Robust deformation capture from temporal range data for surface rendering

Imagine an object such as a paper sheet being waved in front of some sensor. Reconstructing the time‐varying 3D shape of the object finds direct applications in computer animation. The goal of this paper is to provide such a deformation capture system for surfaces. It uses temporal range data obtained by sensors such as those based on structured light or stereo. So as to deal with many different kinds of material, we do not make the usual assumption that the object surface has textural information. This rules out those techniques based on detecting and matching keypoints or directly minimizing color discrepancy. The proposed method is based on a planar mesh that is deformed so as to fit each of the range images. We show how to achieve this by minimizing a compound cost function combining several data and regularization terms, needed to make the overall system robust so that it can deal with low quality datasets. Carefully examining the parameter to residual relationship shows that this cost function can be minimized very efficiently by coupling nonlinear least squares methods with sparse matrix operators. Experimental results for challenging datasets coming from different kinds of range sensors are reported. The algorithm is reasonably fast and is shown to be robust to missing and erroneous data points. Copyright © 2008 John Wiley & Sons, Ltd.     

Sensors for Applications in Magnetic Resonance Environments

This paper analyzes sensing methods compatible with magnetic resonance imaging (MRI) and functional MRI (fMRI) reported in the literature, and presents the three generations of MR-compatible force/torque sensors we have developed for robotic systems to interact with human motion. Conventional sensors such as camera-based measurement systems, strain gauges or commercial force/torque sensors, and optical encoders may be used, if placed sufficiently away from the imaging region and equipped with adequate shielding and filtering in order to minimize electromagnetic interference caused by electric cables, the transducer, and electronics of surrounding equipment. However, electromagnetic interference can be avoided by using light transmission over optical fibers, in which case sensitive and noisy electronic components can be placed outside the MR room, and the MR compatibility issue is restricted to the used materials. Good performance can be obtained with sensing elements made from materials adapted to the location of use, combined with reflected or differential light intensity measurement over optical fibers. We have developed various force and position sensors based on this principle, ranging from MR Safe (for a definition and discussion of the terms MR Safe and MR Conditional, see Gassert , IEEE Eng. Med. Biol. Mag., pp. 12--14, May/Jun. 2008) milled polymer probes to MR Conditional assemblies combining beryllium copper blades with a polymer body, as well as smaller aluminum probes realized through a combination of milling and electric discharge machining. It appears that, in contrast to actuators, good performance is not in tradeoff with MR compatibility.     

Combination of three typing methods for the molecular epidemiology of Aspergillus fumigatus infections. European Research Group on Biotype and Genotype of Aspergillus

This study investigated the source of infection and strain relatedness of Aspergillus fumigatus isolates from bronchial colonisation and invasive aspergillosis (IA) in four transplant patients. Environmental isolates from the patient's home and from the hospital and infecting isolates were obtained for patient A who developed IA. Clinic environmental and colonising isolates were obtained for patient B. Sequential isolates were obtained from various organs from patient C who developed IA and also from patient D who had a bronchitic aspergillosis that developed into IA. Ninety-one A. fumigatus isolates were analysed by three typing methods: multi-locus enzyme electrophoresis (MLEE), random amplified polymorphic DNA (RAPD) and sequence-specific DNA primers (SSDP). The three combined typing methods demonstrated a greater differentiation of isolates than the typing methods used separately or in pairs. This demonstrated the genotypic variability of A. fumigatus and facilitated better epidemiological analysis. Large polymorphisms were demonstrated for each patient isolate between and colonies within various samples. The relatedness of the isolates suggested nosocomially acquired aspergillosis for patient B, but the source of infection for patient A remained unclear. The results suggested at least three multiple infections among the four patients. This study enabled the identification of the source of infection and strain relatedness, which in turn facilitates the development of preventive measures for patient management in the future.     

Scanning electrochemical microscopy with a band microelectrode: theory and application

Scanning electrochemical microscopy (SECM) is described using a band microelectrode tip. Numerical calculations allow the determination of approach curves of an insulating or a conductive substrate, and the numerical analysis is compared to experimental curves. Natural convection provides a steady-state current at the band microelectrode at an infinite distance from the substrate, and the band tip may be used in the SECM configuration as easily as the tip of a disk. Owing to the millimetric dimension of the band microelectrode, the substrate has an influence on the current at much longer distances than with the disk. Finally, the advantage of SECM with a band microelectrode is observed with the fast electrochemical modification of a fluoropolymer surface.     

Identification of non uniform thermal contact resistance in automated tape placement process

In this work focussing on the thermal modeling of the automated tape placement process applied to thermoplastic material, we study the thermal properties of the ply interfaces during in-situ consolidation. Through the comparison of experimental measurements and numerical simulations, we show that it is necessary to consider the existence of an interply thermal contact resistance (TCR). Furthermore, we show that in order to correctly predict the measured temperatures, the value of the thermal resistance has to evolve along the process although a very simple evolution law is sufficient.     

Efficient inverse transform methods for VPL selection in global illumination

Multimedia Tools and Applications - In computer graphics, designing efficient Global Illumination methods is a hot research topic. These methods consist in computing the light distribution inside a...     

Revue de Introduction a la Psychologie de l'Enfant (Tomes 1, 2 et 3).

Reviews the book, Introduction a la Psychologie de l'Enfant edited by Michel Hurtig and Jean-Adolphe Rondal (1981). The three volumes of this handbooks covers theories of child psychology as presented by numerous authories in the field. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Procedural generation of villages on arbitrary terrains

Although procedural modeling of cities has attracted a lot of attention for the past decade, populating arbitrary landscapes with non-urban settlements remains an open problem. In this work, we focus on the modeling of small, European villages that took benefit of terrain features to settle in safe, sunny or simply convenient places. We introduce a three step procedural generation method. First, an iterative process based on interest maps is used to progressively generate settlement seeds and the roads that connect them. The fact that a new road attracts settlers while a new house often leads to some extension of the road network is taken into account. Then, an anisotropic conquest method is introduced to segment the land into parcels around settlement seeds. Finally, we introduce open shape grammar to generate 3D geometry that adapts to the local slope. We demonstrate the effectiveness of our method by generating different kinds of village on arbitrary terrains, from a mountain hamlet to a fisherman village, and validate through comparison with real data.