La recherche pour l'utilisation durable des ressources minérales

L'utilisation éco-efficace des matières premières minérales non renouvelables est l'une des conditions du développement durable. Au moment de Rio+20, le défi reste considérable. La recherche est nécessaire au développement de l'économie circulaire et pour trouver des solutions afin de produire - avec moins d'eau, d'énergie et de déchet - les ressources primaires dont le monde aura besoin au cours des prochaines décennies. Cet article présente une introduction à la recherche française et européenne actuellement déployée dans le domaine des matières premières minérales

A seamless solution for 3D real-time interaction: design and evaluation

This paper aims to propose and evaluate a markerless solution for capturing hand movements in real time to allow 3D interactions in virtual environments (VEs). Tools such as keyboard and mice are not enough for interacting in 3D VE; current motion capture systems are expensive and require wearing equipment. We developed a solution to allow more natural interactions with objects and VE for navigation and manipulation tasks. We conducted an experimental study involving 20 participants. The goal was to realize object manipulation (moving, orientation, scaling) and navigation tasks in VE. We compared our solution (Microsoft Kinect-based) with data gloves and magnetic sensors (3DGloves) regarding two criteria: performance and acceptability. Results demonstrate similar performance (precision, execution time) but a better overall acceptability for our solution. Preferences of participants are mostly in favor of the 3DCam, mainly for the criteria of comfort, freedom of movement, and handiness. Our solution can be considered as a real alternative to conventional systems for object manipulation in virtual reality

Processus d'induction d'émotions dans les environnements virtuels et le jeu vidéo

Les domaines de la réalité virtuelle et du jeu vidéo convoquent les problématiques émotionnelles dans leurs objectifs respectifs de présence et de flow zone. Cependant, la question des méthodologies d'induction d'émotions dans les environnements virtuels de ces médiums n'a pas été largement questionnée. Après avoir défini ce que sont les émotions dans la littérature philosophique, psychologiste et physiologiste, nous cherchons à montrer les liens supposés existants entre l'émotion et les états extatiques de présence en réalité virtuelle et de flow zone dans les jeux vidéo. Nous commençons donc par montrer combien le niveau de connaissance des médiums peut influencer la sensibilité aux inductions d'émotions dans les environnements virtuels. Puis nous mettons en place une stratégie inductive d'émotions basée sur une gestion itérative des niveaux de challenge en lien avec les niveaux de compétences acquises.Nous avons validé au travers de deux expériences empiriques ayant impliquées 176 participants, une méthodologie d'induction d'émotions basée sur un schéma circomplexe. Ce schéma, construit autour de la valence et le niveau d'activation des émotions, permet d'induire des émotions dans les cinq composantes essentielles de la conception d'environnements virtuels pour la réalité virtuelle ou les jeux vidéo : la chromatique, la luminosité, la vitesse des mouvements, la dimension des espaces et le volume des interactions sociales.Mots clés : réalité virtuelle, jeu vidéo, émotions, présence, flow zone.The fields of virtual reality and video games summon the emotional issues in their respective goals of presence and flow area. However the question of methodologies for inducing emotions in virtual environments in these mediums has not yet been widely questioned. After defining what emotions are in the philosophical, as in psychologist and physiologist literature, we seek to show existing links between emotion and states of presence in virtual reality and flow zone in video games. We show how the level of knowledge of the mediums may influence susceptibility to induction of emotions in virtual environments. Then we define a way of inducing emotions based on an iterative level management challenge in relation to the skill level.We validated through two empirical experiments that involved 176 participants a methodology for inducing emotions based on a circumplex pattern. This scheme built around the valence and arousal level of emotion, able to induce emotions in the five essential items component of the design of virtual environments for virtual reality and video games: color, brightness, movement speed, size of the space, and the volume of social interactions.Keywords: virtual reality, video games, emotions, presence, flow area.PARIS-Arts et Métiers (751132303) / SudocSudocFranceF

De la présence à l’incarnation: proposition d’un méta-modèle pour la réalité virtuelle

Les sentiments de présence et d’incarnation sont deux dimensions centrales de l’expérience utilisateur en environnement virtuel immersif. Suite à une revue de littérature portant sur ces deux concepts, nous en proposons une articulation théorique au sein d’un méta-modèle « Présence – Incarnation ». L’introduction de ce modèle aboutit à la proposition d’un questionnaire permettant l’évaluation subjective des sentiments de présence et d’incarnation d’utilisateurs immergés dans une application de réalité virtuelle. Les implications méthodologiques de ce modèle et ses perspectives applicatives sont ensuite évoquées afin d’introduire la ligne directrice de nos travaux futurs

Quantitative and Qualitative Exploration of the Effect of a Wearable Item on Non-Organic Virtual Limb Embodiment and User Behavior in Immersive Environments

This experiment was designed to investigate the potential contribution to the sense of embodiment of a wristband worn by the participants in both real and virtual environments. In addition, two virtual limb models were compared following a mixed between-within subjects design: an organic hand and a non-organic prosthesis matching the proposed task. Quantitative results revealed no significant effect of the wristband, while post-experiment semistructured interviews revealed that the wristband fostered the identification with the virtual limbs for several participants, but that it might be conditioned by interindividual differences. Ownership scores were significantly higher with the virtual hand. However, participants experienced a very high sense of agency with both conditions despite the lack of finger tracking when controlling the prosthesis. Agency was positively correlated with participants' perceived change in their body schema when embodying the prosthesis. Subjective and objective measures demonstrated that participants were less hesitant and that more collisions were recorded at higher speeds against potentially threatening objects with the non-organic prosthesis

A design methodology for parts using additive manufacturing

Additive Manufacturing (AM) allows designer to sidestep several design requirements and to create free forms, hollow parts or direct assemblies. This process also allows direct recycling of plastic into new parts, which eases the raw material supply. However, although several methodologies are used to redes-ign products and parts, none is dedicated to a real design of parts and products in AM. At first, we will sug-gest the base of a new design methodology for an end-user who wants to create a product or a part in AM. Then, we will show an example of using our methodology. Finally, we will conclude on the limits of this methodology and on our next work to validate our methodology

Effects of voluntary heart rate control on user engagement and agency in a virtual reality game

It has been demonstrated that virtual reality (VR) exposure can afect the subjective experience of diferent situations, cognitive capabilities or behavior. It is known that there is a link between a person’s physiological state and their psychological self-report and user experience. As an immersive experience can afect users’ physiological data, it is possible to adapt and enhance the content of a virtual environment in real-time base on physiological data feedback (biofeedback). With the rapid evolution of the physiological monitoring technologies, it is now possible to exploit diferent modalities of biofeedback, in a cheap and non-cumbersome manner, and study how they can afect user experience. While most of the studies involving physiological data use it as a measuring tool, we want to study its impact when direct and voluntary physiological control becomes a mean of interaction. To do so, we created a two-parts protocol. The frst part was designed to categorize the participants on their heart rate control competency. In the second part of the study, we immersed our participants in a VR experience where they must control their heart rate to interact with the elements in the game. The results were analyzed based on the competency distribution. We observed consistent results between our competency scale and the participants’ control of the biofeedback game mechanic. We also found that our direct biofeedback mechanic is highly engaging. We observed that it generated a strong feeling of agency, which is linked with users’ level of heart rate control. We highlighted the richness of biofeedback as a direct game mechanic, prompting interesting perspective for personalized immersive experiences

FEATURE-BASED METHOD TO FORMALISE ADDITIVE MANUFACTURING RELATED DATA AT THE MESOSCALE BASED ON A MEREOTOPOLOGICAL DESCRIPTION

AbstractResearch on additive manufacturing has highlighted methods and guidelines to optimise the design process and improving finished product quality. There is still room for improvement in making AM as reliable as more traditional processes when considering industrial use. In terms of manufacturing, managing print parameters properly can improve reproducibility and repeatability of a part, in addition to its fidelity to the basic geometric model. However, a topological optimised geometry requires more than good parameterisation. Efforts are therefore being made to formalise knowledge so that it is explicit and accessible to designers. This paper proposes an approach based on the spatio-temporal evolution of a geometry during printing to quantify data at the meso scale. Previous studies have been conducted on the description of features in time, space and space-time, and on the influence of their arrangement within a part. Building on this work, a parameterised test specimen was designed to measure the quantitative impact of these arrangements on the final product. The method is then presented and illustrated through a case study to help the designer with quantitative predictive values of geometric parameters

Méthodologie de conception pour la réalisation de pièce en Fabrication Additive

La Fabrication Additive (FA) permet de se libérer d’un grand nombre de contraintes de conception concernant les formes libres, les formes creuses ou encore les assemblages. Ce procédé permet également le recyclage direct de certaines matières plastique, ce qui facilite l’approvisionnement en matière première. Cependant, bien que certaines méthodologies permettent de reconcevoir une pièce pour la réaliser en FA, il n’existe pas encore de véritable méthodologie de conception dédiée à la FA. Dans un premier temps, nous proposerons un travail prospectif sur les bases d'une méthodologie pour un utilisateur final souhaitant concevoir des pièces visant à être réalisée en Fabrication Additive. Nous exposerons ensuite un cas d’utilisation permettant d’illustrer nos propos. Enfin, nous conclurons sur les limites de cette méthodologie et sur les travaux à venir permettant de valider notre méthodologie

A Subjective Review

Virtual Reality (VR) is now an affordable technology that is starting to penetrate the mass market. While cardboard is the most distributed system, it lacks interaction to provide really engaging experiences. Providing low cost solutions to enhance VR experiences is crucial. We hypothesized that the integration of a smart wristband in a VR experience, provide a reliable and comfortable enough setup to add a biofeedback loop to a game. We created a physiologically enhanced game and coupled it with a smart wristband capable of monitoring one's heart rate. We tested our game with and without biofeedback and compared the reported novelty. We observed a high interest of the participants for the integration of smart wearables in VR. We highlighted the stability of our setup, even in mobility and the reported absence of discomfort created by the addition of the wristband