Matra

About: Matra is a based out in . It is known for research contribution in the topics: Signal & Detector. The organization has 1330 authors who have published 1216 publications receiving 17967 citations.

Warhead for missiles

Abstract: A warhead for a guided missile initiated by a proximity fuse, for use against high speed high altitude targets, comprises a fragmentation casing, an outer explosive charge contained in the casing and having a detonator and an inner explosive charge radially separated from the outer charge by an empty space. The inner charge has a detonator and is so arranged that the outer charge is detonated by the shockwave travelling through the radial space. On the other hand, the inner charge does not detonate following explosion of the outer charge. The charges are so shaped that the fragments from the casing are distributed as a radially directed isotopic shower.

3D structure from a monocular sequence of images

Abstract: The authors address the following problem: given a camera moving in an unknown environment, they want to obtain a 3-D description of the environment. A unifying approach is presented by deriving a unique formalism to process uniformly different but complementary features, namely points and linear segments. Different concepts for tracking features are given: (1) 2-D tracker-2-D features are tracked using an order one dynamic model for their evolution; (2) 2-D+estimation tracker-3-D fusion of 2-D features is performed recursively, and then the value predicted at time t for these 3-D features is projected at time t+1 onto the camera focal plane and replaces the dynamic model used in the 2-D tracker, allowing the introduction of 3-D information into the 2-D feature tracker without prior knowledge of the environment; and (3) 3-D tracker-the 2-D tracker disappears, and all computations are 3-D. The 3-D tracker combines the simplicity of the 2-D tracker and the efficiency of the 2-D+estimation tracker. A description is given of the mechanisms of fusion that integrate 2-D measurements into an estimate of the feature 3-D parameters. Uncertainties are taken into account through extended Kalman filtering. Feature parametrizations are chosen to simplify the linearization process and ensure numerical stability. >

Treatment of recurrent nodular goiters with percutaneous ethanol injection: a clinical study of twelve patients.

Abstract: Twelve patients who had previously undergone thyroid surgery received percutaneous ethanol injection (PEI) treatment because of recurrent nodular goiter (3 with a toxic [TN], 2 with a nontoxic cyst...

Analyse de la tenue aux impacts à faible vitesse et faible énergie des stratifiés composites par la mécanique de l'endommagement

Abstract: Resume Les stratifies carbone-epoxy sont sensibles aux chocs. Ceux-ci engendrent des endommagements localises, principalement de la fissuration transverse et du delaminage. La description precise de ces endommagements est indispensable pour etre a meme de prevoir le caractere plus ou moins critique de ces defauts. Le pari de cette etude est qu'il est possible de predire la naissance et la propagation des defauts resultant de petits chocs par la Mecanique de l'Endommagement. Pour cela, un mesomodele d'endommagement developpe au LMT est etendu aux aspects specifiques du cas traite. Les premieres comparaisons essais/calculs sur des configurations experimentales pour lesquelles les mecanismes d'endommagement ont ete determines precisement sont encourageantes.