Sélection et Contrôle à Distance d'Objets Physiques Augmentés

International audienceNotre recherche doctorale concerne l'interaction dans les environnements intelligents. Plus particulièrement, nous considérons la sélection et le contrôle à distance d'objets physiques augmentés. Nos objectifs sont à la fois conceptuels, par la mise en place d'un espace de conception mais aussi pratiques par la conception, le développement et l'évaluation de techniques d'interaction. Nos résultats ont permis de souligner où l'attention de l'utilisateur doit être pour la sélection efficace et plaisante des objets augmentés à travers la comparaison expérimentale de deux nouvelles techniques de sélection d'objets physiques : P2Roll et P2Slide. Les perspectives en vue de la complétude des travaux concernent principalement le contrôle d'objets et incluent (1) l'évaluation des techniques de guidage pour le contrôle gestuel des objets augmentés par un utilisateur novice, et (2) l'évaluation in situ des techniques conçues

Hybridization of Magnetism and Piezoelectricity for an Energy Scavenger based on Temporal Variation of Temperature

Autonomous microsystems are confronted today to a major challenge : the one of energy supply. Energy scavenging, i.e. collecting energy from the ambient environment has been developed to answer this problematic. Various sources have already been successfully used (solar, vibration). This article presents temporal variations of temperature as a new source of exploitable energy. A brief review will take place at the beginning, exposing the different approaches used in the past. Then we will focus our attention on hybridization of magnetism and piezoelectricity. A new kind of thermal generator is proposed and a preliminary model is exposed. Conclusions will be drawn on the suitability of this prototype and the improvements that are needed to increase its potential.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

Magnetic drive system for a new centrifugal rotary blood pump

The purpose of this investigation was to design a novel magnetic drive and bearing system for a new centrifugal rotary blood pump (CRBP). The drive system consists of two components: (i) permanent magnets within the impeller of the CRBP; and (ii) the driving electromagnets. Orientation of the magnets varies from axial through to 60° included out-lean (conical configuration). Permanent magnets replace the electromagnet drive to allow easier characterization. The performance characteristics tested were the axial force of attraction between the stator and rotor at angles of rotational alignment, Ø, and the corresponding torque at those angles. The drive components were tested for various magnetic cone angles, ?. The test was repeated for three backing conditions: (i) non-backed; (ii) steel-cupped; and (iii) steel plate back-iron, performed on an Instron tensile testing machine. Experimental results were expanded upon through finite element and boundary element analysis (BEM). The force/torque characteristics were maximal for a 12-magnet configuration at 0° cone angle with steel-back iron (axial force = 60 N, torque = 0.375 Nm). BEM showed how introducing a cone angle increases the radial restoring force threefold while not compromising axial bearing force. Magnets in the drive system may be orientated not only to provide adequate coupling to drive the CRBP, but to provide significant axial and radial bearing forces capable of withstanding over 100 m/s2 shock excitation on the impeller. Although the 12 magnet 0° (?) configuration yielded the greatest force/torque characteristic, this was seen as potentially unattractive as this magnetic cone angle yielded poor radial restoring force characteristics

Iatrogenias resultantes da inserçāo de mini-implantes

Com o intuito de facilitar e possibilitar uma atuação clinica mais tranquila na instalação desses dispositivos, procurou-se sintetizar nesta revisāo bibliográfica algumas das principais iatrogenias decorrentes desses procedimentos assim como certas manobras e locais que podem auxiliar na diminuição de tais ocorrências. Perfuraçāo do seio maxilar, trauma radicular, fratura do mini-implante, mucosites/peri-implantites, deslize do mini-implante além de injúrias ao feixe vasculonervoso foram as principais iatrogenias encontradas na literatura. Essa pesquisa permitiu a tomada de conhecimento de alguns procedimentos importantes, para que as iatrogenias nāo se intensifiquem, como: a inclinaçāo do dispositivo instalado, a realizaçāo de pre-perfurações, a preferência da instalação do dispositivo em gengiva queratinizadas, as localizações mais seguras para as instalações dos dispositivos de ancoragem temporária entre raízes além de algumas técnicas mais atuais de instalação extra-alveolar desses dispositivos.In order to facilitate and facilitate and make possible a quieter clinical performance in the installation of these devices, we tried to synthesize in this bibliographic review some of the main iatrogenies resulting from these procedures as well as certain maneuvers and places that can help in the reduction of such occurrences. Maxillary sinus perforation, radicular trauma, mini-implant fracture, mucositis/ perimplantites, mini-implant slide and injuries to the vascular-nervous bundle were the main iatrogenic factors found in the literature. This research allowed the knowledge of some important procedures to prevent iatrogenies from intensifying, such as: inclination of the installed device, the accomplishment of pre-perforations, the preference of installing the device in keratinized gingiva, the safest locations for the installation of DAT(s) between roots, and some more current techniques for extra-cellular installation of these devices

Designing Disambiguation Techniques for Pointing in the Physical World

International audienceSeveral ways for selecting physical objects exist, including touching and pointing at them. Allowing the user to interact at a distance by pointing at physical objects can be challenging when the environment contains a large number of interactive physical objects, possibly occluded by other everyday items. Previous pointing techniques highlighted the need for disambiguation techniques. Addressing this challenge, this paper contributes a design space that organizes along groups and axes a set of options for designers to relevantly (1) describe, (2) classify, and (3) design disambiguation techniques. First, we have not found techniques in the literature yet that our design space could not describe. Second, all the techniques show a different path along the axes of our design space. Third, it allows defining of several new paths/solutions that have not yet been explored. We illustrate this generative power with the example of such a designed technique, Physical Pointing Roll (P2Roll)

Hybrid Distributed Computing Infrastructure Experiments in Grid5000 : Supporting QoS in Desktop Grids with Cloud Resources

International audienceHybrid Distributed Computing Infrastructures (DCIs) allow users to combine Grids, Desktop Grids, Clouds, etc. to obtain for their users even larger computing capabilities. In this paper, we present an experimental study of the SpeQuloS framework which aims at providing QoS to Desktop Grid by provisioning on-demand Cloud resources. We describe the experimental platform which relies on Grid5000 to mimic both a Desktop Grid system and a Cloud system. Preliminary results are presented which shows the potential of the SpeQuloS approach

Mobile Pointing Task in the Physical World: Balancing Focus and Performance while Disambiguating

International audienceWe address the problem of mobile distal selection of physical objects when pointing at them in augmented environments. We focus on the disambiguation step needed when several objects are selected with a rough pointing gesture. A usual disambiguation technique forces the users to switch their focus from the physical world to a list displayed on a handheld device's screen. In this paper, we explore the balance between change of users' focus and performance. We present two novel interaction techniques allowing the users to maintain their focus in the physical world. Both use a cycling mechanism, respectively performed with a wrist rolling gesture for P2Roll or with a finger sliding gesture for P2Slide. A user experiment showed that keeping users' focus in the physical world outperforms techniques that require the users to switch their focus to a digital representation distant from the physical objects, when disambiguating up to 8 objects

Apport de la microscopie électronique sous incidence rasante à l'étude des surfaces, application au laiton 70/30

10ème Congrès International d'Optique des Rayons X et de Microanalyse 10th International Congress on X-Ray Optics and MicroanalysisNational audienceOn montre combien la diffraction des électrons (100 keV) sous incidence rasante aide à la compréhension des données obtenues par spectrométrie Auger. On prend pour exemple l'étude d'une surface oxydée de laiton 70/30. Les résultats sont discutés, et confrontés à ceux obtenus en ESCA. L'influence du frottement sur la composition superficielle est observée

LEED studies of lead on copper (100)

Lead layers on copper (100) at coverages from 0.5 to 0.6 were investigated by quantitative LEED and AES measurements and dynamical LEED calculations. Comparisons of intensity measurements with dynamical calculations for the (Wurzel2 x Wurzel2)R45° structure show that the Pb atoms are adsorbed in hollow sites. The Cu---Pb distance is close to the sum of both metallic radii. The dense lead monolayer at a coverage of 0.6 exhibits a c(5 Wurzel2 x Wurzel2)R45° superstructure with cmm symmetry of the diffraction pattern. Calculations for five models were performed under variation of several geometric parameters. Most analogies were found for regular arrangements of distorted (Wurzel2 x Wurzel2)R45° domains, separated by antiphase boundaries. This result is in consistency with observations of poorly ordered (Wurzel2 x Wurzel2)R45° antiphase domains at intermediate coverages