Abstract: With the help of the millimeter wave measurement system, the surface impedance is determined by means of one or a plurality of resonators with very high three dimensional resolution when there are relatively large resonator openings in the millimeter wave range. By means of this, structures with measurements of {fraction (1/10)} the resonator openings can be solved with no trouble (FIG. 1).

Abstract: The method of the invention is based on an optimum combination of multi-carrier modulation with the spread-spectrum technique. The data of a subscriber station are spread, with the data of a subscriber station being modulated on a set of orthogonal spread sequences and superimposed. The data of a subscriber station are transmitted to a partial quantity of subcarriers in the frequency band, with the partial quantity of sub-carriers associated with the individual subscriber stations being disjunct and distributed over the entire transmission band. A channel estimation required for receiving-side data detection is performed by means of filtering in the time and/or frequency direction of reference symbols. A low-complexity maximum-likelihood sequence estimation is possible for data detection. The method of the invention is well-suited for use for both the upstream and downlinks in future cellular mobile-radio systems.

Abstract: Reaction Bonded Ceramics for Ceramic Composite Materials Comprising Mullite as the Main Component and Corundum and Thortveitite or Cerianite as Minor ComponentsThe present invention pertains to reaction bonded mullite-containing ceramic molded parts, a process for their preparation and their use.A particular embodiment of the present invention consists in reaction bonded mullite-containing ceramic molded parts, obtainable by the heat-treatment of a finely dispersed mixture of an aluminum-containing material, a silicon-containing material, and a rare earth metal-containing material in an oxygen-containing atmosphere.

Abstract: In an optical microphone including a light source, a fiber optic cable and a Fabry-Perot interferometer with two reflectors, wherein one end face of the fiber optic cable forms a first reflector and the second reflector is arranged at a distance therefrom and is displaceable by fluctuations in the sound air pressure, the second reflector is the end face of a glass fiber section which is displaceable by induced air pressure by means of a separate diaphragm that is coupled thereto. The light source may be a super luminescent diode (SLD).

Abstract: In a flexible structure, a number n of notches (12a, 12b) is formed in a preferably circular-cylindrical block of material (1). The parallel and equidistant notches (12a, 12b) begin at two diametrically opposed jacket lines (10.sub.1, 10.sub.2) and are at right angles or an acute angle to the longitudinal axis (10) of the block and are made so deep that for joining together (n+1) segments (22), a continuous, approximately rectangular residual cross-sectional region (32) remains, in the form of a residual web. Symmetrically to the longitudinal axis (10), continuous, closed conduits (52, 52.sub.1, 52.sub.2) are formed in the rectangular residual cross-sectional region (32). Moreover, aligned bores (42.sub.1, 42.sub.2) are located at diametrically opposed points, and in them pressure- and/or tension exerting components can be accommodated for bending the flexible structure.

Abstract: In an apparatus for operating a robotic device (1), preferably in minimally-invasive surgery and/or robotics, at least one movable robotic part (11; 12) of the robotic device (1) is connected to a first holding part (60) by way of a first, flexible connecting part (51.sub.1) of a hinge joint (5.sub.1) Moreover, the movable robotic part (11; 12) is connected to a second holding part (61) by way of a second, flexible connecting part (52.sub.1) of the hinge joint (5.sub.1). This connection is produced in such a way that, when the first holding part (60) moves relative to the second holding part (61) or vice versa, the robotic device (1) pivots the first holding part out of its initial position, and when the part (60 or 61) that has been moved relative to the other part has been brought back, the device restores the part to its initial position.

Abstract: The invention relates to a process for magnetic resonance examinations, in particular nuclear spin tomography, whereby a static magnetic field is produced in an examination zone and at least one gradient magnetic field is superposed, whereby unwanted alternating electromagnetic forces are produced, whereby by means of magnetostriction, forces opposing the electromagnetic forces are produced by the same gradient magnetic field and these forces act longitudinally and/or radially and/or around the circumference of the examination zone. Furthermore, the invention relates to a device for magnetic resonance examinations, in particular nuclear spin tomography, with a first generating unit for a static magnetic field, a second generating unit (20) for at least one gradient magnetic field and a support unit (10) for the second generating unit (20), whereby a magnetostrictive material system (11, 12) is provided on the support unit (10).

Abstract: In a device for determining the ozone concentration by utilizing the surface chemiluminescence effect having a fan (13), a chemiluminescence element (8), a photomultiplier (6), a temperature sensor (16), and control electronics (12), an airflow generated by a fan (13) passes via a suction pipe (7) and an adjoining light trap system (17) through a venturi-shaped channel structure (2) along a metal block (9) in which a temperature sensor (16) is housed. The device is calibrated with respect to the temperature dependence of the reaction of a chemiluminescence disc (8) attached to the bottom of the metal block by determining the output voltage of a photomultiplier (6) in dependence on the temperature at a predetermined ozone concentration in the measured air.

Abstract: For automated visual range measurement by a LIDAR system, a distance measuring range is first determined through repeated evaluation of a voltage level U(R) which indicates the intensity of a threshold value. After random initialization of a start value, the start value is then replaced each time with a new mean visual range, resulting in iterative improvements, and the mean visual range in the determined range is then displayed automatically as soon as the visual range lies within the measuring range of the LIDAR system. Using the Klett method, the accuracy can be determined with the aid of a breaking-off criterion in the form of a threshold value with respect to a deviation percentage between a new and a previous calculation. With this method the deviation can be identified to an order of magnitude of about 10%.

Abstract: A light source supplies light to an interferometer or polarimetric sensor and a beam divider divides the emerging light into two or more beam paths. Interference filters having different central wavelengths are provided in the beam paths and can be used to bring the two uncoupled interference signals into quadrature, e.g. by suitable adjustment of the tilting angle. In each beam path, a measuring device for quantitatively measuring the received light is disposed, and the data from the measuring devices are supplied to a data-processing device.

Abstract: A method for weakening a detonation in a container or piping system by dividing up the starting detonation front and bringing it together in an expansion space. The detonation front is divided into a main front and a secondary front and the main front is routed into the expansion space with a longer propagation time, in such a way that when the main front enters into the expansion space, the space contains combustion gases of the secondary front.

Abstract: To convert a rotational movement into an axial movement, rolling or roller bodies (2') are seated by way of a plurality of guide rings (5) and bearings (6) disposed between the guide rings (5) and a spindle nut (3'). The rolling or roller bodies (2') are fixedly spaced relative to the spindle nut (3') and one another, so an axial reception of a force or torque by the spindle nut (3) is transmitted through the rolling and roller bodies (2'), the guide rings (5) and the bearings (6), and, via the rolling or roller bodies (2'), the guide rings (5) and the bearings (6), a rotational movement of the spindle rod (1) is converted into an axial movement of the spindle nut (3'), or vice versa, that is free from pitch errors.

Abstract: For tracking a mono- or stereo-laparoscope in connection with minimally invasive surgery, where the laparoscope is moved by a robot in respect to surgical instruments located in the operation area, surgical instruments are color-coded and are identified in images provided by the camera of the laparoscope. Signals for controlling the robot are derived from the position of the color-coded surgical instruments in images generated by both cameras. The robot automatically brings the laparoscope into such a position that the color-coded surgical instruments are continuously shown in the center area of the monitor device and hold the laparoscope distance to the surgical instrument in the case of stereo. To prevent interfering movements of an image when working with the surgical instruments, the laparoscope continuously tracks the color-coded surgical instruments in such a way that the tracking of the image is controlled relatively lightly in the central area of the monitor, but strongly in its edge area.

Abstract: In a method for azimuth scaling of SAR data without interpolation, raw SAR data in azimuth are multiplied with a phase function H.sub.5 (f.sub.a ;r.sub.o), where f.sub.a denotes the azimuth frequency and r.sub.o denotes the range to a target point, and where a desired scaling factor is entered into the phase function. An azimuth modulation of the SAR data is subsequently adapted with the phase function H.sub.5 (f.sub.a,r.sub.o) to that of a reference range, in a manner so that the azimuth modulation no longer depends on the range. In a last step of the process, a quadratic phase modulation is performed in the azimuth so that, in order to attain an azimuth processing with a very high phase accuracy, the azimuth frequency modulation becomes exactly linear.

Abstract: For less expensive estimation the impulse response x.sub.MOS of a high-resolution, band-limited radar channel in a radar station operating with an expanded transmitted pulse a(t), from a received signal e, over which a correlated or uncorrelated additive interference signal n can be superimposed, with the use of knowledge about the spread code c and the use of a channel estimator with which a so-called linear, optimum unbiased estimation of the radar channel impulse response x.sub.MOS is performed in a time range covering M range gates of interest, the linear, optimum estimation in the unbiased channel estimator is modified in such a way that the pulse response x.sub.MOS of the band-limited radar channel is determined according to the basic principle of a multiplication of the sampled received signal e and an inverse estimation matrix A.sub.E.sup.-1. The matrix A.sub.E is formed by the extension of the rectangular matrix represented by the components c.sub.

Abstract: The invention relates to an absorber designed to absorb radiation and to transfer the energy of the radiation to a heat transport medium. To provide an absorber with high efficiency, the absorber according to the invention comprises a plurality of absorber components (32) attached to each other and having passages (42) formed therein for absorption of radiation and for suctional intake of a heat transport medium. Each absorber component (32) is provided with a dedicated mixing chamber (44) having said passages (42) of said absorber component (32) entering thereinto and comprising flow-restricting outlet orifices for connection to a suction means.

Abstract: A method of correcting measurement errors in a measurement robot resulting from relative movements between an object to be measured and a measurement probe comprises the steps of detecting the accelerations at the probe, detecting the accelerations at or close to the object to be measured, calculating the correction data reproducing the relative movement from the measured accelerations and correcting the measured values recorded by the measurement robot with the correction data. The robot serves for determining shape and/or coordinates of an object to be measured, with a base unit, at least one movable measurement probe arranged on the base unit and a holding device arranged on the base unit for holding the object to be measured, wherein first acceleration are arranged on or close to the measurement probe, and second acceleration pickups are provided on the base unit, and an evaluation device is provided which calculates correction data from the measured data of the first and second acceleration pickups.

Abstract: In a method to resolve ambiguities in a phase measurement for application in radar interferometry, a frequency estimation method is used, starting from conjugate complex products of pairs of adjacent pixels in an interferogram. The resolution of these products is subsequently reduced through successive addition or averaging, after which the differential phase of adjacent resolution levels is determined in each resolution level. The sum of the phase differences yields the estimated value for the phase gradient which is then used in a known method, such as the least-squares method, to reconstruct the absolute phase, thus resolving the phase ambiguities. The method according to the invention serves to resolve phase ambiguities in radar interferograms without producing the known distortions produced by the existing methods. The method is also robust at low coherence values as they occur in repeat-pass interferometry where the existing methods fail.

Abstract: An interface (3) for vibration reduction in structural-dynamic systems comprises a base-side construction element (8) and a structure-side construction element (9) and at least one actuator (14), for example a piezoelectric or a magnetostrictive actuator. The actuator (14) has a main direction (17), and the extension of the actuator (14) in its main direction (17) between a first engagement point (15) on the base-side construction element (8) and a second engagement point (16) on the structure-side construction element (9) can be voluntarily changed by means of a drive signal.

Abstract: In an autonomous navigation system for a mobile robot or a manipulator which is intended to guide the robot through the workspace to a predetermined target point in spite of incomplete information without colliding with known or unknown obstacles. All operations are performed on the local navigation level in the robot coordinate system. In the course of this, occupied and unoccupied areas of the workspace are appropriately marked and detected obstacles are covered by safety zones. An intermediate target point is defined in an unoccupied area of the workspace and a virtual harmonic potential field is calculated, whose gradient is followed by the robot. Mobile robots with such an autonomous navigation system can be used as automated transport, cleaning and service systems.