Abstract: A method of locating the position of a fault on a power transmission line between first and second ends of the line is performed by calculating the complex fault impedance at each of a plurality of assumed fault positions along the length of the line, the fault impedance at each assumed position being calculated utilizing the measurement before and after fault occurrence of the voltage and current at the first end of the line, parameters of the line, and the impedance at the second end of the line; and selecting as the actual fault position the assumed fault position of the plurality of assumed fault positions for which the argument of the complex fault impedance most closely equals zero. The method may be used with single or multi-phase power transmission lines. There is also disclosed a method of determining the form of impedance network at a fault on a multi-phase power transmission line.

Abstract: A method of manufacturing copolymers having magnetic properties, the method comprising a first step of copolymerization, by oxidation in an acid medium, of a first monomer selected from aniline, possibly substituted aniline, and the corresponding iminoquinone forms, and of a second monomer selected from substituted aminoaromatic compounds, wherein the first step comprises: an induction stage during which the first monomer is put into the presence of at least one oxidizing agent and at least one initiating agent; and a production stage during which, after the second monomer has been added, at least one oxidizing agent and at least one initiating agent are added progressively.

Abstract: To generate a carrier frequency, a base station needs an oscillator with a long-term stability better than 5.multidot.10.sup.-8. In the case of crystal oscillators it is therefore necessary to regularly adjust the frequency so as to compensate for frequency drift due to aging. The oscillator (OSC) of a base station (BTS) is automatically tuned with the pulse repetition frequency of the clock (CLK) of a digital communication signal (STM). To prevent variations in the pulse repetition frequency of the clock (CLK) from affecting the stability of the carrier frequency (CAR), the oscillator (OSC) is only tuned during times that a quality indicator contained in the digital communication signal (STM) guarantees a high frequency accuracy of 10.sup.-11.

Abstract: To improve the efficiency and to reduce the temperature rise of a surface emitting semiconductor laser, the laser includes between a buried active layer and a mirror, a current blocking layer incorporating an opening centered on the active layer and having dimensions less than those of the latter. Applications include optical telecommunication systems.

Abstract: A motor-driven cooling ventilator comprises a motor and a ventilator fan disposed on the same axis inside a casing, and has air guide device fixed to the periphery of the stator of said motor and fixed to said casing, said air guide device being means fitted to said stator of the motor.

Abstract: An optical filter is formed by writing at least one long-period Bragg array into an optical fiber which is tapered to define two substantially adiabatic transition areas delimiting an intermediate area in which the long-period Bragg grating is written to produce codirectional coupling between two guided modes in the intermediate area at a wavelength that is a function of the period of the grating.

Abstract: A method of extracting a contour of a contrasted area in a digitized image made up of pixels having different intensity levels defining the contrasted area is based on minimizing the energy of an initial active contour to which are applied stresses derived from a potential image obtained by processing the image. The potential image is obtained from a multifractal analysis of the image so that each element of the potential image is representative of a local fractal dimension in the locality of a corresponding pixel in the image. This improves the behavior of the active contour when it is deformed by the stresses.

Abstract: A gas-blast gas-insulated high-voltage circuit-breaker comprises a fixed main contact, a fixed arc contact and a mobile assembly comprising a main contact, an arc contact and a compression volume cooperating with a fixed piston and communicating with a blast volume leading to a blast nozzle. The compression volume is provided with a valve preventing the gas passing from the blast volume to the compression volume. The piston comprises openings for evacuating the gas from the compression volume during tripping, these openings being closed between the start of compression of the compression volume and the closure of the valve and open upon closure of the valve.

Abstract: A turbocharged diesel engine is described. The engine has a two stage turbocharger assembly including low pressure turbochargers coupled and parallel and arranged in series with a single high pressure turbocharger. This allows all turbochargers to be of comparable dimensions for interchangeability of parts. The turbochargers may be mounted on an enclosure which encloses the turbines and the exhaust gas duct work which communicates with the exhaust pipe to insure that any leaking exhaust gas escapes to the atmosphere via the exhaust pipe. A cartridge is also described which contains the moving parts which can be removed without disturbing the turbine housing.

Abstract: An apparatus for operating a multiple-stand mill train is described which significantly reduces the expense and time for designing, testing and the start-up, including the optimization phase, and for restarting the roll operation of the mill train and which makes it possible to safely train the operators during operation and to extend the functionality of the mill train without creating damage. For this purpose, the entire mill train is simulated by a single physical simulation model (2) in a structured approach based on the technological interrelationship between the individual stands. The simulation model (2) is connected to a central control apparatus (1), wherein the apparatus alone provides the entire control of the mill train and optionally controls individual functions within each of the stands or of individual stands either via actuating members of the mill train or in corresponding units of the simulator model (2).

Abstract: Digital filters are used to simulate the transmission function of a real system by means of echo cancellers, where a high-speed digital signal processor with a large memory is needed to compute and update the filter coefficients. To reduce the cost of the echo canceller, an autocorrelation, i.e. the correlation of a block of a defined number of sampling values of the transmitted signal with received echoes derived from this transmitted signal, is used by the invention to determine the time periods at which an echo arrives, and at which an update of the filter coefficients then takes place. In this way the number of filter coefficients to be computed and the cost of their computation are significantly reduced, so that echo cancellers for telephone terminals can be produced in a cost-effective manner.

Abstract: The present invention relates to a rail or road vehicle including a chassis and a roof, said chassis and said roof both being structural elements, each of which forms a single unit only, the two elements defining a right side plane and a left side plane; wherein at least one structural frame is disposed in each of said side planes, and is secured at its bottom to said chassis and at its top to said roof, and wherein said frames are the only self-supporting face structures of said vehicle.

Abstract: An optical communication system is described wherein a center (1) and distant terminals (3, 4) are connected to a fiber-optic network (2). Each of the terminals (3, 4) has a light source (5, 7) and a modulator (6, 8) connected thereto for transmitting optical signals to the center (1). Each of the modulators (6, 8) controls the respective light source (5, 7) in such a way that the light source (5, 7) emits light only within successive first time intervals T.sub.1L, T.sub.2L which are separated by second time intervals T.sub.1D, T.sub.2D and that the first time intervals T.sub.1L, T.sub.2L are shorter than the second time intervals T.sub.1D, T.sub.2D.

Abstract: A method of manufacturing a blade made of .alpha..beta. titanium including an insert of metastable .beta. titanium,according to the invention:a blade body made of .alpha..beta. titanium is made to the finished design dimensions, said blade body made of .alpha..beta. titanium including a location designed to receive said insert made of .beta. titanium:said insert made of .beta. titanium is put into solution; thenhardening treatment is performed to harden said insert made of .beta. titanium; thensaid insert made of .beta. titanium is welded to said location of said blade body made of .alpha..beta. titanium to the finished design dimensions using a welding technique having localized and controlled energy density.

Abstract: An optical receiver is presented, which can receive and evaluate an optical signal (S) containing interference caused by polarization mode dispersion (PMD). The optical receiver has a splitting facility (1.1) which splits the routable optical signal (S) into two electrical signal components (S.sub.-, S.sub.+). The electrical signal components (S.sub.-, S.sub.+) are processed in an equalizing circuit (1.2). A control facility (1.3) controls the splitting facility (1.1) with the aid of a quality signal (Q) produced by the equalizing circuit (1.2).

Abstract: Comprising one or more resonant cavities in which are produced two resonant modes at two different frequencies f.sub.1 and f.sub.2, both modes having essentially the same field distributions but rotated 90.degree. with respect to each other. Each cavity comprises a tuning element (TS.sub.a) for tuning the resonant frequency f.sub.1 of the first mode along a first axis, a tuning element (TS.sub.b) for tuning the resonant frequency f.sub.2 of the second mode along a second axis perpendicular to the first, input coupling means (IC) and output coupling means (OC) for injecting into and extracting from the cavity, respectively, a radiofrequency signal along axes not parallel to those of resonance. Filter tuning is done by using only two tuning elements, which means that the filter cost is lower and the tuning time is reduced.

Abstract: A spacer is indicated for a high-frequency coaxial cable with an inner conductor, a tube-shaped outer conductor and a dielectric cavity located between the two conductors which, through the use of different materials, has a higher thermal load capacity in the inner conductor area than in the outer conductor area. When installed, the parts, which are composed of different materials and are superimposed in the radial direction, are mechanically interconnected.

Abstract: A spacer is indicated for a high-frequency coaxial cable with an inner conductor, a tube-shaped outer conductor and a dielectric cavity located between the two conductors, which has a higher thermal load-carrying capacity in the inner conductor area than in the outer conductor area, due to the use of different materials. The parts of the spacer which are made of different materials are radially superimposed and are solidly interlocked with each other by means of injection molding.

Abstract: An antiseismic static electrical converter installation comprises a valve assembly mounted on a platform, the platform being suspended at each of two opposite ends from a series of rods which are attached in a spaced-out relationship to a horizontal beam, the beam being mounted on the ground via rubber springs. During an earthquakes movement of the ground causes mainly lateral distortion of the rubber springs and elastic bending of the rods, and, since the natural resonant frequency of the suspension system is designed to be low and the rubber springs are deigned to have significant damping, a high degree of isolation is provided for the platform and the equipment mounted on it. During severe earthquakes, the rods are arranged to suffer a plastic bending which causes them to act like pendulums and changes the natural frequency of the suspension system to increase the damping and provide greater protection.