27 research outputs found
SILICA MEMBRANES - BASIC PRINCIPLES
Basic principles on amorphous silica membranes are presented. The advantages
and disadvantages of microporous amorphous silica are discussed to explain
its use as separative membranes for specific applications. The synthesis
methods are reported and examples of silica membrane designs are given
Monitoring mental workload by EEG during a game in Virtual Reality
During an activity, knowing the mental workload (MWL) of the user allows to
improve the Human-Machine Interactions (HMI). Indeed, the MWL has an impact on
the individual and its interaction with the environment. Monitoring it is
therefore a crucial issue. In this context, we have created the virtual game
Back to Pizza which is based on the N-back task (commonly used for measuring
MWL). In this more playful variant, users must carry out orders from customers
of a pizza food truck. It is an interactive game that involves the audience of
the IHM'23 conference, choosing several parameters like the number of
ingredients. During this experience, the objective is to measure MWL in real
time through an ElectroEncephaloGraph (EEG) and visual feedback on MWL level is
given to the audience. With this demonstration, we propose to present a concept
of a virtual interactive game that measures MWL in real time.Comment: IHM'23 - 34e Conf{\'e}rence Internationale Francophone sur
l'Interaction Humain-Machine, AFIHM; Universit{\'e} de Technologie de Troyes,
Apr 2023, Troyes, Franc
In- and out-plane transport properties of chemical vapor deposited TiO2 anatase films
Due to their polymorphism, TiO2 films are quintessential components of state-of-the-art functional materials and devices for various applications from dynamic random access memory to solar water splitting. However, contrary to other semiconductors/dielectric materials, the relationship between structural/morphological and electrical properties at the nano and microscales remains unclear. In this context, the morphological characteristics of TiO2 films obtained by metal–organic chemical vapor deposition (MOCVD) and plasma-enhanced chemical vapor deposition (PECVD), the latter including nitrogen doping, are investigated and they are linked to their in- and out-plane electrical properties. A transition from dense to tree-like columnar morphology is observed for the MOCVD films with increasing deposition temperature. It results in the decrease in grain size and the increase in porosity and disorder, and subsequently, it leads to the decrease in lateral carrier mobility. The increase in nitrogen amount in the PECVD films enhances the disorder in their pillar-like columnar morphology along with a slight increase in density. A similar behavior is observed for the out-plane current between the low temperature MOCVD films and the undoped PECVD ones. The pillar-like structure of the latter presents a lower in-plane resistivity than the low temperature MOCVD films, whereas the out-plane resistivity is lower. The tree-like columnar structure exhibits poor in- and out-plane conductivity properties, whereas pillar-like and dense TiO2 exhibits similar in- and out-plane conductivities even if their morphologies are noticeably different
La base du crâne et son influence sur la morphologie faciale (approche selon différentes spécialités)
BORDEAUX2-BU Sci.Homme/Odontol. (330632102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF
Imagerie mentale motrice contrôlée par interface cerveau-machine (une porte ouverte sur le système moteur dans la récupération des déficits-rationnel)
Les déficits moteurs du membre supérieur après un accident vasculaire cérébral sont très invalidants et résistent globalement à la plupart des thérapeutiques de rééducation. Quelques-unes seulement ont prouvé leur efficacité. L imagerie mentale motrice, représentation consciente d une action, basée sur l activation subliminale du système moteur cérébral en fait partie. Son caractère subjectif limite son utilisation en routine car elle est difficilement contrôlable quantitativement et qualitativement. Des désordres neuropsychologiques associés à l AVC pourraient aussi dégrader cette faculté cognitive. L interface cerveau-machine est un nouveau dispositif de communication entre cerveau et ordinateur, capable d analyser en direct le signal produit par l activité cérébrale et de la retranscrire en une sortie utilisable sous différentes formes, permettant notamment de réaliser un monitoring de l imagerie mentale motrice. Le signal peut être recueilli en électroencéphalographie ; le meilleur niveau de performance est obtenu à l aide d enregistrements électrocorticographiques sur électrodes placées dans l espace épidural en regard du cortex moteur. Ce monitoring est présenté au patient à type de feedback. Affranchi des afférences pathologiques liées au dysfonctionnement sensitivo-moteur, il peut ainsi par l entraînement, apprendre à contrôler et moduler son activité corticale et grâce aux phénomènes de plasticité cérébrale reformater ses programmes moteurs pour améliorer ses performances motrices réelles. L auteur développe ici le rationnel à l utilisation de l imagerie mentale motrice couplée à cette technologie dans la rééducation des dé cits moteurs du membre supérieur après un accident vasculaire cérébral et propose un protocole de recherche clinique pour en évaluer l ef cacité. Les résultats surprenants d un cas expérimental présenté en prérequis témoignent de sa faisabilité et de son intérêt.NANTES-BU Médecine pharmacie (441092101) / SudocSudocFranceF
Sorption and permeation of water through Plasma Enhanced Chemical Vapour Deposited phosphonic acid-based membranes
International audiencePhosphonic acid-based membranes were prepared by Plasma Enhanced Chemical Vapor Deposition (PECVD) with an input power of 100 W in a continuous or pulsed glow discharge. Comparing both kinds of plasma discharges makes appear that the pulsed configuration gives rise to PECVD materials with longer hydrocarbon chains and thus higher flexible polymer network which consequently present better sorption properties than those prepared from a continuous plasma discharge. Being more hydrophilic and richer in acidic functions than Nafion® 212, PECVD membranes (whatever the kind of plasma discharge, pulsed or continuous, during the deposition of films) present a better water sorption ability. Nevertheless, having a more highly cross-linked structure, they have a lower water diffusion/permeation capacity. Consequently PECVD membranes show singular water management properties which could be a great advantage for the final Proton-Exchange Membrane Electrolyte Cells and Proton-Exchange Membrane Fuel Cells applications
Effect of Task Ludification on Subjective Responses to Mental Workload During Digitalized Cognitive Task.
Cognitive tasks usually used in rehabilitation or evaluation of cognitive functions are viewed as effortful or frustrating, which often leads to participant disengagement and high mental workload (MWL). The challenge is to increase the task’s commitment while decreasing MWL and maintaining similar impact on cognitive functions. Introducing playfulness could decrease the part of MWL due to endogenous factors (like demotivation) without affecting the task’s cognitive aspect. Nevertheless, there is no study investigating the link between ludification, commitment, and MWL and the performance’s repercussions. Therefore, we developed a protocol to compare the subjective MWL for three conditions of a cognitive task that differed depending on the degree of ludification. Overall, our results showed that performances were not influenced by ludification, confirming that it did not reduce the effects on cognitive functions solicited during the task. Regarding the impact on engagement and MWL, it will be discussed in light of different models of MWL
Inter-tasks transferability of a subjective cognitive load classification model
Studying cognitive load (CL) presents several challenges, including the need for accurate and generic CL classification models. Previous studies have solely relied on physiological data to measure CL, as in Appel et al. (2021). However, what about subjective CL measure?Thus, we proposed a three-class classification model of subjective CL through five cognitive tasks: N-back, Corsi, Go/No-Go, WCST, and Dual task (Louis et al. 2023). For this conference, we examined whether a model trained on a Task A could accurately predict the subjective CL classes of a Task B.Firstly, the results showed that Corsi was the most effective task for classifying subjective CL based only on performance and complexity levels, achieving 80% accuracy. Moreover, a classification model trained on N-back, WCST, and Dual task could predict the subjective CL classes of Corsi with over 70% accuracy. This perspective would save time in setting up and training a classification model
Subjective mental workload modeling in tests involving different cognitive functions
Over time, mental workload (MWL) has become a major topic of scientific discussions. Nevertheless, there is no reference model involving standardized cognitive tests with distinct levels of difficulty and allowing to consider the correlation between task performance and MWL based on these levels. Therefore, we have developed an innovative protocol to model the variation of self-reported MWL (via the NASA-TLX and Workload Profile questionnaires) for tests requiring different cognitive functions (memory, mental inhibition, mental flexibility, and divided attention). Each of these tasks is an adaptation of existing cognitive tests, for which three equivalent difficulty levels were established in terms of impact on performance.The results showed that our difficulty levels allowed distinct classes of MWL and that it co-varied negatively with the performance across difficulty. Our protocol has thus provided new benchmarks that can be useful in many domains where it’s essential to be able to infer MWL from test performance