet like climate skeptics, they subordinate climate action to other priorities, putting the construction of a means of escaping this planet above climate action. But why do these post-planetarists wish to fly? Via a close reading of David Brin's Earth, we argue that one of the key characteristics of post-planetary culture is a feeling of hatred and alienation towards the Earth. This hatred is both re-enforced by the ravages of climate change even as it contributes to this destruction by blocking post-planetarists from wholeheartedly engaging in climate action. In order to illustrate an antidote to this pathological cultural reaction to our current crisis, I present a close reading Kim Stanley Robinson's Aurora, exploring how this text is both a critique of post-planetarism and a guide to renewing our love for the Earth
Wall‐slab joint parameter identification of a reinforced concrete structure using possibly corrupted modal data
No full textInternational audienceIn numerical models, the connections among component members are crucial for the prediction of structural behaviour under different type of solicitations. In reinforced structures, the connections are often assumed rigid, what may not be realistic in many practical cases. As alternative, a semi-rigid behaviour depending on a set of independent parameters can be proposed. In this case, a new difficulty arises, which is finding the appropriate values for those parameters. The present study proposes a numerical strategy for identification of the connection parameters based on the Constitutive Relation Error (CRE). To include all available information, an augmented version (Modified CRE) is implemented. The parameters search is iterative and require large amount of system response analysis. To increase the computational efficiency, a reduced order model is adopted. The proposed approach shows low-sensitivity to limited lack of information and also to support condition variability, both of them verified numerically. In this work, experimental tests for a real 1:4 scale structure is utilized for finding the parameters corresponding to the first three modal shapes. A good agreement between numerical predictions and observations is verified, what highlights the accuracy and stability of the proposed numerical approach. The present study may also find applications in the domain of design of experiments