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69 results about "Variational model" patented technology

In the probability model framework, a variational autoencoder contains a specific probability model of data and latent variables . We can write the joint probability of the model as . The generative process can be written as follows.

Rolling bearing fault diagnosis method based on improved variational model decomposition and extreme learning machine

The invention discloses a rolling bearing fault diagnosis method based on improved variational model decomposition and an extreme learning machine. The method comprises: vibration signals of a rollingbearing under different types of faults are collected, the vibration signals are filtered by means of maximum correlation kurtosis deconvolution, parameter optimization is carried out on the maximumcorrelation kurtosis deconvolution method by using a particle swarm algorithm, and an enveloped energy entropy after signal deconvolution is used as a fitness function; the mode number of variationalmodel decomposition is improved by an energy threshold and improved variational model decomposition of the filtered vibration signals is realized to obtain mode matrixes of the corresponding vibrationsignals; singular value decomposition is carried out on the mode matrixes to obtain a singular value vector and a rolling bearing fault feature set is constructed; and the fault feature set is trained by using an extreme learning machine and a rolling bearing fault diagnosis model is established. Therefore, stable feature extraction of the complex vibration signal of the rolling bearing is realized, so that the diagnostic accuracy is improved.
Owner:HEFEI UNIV OF TECH

Image super-resolution reconstruction method and system

The present invention discloses an image super-resolution reconstruction method and a system. According to the method, firstly, the pixel data of a plurality of low-resolution images having the complementary information are acquired. Secondly, according to the pixel data, data consistency items selectively integrating brightness constancy constraints with gradient constraints are constructed and matched feature points are subjected to the initial flow vector updating treatment. Initial flow vectors are substituted into a motion estimation variation model constructed based on data consistency, and then the optimal motion flow vector of each pixel is obtained. Simultaneously, an optimal fuzzy core is constructed based on the brightness of the L0 norm and the fuzzy estimation energy function of a gradient-combined constraint image prior model. Finally, according to the optimal motion flow vector and the optimal fuzzy core, a reconstructed high-resolution image of a variational model is established. Based on the method or the system, the accuracy of motion displacement vectors and the accuracy of fuzzy parameters during the super-resolution reconstruction process can be effectively improved. As a result, an optimal super-resolution reconstruction result is obtained.
Owner:CAPITAL NORMAL UNIVERSITY

Green tide information extraction method

The invention belongs to the technical field of remote sensing image processing, and relates to a green tide information extraction method. The method comprises: obtaining a sea area satellite remote sensing image with a conventional method, screening images of green tide regions, and performing preprocessing operations of geometric correction and image mosaicking; calculating and determining a green tide range by adopting a normalized difference vegetation index; cutting a region of interest in any shape to generate an irregular image file containing the green tide regions; extracting green tide information by adopting a split Bregman fast projection algorithm of a variational level set two-phase image segmentation based Chen-Wees model; and finally, quantitatively calculating the green tide regions by adopting a quantitative formula. The image segmentation based variational model accurately extracts and quantifies the green tide information on the satellite remote sensing image, so that a conventional manual threshold method can be completely replaced and operational application can be realized; and method is scientific and reasonable in principle, low in human factor quantity, high in calculation speed, accurate and stable in result, high in operability, friendly in application environment, high in practicality and easy to popularize.
Owner:国家海洋局北海预报中心

Method for restoring motion blurred image based on total variational model and neutral network

The invention discloses a method for restoring a motion blurred image based on a total variational model and a neutral network, which mainly solves the problem existing in the prior method that the image cannot be accurately restored. The implementation process comprises the following steps of: (1) constructing a Toeplitz matrix; (2) working out gradients in horizontal and vertical directions; (3) initializing the neutral network; (4) working out a neuron output; (5) working out the output of the neutral network; (6) working out a first variation delta E1 of a network energy function; (7) if the neurons are completely updated, jumping to the step (4); otherwise, jumping to a step (8); (8) if the set iterations are reached, outputting a restoration result, otherwise jumping to a step (9); (9) working out a restoration error; (10) if the restoration error is smaller than the set error, outputting the restoration result, otherwise jumping to a step (11); (11) working out the current input bias matrix; (12) working out a second variation delta E2 of the network energy function; and (13) if the summation of the delta E1 and the delta E2 is less than 0, jumping to a step (2); if the summation of the delta E1 and the delta E2 is more than or equal to 0, jumping to the step (3); and if the delta E1 is equal to 0, outputting the restoration result. The method can obtain relatively accurate restored images, and be applied to the restoration of motion blurred images.
Owner:XIDIAN UNIV

Fault diagnosis method under action of central frequency convergence trend

The invention discloses a fault diagnosis method under the action of a central frequency convergence trend. The method comprises the following steps: (1) collecting a dynamic signal x (t) of rotary mechanical equipment; (2) setting initial decomposition parameters of the variational model; (3) decomposing the dynamic signal x (t) by using a variational model with set initial decomposition parameters, and traversing the signal analysis frequency band under the guidance of a central frequency convergence trend to iteratively decompose the dynamic signal x (t) to obtain an optimized mode {m1... Mn... MN} and a corresponding central frequency {omega1... Omegan... OmegaN}; (4) searching a fault correlation mode mI, guiding parameter optimization by the central frequency omega I of the fault correlation mode mI, and extracting an optimal target component containing fault information; and (5) performing envelope analysis on the optimal target component, and diagnosing the rotating mechanicalequipment according to an envelope spectrum. According to the fault diagnosis method provided by the invention, intelligent decomposition of the original dynamic signal of the diagnosis target equipment is realized by adopting a decomposition mode guided by a central frequency convergence trend, the acquired equipment dynamic signal can be adaptively analyzed, and the difficulty of performing mechanical fault diagnosis by a technician by using a variational mode decomposition method is reduced.
Owner:SUZHOU UNIV

Rolling bearing fault diagnosis method based on variational Hilbert-Huang transform

ActiveCN112326245ARealize the effect of noise suppressionAccurately extract fault characteristic frequencyMachine part testingCharacter and pattern recognitionRolling-element bearingHilbert huang transformation
The invention discloses a rolling bearing fault diagnosis method based on variational Hilbert-Huang transform, and the method comprises the following steps: S1, carrying out processing of measurementdata of a rolling bearing through empirical mode decomposition to obtain a plurality of intrinsic mode functions IMFi; S2, screening the obtained IMFi by using a sensitivity criterion to obtain a sensitive mode containing rolling bearing fault information; S3, constructing each sensitive mode into a variational model taking the minimum sum of bandwidths as a target, and solving the variational model to obtain a plurality of finite bandwidth modes; S4, according to the signal characteristics, reconstructing the finite bandwidth modes according to a specified sequence to obtain rolling bearing fault components; S5, using Hilbert-Huang transform for detecting fault components, comparing the fault components with the theoretical fault characteristic frequency, and determining the fault position of the rolling bearing. Rolling bearing data are processed through variational Hilbert-Huang transform, and the effect of rolling bearing noise suppression is achieved.
Owner:AVIC SHANGHAI AERONAUTICAL MEASUREMENT CONTROLLING RES INST

Non-stationary signal state monitoring method and system for nuclear power equipment

ActiveCN111881594AImprove feature expressivenessSolve the problem of noise removalMeasurement devicesDesign optimisation/simulationFeature extractionNuclear power
The invention relates to a non-stationary signal state monitoring method and system for nuclear power equipment. The monitoring method comprises the following steps: acquiring a characteristic signalof each measuring point of the nuclear power equipment in normal operation; carrying out variational mode decomposition on each characteristic signal, and construcitng a constrained variational model;introducing a penalty parameter and a penalty factor, and determining an optimal solution of the constrained variational model; determining modal components according to the optimal solution, screening the modal components, and determining an intrinsic modal function; performing feature extraction on the time sequence by adopting multi-scale weighted permutation entropy, and determining real-timeweighted permutation entropies under different scales; determining a weighted permutation entropy statistical threshold of each weighted permutation entropy under different scales according to the real-time weighted permutation entropies under different scales; and comparing the real-time weighted permutation entropies under different scales with the weighted permutation entropy statistical threshold, and determining the non-stationary signal state of the nuclear power equipment. The detection precision can be improved.
Owner:HARBIN ENG UNIV

Variation-based multi-radar fusion track state estimation method

The invention relates to a variation-based multi-radar fusion track state estimation method, belongs to the field of multi-sensor target tracking and data fusion, and aims to overcome the defect thata radar information processing system often swings back and forth among a plurality of original tracks during track fusion to form a saw-tooth shape which influences of track quality, and the solve the problem that turning bulging and even tracking failure easily occur in a conventional method. Observation information of multiple radars is managed in a unified mode, a variation model containing atarget motion speed transformation curve is constructed, a rapid solving mode of the variation model is given, the solved motion speed curve is used for track extrapolation of all the observation radars, and finally a target state estimation value is estimated and updated. According to the method, correlation of observation information is considered to the greatest extent, the adverse effects of track relative deviation and sudden maneuvering of the target on target estimation are reduced, the target motion speed and the fusion position estimation precision are improved, the track quality is improved, and reliable tracking of the target is obtained.
Owner:STRATEGIC EARLY WARNING RES INST OF THE PEOPLES LIBERATION ARMY AIR FORCE RES INST

Weight-adaptive mixed-order total variation image denoising algorithm

The invention discloses a weight-adaptive mixed-order total variation image denoising algorithm, which comprises the following steps of: preprocessing an image, converting a color image into a grayscale image, and adding Gaussian white noise to the image; constructing an image denoising model by taking the total variation model as a basic framework, and solving minimization under a constraint model; putting forward a high-order total variation model, fusing the high-order total variation model into an image denoising model, dividing an edge texture region and a flat region by the whole algorithm model through the structural information of a noisy image, constructing a weight function, combining the total variation model and the high-order total variation model, establishing a mixed-order total variation image denoising model, and obtaining a minimizedsolution. A gradient constraint term is proposed, a denoising model is introduced, the structural information of the image is ensured, a final weight adaptive mixed-order total variation image denoising model is established, and the solution is minimized. Compared with a traditional algorithm model, the algorithm provided by the invention has the advantages that the peak signal-to-noise ratio is improved by 8-13dB, and the numerical value of the structural similarity is superior to that of the previous algorithm.
Owner:NANJING UNIV OF INFORMATION SCI & TECH
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