Abstract: A method of controlling compaction including obtaining a plurality of sets of process conditions for a plurality of glass ribbons, measuring a compaction value for a glass sheet cut from each glass ribbon of the plurality of glass ribbons, correlating the compaction to the process conditions. The method further includes selecting a predetermined cooling curve including a plurality of cooling rates, modifying the cooling curve by varying cooling rates of the plurality of cooling rates, calculating a predicted compaction value for a glass sheet cut from a glass ribbon drawn using the modified cooling curve, and repeating the modification and predicting until compaction is minimized.

Abstract: A confocal microscope includes a data acquisition unit configured to acquire a rough-shape data indicating a rough shape of a sample, an illumination light source configured to generate illumination light for illuminating the sample, an objective lens configured to concentrate the illumination light on the sample, an optical scanner configured to scan an illuminated place on the sample in a field of view of the objective lens, a stage configured to scan the illuminated place along the rough shape of the sample by changing a position of the objective lens relative to the sample, and an optical detector configured to detect reflected light through a confocal optical system, the reflected light being light that has been reflected on the sample and has passed through the objective lens.

Abstract: In an approach for a component installation, a processor receives sensor data from a sensor scanning a component. The component is to be installed into a receptacle. A processor compares the sensor data to reference data. The reference data is pre-collected data associated with the type of the component and the type of the receptacle. The reference data defines the correct type of the component to be installed in the receptacle. The reference data defines a damage status of the type of the component. A processor determines whether the component has damage. A processor determines whether the component is a correct type of component to be installed in the receptacle. A processor provides an indication for installation.

Abstract: Focus metrology patterns and methods are disclosed which do not rely on sub-resolution features. Focus can be measured by measuring asymmetry of the printed pattern (T), or complementary pairs of printed patterns (TN/TM). Asymmetry can be measured by scatterometry. Patterns may be printed using EUV radiation or DUV radiation. A first type of focus metrology pattern comprises first features (422) interleaved with second features (424) A minimum dimension (w1) of each first feature is close to a printing resolution. A maximum dimension (w2) of each second feature in the direction of periodicity is at least twice the minimum dimension of the first features. Each first feature is positioned between two adjacent second features such that a spacing (w1?) and its nearest second feature is between one half and twice the minimum dimension of the first features. A second type of focus metrology pattern comprises features (1122, 1124) arranged in pairs.

Abstract: An alignment tool for a laser machine tool includes a frame that is mountable to the laser cutting head of the laser machine tool; a first indicator mounted to the frame along an X-axis; a second indicator mounted to the frame along a Y-axis; a position device mounted to the frame, the position device operable to reference upon a surface of the laser cutting head to align the first indicator along an X-axis of the laser cutting head, and to align the second indicator along a Y-axis of the laser cutting head; and a fastener mounted to the frame, the fastener operable to retain the frame to the laser cutting head.

Abstract: A core image acquiring unit is mounted at a position where the core image acquiring unit looks down at a workpiece on a table, such as an upper guide unit of a wire electric discharge machine, the core machining is performed, while fixing the core using a core fixing function, at a stage in which machining is completed to the end point of the machining path of cutting the core, the core and the workpiece are picked up by the core image acquiring unit, from the captured image, it is determined whether a machining groove has a constant width, or adhesion and deposition of machining debris are present in the machining groove, or the core is fixed by a difference in states of the surface light between the core and the workpiece.

Abstract: A support pin arrangement determination assisting method includes displaying an image including a board image that indicates a shape and an arrangement of an already mounted component on the already mounted surface; inputting an arrangement position of the support pin to the displayed image; and displaying a composite image in which a pin arrangement image indicating the input arrangement position is superimposed on the board image. A planar image of the support pin in the pin arrangement image includes an image of a top portion of a shaft and an image of a contact portion which is located on a tip side of the top portion, which has a sectional shape smaller than that of the top portion, and which contacts and supports a lower surface of the board.

Abstract: The present disclosure provides a method of detecting and preventing grind burn from developing on a gear. The method includes performing acoustic emission testing while the gear is being ground during a grinding operation. The grinding wheel is evaluated during an eddy current test to detect material buildup on the grinding wheel which could cause grind burn. In addition, the method includes collecting swarf from the gear during the grinding operation and inspecting the swarf for an indication of grind burn.

Abstract: A medical device for monitoring delivery of a therapy that includes a therapy delivery module to deliver a therapy, a controller to set a therapy delivery control parameter, an optical sensor to produce a signal corresponding to tissue light attenuation, and a processor configured to compute a tissue oxygenation measurement from the optical sensor signal, wherein the controller, the optical sensor, and the processor operate cooperatively to determine a setting of the therapy delivery control parameter corresponding to a maximum tissue oxygenation.

Abstract: A method for making a photolithography mask for formation of electrically conducting contact pads between tracks of a metallization level and electrically active zones of integrated circuits formed on a semiconductor wafer includes forming a first mask region including first opening zones intended for the formation of the contact pads. The first opening zone has a first degree of opening that is below a threshold. A second mask region including additional opening zones is formed, with the overall degree of opening of the mask being greater than or equal to the threshold.

Abstract: A support pin arrangement determination assisting method includes: displaying an image including a board image that indicates a shape and an arrangement of an already mounted component on an already mounted surface; inputting an arrangement position of a support pin to the displayed image; superimposing a pin arrangement image indicating the input arrangement position on the board image to create a composite image; and displaying the composite image. The composite image, a first pin arrangement image, and a second pin arrangement image are superimposed on the board image. The first pin arrangement image is generated by inputting an arrangement position in a state that the board is positioned at the first mounting work position, and the second pin arrangement image is generated on the basis of the first pin arrangement image with an assumption that the board is positioned at the second mounting work position.

Abstract: An apparatus for generating holograms includes a laser source configured to emit a laser beam with a frequency of v; an acoustic optical modulator configured to generate, from the laser beam, a first beam with a frequency of v1 and a second beam with a frequency of v2; a first beam splitter configured to split the first beam into a first reference beam and a first object beam, the first object beam being led to a sample; a second beam splitter configured to split the second beam into a second reference beam and a second object beam, the second object beam being led to the sample; and a detector configured to detect an image composed of a first fringe, based on the first reference beam and the first object beam, and a second fringe, based on the second reference beam and the second object beam.

Abstract: In accordance with one embodiment of the present disclosure, a difference is detected between a first image and a second image. The second image can include at least a portion of the first image reflected from a display panel and light from an object passing through the display panel.

Abstract: A video calibration device comprising an elongated image tube having a length, a first opening at one end of the image tube and a second opening at the opposite end of the image tube. The device includes an elongated sensor tube having a length, a first opening at one end of the sensor tube and a second opening at the opposite end of the sensor tube. The first opening of the sensor tube is adapted to support a video calibration sensor. A video calibration sensor is disposed in the first opening of the sensor tube. The sensor tube is sealingly secured to the image tube at an angle whereby the second opening of the sensor tube and the second opening of the image tube are substantially juxtaposed.

Abstract: An optical comparator arranged for rear projection onto a viewing screen combines an optical projector that projects an optical image of a test part under inspection onto the viewing screen with a video projector that projects an optical image of a pixilated template pattern containing illustrated specifications of the test part onto the same viewing screen. The images of the test part and the pixilated template pattern are projected concurrently onto the viewing screen for visually comparing the form of the test part against its specified form.

Abstract: An optical comparator arranged for rear projection onto a viewing screen combines an optical projector that projects an optical image of a test part under inspection onto the viewing screen with a video projector that projects an optical image of a pixilated template pattern containing illustrated specifications of the test part onto the same viewing screen. The images of the test part and the pixilated template pattern are projected concurrently onto the viewing screen for visually comparing the form of the test part against its specified form.

Abstract: A method and system for synchronizing variations in components or subsystems in an image printing system is provided. The method includes identifying a plurality of image quality defects printed by the image printing system by a controller, said image quality defects each occurring with an associated frequency and each being associated with a component or subsystem of the image printing system; determining a phase difference of the image quality defects by the controller; and adjusting operation of each component or subsystem associated with the image quality defects, such that image quality defects are in phase.

Abstract: An optical comparator arranged for rear projection onto a viewing screen combines an optical projector that projects an optical image of a test part under inspection onto the viewing screen with a video projector that projects an optical image of a pixilated template pattern containing illustrated specifications of the test part onto the same viewing screen. The images of the test part and the pixilated template pattern are projected concurrently onto the viewing screen for visually comparing the form of the test part against its specified form.

Abstract: There is provided a molecularity measurement instrument capable of working out the number of molecules in a sample by comparing a measured value of a light quantity with a theoretical light quantity per a single molecule, and a molecularity measurement method using the same. The molecularity of the sample is quantitatively estimated on the basis of a light quantity having correlation with the molecularity. The molecularity measurement method comprises the step of working out a theoretical light quantity per a single molecule, the step of measuring a light quantity of the sample by use of an image detector, and the step of working out the molecularity of the sample on the basis of a ratio of the light quantity of the sample to the theoretical light quantity as worked out.

Abstract: A substrate inspection method includes forming a conductive thin film on a surface of an inspection target substrate with a pattern formed thereon, generating an electron beam and irradiating the substrate having the thin film formed thereon with the electron beam, detecting at least any of secondary electrons, reflected electrons and backscattered electrons released from the surface of the substrate and outputting signals constituting an inspection image, and selecting at least any of a material, a film thickness and a configuration for the thin film, or at least any of a material, a film thickness and a configuration for the thin film and an irradiation condition with the electron beam according to an arbitrary inspection image characteristic so that an inspection image according to an inspection purpose can be obtained.

Abstract: Methods of subtracting the copper contribution to spectra obtained from a substrate during chemical mechanical polishing are described.

Abstract: A method of using an in-situ aerial image sensor array is disclosed to separate and remove the focal plane variations caused by the image sensor array non-flatness and/or by the exposure tool by collecting sensor image data at various nominal focal planes and by determining best focus at each sampling location by analysis of the through-focus data. In various embodiments, the method provides accurate image data at best focus anywhere in the exposure field, image data covering an exposure-dose based process window area, and a map of effective focal plane distortions. The focus map can be separated into contributions from the exposure tool and contributions due to topography of the image sensor array by suitable calibration or self-calibration procedures. The basic method enables a wide range of applications, including for example qualification testing, process monitoring, and process control by deriving optimum process corrections from analysis of the image sensor data.

Abstract: A method for precise endpoint detection during etch processing of a substrate based on adaptive filtering of the optical emission spectrum (OES) data, even in low open area etching, is provided. Endpoint detection performed in this manner offers the benefits of increased signal-to-noise ratio and decreased computation costs and delay when compared to conventional endpoint detection techniques.

Abstract: In a method for determining a structure parameter of a target pattern, a first series of calibration spectra are determined from at least one reference pattern, each spectra being determined using a different known value of at least one structure parameter of the respective reference pattern. The first series of calibration spectra does not take into account parameters of an apparatus used to produce the reference pattern. A representation of each of the first series calibration spectra is stored in a central library. A second series of calibration spectra corresponding to at least one of the stored spectra for a target spectrum is determined using the parameters of the apparatus for measuring the target spectrum. A measured target spectrum is produced by directing a beam of radiation onto the target pattern. The measured target spectrum and the second series of calibration spectra are compared, where this comparison is used to derive a value for the structure parameter of the target pattern.

Abstract: To generate a simulated diffraction signal, one or more values of one or more photoresist parameters, which characterize behavior of photoresist when the photoresist undergoes processing steps in a wafer application, are obtained. One or more values of one or more profile parameters are derived using the one or more values of the one or more photoresist parameters. The one or more profile parameters characterize one or more geometric features of the structure. A simulated diffraction signal is generated using the one or more values of the one or more profile parameters. The simulated diffraction signal characterizes behavior of light diffracted from the structure. The generated simulated diffraction signal is associated with the one or more values of the one or more photoresist parameters.

Abstract: A method for correcting systematic errors in an optical measurement tool in which a first diffraction spectrum is measured from a standard substrate including a layer having a known refractive index and a known extinction coefficient by exposing the standard substrate to a spectrum of electromagnetic energy. A tool-perfect diffraction spectrum is calculated for the standard substrate. A hardware systematic error is calculated by comparing the measured diffraction spectrum to the calculated tool-perfect diffraction spectrum. A second diffraction spectrum from a workpiece is measured by exposing the workpiece to the spectrum of electromagnetic energy, and the measured second diffraction spectrum is corrected based on the calculated hardware systematic error to obtain a corrected diffraction spectrum.

Abstract: This invention relates to a method for the calibration of linear array photo sensors operating in a specular reflection mode. Errors may be introduced when a highly diffused image is measured by the linear array photosensor that was calibrated in a specular mode. These errors result in artifacts such as streaks in the captured image. The method measures non-uniformity errors using a highly diffuse white reflective surface, and then applies an appropriate scaled pixel-wise correction factor to the image when the sensor is used in the specular mode.

Abstract: An optical measuring system includes a carrying tray for carrying a specimen, a first light source module, a second light source module and an optical measuring module. The first light source module is disposed at the first side of the carrying tray and the specimen is disposed on the optical path of the first light source module. The second light source module is disposed at the second side of the carrying tray and the specimen is disposed on the optical path of the second light source module. The optical measuring module is disposed at the first side or the second side of the carrying tray, and the specimen is located within the probing range of the optical measuring module.

Abstract: In a first aspect according to the invention there is provided a sensing system 100, suitable for sensing the stage of processing of a wafer 200, said sensing system 100 comprising receiving means 110 in the form of a first photosensitive device 110a and a second photosensitive device 110b, detector 120, a comparator 130 and a control system in the form of a programmable logic controller (PLC) 140. The first photosensitive device 110a receives light from the wafer 200, while the second photosensitive device 110b receives ambient light. The light received by the first photosensitive device 110a can be incident ambient light reflected off the surface of the wafer 200, refracted light radiating through the wafer 200, filtered light radiating through the wafer 200 or translucent light radiating through the wafer 200. It is further envisaged that the received light may be filtered through filters (not shown) before being received by the photosensitive devices 110a&b.

Abstract: A measurement light detector detects light transmitted by a light source of an implantable system that is scattered back into an implantable housing, and produces a measurement signal indicative of the intensity of the light detected by the measurement light detector. A calibration light detector detects a portion of the transmitted light that has not exited the housing, and produces a calibration signal that is indicative of the intensity of the light detected by the calibration light detector, which is indicative of the intensity of the light transmitted by the light source. Changes in the intensity of the transmitted light are compensated for based on the calibration signal produced by the calibration light detector. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.

Abstract: The invention provides a source of illumination comprising a base having mounted thereon at least one light-emitting diode light source, a parabolic reflector mounted on the base and surrounding the at least one light-emitting diode, and a transmissive diffuser at the narrow end of the parabolic reflector.

Abstract: A method and apparatus for efficiently executing two types of measurements with an optical measuring device and a scanning electron microscope are provided. For example, the method and apparatus may execute the following steps: calculating an average of the dimensional values of a plurality of scanned feature objects; and calculating an offset of a dimensional value on the basis of a difference between the calculated average value and the dimensional value of the feature object obtained when the light is irradiated. The offset between measurement values between the optical measuring device and the scanning electron microscope can be determined precisely.

Abstract: A defect inspecting apparatus includes a first support unit supporting a standard sample having standard defects, a second support unit supporting a wafer having target defects, a light source irradiating an incident light to the standard sample or the wafer, a light receiving part collecting reflection light reflected from the standard sample and the wafer, a detection part detecting the standard defects and the target defects by using the reflection light, a comparing part comparing information obtained using the reflection light reflected from the standard sample with a predetermined standard information of the standard defects to confirm a reliability of a step for detecting the target defects and a determination portion determining whether the step is allowed to be performed or not.

Abstract: A method, system and computer program product for determining a geometric parameter of an optical spot of a light beam are disclosed. A method comprises: providing a calibration target, the calibration target including a systematic variation in a parameter; measuring the calibration target with respect to the systematic variation using the light beam to obtain a plurality of measurements; and analyzing the measurements and the systematic variation to determine the geometric parameter of the optical spot.

Abstract: A method for checking the operation of a laboratory instrument used in biochemistry by means of an individual test plate (10) by comparing measured values of sample units (20, 21) placed in the wells (12) of the frame plate (11) to previously known measured values verified by a reference device. The sample unit (20) placed in the frame plate (11) of the test plate (10) is a teflon plastic cup (22) provided with an aluminum cover (23), the sample material (24) in powdery form being placed in said cup, or an optical filter (21), which is locked in place by means of a locking spring ring (25).

Abstract: An autofocus for a confocal microscope is realized by means of a confocal microscope arrangement comprising an illumination arrangement for illuminating an object in a raster pattern, first means for generating a first wavelength-selective splitting of the illumination light and second means for generating a second wavelength-selective splitting of the light coming from the object in a parallel manner for a plurality of points of the object, and detection means for detecting the light distribution generated by the second means, wherein an at least point-by-point spectral splitting and detection of an object image in a wavelength-selective manner is carried out and a control signal is generated from the determination of the frequency deviation and/or intensity deviation from a predetermined reference value corresponding to the object position in order to adjust the focal position by means of the vertical object position and/or the imaging system of the microscope.

Abstract: Disclosed is a print quality test structure for devices manufactured by lithography. The test structure allows for visual inspection of the print quality of the device. The test structure decouples the effects of overexposure, underexposure and focus so that corrections can be made for future device manufacturing. By visually inspecting each device during lithography, devices of poor quality can be reworked, and costly testing on all devices can be avoided through device screening.

Abstract: The present invention provides a computer joystick which will convert movements of its control stick into digital signals. The computer joystick comprises a housing with an opening on its top, a control stick, and two optical sensing devices for detecting movements of the control stick in two perpendicular directions and generating corresponding displacement signals. The control stick comprises a handle installed at its top section, a ball-shaped portion installed at its middle section, and a driving mechanism installed at its bottom section. Each of the optical sensing devices comprises an optical panel comprising a plurality of light transmitting holes installed on it, a light source and a plurality of optic sensors installed at opposite sides of the optical panel, and a plurality of comparators for comparing detecting signals generated by the optic sensors so as to generate the displacement signals.

Abstract: A method and associated apparatus for measuring chemical concentration in a liquid sample based on spatial separation and resolution of light is disclosed. The method is preferably applied to sensitive, quantitative, luminescence-based biosensors which reads the analyte concentration via spatial distribution of the emitted light. The detection of light is used to assess the spatial position, rather than the intensity or wavelength, of emitted light. A bioluminescent or chemiluminescent reaction requiring, for example, ATP, NADPH or NADH as a specific, and sensitive co-factor is used. ATP or NADH concentration is modulated, “tuned,” and/or regulated via, for example, an enzyme which consumes (“consumase”) ATP, NADPH, or NADH, thereby producing a spatial distribution of ATP or NADH and a spatial distribution in the emitted light.

Abstract: A device for inspecting a printed image of a product of a printing press, comprising an image detecting device that furnishes actual image data of the product, and a comparison circuit comparing the actual image data with master image data from a defect-free master image, dividing means for performing a preselectable division of the printed image into inspection areas, and wherein if a defect is detected by the comparison circuit the associated inspection area is designated as being defective.

Abstract: A method and apparatus for determining optical mask corrections for photolithography. A plurality of grating patterns is printed onto a wafer utilizing a photomask having at least one grating. Each grating pattern within the plurality of grating patterns is associated with known photolithographic settings. Each grating pattern is illuminated independently with a light source, so that light is diffracted off each grating pattern. The diffracted light is measured utilizing scatterometry techniques to determine measured diffracted values. The measured diffracted values are compared to values in a library to determine a profile match. A 2-dimensional profile description is assigned to each grating pattern based on the profile match. A database is compiled of the profile descriptions for the plurality of grating patterns. Photomask design rules are then generated by accessing the database containing the 2-dimensional profile descriptions.

Abstract: A method for inspecting a reticle to evaluate the degree of corner rounding of a feature of a test pattern includes placing a reticle having a photomask formed thereon under a microscope. The photomask has a pattern corresponding to features of a semiconductor chip design defined therein. In addition, the photomask further has a test pattern and a crosshair orientation mark defined therein. The test pattern has at least one test corner for evaluating a degree of corner rounding when the test pattern is defined in the photomask. The crosshair orientation mark is defined in the photomask to orient a crosshair of the microscope relative to the test pattern. Once the crosshair of the microscope is aligned with the crosshair orientation mark, the crosshair of the microscope is used to evaluate the degree of rounding of the test corner of the test pattern.

Abstract: A test slide for the calibration, characterization, standardization, use and study of photon and electron microscopes. The slide is created by forming patterns with specific types of geometries on suitable substrates and these slides provide a standard for comparison of image forming capability of any type of microscope imaging system including, without limitation, light, UV, and X-ray photon microscopical imaging systems operating in transmission or reflection modes, and other microscope techniques. Microscopists can employ one of these slides to compare images of the slide which have been produced by the microscope system under consideration with a known, accurate, image of the slide to better understand the fidelity and accuracy of the microscope system under consideration. The test patterns can also comprise reference images which can be images created by a graphic artist or the like or which can be actual images of samples, these images being either two dimensional or three dimensional.

Abstract: The invention provides a unique method and apparatus for detecting defects in an electronic device. In one preferred embodiment, the electronic device is a semiconductor integrated circuit (IC), particularly one of a plurality of IC dies fabricated on a wafer of silicon or other semiconductor material. The defect detection operation is effectuated by a unique combination of critical dimension measurement and pattern defect inspection techniques. During the initial scan of the surface of the wafer, in an attempt to locate the appropriate area for a critical dimension (CD) feature or element that is to be measured, a “best fit” comparison is made between a reference image and scanned images. The critical dimension measurements are conducted on a “best fit” image. In addition, a “worst fit” comparison is made between the reference and scanned images. A “worst fit” determination represents pattern distortions or defects in the ICs under evaluation.

Abstract: A visibility range measuring apparatus for detecting visibility range in a passive fashion without suffering erroneous operation even in the case of such a situation that a plurality of visibility range measuring apparatuses exist within a coverage thereof. The apparatus includes a camera mounted on a motor vehicle for taking a picture of parts of a lane-dividing mark lines extending forwardly in front of a motor vehicle and a visibility-range determining control unit for determining the visibility range through comparison of luminances at a plurality of locations of the lane-dividing mark line, which locations differ from one another with respect to the location of the motor vehicle.

Abstract: A method for verification of components installed on a printed circuit board includes the step of capturing an image of an entire printed circuit board and components mounted thereon using a scanning device. After it has been determined that a printed circuit board having no defects, the scanned image of the circuit board has no defects is stored in a memory. The image of the entire printed circuit board under test, and having potential defects is then captured using a scanning device. The image of the printed circuit board under test is then stored in a memory. The stored image of the printed circuit board having no defects is then overlaid in registration with the stored image of the printed circuit board with potential defects on a display in alternating sequence in order to visually provide an indication of a defective component or defective component placement on the printed circuit board under test to an operator.

Abstract: The invention relates to an optoelectronic sensor comprising a light transmitter for the transmission of light signals into a monitored region, and also a light receiver for the reception of light signals transmitted by the light transmitter, wherein an evaluation circuit which is directly or indirectly acted on by the light receiver is provided for the production of an article detection signal in the case when an object is present in the monitored region. The light receiver is formed as a spatially resolving receiver element for the determination of the position of the center of intensity of the received light in the region of the light sensitive area of the receiver element. A memory element which co-operates with the evaluation circuit is provided for the storage of at least desired position of the center of intensity of the received light.

Abstract: Terminal groups (2a), (2b), (2c) and (2d) extending in respective directions, of an IC (1 ) disposed on a stage (11 ) are reflected by first mirrors (31a), (31b), (31c) and (31d) down toward second mirrors (32a), (32b), (32c) and (32d). The terminal groups are reflected by the second mirrors toward the center and are further reflected by third mirrors (33a), (33b), (33c) and (33d) downward. The reflected terminal groups are received by a lens unit (35 ) and image taking means to be displayed in a display screen so that front images of the terminal groups of the IC (1 ) in the respective directions as viewed from the sides thereof can be displayed in the same display screen. Accordingly, the terminal groups in the respective directions can be inspected at one time.

Abstract: For evaluating the optical quality of a glass product utilizing a projection technique, a camera and a computer, the image observed is compared with a reference image reconstructed by means of a convolution window which is displaced over the entire projected image. The illumination at the boundaries is reconstructed by an extrapolation by two-dimensional linear regression.

Abstract: The off-axis joint transform correlator improves on the extant on-axis jo transform correlator by eliminating the requirement for a second laser frequency and the means for blocking the first laser frequency from propagating beyond a given point in the correlator. These eliminations are accomplished by using a beamsplitter and a mirror to bring a second portion of the first frequency at an angle to read the pattern information written onto a spatial light modulator by the first portion.