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196 results about "Multiple-scale analysis" patented technology

In mathematics and physics, multiple-scale analysis (also called the method of multiple scales) comprises techniques used to construct uniformly valid approximations to the solutions of perturbation problems, both for small as well as large values of the independent variables. This is done by introducing fast-scale and slow-scale variables for an independent variable, and subsequently treating these variables, fast and slow, as if they are independent. In the solution process of the perturbation problem thereafter, the resulting additional freedom – introduced by the new independent variables – is used to remove (unwanted) secular terms. The latter puts constraints on the approximate solution, which are called solvability conditions.

System and device for multi-scale analysis and representation of physiological data

System comprised of a medical device and method for analyzing physiological and health data and representing the most significant parameters at different levels of detail which are understandable to a lay person and a medical professional. Low, intermediate and high-resolution scales can exchange information between each other for improving the analyses; the scales can be defined according to the corresponding software and hardware resources. A low-resolution Scale I represents a small number of primary elements such as intervals between the heart beats, duration of electrocardiographic PQ, QRS, and QT-intervals, amplitudes of P-, Q-, R-, S-, and T-waves. This real-time analysis is implemented in a portable device that requires minimum computational resources. The set of primary elements and their search criteria can be adjusted using intermediate or high-resolution levels. At the intermediate-resolution Scale II, serial changes in each of the said elements can be determined using a mathematical decomposition into series of basis functions and their coefficients. This scale can be implemented using a specialized processor or a computer organizer. At the high-resolution Scale III, combined serial changes in all primary elements can be determined to provide complete information about the dynamics of the signal. This scale can be implemented using a powerful processor, a network of computers or the Internet. The system can be used for personal or group self-evaluation, emergency or routine ECG analysis, or continuous event, stress-test or bed-side monitoring.
Owner:SHUSTERMAN VLADIMIR

Method for estimating 3D posture of a human body combining densely connecting attention pyramid residual network and equidistance restriction

A method for estimating 3D posture of a human body combining densely connecting attention pyramid residual network and equidistance restriction is composed of a discriminative human body 2D posture estimation part and a generative human body 3D posture estimation part. Firstly, a 2D human posture estimation model is constructed. The 2D human posture estimation model includes attention pyramid residual blocks and a funnel sub-network composed of several attention pyramid residuals. The attention pyramid residuals are used for multi-scale image feature extraction, and the funnel sub-network is used to generate human joint thermodynamic map. In order to solve the problem that the environmental context information is not fully utilized, the attention mechanism and multi-scale analysis are combined to capture the environmental context characteristics. In order to solve the problem of gradient disappearance / gradient explosion, the dense connection network is combined with the above attentionmechanism to improve the discrimination of a feature map. Then the loss function is constructed and the equidistant constraint term is introduced to fit the 3D posture of a human body by minimizing the loss function. The method of the invention has obvious advantages in the human body 3D posture estimation task.
Owner:杭州云栖智慧视通科技有限公司

Method and System of Utilizing ECG Signal for Central Venous Catheter Tip Positioning

Disclosed herein are a method and a medical system for utilizing of a intravascular ECG signal for central venous catheter placement. The medical system is capable of detecting the position of a catheter tip and assessing its location relative to the cavoatrial junction. The detection and assessment are performed by a multiscale analysis of the complexity of the intravascular signal data points.
Owner:CR BARD INC

SAR (Synthetic Aperture Radar) image sea-land segmentation method based on wavelet transform and OTSU threshold

The invention relates to an SAR (Synthetic Aperture Radar) image sea-land segmentation method based on a wavelet transform and OTSU threshold. According to the method, speckle noise in an SAR image is suppressed by using the noise smoothing property of wavelet transform; then land areas are roughly segmented by using an unsupervised optimal OTSU threshold method, and the detection results under each scale are merged based on the multiscale analysis property of wavelet transform; and finally the final coastline detection results are obtained through automatic subsequent treatment and edge tracking. Compared with the prior sea-land segmentation methods, the SAR (Synthetic Aperture Radar) image sea-land segmentation method comprehensively utilizes the speckle noise suppressing and multiscale analysis function of wavelet transform and the self-adaptive, unsupervised and high-robustness properties of the OTSU threshold algorithm, and has great improvement in automation degree, universality, simplicity and applicability of high-resolution SAR images.
Owner:BEIHANG UNIV

Digital image enhancement method and device based on wavelet restruction and decompose

The invention relates to a digital image reinforcing method based on wavelet reconstruction and decomposition and a device thereof, which belongs to the image data processing field. The digital image reinforcing method comprises image pretreatment, decomposition process, transformation process and reconstruction process, and is characterized in that the image decomposition process comprises multi-group integrals and down-sampling process; the transformation process comprises the statistics, analysis and modification processes of mid data information; the reconstruction process comprises multi-group up-sampling, integrals and adding processes; in the transformation process, adaptive histogram equalization technology and noise restraining are adopted. The invention, based on multi-scale analysis, realizes to reinforce the contrast of digital image and prevents noise simultaneously through the wavelet decomposition, transformation and reconstruction and adopting the adaptive histogram equalization technology and noise restraining in transform domain and can be widely used in such fields related to the improvement of digital image quality as medical information systems, industrial nondestructive testing systems and other similar image systems.
Owner:SHANGHAI MEDICAL EQUIPMENT WORKS CO LTD

High-speed automatic multi-object tracking method and system with kernelized correlation filters

A high-speed automatic multi-object tracking method with kernelized correlation filters is provided. The method includes obtaining an image frame from a plurality of image frames in a video, extracting a foreground object sequence from the obtained image frame, and determining similarity between each foreground object of the extracted foreground object sequence and a tracked object. The method also includes calculating HOG features of the foreground objects with a lower similarity, obtaining training samples for each of the foreground objects with the lower similarity using a circular matrix, obtaining a classifier via a kernel method accelerated by FFTW, and obtaining tracking points using a sparse optical flow. Further, the method includes detecting object matching responses using a detection response function, performing multi-scale analysis for the object based on an optical flow method, and processing a next image frame of the plurality of image frames in the video until the video ends.
Owner:ZHEJIANG SHENGHUI LIGHTING

Signal identification and classification method

The invention provides a signal identification and classification method. The method comprises the followings steps of: carrying out noise reduction on initial data containing higher noise by utilizing a wavelet transform method, decomposing signals into high-frequency information and low-frequency information in data analysis, carrying out noise cancelling on the signals by adopting a soft thresholding method and then carrying out signal reconstruction; carrying out further decomposition on the high-frequency part which is not detailedly classified by multiscale analysis while inheriting allthe favorable time-frequency localization advantages of the wavelet transform; analyzing the signals within different frequency bands after multi-layered decomposition by utilizing the wavelet packettransform to extract out characteristic information reflecting a system state; transforming the characteristic vectors of input signals into a high-dimensional characteristic space through non-lineartransform and then solving for an optimal linear classification plane in the high-dimensional characteristic space. The invention overcomes the defects of difficult determination of a network structure, low convergence rate, requirement on large quantities of data samples during training, and the like in neural network learning and enables the neural network learning to be with the characteristics of high precision and strong real time in the aspect of practical application of engineering.
Owner:HARBIN ENG UNIV

Heterology remote sensing image registration method

The invention discloses a heterology remote sensing image registration method. According to the core idea, multi-scale matching is taken as a basis; straight line intersection points are used as elements; the point matching method of a joint Voronoi map and a spectrogram is used; iteration feature extraction and a matching policy are integrated; and the problems of heavy dependence on feature extraction, poor reliability, low accuracy and the like of the existing method are overcome. The method comprises the steps that multi-scale analysis is carried out on original images; straight line extraction and intersection point acquiring are carried out on the coarsest scale; the point matching method of the joint Voronoi map and the spectrogram is carried out on intersection point sets to acquire a homonymous point pair; whether a matching result is qualified is detected: if the matching result is qualified, going to the next step is carried out, otherwise self-adaptive parameter adjustment is carried out and straight line extraction and point set matching are carried out again; original transformation is carried out on the images to be registered, and straight line features are respectively extracted; homonymous straight line segments are searched, and a candidate homonymous point pair is acquired; a KNN map is used to acquire an accurate matched point pair; and a transformation parameter is solved. The method provided by the invention is mainly used for the registration of visible light, infrared, synthetic aperture radar (SAR) and other heterology remote sensing images.
Owner:WUHAN UNIV

Multi-scale analyzing method for buffeting response of large-span bridge

The invention relates to a multi-scale analyzing method for buffeting response of a large-span bridge, which is a method for analyzing and calculating a fine buffeting response of a main girder and solving the difficult problem in bridge buffeting analysis. Comparison between actually measured data of a structure health monitoring system and a calculating result of the buffeting response is realized on a stress level. Based on the traditional buffeting analyzing technique for a large-span bridge structure, a multi-scale finite element modeling technique is introduced into the structure so as to obtain the fine buffeting response of key parts of the structure and then the feasibility and the effectiveness of the analyzing technique for the fine buffeting response are improved. Compared with the traditional method for obtaining the fine buffeting response, the multi-scale analyzing method for the buffeting response of the large-span bridge has the advantages of obviously improving the analyzing efficiency and the accuracy of an analyzing result with the introduction of a multi-scale technique, saving the cost and being convenient for popularization and application in broad engineering personnel. As health monitoring of large-sized bridge structures has become a development trend, the technique can inevitably generate great economic and social benefits.
Owner:SOUTHEAST UNIV

Optical image and SAR image automatic registration method within multilevel multi-feature constraint

ActiveCN103345757ATroubleshoot auto-registration issuesImage analysisPlane segmentationMultilevel model
The invention provides an optical image and SAR image automatic registration method within multilevel multi-feature constraint. The optical image and SAR image automatic registration method within the multilevel multi-feature constraint comprises the following steps that optical images and SAR images are preprocessed, multi-scale level set segmentation is conducted, and a plane segmentation result is obtained; when similar plane targets exist, a coordinate set of centroid points of areas seemingly provided with the same name is calculated; when similar plane targets do not exist, multi-scale analysis is conducted on the images by means of wavelet transformation, extraction of lower-layer linear characteristics and point set matching are conducted on the thickest image, and lower-layer registration transformation parameters are extracted; high-layer linear characteristics is extracted, a control-point matching degree function is defined according to the lower-layer transformation parameters, and high-layer point set matching is conduced; finally, a matched point pair is precisely judged out through the KNN image from the structure, a wrong matched point pair is eliminated, transformation parameters of the matched point pair are obtained according to a polynomial transformational model, and a final registration result is obtained.
Owner:WUHAN UNIV

Aquaculture water quality short-time combination forecast method on basis of multi-scale analysis

The invention discloses an aquaculture water quality short-time combination forecast method on the basis of multi-scale analysis. The method includes the steps that water quality time sequence data are acquired online and repaired; through empirical mode decomposition, the selected water quality time sequence sample set data are decomposed into IMF components and residual rn components, wherein the IMF components and the residual rn components are different in frequency scale; the IMF components and the rn components are classified, a manual bee colony optimization least square support vector regression machine, a BP neural network and an autoregressive sliding average model are respectively selected for forecast according to classifying features, and finally, all results are weighed and summed to obtain a water quality time sequence forecast result. According to the method, the original water quality time sequence data are decomposed into the components different in time frequency through the empirical mode decomposition, and change conditions in original water quality sequences can be mastered more accurately; advantages of the manual bee colony optimization least square support vector regression machine, advantages of the BP neural network and advantages of the autoregressive sliding average model are complemented and combined, and thus performance of a combined forecast model is effectively improved.
Owner:GUANGDONG OCEAN UNIVERSITY

High-resolution remote sensing image segmentation method based on inter-scale mapping

The invention discloses a high-resolution remote sensing image segmentation method based on inter-scale mapping. The high-resolution remote sensing image segmentation method has the advantages that aiming at geographical object extraction involved in objet-level change detection, the high-resolution remote sensing image multi-scale segmentation method based on wavelet transform and an improved JSEG (joint systems engineering group) algorithm is provided; aiming at a key problem that a conventional JSEG algorithm affects segmentation accuracy in high-resolution remote sensing image segmentation, a corresponding improvement strategy is adopted to achieve a good effect; wavelet transform is introduced to serve as a multi-scale analysis tool, excessive rough color quantization of the conventional JSEG algorithm is abandoned, and thus, detail information in original images is kept to the utmost; a novel inter-scale segmentation result mapping mechanism is set up, image segmentation of a current scale is realized on the basis of a segmentation result of a previous scale, and correction of the segmentation result of the previous scale is also realized, and thus, accumulation of inter-scale segmentation errors is decreased effectively; finally, an improved multi-scale segmentation strategy and an improved region merging strategy are provided, and over-segmentation and mistaken merging are effectively reduced.
Owner:HOHAI UNIV

Flexible DC power transmission overhead line fault rapid determining method without setting threshold

The invention relates to a flexible DC power transmission overhead line fault rapid determining method without setting a threshold. The method is characterized in that single-end travelling wave signals which are rapidly spread in a power transmission line during a fault are employed as original data for fault determination, the rapidness and the economic benefits are excellent; and mold maximum change conditions after single-end transient voltage travelling wave signals and single-end transient current travelling wave signals are subjected to wavelet multiple dimensioned analysis are taken as a criterion for determining whether a system generates a fault and whether the fault is a zone inside fault or a zone outside fault, and at the same time, amplitude of forward traveling waves and backward travelling waves of the single-end transient voltage travelling wave signals is taken as a fault direction criterion. The method is simple in principle, is effective, is easy to implement, does not require setting and arranging a threshold value, avoids determining errors and protection maloperation which are easily caused by manual arrangement and setting of the threshold through reliance on engineering experience in a conventional method, and the reliability is higher compared to other methods. Finally, through combination with wavelet feature entropy identification fault types, wrong determination is effectively prevented, and the fault identification accuracy is effectively improved.
Owner:STATE GRID FUJIAN ELECTRIC POWER CO LTD +2

Multiscale analysis of areas of interest in an image

A system identifies areas of interest (e.g., locations of text or objects) in an image in a way that reduces memory requirements, computer processing requirements, and computation time. The system analyzes a downscaled version of an input image using a convolutional neural network that has been trained to recognize areas of interest in coarse, low resolution, images. Based on the output of the coarse neural network, the system predicts particular segments of the image that are most likely to include areas of interest. A second convolutional neural network that has been trained to identify areas of interest in fine, high resolution images analyzes only those segments of the image that the coarse neural network selected for further examination. A reconstruction of the analysis locates likely areas of interest for the whole image.
Owner:UBER TECH INC

Partitioning algorithm for choroidal neovascularization in OCT image

The invention discloses a partitioning algorithm for choroidal neovascularization in an OCT image. The algorithm includes steps of S01, designing a structure prior learning method for a training image and constructing a structure prior matrix used for distinguishing a choroidal neovascularization zone and a background zone; S02, converting the OCT original image to a saliency enhancing image used for enhancing the saliency of the choroidal neovascularization zone based on the structure prior matrix; S03, adopting multi-scale analysis on the saliency enhancing image and dividing the saliency enhancing image into m scales; S04, acquiring m trained convolutionneural network model based on each scale training; S05, processing a testing image by utilizing the step S01, S02, S03 and performing testing by utilizing the trained convolutionneural network model in the step S04, outputting m portioning results and fusing the m partitioning results into the final partitioning result. By adopting the algorithm provided by the invention, the precision of partitioning of the choroidal neovascularization in the OCT image can be improved distinctively.
Owner:SUZHOU BIGVISION MEDICAL TECH CO LTD

Method and system of utilizing ECG signal for central venous catheter tip positioning

Disclosed herein are a method and a medical system for utilizing of a intravascular ECG signal for central venous catheter placement. The medical system is capable of detecting the position of a catheter tip and assessing its location relative to the cavoatrial junction. The detection and assessment are performed by a multiscale analysis of the complexity of the intravascular signal data points.
Owner:CR BARD INC

Extraction method of visual salient regions based on multiscale relative entropy

The invention discloses an extraction method of visual salient regions based on multiscale relative entropy. The extraction method of the visual salient regions based on the multiscale relative entropy comprises extracting different global color feature characteristic patterns and direction characteristic patterns from input images, carrying out gaussian pyramid decomposition and multiscale normalization on the global color feature characteristic patterns and the direction characteristic patterns, respectively computing color partial relative entropy and direction partial relative entropy of respective feature space, respectively normalizing results of the different feature space, carrying out linearity superposition of the results of the different feature space, linearly adding color saliency maps and direction saliency maps together, carrying out two-dimensional gaussian smoothing, and therefore extracting visual salient regions. Compared with a traditional method, the extraction method of the visual salient regions based on the multiscale relative entropy takes a full account of color features and direction features reflecting global significance and relative entropy reflecting partial novelty, adopts a method of multiscale analysis, and has the advantages of being effective and reliable. The extraction method of the visual salient regions based on the multiscale relative entropy is capable of being used for self-adaption compressed sampling and target detection of natural images, remote sensing images and the like, and is wide in application prospect of lowcost imaging devices.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS

Multi-scale analysis-based greenhouse field plant leaf margin extraction method and system

ActiveCN104318546AReduce false recognition rateImprove edge detection accuracyImage enhancementImage analysisMultiple-scale analysisLeaf recognition
The invention belongs to the digital image processing technical field and relates to a multi-scale analysis-based greenhouse field plant leaf margin extraction method and system. According to the method, differences of information of images in different scale spaces are utilized, and different segmentation methods are selected, and comprehensive analysis is performed, and as a result, ideal segmentation results can be obtained; after an experimental image is obtained, proper smoothing filtering is performed on the image, and classified processing is performed on different types of pseudo edges in the image; and based on different situations of Canny edge detection in a comprehensive scale space and OTSU threshold segmentation in different scales and different characteristics of various kinds of pseudo edges, with methods such as morphological processing and logical operation methods adopted, internal and external pseudo edges are removed through utilizing bitwise operation, and therefore, edge detection accuracy can be improved, and leaf recognition error rate can be reduced.
Owner:CHINA AGRI UNIV

Intrusion detection and location method of distributed fiber optic fence based on φ-otdr

InactiveCN102280001AIntrusion detectionDefensiveBurglar alarmDistributed intrusion detectionFiber
The invention discloses a distributed optical fiber fence intrusion detection and location method based on a phi-OTDR (Optical Time Domain Reflectometer), and the method comprises the following steps of: firstly, subtracting an acquired ith signal by an acquired (i-1)th signal to obtain a preprocessing monitoring signal; secondly, carrying out at least four-layer wavelet decomposition on the preprocessing monitoring signal by adopting a plurality of wavelet functions; thirdly, judging whether actual intrusion exists according to the consistency of distribution positions of maximum-wavelet mode maximums in all scale signals; fourthly, judging that the actual intrusion exists if the distribution positions of the maximum-wavelet mode maximums in at least three scale signals are consistent; fifthly, corresponding multiplying the scale signals in which the intrusion exists and the distribution positions of the maximum-wavelet mode maximums are consistent to obtain a composite signal of which pseudo maximums are inhibited and mode maximums at a catastrophe point are enhanced, using a position corresponding to the maximum-mode maximum in the composite signal as a position of the determined intrusion point, determining the intrusion generation and the intrusion position by combining various composite signal judgment results of wavelet multi-scale analysis according to the majority voting criterion.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

Potential field abnormal separation method based on wavelet spectral analysis

The invention provides a potential field abnormal separation method based on a wavelet spectral analysis. The method, which is implemented on a computer, comprises the following steps that: gridding is carried out on a potential field abnormal signal observed by an irregular grid so as to form a potential field abnormal signal of a regular grid; according to a purpose of potential field separation abnormity and a wavelet basis characteristic, a wave basis function is determined; and a wavelet multiple dimensioned analysis is carried out on the potential field abnormal signal of the regular grid so as to obtain potential field abnormal signals under different dimensions; radial power spectrums of the potential field abnormal signals that are obtained under different dimensions are respectively calculated; and according to the radial power spectrums of the potential field abnormal signals obtained under the different dimensions, corresponding filed source body depths are respectively estimated. By employing the provided method in the invention, quantitative evaluation can be carried out on field source depths corresponding to separated potential field abnormal signals.
Owner:INST OF GEOLOGY & GEOPHYSICS CHINESE ACAD OF SCI

Frequency profiles for non-contact range measurement with multi-scale analysis

A method for constructing a frequency profile of an emitted signal suitable for use in a non-contact ranging system with multi-scale spectral analysis includes determining N stepped frequency chirps, wherein each frequency chirp of the N stepped frequency chirps has a linear FM modulation of predetermined bandwidth and slope, and wherein a starting frequency for each of the plurality of stepped frequency chirps is chosen so that a non-linear step profile is created which extends over a predetermined total bandwidth, sorting the plurality of N stepped frequency chirps into P sub-sequences, where P is equal to the product of decimation factors to be used in the multi-scale spectral analysis, and ordering the P sub-sequences end to end in time.
Owner:HACH CO

Texture force touch sensing method based on single image fractional order processing

InactiveCN104050683AEnhanced Edge ProfilesEnhanced detail texturesInput/output for user-computer interactionImage enhancementDamping factorPattern recognition
The invention discloses a texture force touch sensing method based on single image fractional order processing. The method includes the steps that a fractional differential algorithm is utilized, the order gamma of the fractional differential algorithm is adjusted dynamically, an enhanced texture image is obtained, original image texture information is extracted from the enhanced texture image, and multi-scale analysis of the detail texture and the edge contour of different rates of gray level changes is achieved from the point of image airspace gray level change features; force touch rendering is carried out on the virtual surface texture, and tangential force frictional damping coefficients of a force touch sensing model are controlled on the basis of gradient vector distribution of the enhanced texture image; obtained resultant force is calculated and fed back to an operator through a hand controller. By the utilization of sensibility of fractional differential to detail information, the sense of reality of texture force touch sensing is enhanced by manually selecting orders, extracting texture information in a two-dimensional image signal from different scales and converting the texture information into frictional damping control.
Owner:SOUTHEAST UNIV

Micro-motion target characteristic extraction method and system based on wavelet multi-scale analysis

The invention provides a micro-motion target characteristic extraction method and system based on wavelet multi-scale analysis. The micro-motion target characteristic extraction method based on wavelet multi-scale analysis comprises the steps that a micro Doppler model of a precessional motion target and a micro Doppler model of a rolling target are established, narrow-band radar scattering cross section data of the precessional motion target and narrow-band radar scattering cross section data of the rolling target are obtained based on ballistic trajectory simulation, the high-frequency component of the narrow-band radar scattering cross section data of the precessional motion target and the high-frequency component of the narrow-band radar scattering cross section data of the rolling target are extracted by means of wavelet multi-scale analysis, and column diagram characteristics are extracted aiming at the high-frequency component of the precessional motion target and the high-frequency component of the rolling target. According to the micro-motion target characteristic extraction method based on wavelet multi-scale analysis, the micro Doppler high-frequency components of the targets in different micro-motion forms are separated out by means of wavelet multi-scale analysis, new characteristics are extracted for recognizing the truth of targets, and the recognition accuracy of precessional motion targets and rolling targets is improved.
Owner:BEIJING INST OF ENVIRONMENTAL FEATURES

Image fusion quality evaluation method

InactiveCN104008543AAvoid the consequences of different evaluation resultsObjectiveImage analysisPattern recognitionMultiple-scale analysis
The invention discloses an image fusion quality evaluation method. The image fusion quality evaluation method comprises the steps of obtaining source images, carrying out image preprocessing, carrying out image fusion and carrying out fusion quality evaluation. According to the step of obtaining the source images, the source images need to be synchronous in time and cover the same area in space. According to the step of carrying out image preprocessing, the quadratic polynomial registration method is adopted and the nearest neighbor interpolation method is adopted for resampling. According to the step of carrying out image fusion, the fusion method combining the multiscale analysis method and the component substitution method is adopted for the source image to obtain fusion images through different fusion methods. According to the step of carrying out fusion quality evaluation, cross entropy and structural similarity of the fusion images and the source images are calculated, a weighting function model of the cross entropy and the structural similarity is built, and then a total fusion quality evaluation value under a preset weight is calculated. According to the image fusion quality evaluation method, the problems that evaluation indexes are multiple and related and subjective evaluation varies from person to person in a traditional fusion quality evaluation method are solved. The image fusion quality evaluation method is simple and universal.
Owner:HOHAI UNIV

Bridge deformation multi-frequency dynamic analysis method based on combined differential GNSS

The invention discloses a bridge deformation multi-frequency dynamic analysis method based on a combined differential GNSS and relates to the field of bridge deformation monitoring technologies. According to the method, an orthogonal wavelet fast decomposition algorithm is utilized to process a bridge GNSS monitoring signal, an analysis signal is separated on different bands, and multi-scale analysis is performed on a deformation signal; a high-frequency signal is utilized to analyze wink movement of a bridge under the action of external forces such as wind power, vehicle passage or other seismic disasters, and a de-noised low-frequency signal is utilized to analyze a deformation track of a bridge dynamic deformation body; and last, the analysis result is utilized to further analyze the bridge deformation trend. Therefore, by analyzing the characteristics of different frequencies in the GNSS monitoring signal, a static response and a dynamic response of the bridge can be effectively decomposed, the problem that the reason for bridge deformation caused by a bridge three-dimensional displacement change cannot be judged through an existing bridge monitoring system is solved, subsequent monitoring analysis is effectively guaranteed, and a good guarantee is provided for safety monitoring of the bridge.
Owner:CHINA ACAD OF TRANSPORTATION SCI +1

Grain size nondestructive evaluation method based on haar wavelet

The invention discloses a grain size nondestructive evaluation method based on haar wavelet. The method comprises the following steps: data acquisition is conducted on a reference test block, time-size distribution is obtained by utilizing haar wavelet transform, furthermore, the average multi-scale attenuation coefficient of all reference blocks is calculated, an ultrasonic multi-scale attenuation evaluation model for the average grain size is built according to the preset size assembly and the preset normalized weight, and finally grain size evaluation of the test block of which the grain size is unknown is realized through the built ultrasonic multi-scale attenuation evaluation model of the average grain size. The method reduces system errors in grain size measurement; for test blocks of which the average grain size is 103.5 [mu]m measured by adopting metallography, the evaluation result is 101.7 [mu]m, and the error is controlled to be + / -2%. Therefore, through multi-scale analysis of original ultrasonic A signals, the method provided by the invention can discover more rich grain size information in the original ultrasonic A signals, and further improves the nondestructive evaluation precision of the grain size.
Owner:CENT SOUTH UNIV

Multi-dimensional predicting method for strength of braided ceramic base composite material

The invention provides a multi-dimensional predicting method for strength of a braided ceramic base composite material. Firstly a parameterization method is used for establishing a braided ceramic base composite material single-cell model which comprises yarns and a matrix, and then period grid dividing is performed. Afterwards a mesomechanics method is used for simulating the mechanics behavior of the yarn unit. Furthermore a strain conversion matrix is used for converting a yarn element stiffness matrix from a local coordinate system to an integral coordinate system. Finally through applyingan increment type periodic boundary condition, a micro-stress and a strain field of a single cell are calculated. A volume averaging method is used for obtaining a microscopic stress and strain of the braided ceramic base composite material. If a failure unit band which penetrates through the single cell is formed, failure of the braided ceramic base composite material is determined, and the single-cell average stress is the strength of the braided ceramic base composite material. According to the multi-dimensional predicting method, the multidimensional analysis method in which macrography and mesography are combined is utilized. The strength of the braided ceramic base composite material can be accurately predicted without dependence to a large number of experiments with time consumption and high cost.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS

Dynamic monitoring method for gas solid fluidized bed and system thereof

The invention discloses a dynamic supervising method for gas-solid fluidized bed and the system. The method is: using wavelet analysis technology to analyze the pressure vibration signal, judging its flow state, displaying the flow state with capacitance chromatography imaging technology, measuring the aperture rate and its vibration of the fluidized bed, extracts the character value and carries on flow state judgment, using multi-sensor information melting technology to carry on flow state judgment, upgrading the accuracy of the judgment. The supervising system has a fluidized bed main body, under which there has a gas distribution board, gas chamber, on the external wall in the middle of the main body there arranges a capacitance chromatography imaging sensor, pressure sensor, the capacitance chromatography imaging sensor is connected to the tiny capacitance measuring model, data collecting system, and computer, the pressure sensor is connected to A / D converting card, and computer.
Owner:ZHEJIANG UNIV

Wind turbine converter fault diagnosis method based on wavelet transformation and DBN

The present invention relates to a wind turbine converter fault diagnosis method based on wavelet transformation and a DBN and belongs to the field of wind turbine converter fault diagnosis based on wavelet transformation and DBNs and provides a wind turbine converter fault diagnosis method based on wavelet transformation and a DBN. As the installed capacity of wind turbines increases, the wind turbines occupy an increasingly high portion in a power grid, and thus, fast identification of the locations of wind turbine faults is pivotal to the stable operation of the wind turbines and the powergrid. According to the method, multi-scale analysis is performed on signals through using wavelet transformation; fault signal feature vectors are extracted; and the DBN performs supervised learning on the feature vectors, so that a fault identification model can be obtained. The method can excellently identify converter faults.
Owner:CHONGQING UNIV
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