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386 results about "Window function" patented technology

In signal processing and statistics, a window function (also known as an apodization function or tapering function) is a mathematical function that is zero-valued outside of some chosen interval, normally symmetric around the middle of the interval, usually near a maximum in the middle, and usually tapering away from the middle. Mathematically, when another function or waveform/data-sequence is "multiplied" by a window function, the product is also zero-valued outside the interval: all that is left is the part where they overlap, the "view through the window". Equivalently, and in actual practice, the segment of data within the window is first isolated, and then only that data is multiplied by the window function values. Thus, tapering, not segmentation, is the main purpose of window functions.

Metering equipment interference signal suppression method and system in electromagnetic compatibility test

The invention discloses a metering equipment interference signal suppression method and system in an electromagnetic compatibility test, and the method comprises the steps: obtaining an input signal of metering equipment in the electromagnetic compatibility test, performing windowing processing on the input signal by adopting a self-adaptive fractional order window function, and then obtaining a frequency spectrum component of the input signal through self-adaptive fractional order Fourier transform; calculating the amplitude of the frequency spectrum component, comparing the amplitude with a power threshold value, and screening out the frequency spectrum component of the interference signal; establishing a spectrum model of the interference signal based on the interference signal spectrum component; and generating a frequency domain compensation signal considering interference signal phase correction, converting the frequency domain compensation signal into a time domain compensation signal, and superposing the time domain compensation signal and the input signal to obtain a signal after interference suppression. According to the method, the frequency spectrum characteristics of the signals in different frequency bands can be ensured to be clear, the interference signal components can be accurately identified, the energy distribution of the interference signals can be effectively simulated, and the high-efficiency interference suppression capability can still be kept in a variable signal environment.
Owner:STATE GRID JIANGSU ELECTRIC POWER CO LTD MARKETING SERVICE CENT

Wellhead data acquisition modeling system

The invention discloses a wellhead data acquisition modeling system. The wellhead data acquisition modeling system comprises a data acquisition module, a hydraulic characteristic processing module, a well layer coupling modeling module and an interaction control module, the invention belongs to the technical field of well water monitoring management, based on an adaptive time-frequency analysis method, a dynamic window function enhanced by local frequency spectrum entropy is introduced, feature extraction and abnormal early warning are performed on transient hydraulic fluctuation signals, and the time-frequency resolution and change recognition capability of the hydraulic signals are remarkably improved; a dynamic coupling model between a water pumping system and an aquifer is constructed by combining a multi-scale parameter coordination mechanism, and accuracy and dynamic adaptability of well layer response modeling are realized by introducing a gap compression lag function and a joint parameter calibration method; and the interaction control module implements model prediction control according to the hydraulic feature vector, the hydraulic anomaly early warning signal and the well layer coupling prediction parameter combination, and outputs wellhead data acquisition decision support data.
Owner:SHANDONG HUADI INTELLIGENT TECH CO LTD

Traveling wave head extraction method and system, electronic equipment and storage medium

The invention provides a traveling wave head extraction method and system, electronic equipment and a storage medium. The method comprises the following steps: detecting an original traveling wave signal to obtain the original traveling wave signal; calculating the fast Fourier transform of the original traveling wave signal and the fast Fourier transform of the window function introducing the correction factor so as to respectively obtain a discrete form of the original traveling wave signal and a Gaussian function under the optimal frequency; calculating a product of a discrete form of the original traveling wave signal and a Gaussian function under the optimal frequency according to the frequency sampling point, and calculating to obtain discrete S transformation; intercepting two-dimensional diagrams of the traveling wave fault signal with time and amplitude as an x axis and a y axis; on the basis of discrete S transformation of the traveling wave, the amplitude difference of adjacent time nodes in the two-dimensional diagram is adopted, a threshold value is set at the same time, the detection time of a first traveling wave head is obtained, the position of a sudden change point is determined, and the traveling wave head is extracted. According to the method, various fault transient states can be detected, the detection speed is high, the sensitivity is enough, and the influence of noise can be effectively reduced.
Owner:EAST CHINA JIAOTONG UNIVERSITY

Monomer tank transportation risk early warning method and system based on intelligent sensor

The invention discloses a single tank transportation risk early warning method and system based on an intelligent sensor, and relates to the technical field of risk early warning, and the method comprises the steps: collecting data in a single tank for preprocessing, employing a two-dimensional shallow water wave model to calculate liquid fluctuation, and generating iteration sequence data; applying a Hanning window function, calculating spectrum energy distribution according to the spectrum amplitude, extracting primary frequency and secondary frequency data, and calculating the amplitude ratio of the primary frequency to the secondary frequency; according to the method, through coupling of the continuity equation and the momentum equation, the height change and the velocity field distribution of the liquid can be comprehensively described, the dynamic behavior of the liquid in the single tank can be accurately reflected, the dynamic change of the liquid height gradient and the velocity field gradient is considered, and the complex liquid fluctuation phenomenon can be captured; a window function is applied to perform weighting processing on the data to weaken the weight of the data at two ends of the time sequence, so that the middle part of the data contributes more remarkably to the spectrum.
Owner:YANGZHOU UNIV

Time-frequency analysis method for impact signal positioning based on transient scale extraction transformation

The invention discloses a time-frequency analysis method for impact signal positioning based on transient scale extraction transformation, and belongs to the technical field of mechanical vibration signal processing. The method comprises the following steps: collecting a rotating machine fault vibration signal, and reconstructing a signal model through Hilbert transform and a Dirac function; a transition matrix is generated by using a Gaussian window function traversal model, and matching and Fourier transform are carried out in combination with a discretized scale basis function; solving a frequency partial derivative of a transformation result to generate a time redistribution operator, and redefining by a Dirac function to obtain a transient scale extraction operator; based on the sub-time-frequency representation of scale-based rotation discretization, screening optimal matching results of each time center through a maximum kurtosis value, and integrating the optimal matching results into a complete time-frequency representation; and finally, redistributing a time-frequency coefficient by using a transient extraction operator to realize accurate positioning of the impact component. According to the method, the problems of serious impact energy diffusion and insufficient positioning precision in existing time-frequency analysis are solved, and the time-frequency representation readability and the impact positioning reliability are remarkably improved.
Owner:BEIJING ZHONGYUAN RISEN TECH CO LTD

Short-time fractional Fourier transform time-frequency analysis method based on window decoupling

The invention discloses a window-based decoupling short-time fractional Fourier transform time-frequency analysis method. The method comprises the following steps: S1, acquiring non-stationary signal data generated under power quality disturbance in a power grid; s2, segmenting the non-stationary signal into a plurality of parts based on signal waveform characteristics, and setting an initialized virtual window function for discrete short-time fractional Fourier transform, wherein the window function only provides an interface for calling of a specific window function; s3, calling different window functions for each segmented sub-segment signal to obtain windowed sub-segment signals under a specific window function; and S4, discrete fractional Fourier transform is applied to the sub-segment signals obtained in the step S3 to obtain time-frequency results of the sub-segment signals under different windows, and finally, frequency spectrums of the sub-segment signals are spliced according to a time sequence and output by an oscilloscope. Based on the characteristics of non-stationary signals generated under power quality disturbance in a power grid, different window function analysis signals can be called in one task by setting a virtual window function interface, and the window-based decoupling short-time fractional order Fourier transform time-frequency analysis method is formed. According to the method, the coupling between fractional Fourier transform and a specific window is reduced, the expandability of a program is improved, and more accurate signal local spectrum features can be obtained.
Owner:HUAIYIN TEACHERS COLLEGE

Intelligent power distribution monitoring system and method

The invention relates to the technical field of data monitoring, and discloses an intelligent power distribution monitoring system and method, and the method comprises the steps: collecting current and voltage signals of a preset point location, and building a signal data link; preprocessing the signal data chain based on a windowing function to obtain a windowed data chain, and determining an overlapping proportion according to the length of the windowed data chain to perform window division to obtain a plurality of frequency spectrums; the spectrums are compared in pairs, and whether abnormal early warning is carried out or not is judged according to the comparison result; when early warning is judged, processing each frequency spectrum based on Hilbert transform to obtain an instantaneous envelope and an instantaneous phase, and obtaining a phase difference value of two harmonics with the same frequency in all the frequency spectrums; and comparing the phase difference value and the spectrum similarity as feature data with a historical early warning data set for early warning. According to the method, the problems that a traditional method depends on a fixed threshold value and is slow in response and high in false alarm rate are solved, and the identification accuracy and response timeliness of dynamic harmonic abnormity are improved.
Owner:SHANDONG XIANGSHENG ELECTRIC POWER ENG CO LTD

Calculation method and system for multi-point detection of gas nonmetal pipeline based on active sound source

The invention discloses a calculation method and system for multi-point detection of a gas nonmetal pipeline based on an active sound source, and relates to the technical field of pipeline monitoring and management, and the method comprises the following steps: 1, monitoring the change of a sound signal in the gas nonmetal pipeline according to the change of a transmitted laser signal through an optical fiber of a distributed acoustic assembly as a sensing medium, according to the invention, the optical fiber of the distributed acoustic assembly is used for monitoring the change of the acoustic signal in the gas non-metal pipeline, the frequency offset, intensity and delay change of the laser signal are converted into the frequency, amplitude intensity and sound wave source of the acoustic signal in a correlation manner, and the adaptive filter is used for dynamically updating the filter coefficient. A window function is adopted to carry out framing processing on sound signals, short-time Fourier transform is applied, real classification labels are distributed to the sound signals through a random forest algorithm, a triangulation positioning method is applied to determine space coordinates of the sound signals, and accurate monitoring and classification of the pipeline state are achieved.
Owner:XIAN GUANCHANG ENVIRONMENTAL PROTECTION TECH CO LTD

High-precision spectral interference signal demodulation method for micro distance measurement

The invention discloses a high-precision spectral interference signal demodulation method for micro distance measurement. The method comprises the steps of S1, interference spectrum shaping; measuring an interference spectrum and a reference spectrum; selecting a six-item combined cosine window as a primary function of an interference signal to obtain a shaped interference spectrum; s2, performing non-uniform Fourier transform to obtain a frequency spectrum of the target signal; s3, on the basis of a multi-spectral-line interpolation algorithm, interpolation is carried out on the window function to solve a fitting function, and a center frequency k is obtained; and S4, outputting a result. And solving and outputting an optical path difference d. According to the method, a six-item cosine combination window is selected as a primary function of an interference signal, and the problem that the accuracy of signal extraction is influenced by mutual superposition of side lobes and even main lobes of a direct current item and a solved frequency item is solved; an interference spectrum is processed by using a fast non-uniform Fourier transform algorithm, accuracy can still be kept under the conditions that the distance to be measured is increased and sampling is gradually sparse, and the problem of resampling deviation caused by a traditional interpolation method can be solved.
Owner:HEFEI UNIV OF TECH

Data processing method and device

The invention discloses a data processing method and device, relates to the field of databases, and can reduce the overhead of processing query statements including connection operation and window functions by a server and improve the data processing efficiency. The method comprises the following steps: obtaining a query statement, wherein the query statement comprises a connection operation for connecting a first list and a second list based on a first connection condition and a window function; an ordered memory index is constructed based on records in the first list, data records of the ordered memory index store values of connection keys corresponding to the records in the first list, matching mark values, results of the window functions and input parameters of the window functions, and search keys of the ordered memory index comprise the connection keys; according to the first connection condition and the value of the search key, the record in the second list is used for detecting the ordered memory index; and if the record in the second list and the data record of the ordered memory index meet the first connection condition, updating a matching mark value corresponding to the data record.
Owner:HUAWEI TECH CO LTD

Digital electric energy metering method and device based on window function and electronic equipment

The embodiment of the invention provides a digital electric energy metering method and device based on a window function and electronic equipment, and relates to the technical field of electric energy metering. The method comprises the following steps: intercepting an electric energy signal from a monitoring signal by adopting a Hanning double-window function, and obtaining frequency spectrum information of the electric energy signal; correcting the amplitude of inter-harmonics in the frequency spectrum information based on the maximum spectral line in the frequency spectrum information; adjusting the weight of each harmonic wave in the frequency spectrum information through a least square algorithm based on a variable forgetting factor to obtain an adjusted electric energy signal; and inputting the adjusted electric energy signal into a self-adaptive linear combiner to obtain an electric energy signal for metering. According to the implementation mode provided by the invention, analog-to-digital conversion in electric energy metering is avoided, and meanwhile, better dynamic performance and metering precision are achieved.
Owner:BEIJING SMARTCHIP MICROELECTRONICS TECHNOLOGY CO LTD

Modal parameter automatic identification method based on multi-scale space

The invention belongs to the field of structural modal identification, and particularly relates to an automatic modal parameter identification method based on a multi-scale space, which comprises the following steps: collecting a vibration data sample from a target structure, the vibration data sample comprising an acceleration signal of the structure; selecting power spectrum calculation parameters including a window function and a fast Fourier transform (FFT) length; performing frequency spectrum estimation on the acceleration signal by using interpolation power spectrum estimation to obtain frequency spectrum data; analyzing the spectrum data by using a multi-scale space algorithm, and detecting a peak value in the spectrum data to obtain a peak value frequency; through a frequency domain decomposition method, according to the peak frequency, modal parameters of the structure are calculated, the modal parameters comprise the modal frequency and the damping ratio, interpolation power spectrum estimation and a multi-scale space algorithm are innovatively combined, automatic and accurate identification of the modal parameters is achieved, and the identification precision and efficiency are remarkably improved.
Owner:HARBIN INSTITUTE OF TECHNOLOGY (SHENZHEN) (INSTITUTE OF SCIENCE AND TECHNOLOGY INNOVATION HARBIN INSTITUTE OF TECHNOLOGY SHENZHEN) +5

Disturbance quantification model and rooting method combined multi-parameter estimation algorithm in interference measurement

The invention relates to a multi-parameter estimation algorithm combining a disturbance quantification model and a rooting method in interference measurement. In order to solve the problems that in the prior art, the disturbance degree of a sequence is difficult to quantify, and harmonic key parameters are influenced by spectrum leakage, the invention provides the following innovative scheme: firstly, a sequence multi-classification measurement entropy quantification model is constructed, and quantitative evaluation of the signal noise degree is realized; secondly, through a Hankel matrix construction and rooting parameter estimation method, realizing accurate estimation of the harmonic frequency of the real-value signal; meanwhile, an amplitude correction algorithm based on window function characteristics is designed, and the signal sampling condition is effectively judged; and finally, through matrix weighting operation of a phase demodulation function, efficient reconstruction of an optical surface shape is realized, the problems of spectrum leakage and disturbance quantification in a traditional method are solved, and the method has relatively high measurement precision.
Owner:HUZHOU UNIVERSITY

Query optimization method, storage medium and equipment

The invention relates to a database technology, in particular to a query optimization method, a storage medium and equipment. The query optimization method comprises the following steps: obtaining a to-be-processed query statement; judging whether the to-be-processed query statement contains a window function or not; and if yes, converting the window function into transverse connection, and generating an optimized query statement based on the transverse connection. According to the query optimization method, the window function in the query statement is converted into the transverse connection, so that the window function in the query statement is eliminated, the corresponding grouping and sorting operation is removed, the problem of high performance loss caused by excessive unnecessary grouping and sorting operation due to execution of the window function is avoided, and the query efficiency is improved. And the execution efficiency of the query statement is improved, so that the performance of the database is improved.
Owner:CETC JINCANG (BEIJING) TECH CO LTD

Power quality disturbance detection method based on improved adaptive S transformation

The invention belongs to the technical field of power quality disturbance detection, and particularly relates to a power quality disturbance detection method based on improved adaptive S transformation, which comprises the following steps of: designing window width control factors of two Gaussian windows, flexibly adjusting time domain window widths and frequency spectrum characteristics of the Gaussian windows, and forming a global adaptive Gaussian window; taking upper and lower limits of time-frequency two-domain resolution as constraint conditions, taking enhanced signal energy concentration ratio as a target function of an optimization scheme, and adopting an interior point method to carry out parameter solving; performing fast Fourier transform on the signal and setting a threshold value, and defining a part higher than a threshold value point as a characteristic frequency point ki; screening calculation at a non-characteristic frequency point, only performing time-frequency transformation at a characteristic frequency point ki, and constructing a fast algorithm for improving adaptive S transformation; and obtaining a final disturbance characteristic information value. According to the method, the global adaptive Gaussian window is constructed as a kernel function for improving adaptive S transformation, the effective window length and the frequency spectrum of the window function can be automatically adjusted along with the change of the detection frequency, window parameters are prevented from being frequently switched for improving the time-frequency resolution, and various power quality disturbances are efficiently and accurately detected.
Owner:TAIYUAN UNIVERSITY OF TECHNOLOGY

High-precision measuring method and device for harmonic waves / inter-harmonic waves of power broadband signals

The invention discloses a power broadband signal harmonic / inter-harmonic high-precision measurement method and device. The method comprises the following steps: constructing a constrained N-element linear equation set for solution according to a windowed signal spectrum asymptotic expression, designing a normalized N-order W-window function with the performance of analyzing a digital frequency interpolation coefficient and a minimum sidelobe, performing double weighting on a broadband signal by using different-order W-windows, performing spectrum density detection based on an amplitude spectrum, and determining the spectrum density of the broadband signal according to the detected spectrum density. And a W window frequency interpolation factor and a correction formula are adaptively switched according to a detection spectral line difference value to measure a broadband signal. The method does not need to fit a frequency interpolation coefficient, is small in calculation amount, is high in robustness, is easy to achieve, and effectively achieves the real-time high-precision measurement of harmonic / inter-harmonic parameters in a broadband range.
Owner:NARI NANJING CONTROL SYSTEM CO LTD

Broadband signal spectrum analysis method based on spectrum leakage suppression and improved FFT algorithm

A broadband signal spectrum analysis method based on spectrum leakage suppression and an improved FFT algorithm comprises the following steps: setting a broadband signal model comprising a fundamental wave frequency offset signal and a plurality of broadband oscillation signals according to broadband signal characteristics; based on a Fourier transform theory, analyzing a spectrum leakage generation mechanism of the broadband signal; a Nuttall-Kaiser combination window function is designed, and is used for suppressing the spectrum leakage of the broadband signal; the FFT algorithm is improved, and side lobe attenuation is suppressed by using the convolution window property so as to reduce the influence of spectrum leakage. According to the broadband signal spectrum analysis method based on spectrum leakage suppression and the improved FFT algorithm, spectrum leakage is effectively reduced while high frequency resolution of broadband signals is guaranteed, and meanwhile the method has the advantage of being high in measurement accuracy.
Owner:CHINA THREE GORGES UNIV

Filter coefficient determination method, compensation method, device and equipment for amplitude bandwidth compensation

The invention relates to a filter coefficient determination method and device for amplitude bandwidth compensation, a compensation method and device and computer equipment. The method comprises the following steps: acquiring a first amplitude-frequency response of a to-be-compensated bandwidth of a channel in a frequency sweeping mode; determining an ideal filter coefficient of a filter for compensation based on the first amplitude-frequency response; obtaining each window function, cutting off the ideal filter coefficient through each window function, and determining a target window function based on a first error between the amplitude-frequency response corresponding to the ideal filter coefficient after cutting off and the amplitude-frequency response corresponding to the ideal filter coefficient before cutting off; and determining a target filter coefficient based on the target window function and the ideal filter coefficient. By adopting the method, FPGA (Field Programmable Gate Array) resources can be saved, and a better compensation effect can be obtained.
Owner:HANGZHOU CHANGCHUAN TECH CO LTD

Wide spectrum interference dark weak signal enhancement method for high aspect ratio micro-nano structure measurement

The invention discloses a wide-spectrum interference weak signal enhancement method for high aspect ratio micro-nano structure measurement, and relates to the technical field of semiconductor measurement. The method comprises the following steps: acquiring a wide-spectrum interferogram, and performing two-layer two-dimensional discrete wavelet transform to obtain a first-stage wavelet coefficient group; performing nonlinear enhancement on the wavelet coefficient, and outputting a nonlinear enhanced wide-spectrum interferogram; performing three-layer two-dimensional discrete wavelet transform on the wide-spectrum interferogram after nonlinear enhancement to obtain a second-stage wavelet coefficient group, and calculating a Bayesian threshold value; a neighborhood sliding window function is set, and a Bayesian threshold is combined to carry out local denoising enhancement on the second-stage wavelet coefficient; reconstructing the second-stage wavelet coefficient after local de-noising enhancement to obtain a wide-spectrum interference pattern after local de-noising enhancement; and determining an optical path position by adopting an improved gravity center method according to the wide-spectrum interferogram after local denoising enhancement, and calculating a depth value of the to-be-measured sample. According to the method, the stripe contrast is enhanced, the noise is suppressed, and the depth measurement capability is improved at the same time.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS +1

Ultrasonic water meter flow measurement data processing method and device, electronic equipment and storage medium

The invention provides an ultrasonic water meter flow measurement data processing method and device, electronic equipment and a storage medium, and the method comprises the steps: obtaining ultrasonic signals in a downstream direction and a countercurrent direction, and respectively forming a first time domain signal and a second time domain signal; performing window function windowing and framing processing on the two time domain signals to obtain a corresponding signal frame sequence; respectively executing Fourier transform and frequency domain filtering, and recovering the first time domain signal frame sequence and the second time domain signal frame sequence through inverse transformation; splicing the recovered frame sequence, and analyzing and extracting a propagation time difference through a cross-correlation function; calculating the flow velocity according to the propagation time difference, and obtaining the water flow in combination with the pipeline cross-sectional area. Thus, the most probable propagation time difference is extracted through the cross-correlation peak value, the signal quality is enhanced in combination with frequency domain filtering, and the anti-interference performance and the overall precision of flow velocity measurement can be effectively improved.
Owner:TIANJIN JINCHAOLIDA TECH CO LTD

Harmonic and inter-harmonic parameter estimation method and system based on improved Gaussian convolution window

The invention belongs to but is not limited to the technical field of power systems, particularly relates to a harmonic and inter-harmonic parameter estimation method and system based on an improved Gaussian convolution window, and provides a new harmonic and inter-harmonic parameter estimation method based on windowing FFT (Fast Fourier Transform) on a sampling signal by utilizing an improved Gaussian window function. Harmonic and inter-harmonic parameters can be detected with high precision in a short time. The method comprises the following steps: for a signal containing harmonic waves, representing the signal as the sum of a signal component with the maximum amplitude and other signal components, estimating a parameter of the signal component with the maximum amplitude by using a bispectral interpolation algorithm based on a least square method, and reconstructing the signal component with the maximum amplitude by using the estimated parameter; and subtracting the reconstructed maximum amplitude signal component from the original signal, carrying out the process to extract a second amplitude signal component parameter, and repeating the steps until all harmonic signal parameters are extracted.
Owner:CENT CHINA BRANCH OF STATE GRID CORP OF CHINA +1

Water supply network leakage noise detection method and system and medium

The invention relates to the technical field of pipe network acoustic detection, in particular to a water supply pipe network leakage noise detection method and system and a medium. The method comprises the following steps: constructing a physical model of leakage noise based on fluid mechanics and a sound propagation rule; generating simulated leakage noise data based on physical model parameterization so as to simulate leakage noise data under extreme physical conditions; a set of the actually measured leakage noise data and the simulated leakage noise data is used as leakage noise sample data, and time domain statistical characteristics and frequency domain statistical characteristics of the signals are obtained through quantification according to the leakage noise sample data; based on the statistical characteristics, dynamically adjusting window function parameters and performing short-time Fourier transform processing to obtain a resolution-optimized time-frequency image; and constructing a CNN classification model, training the model based on the resolution-optimized time-frequency image, and outputting prediction probabilities of leakage noise and environmental noise. While the water supply pipe network leakage noise detection precision is improved, hardware dependence is eliminated, and efficient pure acoustic end-to-end pipe network leakage detection is realized.
Owner:ZHEJIANG HEDA TECH

High-frequency digital filtering system based on fast Fourier transform

The invention discloses a high-frequency digital filtering system based on fast Fourier transform, which is characterized in that an analog signal is acquired and converted into a digital signal, a preprocessing module is used for denoising the digital signal, and window processing is carried out on the digital signal through a window function; the Fourier transform module converts a time domain signal into a frequency domain signal through fast Fourier transform and then performs frequency domain separation, the digital filtering module filters the signal through multiplication operation and transmits the filtered signal to the inverse Fourier transform module, the inverse Fourier transform module converts processed frequency domain data back to the time domain signal, and the inverse Fourier transform module transmits the time domain signal to the digital filtering module. The post-processing module carries out window removal processing on the time domain signal and then converts a digital signal into an analog signal to be output, high-frequency digital filtering is carried out through Fourier fast transform, spectrum characteristics of a complex signal are accurately processed, the filtering quality of the high-frequency signal is guaranteed, and the subsequent signal processing effect is improved.
Owner:GUIZHOU POWER GRID CO LTD

Harmonic analysis method based on double buffer window function optimization

The invention discloses a harmonic analysis method based on double buffer window function optimization, and relates to the technical field of harmonic analysis and signal processing of a power system, and the method comprises the steps of hardware initialization, double buffer initialization, FFT module parameter configuration, data acquisition, buffer switching, data extraction and windowing and FFT processing. Parallel data acquisition and processing are realized through a double-buffer ping-pong mechanism, spectrum leakage is suppressed by applying a Hanning window function, and FFT calculation is performed after signal amplitude is recovered through a compensation factor; according to the method, the data acquisition continuity and real-time performance are improved, the harmonic amplitude error is controlled within + / -0.5%, the hardware resource utilization rate is optimized, and the method is suitable for power grid electric energy quality monitoring.
Owner:SHANGHAI HOLYSTAR INFORMATION TECH

Paillier homomorphic encryption hardware accelerator based on residual number system and number theory transformation and acceleration method of Paillier homomorphic encryption hardware accelerator

The invention provides a Paillier homomorphic encryption hardware acceleration method and a Paillier homomorphic encryption hardware acceleration device based on a residual number system (RNS) and number theory transformation (NTT), which are suitable for high throughput parallel computing of large integer modular operation. The system adopts a modular architecture, comprises an RNS conversion cluster, an NTT core array, a modular domain multiply-accumulate unit and a CRT reconstruction module, and supports homomorphic addition, multiplication and modular exponent operation on a ciphertext. Low latency and high energy efficiency of encryption operation are realized by mapping a large integer to a plurality of small module domains for parallel processing and combining NTT fast convolution and a window function table look-up strategy. The method can be widely applied to privacy computing, cloud security and edge encryption scenes.
Owner:HANGZHOU TOPOLOGY MACRO SEMICONDUCTOR CO LTD

SNR test method and system based on ATE test platform, medium and equipment

The invention discloses an SNR test method and system based on an ATE test platform, a medium and equipment, and the method comprises the steps: adjusting the original signal frequency of an analog signal or the original sampling frequency of a to-be-tested chip according to a preset undersampling algorithm, controlling a preset signal generator, outputting the analog signal to the to-be-tested chip, and outputting the analog signal to the to-be-tested chip; sending the analog signal to the to-be-tested chip to enable the to-be-tested chip to carry out undersampling on the analog signal to obtain sampling data, and converting the sampling data into a digital signal; and processing the digital signal according to a signal-to-noise ratio calculation algorithm preset by the ATE test platform to obtain a signal-to-noise ratio test result, and completing the signal-to-noise ratio test of the to-be-tested chip. By using the improved undersampling algorithm, when the analog signal frequency and the sampling frequency do not meet the Nyquist sampling law, the frequency of the analog signal or the sampling frequency is adjusted, spectrum leakage can be effectively reduced, signal-to-noise ratio testing can still be carried out on the premise that a window function does not need to be used, and therefore the testing process is simplified, and the testing efficiency is improved. The test efficiency is improved.
Owner:GUANGZHOU GRG METROLOGY & TEST CO LTD

Radar waveform design method for suppressing autocorrelation sidelobe based on multi-carrier phase coding

The invention relates to a radar waveform design method for suppressing an autocorrelation sidelobe based on multi-carrier phase coding. The method comprises the following steps: acquiring a chaos sequence with pseudo-randomness; according to the chaos sequence, an OFDM method and a phase encoding method are adopted for processing, and an MCPC radar signal is obtained; according to the MCPC radar signal, the power difference between a maximized target and a sidelobe peak value, the minimum peak value sidelobe level and the minimum integral sidelobe level are accurately measured for processing, and a pulse compression sidelobe of the radar signal is obtained; pulse compression sidelobes of the radar signals are processed in a subcarrier amplitude windowing mode, and radar signals of multi-carrier phase coding suppression self-correlation and cross-correlation sidelobes are obtained; the self-correlation sidelobe is taken as an optimization target, and a genetic algorithm is adopted to optimize a carrier weighted window function to reduce the self-correlation sidelobe. The radar signal designed by the method has good anti-interference performance and sidelobe reduction performance.
Owner:CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY

Seismic data time-frequency analysis method and system based on time sparse S transformation

The invention discloses a seismic data time-frequency analysis method and system based on time sparse S transformation, and the method comprises the steps: collecting seismic data, carrying out the time-frequency analysis of the collected seismic data through S transformation, and obtaining a time-frequency spectrum containing the time-frequency characteristics of the seismic data; based on sampling duration and sampling rate characteristics of the seismic data, obtaining a window function of each frequency of the seismic data by using S transformation time-frequency analysis; and constructing a Toeplitz matrix based on a window function, carrying out reverse convolution along the time direction by using the time-frequency spectrum and the Toeplitz matrix, and traversing all frequencies to obtain a seismic data analysis result. The method is applied to time-frequency analysis of seismic data for the first time, a good effect is achieved in multi-scale analysis of two-dimensional actual seismic data, the time resolution of time-frequency analysis of the seismic data is remarkably improved through de-windowing processing, and thin-layer identification of transient signals and seismic data is more accurate especially in a high-frequency part.
Owner:NORTHEAST GASOLINEEUM UNIV

GNSS-R SAR image cross-correlation registration method based on improved window function

The invention relates to the field of GNSS-R SAR image cross-correlation registration, in particular to a GNSS-R SAR image cross-correlation registration method based on an improved window function. The scheme comprises the following steps: extracting a matching region from a main image, and extracting a reference region from a slave image; performing sliding traversal in the matching region and the reference region by using an improved elliptical weighted window function, and calculating coherence coefficients under translation positions one by one to obtain a coarse registration offset; performing multiple cubic interpolation on the time sequence image to obtain a primary image and secondary image interpolation result with sub-pixel precision, re-selecting a matching area and a reference area on the interpolated image, and repeating sliding traversal and coherence coefficient calculation to obtain a fine registration offset; and performing interpolation resampling on all the slave images based on the final registration offset to obtain a time sequence image set of which the registration precision is a sub-pixel level. The GNSS-R SAR image cross-correlation registration method is suitable for GNSS-R SAR image cross-correlation registration.
Owner:BEIHANG UNIV

Room sound calibration method based on intermediate frequency reverberation time and related equipment

The invention relates to the technical field of audio sound calibration, and discloses a room sound calibration method based on intermediate frequency reverberation time and related equipment, which are used for improving the accuracy of a sound calibration result. The room sound calibration method based on the intermediate frequency reverberation time comprises the following steps: acquiring a room impulse response of a target room and calculating the intermediate frequency reverberation time; according to the intermediate frequency reverberation time, the recommended window length of the frequency correlation window is determined by querying a predefined mapping relation, and the mapping relation is established based on acoustic association between the room reverberation time and the analysis window length; based on the recommended window length, determining the actual window length of the actual application in combination with the user setting mode; performing time domain windowing and frequency-related transfer function estimation processing on the room impulse response according to the actual window length to obtain window function weighted transfer function estimation; filter calibration coefficients are generated based on the transfer function estimates and applied for audio calibration.
Owner:LINKPLAY TECHNOLOGY INC NANJING