Calibration of Visual Sensors and Actuators in Distributed Computing Platforms

Many novel multimedia applications such as virtual immersive environments use multiple sensors and actuators. We present in this paper a novel approach for position calibration of visual sensors and actuators, i.e. cameras and displays, in a distributed network of general purpose computing devices. The proposed approach is very suitable for the calibration of mobile setups since (a) synchronization of the setup is not required, (b) it works fully automatic, (c) only weak restrictions are imposed on the positioning of the cameras and displays, and (d) no upper limit on the number of cameras and displays to calibrated is imposed. Corresponding points across different camera images are established automatically and found with subpixel accuracy. Cameras do not have to share one common view, only a reasonable overlap between camera subgroups is necessary. The method has been sucessfully tested in numerous multicamera environments with a varying number of cameras. It has proven itself to work extremely accurate. Performance results are reported

Precise Visibility Determination of Displays in Camera Images

In many novel application scenarios such as smart rooms or sensing rooms visual sensors (such as cameras) need to know which visual actuators (such as displays) are visible to them. Often only parts of a display are visible from a camera. Therefore, a novel algorithm for precise visibility determination is presented. The algorithm makes the assumption that the displays are active, i.e., they can be controlled by the application. Under these conditions the algorithm determines precisely where which parts of a display are imaged by a camera

The history of education and the study of educational administration

This publication does not have an abstract

Circuit imprimé à structure multicouche à faibles pertes diélectriques et refroidi

The invention relates to the field of printed boards, and more specifically a printed circuit with a multi-layer structure. According to the invention, the printed circuit (100) with a multi-layer structure comprises: - a first layer (1) machined to form a spotface passing through the layer, - a second layer (2) comprising a first cavity (23) passing through the layer, - a third layer (3) comprising, on one face, an electronic component (33) such that it is in the first cavity, - a fourth layer (4) comprising a second cavity (43), - a heat conducting element with two parts: o one (13) made from metal called a thermal cover, inserted into the spotface (18) of the first layer so as to mechanically and electrically close the first cavity, o the other (14) made from a dielectric material with heat conduction >30W/(m.K), placed in the first cavity so as to be in contact with the electronic component

Contribution a la modelisation des transistors a effet de champ en arseniure de gallium pour les circuits integres monolithiques microondes

SIGLECNRS RP 207 (178) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Electromagnetic and Thermal Study of a Low Loss and Compact Air Dielectric Stripline in X-band

International audienceThis letter reports the concept of a microwave transmission line suspended in the air, and a methodology for electromagnetic and thermal optimization of these structures in X-band (8-12 GHz). A reliable printed circuit process allows us to obtain a compact, low loss and reproducible stripline structures. The measured stripline circuits demonstrate losses from only 4.2 dB/m to 5.2 dB/m at 9 GHz. The use of periodic ceramic contacts increases the power capability up to 50 W. The final structure is low loss and compact with high power handling in order to be used in power combination in X-Band

Determinants of adherence and consequences of the transition from adolescence to adulthood among young people with severe haemophilia (TRANSHEMO): study protocol for a multicentric French national observational cross-sectional study

International audienc