Holo3

The purpose of this study was to conduct a pilot randomized controlled trial to evaluate the efficacy of an intervention for enhancing the language development of young children enrolled in home visiting programs. The participants were 59 children (18–30 months old) enrolled in one of three types of home visiting programs. Children's language skills were assessed pre- and post-intervention with the Preschool Language Scale. To estimate the impacts of the intervention on children's language scores, we conducted a two-level hierarchical linear model. Results from this model provide promising evidence for the benefits of using systematic parent-implemented language interventions.

Widely used for surface slopes measurements and for three-dimensional shape reconstruction, deflectometry is a particularly powerful technique that can also be applied for defects detection on specular surfaces. In the visible domain, deflectometry is usually based on the projection of complex encoded light patterns and necessitates heavy processing that makes it not suitable for inline inspection. In this paper, A new deflectometry based approach that is more adapted for inline inspection of linearly moving parts (parts on conveyors) is proposed. Based on a more affordable and a simpler hardware setup, the new approach allows at the same time for a proper localization and a precise geometrical quantification of any defects on the scanned specular surfaces. The proposed approach uses a fast and simple processing algorithm that lends itself very well to real-time inspection. The new method is tested and validated in laboratory for the inspection of defects on specular surfaces of plastic parts.

Performing complex tasks within a 3-D virtual environment, such as labeling 3-D point clouds, is still an ongoing research challenge. We propose Go'Then'Tag (GTT), a tool-set that helps users to edit complex 3-D data sets, and tag them at different levels. It allows to quickly select a subset of points in the 3-D point cloud and edit a tag associated to it. Our framework also comes with a tool to edit and manipulate a tree of tags, that allows overlapping hierarchies of tags. The interaction is handled through a tracked multi-touch device that combines 2-D and 3-D interaction techniques in a single device.

Within the framework of a French research program, we have developed an optical system dedicated to the measurement of works of art. The purpose is to record the actual optical characteristics of the objects' surfaces in order to be able to display the art object on a screen with a high degree of realism. Three types of data are recorded: 3D shape, true colours and texture. The 3D shape is obtained using a structured light sensor that gives a dense point cloud. A specific procedure allows automatic registration of several point clouds without any contact with the surface. The colours maps are recorded with the structured light sensor's RGB camera and using a built-in lighting system. Both camera and lighting are calibrated using a well-defined procedure. Merging the colour data with the 3D data is straightforward because the same camera is used for both tasks. The texture information is related to the so-called BRDF (Bi-directionnal reflectance distribution function): at each point on the surface, the reflectance is a function of the direction of observation and the direction of illumination. To record this complex texture information, several illumination sources are used, as well as an additional moving camera. Thus, for one 3D point cloud, a complete set of colour pictures is processed to produce texture files that are directly linked to the 3D points. The paper details the measurement procedure as well as the associated data processing. Several results are presented.

ABSTRACT Structural intensity is a powerful tool which give transfer path of the vibration energy within a structure. Additional dataprocessing allows then to localise sources and sinks ofthat energy.The measurement of these quantities is possible using classical means (accelerometers, stress gauges, . . .) but the data processing is complex and require a lot of accurate sensors because it is based on spatial derivatives of high order. Theoptical techniques (laser vibrometry, holography, . . .) are more suited for that purpose because of the high density ofmeasuring points and because of the well-known advantages of these methods : reduced measurement time and no modification ofthe mass parameters ofthe structure as it is the case when using contact sensors.Within the frames of a BRITE-EURAM program called VIP (Vibration Intensity Processing using full-field multi-pulselaser technique), a TV-holography equipment has been developed, working with a 25 Hz pulsed laser and allowing easy onsite measurements. A measurement procedure has been defmed and a specific data processing has been developed for thedetermination of structural intensity fields.Instead of recording one interferogram only as it is usually done, the equipment allows to record complete sequences ofinterferograms at 25 Hz. This large amount of data which include several (2 at least) mterferograms with some additionalinformation (temporal and frequency domain) is processed in order to reconstruct accurately the complete vibration signal.Different kinds of output data are then given : operational deflection shape, amplitude and phase, Structural Intensity fieldand its divergence through a further step of data processing. The complete procedure with the associated data processing hasbeen tested (for various configurations of excitation and damping) first on a clamped plate, then on a cylinder and at the endon several industrial components.This paper describe the general measurement procedure and the equipment used. The data processing is also presented andvarious measurement results are shown. The conclusion gives the main advantages and limitations of the method andevaluate the application possibilities.Keywords : Vibration, Structural Intensity, TV-Holography, Speckle Interferometry, Modal Analysis, Cadenced PulsedLaser.

Buried mine detection is a very complex problem. Many types of mines contain few metallic parts, which complicates the detection with classical electromagnetic systems. In this work we have studied the application of holographic interferometry techniques to the visualization of seismic wave propagation. Perturbations of the wave propagation can reveal the presence of a buried object. At first, classical holographic interferometry is tested to follow the propagation of the seismic wave. To make the holographic acquisition system more portable, we have also tested the speckle interferometry technique. Results concerning both methods are shown and discussed.