95 results about "Fft fast fourier transform" patented technology

The invention relates to the technical field of audio signal processing, and discloses a high-sampling-rate audio analysis optimization method and system, a storage medium and equipment, and the method comprises the steps: upgrading an FFTW (Fast Fourier Transform) library, and building an optimized memory management mechanism; carrying out adaptive framing processing on the input audio data, and optimizing the data access efficiency by adopting a multi-stage cache system; the calculation precision of the FFT fast Fourier transform is dynamically adjusted, and the calculation of the FFT fast Fourier transform is optimized by pre-calculating and caching an FFTW plan; performing clock synchronization optimization and jitter elimination on the COAX digital audio signal; establishing a multi-dimensional result cache matrix and an intelligent multiplexing decision tree, and reducing repeated operation through intelligent cache prediction and similarity calculation; system performance indexes are monitored in real time, adaptive parameter adjustment is realized based on an optimization objective function, audio quality and system stability are monitored in combination with subjective and objective evaluation mechanisms, repeated operation is remarkably reduced, and calculation resource allocation is optimized on the premise of ensuring sound quality.

Technologies directed to respiration monitoring based on noise channel state information (CSI) data are described. A method includes receiving CSI data representing channel properties of a wireless channel used by a first wireless device and a second wireless device located in a geographical region. The method generates a set of CSI samples by sampling the CSI data and removes one or more outlier CSI samples using a sparse outlier process, and removes a cluster of outlier samples using a cluster outlier process. The method determines Fast Fourier Transform (FFT) data for each channel subcarrier index and a signal-to-noise ratio (SNR) value for each channel subcarrier index, and identifies a first number of channel subcarrier indexes having highest SNR values to obtain a subset of FFT data, which represents a breathing spectrum. The method determines a respiratory rate of a user in the geographical region from the subset of the FFT data.

The invention discloses a data management method and device, electronic equipment and a storage medium, and belongs to the technical field of electronic equipment. The method comprises the following steps: carrying out fast Fourier transform (FFT) calculation on first data stored in an annular buffer area of the scintillation sensor, and obtaining a first calculation duration for carrying out FFT calculation on the first data; predicting a second prediction duration of the next FFT calculation based on a first prediction duration of the previous FFT calculation and the first calculation duration; determining a target window value based on the second prediction duration and an FFT calculation reference duration; and according to the target window value, storing second data collected by the scintillation sensor into the annular buffer area.

A multi-mode surface-wave free-field inversion method based on dispersion properties of layered media addresses the inaccuracy in existing methods that ignore higher modes. A novel approach for characterizing the participation quantity of each mode is proposed based on an energy flux density, which is applied to calculate a modal participation factor through dispersion curves and the frequency-domain dynamic stiffness matrix. Next, the ground surface-wave components with dispersion properties are transferred from the time domain to the frequency domain and decomposed into harmonic components composed of individual frequencies by the Fast Fourier Transform technology. These harmonic components continue to be decoupled as multiple modes by the modal participation factors, with each single-mode component being inverted to construct single-mode surface-wave free fields. Finally, all single-mode surface-wave free fields are superimposed following the mode superposition principle to form the multi-mode surface-wave free fields.

The invention discloses an equipment fault diagnosis method based on a depth Brown distance and an attention mechanism, and the method comprises the steps: obtaining fault vibration signal data, and generating corresponding time-frequency image data through fast Fourier transform and spectrum feature calculation; taking the time-frequency image data as a query sample, and combining a preset support set to construct a small sample learning task; performing feature extraction based on a preset weighted multi-scale wide kernel feature dynamic extraction network to obtain a query sample feature map and a multi-class support sample feature map; and then performing fault diagnosis based on the trained fault diagnosis model to obtain a corresponding fault diagnosis result. Wherein the fault diagnosis model comprises a global measurement module based on an attention mechanism, a local measurement module based on a depth Brownian distance and a classifier. According to the method, adaptive multi-scale feature extraction is realized, fault diagnosis is performed from local and global dimensions, and the fault diagnosis precision and reliability in a small sample scene are remarkably improved.

The invention relates to a vibration signal detection system for motor state diagnosis and a method thereof, the system comprises a piezoelectric acceleration sensor, a charge transfer module, a range selection module, an amplification module, an oscilloscope acquisition module and a data analysis module which are connected in sequence, and the piezoelectric acceleration sensor is used for acquiring charges generated by vibration; the charge transfer module is used for determining charge change in the vibration process; the range selection module is used for adjusting the gain of the amplification module; the amplification module is used for amplifying the charge change signal; the oscilloscope acquisition module is used for acquiring the amplified charge change signal; and the data analysis module performs fast Fourier transform and frequency sweep sampling calculation processing on the signals acquired by the oscilloscope acquisition module to obtain a vibration frequency value. Compared with the prior art, the method detects the dynamic process of vibration, is rich in perceivable characteristic parameters, effectively improves the measurement precision of motor vibration signals, and is suitable for motor state diagnosis application based on technologies such as deep learning.

The invention discloses a film thickness measurement method and system based on a line scanning hyperspectral camera, and relates to the technical field of hyperspectral imaging, and the method comprises the steps: obtaining a reflection or transmission spectrum image and a dark noise image, and carrying out the denoising processing; using a hyperspectral camera and an integrating sphere to carry out radiation correction on the reflected or transmitted spectral image; acquiring a film reflectivity or transmissivity spectrum according to the transmission spectrum without the film or the standard specular reflection spectrum; and determining the number of global interference periods according to a reflectivity or transmissivity curve, and calculating by using a fast Fourier transform method or a spectrum fitting method to obtain the film thickness. Image data with space and spectrum information is acquired through a hyperspectral camera, high-precision film thickness measurement under global imaging and dynamic scanning is realized through an algorithm combining fast Fourier transform and spectrum fitting, and meanwhile, the film thickness measurement precision is improved by adopting dark noise correction and integrating sphere radiation correction. The quantitative accuracy of incident light and sample reflection or transmission light is ensured, and the detection efficiency is greatly improved.

A device for detecting and analyzing vital fields includes: a dielectric barrier discharge array fabricated on a thin substrate with low dielectric loss; an air permeable sheet for electrical insulation from the skin; a transformer for generating sufficient AC voltage to cause air breakdown in the array; a signal transformer and bypass capacitor for isolating the radio frequency current from the plasma discharge; circuitry for amplification and narrow-band spectrum analysis of the plasma discharge current. The amplified signal from the plasma discharge current is gated to include only signal from the part of the drive waveform where plasma discharge predominantly occurs. Frequency converters reduce the complexity of narrow-band spectrum analysis; spectrum analysis is done by Fast Fourier Transform analysis of the frequency converter outputs. The different FFT results are compared and analyzed to aid the user with the correct array placement on the body, and the detection of medical conditions.

Provided are a jamming signal generation method and system. The method includes receiving a synthetic aperture radar (SAR) transmission signal by an SAR, determining a first form and position of a noise patch in a predefined coordinate system, transforming the predefined coordinate system into an SAR image formation plane (IFP) coordinate system, based on a coordinate system transformation function, determining a second form and position transformed from the first form and position of the noise patch in an SAR image using the SAR IFP coordinate system, generating a first reflectivity map model, based on the second form and position of the noise patch, generating a second reflectivity map model by performing two-dimensional fast Fourier transformation on the first reflectivity map model, and generating an SAR jamming signal based on a convolutional product of the second reflectivity map model and a reference signal.

The invention discloses a generator stator winding dynamic turn-to-turn short circuit fault detection method and device, and relates to the technical field of generator state monitoring and fault diagnosis, and the method comprises the steps: measuring a generator rotor vibration signal in real time; transforming the vibration signal from a time domain signal to a frequency domain signal by using fast Fourier transform; and comparing the collected time domain signal and the converted frequency domain signal with each component of the frequency spectrum of the vibration signal under the normal condition, and judging whether the generator has a winding dynamic turn-to-turn short circuit fault or not. Whether the dynamic turn-to-turn short circuit fault of the stator winding occurs in the generator is identified by detecting the rotor vibration of the generator. The method is simple and easy to implement, overcomes the defects of winding dynamic turn-to-turn short circuit fault detection at present, is obvious in detection characteristic and good in effect, and provides reference for detection and diagnosis of generator stator winding dynamic turn-to-turn short circuit faults.

The invention discloses a heart rate detection method implemented by using a composite remote photoplethysmography (rPPG), comprising the following steps: continuously capturing an input frame, the input frame having a face image; calculating a plurality of feature points in the face image to obtain a skin color mean value and storing the skin color mean value in a first queue; executing a POS algorithm and a CHROM algorithm based on the skin color mean value of the plurality of input frames in the first queue to generate a first rPPG waveform signal and a second rPPG waveform signal respectively; performing reverse merging processing on the first rPPG waveform signal and the second rPPG waveform signal to generate a merged waveform signal; performing a fast Fourier transform process on the merged waveform signal to generate a merged spectrum; and performing spectrum analysis processing on the combined spectrum to extract heart rate output.

In certain embodiments, a surgical handpiece system includes a phacoemulsification tip, a fluid management system, an ultrasonic drive system, and a controller. The phacoemulsification tip is attached to a shaft. The fluid management system is configured to manage inflow and outflow of fluid from an ocular surgical site. The ultrasonic drive system is configured to generate torsional and longitudinal vibrations in the phacoemulsification tip. The controller is configured to analyze applied voltage and current to the ultrasonic drive system using Fast Fourier Transforms (FFTs), and tune applied frequencies of the torsional and longitudinal vibrations according to at least one resonant frequency.

Aspects and implementations disclosed are directed to systems and techniques protecting cryptographic operations that involve computing a discrete transform (DT) of a polynomial by randomizing basis vectors of a finite field, identifying a first auxiliary polynomial and a second auxiliary polynomial, computing the DT of the polynomial using the randomized basis vectors, the DT of the first auxiliary polynomial, and the DT of the second auxiliary polynomial, and computing a plaintext output corresponding to the ciphertext input using the DT of the polynomial. Further protection techniques include masking the polynomial and computing the DT of the polynomial using the DT of the masked polynomial.

The invention relates to the technical field of gas detection, and discloses a gas detection method and device for an infrared gas analyzer, and the method comprises the steps: obtaining the light cutting frequency of a light cutting device, capturing a photoelectric signal according to the light cutting frequency, determining a square wave signal, and if the square wave signal triggers an interrupt signal, judging a sampling mark of the infrared gas analyzer, if the sampling mark is true, a capacitance detector is called in a preset sampling period to convert the light quantity difference between the measuring gas chamber and the reference gas chamber into an electric signal; the sampling mark is changed to be false, the interrupt signal is eliminated, the electric signal is subjected to fast Fourier transform algorithm calculation to obtain a target signal amplitude value, the target gas concentration of the detected gas is obtained through the target signal amplitude value and a preset corresponding relation, and the preset corresponding relation represents the corresponding relation between the signal amplitude value and the gas concentration; the gas detection method for the infrared gas analyzer, which is more practical and more accurate, is provided by the method.

The invention discloses a two-dimensional real-time back projection sensing imaging method, device, equipment and medium based on a multi-antenna system, and the imaging method comprises the following steps: S1, carrying out Hilbert transform, frequency shift and fast Fourier transform on an echo signal, and outputting an echo signal frequency spectrum; s2, performing matched filtering on the sending signal and the echo signal, and outputting a time domain pulse compression result; s3, calculating the coordinates of the imaging area according to the imaging area and the grid size, and calculating the pixel signal intensity corresponding to the image through two-dimensional interpolation according to the pulse compression result; calculating a phase compensation factor by using the coordinates of the imaging area, performing phase compensation on an interpolation result, and finally outputting and pre-storing a two-dimensional range profile; and S4, windowing and superposing the multi-channel two-dimensional range profile, and outputting a two-dimensional SAR image in real time. Based on the SAR simulation imaging method, multi-antenna echo signals can be processed, the angle resolution can be improved, and real-time sensing imaging of the indoor environment can be achieved.

A uniform circular array (UCA) is assisted with an analog inverse fast Fourier Fast transform (IFFT) / fast Fourier transform (FFT) precoder to reduce computational complexity in one or more line-of-sight (LoS) multiple-input multiple-output (MIMO) networks. Each port of the UCA includes a steerable miniaturized array with beam steering capability. Analog beam steering is performed via one of the analog IFFT / FFT precoder or one of the steerable miniaturized arrays in a port of the UCA, for improving one or more properties of steering one or more beams toward one or more intended destinations in the one or more LoS MIMO networks.

Reconfigurable digital logic circuits and methods of operation can be used to accelerate computation of Fast Fourier Transforms (FFT) and discrete Fourier transforms (DFT) for a range of sizes. In some embodiments, the same circuit can be reconfigurable to support FFT of any size 2k (for positive integer k) and DFT for of any size 2a*3b*5c for non-negative integers a, b, c.

The application discloses a kind of two-dimensional real-time back-projection perception imaging method, device, equipment and medium based on multi-antenna system, wherein, imaging method includes the following steps: S1, echo signal is carried out hilbert transform, frequency transfer and fast fourier transform, and echo signal spectrum is output;S2, echo signal and echo signal are carried out matched filtering, and time domain pulse compression result is output;S3, according to the imaging area and grid size calculation imaging area coordinate, according to pulse compression result, the corresponding pixel signal intensity of image is calculated by two-dimensional interpolation;Then the imaging area coordinate is used to calculate phase compensation factor, and the interpolation result is phase compensated, and finally two-dimensional range image is output and pre-stored;S4, to the multi-channel two-dimensional range image is windowed and superimposed, and two-dimensional SAR image is output in real time.The application is based on SAR simulation imaging method, can process multi-antenna echo signal, can improve angle resolution and realize real-time perception imaging of indoor environment.

The present invention discloses an automated classification method for regression test error simulation waveforms based on a Mamba neural network architecture, belonging to the field of integrated circuits. The method comprises parsing a simulation waveform file obtained from a regression test, converting a key signal waveform into a discrete sequence of integer waveforms; normalizing the numerical range of the waveform sequence to the 0-1 interval, intercepting a fixed length and inputting it into a Mamba neural network model, with the network outputting two parameters: block size and block starting position; dividing the waveform using the two characteristic parameters output by the network, calculating the thickness, degree of fluctuation, and mean characteristics of each waveform block, and calculating the overall characteristics; performing a fast Fourier transform on the waveform using integer multiples of the waveform block size as a window, and calculating frequency domain features; and merging the extracted features into a multidimensional feature vector and inputting it into a support vector machine to output a final classification result. The present invention can effectively improve the accuracy of diagnosing the cause of regression test failure, replace the manual triage process, and improve verification efficiency.

The invention discloses a speech recognition method based on an STO array and a dynamic time planning algorithm. The method includes processing speech signals using an STO array and identifying them using an improved dynamic time planning algorithm. The STO can generate a stable microwave signal in the absence of an external magnetic field. The method first pre-processes the signal in the time domain, then performs a fast Fourier transform, and then converts the power spectrum into a current signal by calculation and passes it into the STO array, obtaining the output frequency corresponding to each current segment as a feature vector. Finally, the feature vector is processed using an improved dynamic time planning algorithm to achieve recognition. The method utilizes an array constructed of nano-scale STO devices, combines the characteristics of STO such as its ability to flip without a magnetic field and high frequency adjustability, and improves the algorithm to limit the distance and increase the training library, thereby realizing a speech recognition hardware improvement system, which is expected to achieve highly integrated and high-recognition speech recognition.

A method, system, and apparatus for a wireless receiver with intermediate frequency (IF) detection and local oscillator (LO) frequency correction is disclosed. According to one aspect, the wireless receiver is configured to include a LO configured to generate a local oscillator signal, the LO not being phase-locked. The wireless receiver includes a mixer configured to mix the LO signal with an amplitude shift keying (ASK) modulated signal to produce an intermediate frequency (IF) signal. The wireless receiver also includes a tuning circuit configured to estimate a frequency of the IF signal and tune the LO according to the estimated intermediate frequency, and tune the LO to compensate for IF frequency drift. The IF frequency estimation is based on a correlation of the signal in a plurality of frequency bins of a fast Fourier transform (FFT) of the IF signal.

Reducing noise and dose (radiation or contrast) for perfusion imaging in Computed Tomography Perfusion (CTP), Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT), and Magnetic Resonance Imaging (MRI) medical scanning devices by using a k-space based method. The time sequence of images from the scanner data set is converted as necessary, such as using a 2D Fast Fourier Transform (FFT), into a k-space having multiple timeframes. View-shared averaging is performed to reduce noise and preserve spatial and temporal resolutions of CTP, PET, SPECT and MRI data by progressively increasing the number of time frames for view-shared averaging for more distant regions of “k-space”, before converting the data, such as through a 2D FFT into a time sequence of noise reduced images.

Technologies for compilers that implement non-power of two Fast Fourier Transform (FFT) algorithms are described. The non-power of two FFT algorithm uses a recursive function to generate a hardware design of a set of compute blocks of a fixed-point digital signal processor (DSP) and routing data between the compute blocks. The compiler receives input specifying a sequence of indexes and a bit width of the fixed-point DSP and performs a process. The process splits the sequence using a recursive loop, determines a number of multiplications in the hardware design, and generates a trace graph of the non-power of two FFT algorithm. The process is entered via the recursive function and exists when the recursive loop decrements to a specified value corresponding to a Radix-3 or Radix-2. The compiler outputs data, including the hardware design, the number of multiplications in the hardware design, and the trace graph.

The present invention discloses a low-voltage intelligent broadband harmonic detection method and a detection device, belonging to the technical field of harmonic detection in power systems, including: denoising an input signal to obtain an initial signal; performing discrete wavelet transform based on the obtained number of transformation times to separate the initial signal into a low-frequency signal and a high-frequency signal; weighting the low-frequency signal based on a Hanning window to obtain a weighted signal, performing fast Fourier transform on the weighted signal to obtain a first harmonic spectrum, and performing feature extraction and spectrum correction on the first harmonic spectrum to obtain a first detection result; performing frequency reduction processing on the high-frequency signal through an orthogonal digital mixing function to obtain a frequency-reduced signal, performing band-selective fast Fourier transform on the frequency-reduced signal to obtain a second harmonic spectrum, and performing feature extraction on the second harmonic spectrum to obtain a second detection result. It overcomes the technical problem in the prior art that it is difficult to improve the real-time performance while improving the detection accuracy, and significantly improves the accuracy and real-time performance of harmonic detection.

The present application discloses a method and an electronic device for reducing echo residue. The method for reducing echo residue can be applied to the electronic device, and comprises: performing echo cancellation on a voice input signal according to an echo reference signal to obtain an echo cancellation signal; converting the echo reference signal into a reference spectrum signal of each frame by fast Fourier transform; converting the echo cancellation signal into a voice spectrum signal of each frame by fast Fourier transform; obtaining an a priori signal-to-noise ratio of a current frame by using the reference spectrum signal of the current frame and the voice spectrum signal of the current frame according to an additive noise principle; filtering the voice spectrum signal of the current frame by a Wiener filter coefficient of the current frame determined by the a priori signal-to-noise ratio of the current frame to obtain a target spectrum signal of each frame; and converting the target spectrum signal of each frame by inverse fast Fourier transform to obtain a target voice signal. Therefore, the method for reducing echo residue can accurately filter out residual echo.

The present invention relates to a vibration detection method for a circuit breaker mechanical fault, comprising the following steps: 1. magnetically adsorbing or adhering a vibration sensor to the surface of a housing at an operating mechanism of a circuit breaker under test; 2. closing the circuit breaker to excite vibration, whereupon the vibration sensor collects a vibration signal, transmits the signal to a vibration signal analysis and processing instrument, and records the vibration signal; 3. the vibration signal analysis and processing instrument obtains the magnitude of the vibration amplitude, performs a fast Fourier transform on the vibration signal within a range of 0-8000 Hz, and performs a three-layer wavelet packet decomposition on the vibration signal using a packet processing unit of an industrial computer; and 4. calculating the maximum amplitude a of the vibration, and obtaining the energy value e of each frequency band. i 5. The original data of the load vibration test of the circuit breaker during commissioning are also subjected to fast Fourier transform and three-layer wavelet packet decomposition in the range of 0-8000Hz to calculate the maximum amplitude A of the vibration and the energy E of each frequency band. i ; 6. Determine whether there is a spring fatigue loosening fault; 7. Determine whether there is a transmission mechanism jamming fault; 8. Display the fault condition.

A system for determining a trigger amplitude indicating an early sign of material fracture in a test sample includes a microphone that converts acoustic emissions emitted by the test sample into electrical signals. A load is applied to the test sample, and acoustic emissions are emitted when the load causes deformation of the test sample prior to material fracture. A control module communicates electrically with the microphone and executes instructions to monitor and filter the electrical signals generated by the microphone. The control module converts the electrical signals generated by the microphone into individual frequency components based on a Fast Fourier Transform (FFT). Each frequency component includes a peak intensity. The control module determines the trigger amplitude based on the peak intensities of the individual frequency components obtained from the FFT.

This invention relates to a method and apparatus for resolving velocity ambiguity based on constant frequency assistance. The method includes the following steps: a radar sequentially transmits a constant frequency band signal and a linear continuously modulated pulse train, and acquires the radar echo signal; both the constant frequency band echo signal and the sawtooth band echo signal are mixed to obtain a constant frequency band intermediate frequency signal and a sawtooth band intermediate frequency signal; the constant frequency band intermediate frequency signal is processed by a fast Fourier transform to obtain a target true velocity estimate; the sawtooth band intermediate frequency signal is sequentially processed by a two-dimensional fast Fourier transform, a two-dimensional constant false alarm rate (CFAR) processing, and a centroid condensation processing to obtain a target range velocity estimate; based on a velocity matching method using a Fourier rotation factor, the target true velocity estimate is matched with the target range velocity estimate to obtain the true velocity of all targets. This method not only resolves velocity ambiguity but also improves velocity accuracy, offering advantages such as high velocity measurement accuracy, high real-time performance, and simplicity.

The present application relates to the field of bark stopper, and provides a bark stopper control device with noise reduction and a method thereof, which comprises a fixing device wearable on the neck of a pet dog, a shell, a bark stopper device, a main microphone sound collection module, a vice microphone sound collection module, a differential amplifier module and a microprocessor. The main microphone sound collection module and the vice microphone sound collection module respectively collect barking sounds, amplify the barking sounds and send the amplified barking sounds to the differential amplifier module to filter environmental noise. The differential amplifier module adopts inverse sound waves to offset and filter the environmental noise, and outputs a noise-free barking sound signal to the microprocessor. The microprocessor performs fast Fourier transform to calculate frequency domain characteristics and determine whether the frequency domain characteristics conform to the barking frequency characteristics of the pet dog stored in the microprocessor. If the pet dog barks, the microprocessor controls the bark stopper device to stimulate the pet to bark. The present application solves the problem of high false triggering rate of the existing bark stopper.

In at least one embodiment, a well inspection method (600) and system (500) is disclosed. The method (600) includes transmitting (602) an acoustic signal from a well inspection tool into a casing structure, receiving (604) return signals from the casing structure to the well inspection tool, performing (606), using at least one processor associated with the well inspection tool, a Fast Fourier Transform (FFT) on a plurality of frequencies of the return signals to generate spectrogram data, determining (610) entropy spectra from the spectrogram data, and determining (612) casing loadings associated with the casing structure based at least in part on the entropy spectra.