Abstract: In a multi-carrier system, the pilot carrier which is transmitted between two stations for synchronisation purposes, is re-allocated to a new frequency whenever it is disturbed by noise or a single frequency disturber in the vicinity thereof. A less noisy frequency is selected by means of a specific criterion to be fulfilled, for instance based on signal to noise ratio measurements performed for all carriers in the multi-carrier system.

Abstract: AC/DC power converter device comprising a full-wave rectifier (R) the output of which is applied to a direct current module which has two outputs: the main output is connected to the load via a capacitor (C1) which transfers a first power level (P1), and the auxiliary output is formed by a capacitor (C2) and a direct current converter (DC) which stores a second power (P2) and transfers it to the load during the full cycle of the input power wave (PE). As a result the second power level (P2) is continuously topping up the first power level (P1).

Abstract: Monolithic integrated optical semiconductor components with a buried ridge stripe waveguide (BRS) are used for optical communications. They contain active (AB) and passive (PB) waveguide regions. High absorption losses occur in passive waveguide regions with a buried ridge stripe waveguide, while passive waveguide regions with low-loss rib waveguides have reflections and leakage losses in the junction with the active waveguide regions. A semiconductor component (BE2) according to the invention has a buried ridge stripe waveguide (BRS) in active (AB) as well as passive (PB) waveguide regions, which is covered by a cap layer (DS). In addition the passive regions (PB) have a semi-insulating or undoped cladding layer (MS) between the ridge stripe waveguide (BRS) and the cap layer (DS). A process is furthermore indicated whereby a semiconductor component according to the invention can be manufactured.

Abstract: A fiber optic cable comprises a plurality of packages each made up of a plurality of optical fiber ribbons. The packages are arranged in a tight structure incorporated in a polymer resin so that the packages themselves constitute reinforcements that impart strength to the cable and prevent curvature of the optical fibers due to variations in temperature. This eliminates the need to incorporate any central and/or peripheral reinforcing member into the cable.

Abstract: A semi-automatic method of extracting a contour in a digital image using a combined active contour and starter/guide approach is based on an iterative process of deforming an active contour to obtain a current trace and extending the current trace by a straight line segment. An initial contour is entered into the image to seed the iterative process. Local analysis of the digital image at a point of the initial contour determines a first reference datum. At each iteration this analysis is carried out locally at a plurality of points around the end point of the current trace to determine, by correlation with the first datum, the orientation of the straight line segment extending the current trace.

Abstract: A low noise amplifier structure based on a Differential Difference Amplifier (DDA1) having a differential output (outp, outn) and two differential pairs of input terminals (N1, P1; N2, P2). The input signal (V.sub.IN) is applied to terminals (N2, P1) which belong to different differential pairs. In this way, none of the differential pairs receives a high input signal, and hence none of them cause unacceptable harmonic distortion. The dynamic input range is thus high. The gain of the structure is determined by a resistive circuit (R2a, R2a'; R2b, R2b') coupled to the remaining terminals (N1, P2) of the differential pairs. The common mode of these remaining terminals (N1, P2) is, independently from the output common mode, biased at the input common mode via a common mode feedback circuit (DDA2; GL1, GH1, GH3, R2a, R2a'; GL2, GH2, GH4, R2b, R2b') based on a second differential difference amplifier (DDA2).

Abstract: An electrical transmission line for conveying and limiting current by using a plurality of tubular portions made from a superconductive material. The tubular portions have a high critical temperature and are connected end-to-end by flexible, electrically conductive metal or alloy joints. A cryogenic fluid flows inside a first tube within the tubular portions. A vacuum is maintained inside a second tube around the tubular portions.

Abstract: In a method of fabricating a surface-emitting laser, to assure good electrical confinement and good flatness of the mirrors defining the resonant cavity of the laser an electrical confinement layer is formed by carrying out the following steps:forming an undercut layer,at least one growth step on the undercut layer,forming a mesa defining the shape and the location of the top mirror and exposing the undercut layer on its vertical walls, andcontrolled lateral etching of the undercut layer. Applications include the fabrication of a semiconductor laser on a III-V (e.g. InP or GaAs) substrate.

Abstract: A composite based on a superconducting oxide having a high critical temperature, characterized by the fact that it is constituted by glass and said oxide, the glass being such that its vitreous transition temperature is not greater than 750K, the volume fraction of the glass lying in the range 2% to 40%, said oxide existing in the glass in the form of crystallites having substantially the same orientation.

Abstract: A method is described to estimate the current datapacket rate CCR.sub.i called herein current cell rate, of a connection out of a plurality of connections which are carrying datapackets via a multiplexed transmission channel in a communication network. The method includes the steps of storing in a buffer (B) incoming datapackets of the connections, determining the total number of datapackets BC.sub.TO in the buffer (B), determining the number of datapackets of the connection BC.sub.i in the buffer (B), measuring an aggregate input datapacket rate C.sub.IN of the buffer and estimating the current datapacket rate CCR.sub.

Abstract: The invention is drawn to organic compounds of the general formulae L--A--Z or L--A'--L' as defined in the specification. The compounds are readily crystallizable and can be used for their ferromagnetic properties.

Abstract: A method consists in assigning an authorization level (AUTH) to a client object and a "dynamic" sensitivity level (DSL) to a method (or data processing procedure) of a server object (ProcObjSv). The dynamic sensitivity level is computed based on static sensitivity levels (SSLs) at the moment when the server object is instantiated. The authorization level of the client object is passed to the method of the server object when the method of the server object is invoked by the client object, and this authorization level (AUTH) is compared with the dynamic sensitivity level (DSL) of the method in order to control access. The method makes it possible to implement a multi-level security model.

Abstract: The fiber-drawing furnace includes a graphite tube positioned vertically, heated by induction, and subjected internally to an inert atmosphere, said tube internally defining a fiber-drawing chamber. In the furnace said graphite tube is a double-walled tube having an inner wall and an outer wall, its inner wall is porous and separates the fiber-drawing chamber from a peripheral chamber defined between the walls and subjected to a flow of inert gas which diffuses through said porous wall into said fiber-drawing chamber. Application to drawing down an optical-fiber preform.

Abstract: A method of producing a superconductive coating (19) on an elongated substrate (12) is indicated, whereby the substrate (12) is drawn through a deposition chamber (1) in which it is also heated in a heating zone (2) and is coated with a superconducting material. To improve the current carrying capacity, the substrate (12) is coated with the superconducting material in a geometric form which differs from the use of the finished product in a way so that a compressive strain is created in the substrate plane of the superconductive coating (19) for the geometric form of the substrate (12) taking place when it is put to use.

Abstract: The invention provides copolymers having magnetic properties, said copolymers containing aminoaromatic groups, and being based on a structural unit comprising:a first group of aminoaromatic compounds chosen from aniline derivatives and the corresponding iminoquinone forms; anda second group of substituted aminoaromatic compounds chosen from substituted amino compounds containing at least two condensed benzene rings, substituted polycyclic compounds containing at least one aniline structural unit in their structure, compounds derived from aniline and carrying a substituent bonded to the ring by means of an ethynylidene or paraphenylene link, and the corresponding iminoquinone compounds.

Abstract: An apparatus for monitoring a moving filamentary product having a device for monitoring the centering of the filamentary product relative to the coating, and a device for monitoring the quality of the coating. The centering monitoring device includes two light sources positioned at 90.degree. to each other in a plane perpendicular to the filamentary product. The coating quality monitoring device includes an optical receiver disposed between the two light sources in the same plane, and at 45.degree. to each of them, to receive the light beams reflected by the coating.

Abstract: A method of extracting the contour of an object having two lateral edges, for example a road, from a digitized photographic image using an automatic active contour propagation process, comprises the steps of entering first and second initial contours near respective lateral edges of the object in the image. The first initial contour is propagated by means of a first automatic active contour propagation process and the second initial contour is propagated by means of a second active contour propagation process. Each propagation process uses, firstly, an energy model including a term relating to elastic coupling forces between paired points of the first and the second initial contours and, secondly, a direction of prolongation of the active contour defined as an average of two prolongation directions determined for the first and the second active contours, respectively.

Abstract: A device is indicated for flanging the end of a metal tube to achieve a circumferential surface extending outward at right angles from the tube. It has the form of a cylindrical housing with a flange at its open end for fastening a clamping tool which is fastened to the tube, and its other end is closed by a bottom part. The housing has a flanging attachment that is able to rotate around the longitudinal axis of the housing, and a hand-wheel which is attached to a connecting element and extends outward through the bottom part. The hand-wheel is rigidly linked to a guide part of the flanging attachment by a threaded rod which fits through a suitably threaded bore in the bottom of the housing. A pressure element of the flanging attachment is guided by a pin which also forms part of the flanging attachment. The pressure element is operationally attached to the guide part so that it is able to rotate with it around the longitudinal axis of the housing.

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.