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.

Ventilation device for an electronic cabinet

Abstract: The device according to the invention comprises ventilation openings (5) emerging into the front of the electronic cabinet beneath subassemblies (2) to be ventilated, and lower deflecting metal sheets (6) disposed under each opening (5) and inclined in order to guide a flow of air entering via a ventilation opening towards a connection conduit (6) comprising a section integral with a pivoting panel carrying the subassemblies (2), and a section attached to a chimney (10).

Evaluation of fast algorithms for finding the nearest neighbor

Abstract: In speech recognition systems as well as in speech coders using vector quantization, the search for the nearest neighbor is a computationally intensive task. We address the problem of fast nearest neighbour search. State of the art solutions tend to approach logarithmic access time. The problem is that such performance is generally achieved at the expense of a significant increase in storage requirements. We compare several known approaches and propose new extensions. These new contributions allows for a significant reduction in memory requirements without impacting the performance in terms of number of distances computed and optimality of the search.

Development of a fault tolerant computer system for the HERMES space shuttle

Abstract: The authors present the full tolerant computer system that has been developed and tested by Matra Marconi Space in the framework of European space shuttle HERMES project. This system has been designed to cope with high safety and reliability requirements (FO/FS) and less than 10/sup -6/ (for the probability of a catastrophic event induced by a system failure). The system is composed of four tightly synchronized computers running in parallel, with each computer broadcasting its input and output data towards the other computers implementing a fault masking concept based on a bit-to-bit vote. The authors present the major requirements and the rationale that led to the actual architecture. A detailed technical description of the system is provided, addressing functional, hardware, and software aspects. Information about the development activities is given, and the results and lessons learned are discussed.

The Batch Manufacture of Stirling-Cycle Coolers for Space Applications Including Test, Qualification, and Integration Issues

Abstract: The Cryogenic Systems Group in Matra Marconi Space (UK) Ltd has been continuously involved in the development of Stirling Cycle coolers since 1986. The work started out under British Aerospace Space Systems Ltd which was acquired by MMS in 1994. A 50–80K Stirling cycle cooler has been developed with a heat lift capability of 1700 mW at 80K and 1100mW at 65K for a single compressor, single displacer unit. For most applications two coolers will be mounted in mechanical opposition for vibration cancellation purposes and therefore doubles the heat lift capability potential. This 50–80K cooler is a direct design derivative of the existing 80K cooler, formerly known as the BAe 80K cooler. The design changes incorporated were minimal and therefore achieves very strong linkage to the original Oxford 80K cooler for ISAMS. Fifteen of these coolers have been manufactured as a single batch quantity for various earth observation space instruments. The programme requirements are briefly presented, and the experience gained in manufacture and acceptance testing is discussed. During 1995 a cooler from this batch was allocated to a generic qualification test programme, including flight vibration, thermal vacuum and EMC testing before being put onto long term life testing. The data from this test programme is presented, including an update of the life test.