Abstract: The filtering coefficients of a frequency domain stereophonic echo canceller are adapted by a method which takes account of the cross-correlation between the input signals relating to the two channels. In particular, the adaptation process takes account of the coherence function, reducing the problems commonly encountered with stereophonic cancellation schemes when relatively correlated input signals occur.

Abstract: A shut-off system for an orifice of a duct, particularly for an orifice of an air inlet passage that allows air into the combustion chamber of a ramjet, includes a shutter for shutting off the orifice of the duct, and a controllable actuating device capable of acting on the shutter to uncover the orifice. The shutter includes a removable cap which is held on the duct and a locking device which keeps the cap on the duct by at least one locked jaw, which is unlockable. The actuating device includes at least one controllable striker which is capable of unlocking the jaw in such a way as to cause the cap to be ejected from the duct and to uncover the orifice.

Abstract: A method/apparatus for use of the power/frequency characteristics of the candidate transmission for which the frequency must be allocated, the method/apparatus providing a power spectrum of the cumulative effect of the power/frequency characteristic of at least a portion of the existing transmission at a plurality of center frequencies within the frequency spectrum at the time of allocation, calculating allocation based on a first function of a combination of the power spectrum and the power/frequency of the candidate transmission, the first function being determined at different frequencies at the time of allocation, selecting a center frequency for the candidate transmission from the frequency spectrum based on a minimum value among the calculated allocation values or based on a calculated allocation value being below a first threshold value.

Abstract: The nose gear of an aircraft comprises a main group of at least one wheel (10) in permanent contact with the ground and a secondary group of at least one wheel (12), which is normally spaced from the ground, when the aircraft is on the ground. In the case of emergency braking due to an aborted takeoff or in the case of a blowout of a tire of a wheel (10) of the main group, the wheel or wheels (12) come into contact with the ground. This avoids an oversizing of the nose gear.

Abstract: In order to manufacture a sandwich panel using the RTM technique, a stack comprising a core (10) with open cells, a film (12) of intumescent material covering each of the faces of the core (10), a dry barrier fabric (14) covering each of the films (12) and an overlay of dry fibers (16) covering each of the barrier fabrics is placed in a mold. During polymerization of the films (12), pressurization of the mold and the presence of the barrier fabrics (14) prevent penetration of the foam into the overlays (16). The resin is then injected into the mold and then polymerized, without danger of penetration into the cells of the core (10).

Abstract: To monitor the operating state of a composite structure formed from at least two different materials and subject to a uniform force or load over its entire surface, the deformation at the interface between the two materials is measured. A comparison with a reference quantity of the structure, normally produced by the force applied thereto, indicates the operating state. When the composite structure forms the wall (14) of a reservoir (10), monitoring takes place in an instrumentation box (30) joined to the reservoir. When a critical threshold is exceeded, an alarm indicator (32) is triggered on the box (30).

Abstract: The invention relates to a method of estimating a transmission channel from a signal (S) received by that channel. The received signal corresponds to a transmitted training sequence, and the method includes the following steps: acquiring a statistic of the transmission channel, establishing an estimate (Xp) of the impulse response of the channel weighted by the statistic of the channel of the received signal (S).

Abstract: In order to avoid an operator forgetting to actuate locking mechanism interposed between two elements, such as the pod cowls (12, 14) of an aircraft engine, when said elements are in the closed position, use is made of a closure fault indicator. Said indicator comprises retractable abutment members (42, 44) automatically maintaining the two elements spaced from one another in a visible manner, when said elements are moved from their open position into their closed position.

Abstract: The method determines a deviation between a modulation frequency, combined with a first baseband signal to form a transmitted signal and a frequency used by the receiver to form a second baseband signal from a received signal, in order to adjust the frequency used by the receiver. Knowing a time segment of the first signal and the time position of a corresponding segment of the second signal, whereby the segments comprise N samples at a sample frequency Fe, a frequency transform Y(f), of size N, of the product of the complex conjugate of said segment of the first signal by the corresponding segment of the second signal is calculated, and the frequency deviation &Dgr;f which makes the frequency transform Y(f) as close as possible to C.

Abstract: A digital speech signal processed by successive frames is subjected to noise suppression taking account of estimates of the noise included in the signal, updated for each frame in a manner dependent on at least one degree of vocal activity. A priori noise suppression is applied to the speech signal of each frame on the basis of estimates of the noise obtained on processing at least one preceding frame, and the energy variations of the a priori noise-suppressed signal are analyzed to detect the degree of vocal activity of said frame.

Abstract: Control system for a control surface (100) of an aircraft comprising at least one actuator (102, 104) of the control surface, connected to a hydraulic circuit and equipped with at least two power jacks (110) capable of operating in at least one activated mode and one deactivated mode. According to the invention, the system also comprises a control unit (114) capable of making a number of jacks operate in activated mode depending on the aircraft flight conditions. Application to aircraft.

Abstract: The equipment has a wire interface for connection to a wire-Line telecommunication network and an air interface to communicate with mobile stations in accordance with a cellular network operating mode. Each mobile station operates in conjunction with a plug-in subscriber identity module containing parameters used to set up and/or manage the calls. The equipment also has a data reader/recorder suitable for receiving a subscriber module, reading certain parameters from it and writing to it other parameters dependent on the equipment. Telephone calls using a mobile station in conjunction with a subscriber identity module previously inserted in the reader/recorder may then be set up via the wire-line network.

Abstract: Using a group of spectral components from an audio signal, a coder produces a digital data stream (&PHgr;) including the quantification indices (QE0m) of at least some of the spectral components (E0m). The coder, or a transcoder situated downstream, selects at least one pair of components exhibiting a maximum correlation out of the group of spectral components, and includes in its digital output data stream identification information for each pair selected. At least some of the quantification indices are included in the output data stream for only one of the components for each pair selected. The decoder will use these to obtain the suppressed indices for the other component of the pair.

Abstract: A device supports a motorized flying instrument in a wind tunnel. To carry out tests in a wind tunnel on a motorized flying instrument (10), with the motor on, under different attitudes hands off, the instrument is connected to the fixed structure (15) of the wind tunnel (11) by a mounting device (12) at least one of the supports (14, 16) of which is fitted with a length adjustment system, such as a hydraulic jack (28). This jack (28) is remote controlled, in real time, by a control system (42).

Abstract: An Eyepiece-support arm assembly device on an aircraft. The device comprises flanges formed on the eyepiece-support arm and on a support attached to the aircraft, along with a retention belt (32) liable to be set to a locking status, wherein the arm is immobilised in relation to the support, a setting status, wherein the arm can be moved between a position for use and a retracted position, and a disassembly status allowing the assembly and disassembly of the eyepiece-support arm, without modifying the setting. The status is changed by operating levers (44, 46).

Abstract: Blanking-cap system for an orifice of a duct, in particular for an orifice of an air-intake duct into the combustion chamber of a ramjet. The blanking-cap system (16) includes a glass blanking cap (15) and a destruction device (17) which comprises a projectile (18) capable of destroying the blanking cap (15), and a controllable projection means (19), which is capable of projecting the said projectile (18) and which is arranged outside the conduit (7) while being oriented in such a way as to be able to project the said projectile (18) onto the said blanking cap (15).

Abstract: A telecommunication system has a space segment which includes a satellite carrying a multibeam telecommunications payload and a terrestrial segment comprising gateways for access to a terrestrial network. There is one gateway within a terrestrial coverage of each beam or of a group of beams. User terminals communicate with the payload of the satellite. The payload has, on a forward path from any gateway to any user terminal, a frame by frame routing unit for messages transmitted in time division multiplex. On a return path from a user terminal to a gateway the payload has a routing unit operating within each group of carriers belonging to a given beam.

Abstract: The present invention relates to a device for aiding the identification of subassemblies of an item of equipment (E) including a number of subassemblies and equipped with a storage unit (US) storing references. According to the invention, said device includes a memory (7) recording the references stored in the storage unit (US), an external electrical power supply means (9) for the memory (7), a means (13) of isolation both electrically and in terms of software processing, and a connection means (10) connected to the memory (7) and to which can be connected a reader (L) capable of reading and telling back the references which are recorded in the memory (7) and which relate to said subassemblies of the item of equipment (E).

Abstract: The present invention relates to a suspension device (4) for connecting an item of on-board equipment (2) to the structure (3) of a vehicle, particularly a rotary-wing aircraft, said suspension device (4) comprising first and second parts (5, 6) shaped in the form of plates and capable of being fixed to said structure (3) and to said item of equipment (2), and suspension means (7) which are arranged between said first and second parts (5, 6). According to the invention, the suspension device (4) additionally comprises a locking system (20) capable of bringing the suspension device (4) into one of two positions: a locked position in which the locking system (20) immobilizes the first and second parts (5, 6) one with respect to the other, and an unlocked position in which the locking system (20) releases said parts (5, 6) so that they can move relative to one another, and means (21) for controlling the locking system (20).

Abstract: The base station has an antenna system comprising a housing for fixing it to a support and one or several radiating slots. It is designed for transmitting, in a first direction substantially perpendicular to the front surface of the housing, an electric field with polarization oriented along a second direction substantially parallel to the front surface, and for transmitting, in another direction closer to the second than to the first direction, an electric field with polarization substantially oriented along the first direction. The base station is well adapted to indoor environments in microcells or picocells. It can be fixed vertically on a wall or be horizontally suspended to a ceiling, without requiring separate antenna systems for these two installation modes.