217results about How to "Avoid aliasing" patented technology

A method and an apparatus measure blood oxygenation in a subject. A first signal source applies a first input signal during a first time interval. A second signal source applies a second input signal during a second time interval. A detector detects a first parametric signal responsive to the first input signal passing through a portion of the subject having blood therein. The detector also detects a second parametric signal responsive to the second input signal passing through the portion of the subject. The detector generates a detector output signal responsive to the first and second parametric signals. A signal processor receives the detector output signal and demodulates the detector output signal by applying a first demodulation signal to a signal responsive to the detector output signal to generate a first output signal responsive to the first parametric signal. The signal processor applies a second demodulation signal to the signal responsive to the detector output signal to generate a second output signal responsive to the second parametric signal. The first demodulation signal and the second demodulation signal both include at least a first component having a first frequency and a first amplitude and a second component having a second frequency and a second amplitude. The second frequency is a harmonic of the first frequency. The second amplitude is related to the first amplitude to minimize crosstalk from the first parametric signal to the second output signal and to minimize crosstalk from the second parametric signal to the first output signal.

A chopped Hall effect sensor topology includes a switched Hall plate, an amplifier responsive to an output of the switched Hall plate and a filter stage responsive to the output of the amplifier and including an anti-aliasing filter and a selective filter that is tuned to the modulation frequency. The switched Hall plate includes a Hall element and a Hall plate modulation circuit that modulates the Hall offset signal component or the magnetic signal component. In embodiments in which the Hall offset signal component is modulated by the switched Hall plate, the amplifier, if chopped, includes an even number of additional modulation circuits. In embodiments in which the magnetic signal component is modulated by the switched Hall plate, the amplifier contains an odd number of modulation circuits. The described topology provides a low noise, fast response time Hall effect sensor.

A system and method is provided for preventing the occurrence of aliasing at the edges of polygons in 3D graphics. The system may detect both polygon geometric edges and Z edges due to intersection of multiple polygons. In one embodiment, the system includes an edge anti-aliasing module configured to selectively super-sample edge portions of primitives. The system further includes a coarse memory for storing information of pixels that are not super-sampled and a fine memory for storing information of pixels that are super-sampled by the edge anti-aliasing module.

A solid-state imaging device includes: a plurality of light-receiving elements which are arranged by rows and columns; a plurality of vertical transfer units each of which is arranged for a corresponding column of the light-receiving elements, and vertically transfers a plurality of signal packets and dummy packets, the signal packet including charges read from the light-receiving elements, the dummy packets being packets other than the signal packets, and N columns of the vertical transfer units forming one column group; a plurality of hold units which are arranged for final stages of the vertical transfer units in N columns except M column in the column group, and each of which mixes, holds, and vertically transfers charges of the signal packets and the dummy packet without depending on vertical transfer from upstream of the corresponding vertical transfer unit; a horizontal transfer unit which mixes, holds, and horizontally transfers the charges transferred from the hold units or the vertical transfer units in the M column in the column group; and a driving unit which drives the vertical transfer units, the hold units, and the horizontal transfer unit, wherein the driving unit perform the driving, so that a signal packet and a plurality of dummy packets in an identical column are mixed together into a mixed packet in each of the holding units, charges of the mixed packet are held in the hold unit, the held charges of the mixed packet are vertically transferred to the horizontal transfer unit so that the mixed packet is mixed with a mixed packet of a different hold unit which is vertically transferred from the different hold unit to the horizontal transfer unit.

The invention provides a simulation method for a linear frequency modulation continuous wave synthetic aperture radar video signal, which comprises the following steps: simulated synthetic aperture radar system parameter information is set and read; the information parameter of a target is set; a simulated time is treated with discretization; the instantaneous positions of a radar platform and the target are respectively calculated, and a distance vector between a phase center and the target is obtained according to geometric position relation; a one-dimension echo signal is obtained by combining the echo signal mathematic model of the synthetic aperture radar and radar system parameters; the one-dimension signal is divided according to pulse repetition period and formatted into a two-dimension signal, the two-dimension signal with Na multiplied by Nr is obtained after the total data is stored, thus finishing the fine simulation of the linear frequency modulation continuous wave synthetic aperture radar video signal. The more accurate echo simulation signal can be obtained by utilizing the simulation method, and the simulation method is especially suitable for a frequency modulation continuous wave signal with high-speed movement, long distance and severe oblique observation condition of the radar and has more excellent realization efficiency, and stronger adaptability and compatibility.

The invention discloses a sampling time error calibrating device and method of a multi-channel parallel analog-to-digital conversion system. The method comprises that analog input signals are input at the input end of a TIADC system; the output end of the TIADC system is connected with the input end of a sampling time error estimation circuit via a switch circuit; the output end of the TIADC system is also connected with the input end of a multiplexer, and sends sampling time error values to a sampling time error compensating circuit; and the output end of the multiplexer and the output end of the sampling time error estimating circuit are connected to the input end of the sampling time error compensating circuit, and output signals at the output end of the sampling time error compensating circuit serve as calibrated output signals. According to the sampling time error calibrating device and method, sampling time errors of the TIADC system are calibrated, the problem of aliasing is solved, the operation speed of the calibration circuit is increased, and convenience is provided for hardware realization.

The invention discloses an unsupervised domain adaptation classification method based on inter-class matching, so as to solve the technical problem that the present classification method for images between different domains is poor in classification performance. According to the technical scheme, according to samples in a source image domain and a target image domain, the maximum average difference model for classes is built. A linear projection method is used to build a feature representation model for domain migration, the source domain samples and the target domain samples are projected to the same hidden feature space. In joint consideration of the supervision information of the source domain samples and hidden low-rank structural features between samples in the target domain, a robust target domain classification model is built, and all unlabeled samples in the target domain are marked. A joint optimization model with minimization of the distribution difference of the same class between domains as a target is built, an alternating minimization optimization method is used, alternating iteration of the feature representation model and the classification model is carried out until convergence, the optimal target domain classification result is obtained finally, and the classification performance is good.

The present invention discloses a display module and an electronic device. The display module comprises a display device, wherein the display device comprises a display panel for performing image display, and the display panel comprises a plurality of display pixels; and a photosensitive device, wherein the photosensitive device comprises a photosensitive panel, and the photosensitive panel and the display panel are arranged in a stacked manner for obtaining predetermined biometric information of a target object touching or approaching the display module by sensing an optical signal. The display device further comprises a display driving circuit, for driving the display pixels to be lit in a time-sharing manner when the photosensitive panel performs the biometric information sensing. The electronic device comprises the display module.

The invention discloses a method and system for switching accompaniment / original audio data. The method includes the steps that original audio files of a single track, accompaniment audio files of the single track and audio formats of the original audio files and the accompaniment audio files are obtained; the original audio files and the accompaniment audio files are arranged alternately according to the audio formats and are combined into dual-track audio files; the mode of coding through dual tracks is used for coding the dual-track audio files, and coded files are obtained; the coded files are sent to a client side which is used for decoding, switching and playing the coded files. According to the scheme, the mode of independent coding with the dual tracks is used for coding the dual-track audio files, and aliasing of the accompaniment audio data and the original audio data can be avoided. Due to the fact that the accompaniment audio data and the original audio data can be played only by sending one file to the client side, the requirement for the bandwidth is low, and therefore transmission efficiency is improved. In addition, only one part of data need to be decoded at the client side, and playing efficiency is improved.

A data acquisition system (DAS) (30) for a computed tomography (CT) scanner (12) includes a two-dimensional array (32) of detectors (34) which is arranged to detect x-rays produced by the CT scanner (12). Each detector (34) is divided into two sub-detectors (34a, 34b) along an axial direction (z). A high-speed switching circuit (40) combines selected adjacent sub-detector outputs (34a, 34b), e.g. combining a sub-detector n alternately with sub-detectors (n−1) and (n+1). The high-speed switching circuit (40) switches its configuration between DAS measurements to produce interlaced DAS output signals along the axial direction (z).

The invention relates to a single sound source localization method based on phase difference regression. The single sound source localization method comprises the steps of converting a sound source signal received through a microphone array into a digital sound signal; preprocessing the digital sound signal, and then extracting the spectrum of the digital sound signal of each microphone in the microphone array; calculating a spatial correlation matrix of each frequency point at time t using the spectrums of the digital sound signals of all the microphones at the same frequency point at adjacent time; decomposing the spatial correlation matrix at each frequency point is at time t to obtain a main eigenvector at each frequency point at time t; solving a phase difference set of M pairs of microphones at each frequency point at time t by using the main eigenvector at each frequency point at time t; and by an iterative method, conducting regression of the phase difference to obtain an incident direction angle of the sound source at time t.

The invention relates to a method and a device for digital front-end filtering. The method comprises the following steps: firstly, an analog base-frequency signal is introduced into an analog-digital conversion component by an input pin; after up-sampling is carried out on the analog base-frequency signal, the analog base-frequency signal is converted into sampling signals I and Q for output; the sampling signals I and Q enter a control unit via a data wire and are respectively output to a digital filter I and a digital filter Q; digital filtering is respectively carried out on the entering digital signals I1 and Q1, and digital signals I2 and Q2 after filtering are obtained; and one-time down-sampling is carried out on the digital signals I2 and Q2, and data obtained by sampling are output under the matching of a new sampling clock according to a new data rate. The method has the advantages that the waveform further approaches to an analog value, and the superimposition and the distortion of the frequency spectrum are avoided. A programmable component is adopted to realize the method for digital front-end filtering, and the design is flexible. The digital filters only use an adder and a shift register, thereby enhancing the efficiency of the whole digital front end and lowering the cost of the system.

The invention discloses a signal collecting method based on a safe input system and the system of the signal collecting method. In a rail transportation system, input signals are collected through an input circuit module and output to a processor module. As a plurality of input signal modules are arranged, in order to avoid aliasing of the signals, the return checking end of the input circuit module is used for comparing return checking signals and stimulus signals, the input signals and the stimulus signals generated by the processor module are superimposed to generate the return check signals, and whether the input signals are correct is judged. The input signals and the corresponding stimulus signals respectively have two code bits at least, each code bit at least has two code distances, aliasing of the signals of adjacent channels is avoided by increasing the code distances of the code bits, correctness of the collected signals is guaranteed, and mistaken collection of the signals is avoided. It is guaranteed that in the rail transportation system, the signals are accurately controlled and a train is normally scheduled when the train operates, and normal operation of the train is guaranteed.

The invention discloses an EMI-filter-based electromagnetic interference noise measuring and suppressing system. The system comprises a linear impedance stabilization network, a signal selection module, a noise amplification module, a filter module, an A / D sampling module, a central control module and a serial port communication module, wherein an extraction signal output end of the linear impedance stabilization network passes through the signal selection module and is input into the input end of the noise amplification module; the output end of the noise amplification module sequentially passes through the filter module and the A / D sampling module and is in two-way connection with the central control module; the central control module communicates with an upper computer by virtue of the serial port communication module; the signal selection module comprises a noise separation circuit and an external relay normally-closed contact K1-1, a relay normally-opened contact K1-2 and a relay normally-opened contact K2-1; the relay normally-closed contact K1-1 and the relay normally-opened contact K1-2 serve as mutually reverse action contacts. The EMI-filter-based electromagnetic interference noise measuring and suppressing system has the advantages that the data can be sampled and regulated, the noise modal is quickly and accurately separated, the external interference is resisted, and the interference of the system on other devices can be simultaneously suppressed.

An automation system and a method for controlling a process and for monitoring the condition of process equipment. The method comprises the steps of measuring process signals indicating the condition of the process by means of a first sensor; measuring condition monitoring signals indicating the condition of process components by means of a second sensor; processing the process signals by means of a first I / O module; processing the condition monitoring signals by means of a second I / O module; transmitting the processed process signals obtained from the first I / O module to a process station. The method also comprises the steps of transferring the processed condition monitoring signals obtained from the second I / O module to the same process station; and processing both the said processed process signals and the said processed condition monitoring signals by process station software in the said process station.

The present invention relates to an adaptive STFT based rotary machine order tracking method. A scale function of a window function is determined based on the principle that the length of the window function decreases as the rotating speed increases and is plugged into adaptive STFT, and an original vibration signal is subjected to adaptive STFT. Thereafter, an order component is extracted from a transformed time-frequency spectrum, and the order component is subjected to inverse transformation to obtain a time domain curve of the order component, thereby achieving the order tracking. The method provided by the invention effectively overcomes the defect of fixed window length of STFT based order tracking, and prevents the problem of aliasing of time-frequency spectrum, providing an effective technical means for detail analysis of the vibration characteristics and fault diagnosis in a speed increasing process of the machine.

The invention provides a method and apparatus used in a receiver for sampling RF signals, particularly to provide a method and apparatus for greatly decrease the sampling rate performed in RF band. The invention provides an apparatus for sampling a RF signal including a plurality of interference frequency components and a useful frequency component, comprising: a filtering unit for filtering out at least one preset interference frequency component from the RF signal to generate a notch-filtered RF signal; a sampling unit for sampling the notch-filtered RF signal at a preset sampling rate to generate a discrete analog signal. The sampling unit can be implemented by a plurality of notch filters. RF sampling can be simply and conveniently implemented by using the method and apparatus according the invention, and the sampling rate can be decreased to about 1 / N of the carrier frequency of the useful frequency component, which is much lower than the sampling rate in existing RF sampling scheme. The method and apparatus according the invention can greatly decrease power dissipation when sampling.

The invention discloses a wavelet-decomposition-based SAR image change detecting algorithm of a multi-scale level set, and belongs to the field of remote sensing image processing. The wavelet-decomposition-based SAR image change detecting algorithm mainly solves the problem that a speckle noise effect is serious in an SAR image change detecting process. The wavelet-decomposition-based SAR image change detecting algorithm is implemented in the following steps that (1) a difference image of two registered SAR images in the same region and at different time phases is obtained by adopting logarithm ratio operators; (2) multilayer wavelet decomposition is conducted on the difference image through SWT so as to obtain images with different resolution ratios; (3) the images with the low resolution ratios are preliminarily segmented through a level set algorithm, and the outlines of obtained segmented images are used as initialization curves of the level set algorithm of the images with the higher resolution ratios; (4) the step (3) is repeated in a layer-by-layer mode until final segmented images are obtained by conducting level set segmentation on the images with the high resolution ratios. According to the wavelet-decomposition-based SAR image change detecting algorithm, the multi-scale application overcomes the defect that a closed curve is prone to getting into local optimum in a level set evolutionary process, and robustness on noise is enhanced; the wavelet-decomposition-based SAR image change detecting algorithm is applied to change detecting of the SAR images, the detecting effect and detecting accuracy are improved obviously, and the change detecting process is accelerated.

The optical transfer function of imaging optics is carried out with a plurality of tilted edges with respect to the edge-response detection line. The effect of the tilt is to stretch out the edge response so that fine details can be detected even operating at a spatial frequency below the Nyquist limit of the detector. The use of multiple targets, each corresponding to a sub-region of the field of view of the optics being tested, enables the simultaneous characterization of the full field of view of the test optics with a single measurement without the use of a magnifying objective. The result is a rapid measurement and a simpler apparatus suitable for high-throughput testing. A pair of tilted edges can be used in a target to also determine the sagittal and tangential OTFs (as well as that of any other arbitrary cross-section). All of these data are acquired with a single measurement.

The invention discloses an OLED display panel and an OLED display device. The OLED display panel is respectively configured with a first power bus and a second power bus, first sub-pixels of a centraldisplay area are enabled to be electrically connected to the first power bus and obtain first driving voltage from the first power bus, and second sub-pixels of a transitional display area are enabled to be electrically connected to the second power bus and obtain second driving voltage from the second power bus; and the area of the second sub-pixels is less than the area of the first sub-pixels,and the second driving voltage provided by the second power bus is higher than the first driving voltage provided by the first power bus, thereby being capable of compensating the brightness difference between the first sub-pixels and the second sub-pixels, thus enabling the brightness of the whole special-shaped display area to keep in balance, and avoiding a visual saw-tooth phenomenon caused by the brightness difference of different areas.

The invention provides a super-resolution image reconstruction method and device, a medium and computing equipment. The method comprises the steps that the brightness image and the color image of an original image are extracted; up-sampling processing is performed on the brightness image so as to obtain a first brightness image; the first brightness image is inputted to N layers of convolutional neutral networks which are obtained pre-training and used for outputting high-frequency images, N layers of convolutional forward processing is performed on the first brightness image in the N layers of convolutional neutral networks and a first high-frequency image is obtained, wherein N is an integer greater than 3; the first brightness image is fused with the first high-frequency image so as toobtain a second brightness image; and the second brightness image is fused with the color image so as to obtain the super-resolution image of the original image. The super-resolution image of the original image obtained through reconstruction can include more image details so that the super-resolution image effect is great.