Abstract: The present invention relates to a filtering procedure for recursive digital filters installed in signal processors (DSP) operating with integers. It comprises two calculation procedures coupled with the classical calculation procedure of a recursive filter, the first of which, when calculating the output value of the sample, takes into account the remainders of integer divisions by the scale factor, coming from calculating the output values for the previous samples, and the second of which replaces the default value from dividing the integer by a scale factor by the integer value closest to the result of actual division.

Abstract: A device and method for guiding or steering projectiles (self-propelled or non-self-propelled), or missiles, and for steering a supersonic projectile, or a missile, having a nose, generally in the shape of a cone, having a more or less pointed end, and capable of creating a plasma discharge near the end of the projectile over a limited sector of the outer surface of nose.

Abstract: A device and method for guiding or steering projectiles (self-propelled or non-self-propelled), or missiles, and for steering a supersonic projectile, or a missile, having a nose, generally in the shape of a cone, having a more or less pointed end, and capable of creating a plasma discharge near the end of the projectile over a limited sector of the outer surface of nose.

Abstract: The present invention relates in particular to the field of devices using stimulated emission, specifically to a device for collimating high-brightness laser diode array (1) characterized in that by comprising at least one optical fiber (2) whose first end (7) is thermoformed and is located in the vicinity of an opposite the high-brightness array (1), the numerical aperture of said optical fiber end being greater than the numerical aperture of the source.

Abstract: An optical igniter includes a pyrotechnic substance and an optical fiber, one end of which is connected to a source of laser radiation and the other end of which is inserted in a connector. A removable mechanical connection is provided between the optical fiber connector and the pyrotechnic substance. A glass rod between the optical fiber connector and the pyrotechnic substance has its axis aligned with the axis of the optical fiber and is made of graded index glass in one part or two coaxial parts. It is in contact with the pyrotechnic substance and with the end of the optical fiber. Laser radiation from the end of the optical fiber passes through the glass rod and is focused onto the face of the glass rod in contact with the pyrotechnic substance.

Abstract: A first stage of a shock-detonation transition type two-stage optical detonator contains a pyrotechnic substance and an optical fiber, one end of which is connected to a source of laser radiation. The first stage pyrotechnic substance is separated from a pyrotechnic substance of the second stage by a metal plate, one face of which is in contact with the first stage pyrotechnic substance and whose other face is adjacent a cavity which separates it from the second stage pyrotechnic substance and whose edge portion bears against the end of a confinement member confining the second stage pyrotechnic substance.

Abstract: The present invention relates to a filtering procedure for recursive digital filters installed in signal processors (DSP) operating with integers. It comprises two calculation procedures coupled with the classical calculation procedure of a recursive filter, the first of which, when calculating the output value of the sample, takes into account the remainders of integer divisions by the scale factor, coming from calculating the output values for the previous samples, and the second of which replaces the default value from dividing the integer by a scale factor by the integer value closest to the result of actual division.

Abstract: The invention relates to a hearing protector for attenuating, selectively or not, noises that can have an intensity of up to 190 dB, designed to be inserted in sealing fashion into the auditory canal. The hearing protector includes a flexible cylindrical body that has a ferrule at each end. At least one of the two ferrules has a channel that runs from one end of the ferrule to the center of the cylindrical body and contains an acoustic filter. When the two ferrules each contain an acoustic filter, the filters may or may not be identical.

Abstract: Acoustic valve capable of selective and non-linear filtering of sound and placeable in a perforated ear plug. The acoustic valve consists of a tube enclosing two rigid disks axially spaced opposite each other, each of the disks containing at least one perforation. The total perforated surface of at least one disk is between 0.03 and 0.5 mm.sup.2.

Abstract: The invention relates to a hearing protector for attenuating, selectively or not, noises that can have an intensity of up to 190 dB, designed to be inserted in sealing fashion into the auditory canal. The hearing protector includes a flexible cylindrical body that has a ferrule at each end. At least one of the two ferrules has a channel that runs from one end of the ferrule to the center of the cylindrical body and contains an acoustic filter. When the two ferrules each contain an acoustic filter, the filters may or may not be identical.

Abstract: A method of polarizing at least one large area sheet of ferroelectric material (1). The method comprises the following successive steps: placing films of ferroelectric material (2, 3) of thickness e.sub.1 against two opposite faces (1a, 1b) of the sheet (1) of thickness e.sub.2, the thickness e.sub.1 being a function of the respective coercive fields of the materials constituting the sheet (1) and the films (2, 3); placing electrodes (4, 5) on either side of and against the films of ferroelectric material (2, 3); compressing the resulting complex; and applying a cyclical voltage between the two electrodes (4, 5).

Abstract: A method of polarizing selected areas of a foil of ferroelectric material, wherein electrodes are deposited in such a way on the opposite surfaces of the foil that the zone to be polarized extends between these two electrodes. The zone to be polarized is compressed and a variable voltage is applied across the electrodes. Each electrode is connected to an insulating support whose surface exceeds that of the zone to be polarized on the foil of ferroelectric material. Besides the electrode, the insulating support has a layer of dielectric material whose external surface is level with the external surface of the electrode.

Abstract: An electrical procedure depolarizes completely or partially a ferroelectric material which had been polarized before in at least one of its regions. A low-frequency alternating electric field is applied to the material whose amplitude exceeds the coercive field E.sub.c and is then decreased step by step. In a preferred embodiment the selected maximum value is 1.3 times that of the coercive field E.sub.c. It is also possible to depolarize the material selectively so that there are polarized zones remaining. The procedure may be applied to produce materials for piezoelectric or pyroelectric transducers as well as to obtain materials with improved dielectric strength.

Abstract: The sabot (16) relates to a projectile (11) which can be accelerated in an accelerator comprising a tubular preaccelerator followed by RAM acceleration tubes. It consists of an outer band (18) which is designed in a way to be attached to the radial fins (13) at the rear of the projectile (11) and to support the peripheral sealing elements (25) and a subcaliber base plate (31) of relatively small thickness, which is designed in such a way that it rests on the outer band (18) with its perimeter, and if necessary on the projectile base (7) with its center part, and that it separates from the projectile (11) and the outer band (18) before the projectile (11) enters into the acceleration tubes.

Abstract: The subject matter of the invention is a technique which allows three components of the velocity of fluid flows to be measured simultaneously by means of methods based on the use of laser Doppler anemometry. In the present case an Argon-Ion laser serves as a light source for a conventional two-component system which produces with the blue line at 488 nm and with the green line at 515 nm two interference fringe patterns in the probe volume. The interference fringes are in this case oriented at a high angle to each other. The same Argon-Ion laser is used as a light source for pumping the dye laser which emits at a wavelength of approximately 600 nm. With this beam of light a third interference fringe system is generated which is also at a high angle with respect to the other two ones. The separation according to the three colors of the scattered light emanating from the probe volume is achieved by means of usual interference filters or colored filters.

Abstract: The power supply of a laser tube which, according to the invention comprises devices for pulse formation and means for pulse triggering and is characterized in that it contains a pre-ionization circuit (4, 6) to form a pre-ionization pulse, and an excitation circuit (17, 22) to form an excitation pulse, and devices for synchronization (15) of the pre-ionization pulse and the excitation pulse.

Abstract: According to the invention, the metal vapor laser tube comprises a cylindrical plasma tube (1), which is located inside a leak-proof container (2) and which is surrounded by a thermal insulating material, an electrode (6) at each end of the plasma tube, and a cylindrical return conductor (9) coaxial to the plasma tube (1) which is connected with one of the electrodes, and characterized in that the return conductor (9) has a radius R of about: ##EQU1## where: e=exponential function,r=radius of the plasma tube, expressed in centimeters,dE/dV=energy density of the plasma, expressed in millijoules per cubic centimeter,ro=specific resistance of the plasma, expressed in Ohms.times.centimeter,U=electrical field, expressed in volts per centimeter.