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256 results about "Eigenvalues and eigenvectors" patented technology

In linear algebra, an eigenvector (/ˈaɪɡənˌvɛktər/) or characteristic vector of a linear transformation is a nonzero vector that changes at most by a scalar factor when that linear transformation is applied to it.

Comprehensive evaluation method of smart power grid construction based on principal component cluster analysis

The invention relates to a comprehensive evaluation method of smart power grid construction based on principal component cluster analysis, which is technologically characterized by comprising the steps that at the step 1, a generally approved comprehensive evaluation index system of the smart power grid construction is established or selected; at the step 2, index data is processed by standardization; at the step 3, an index data correlation coefficient matrix is established, an eigenvalue and an eigenvector of the matrix are solved, and a principal component expression is generated; at the step 4, a principal component variance contribution rate and a cumulative variance contribution rate are calculated, and quantity of principal components is determined; at the step 5, a comprehensive principal component evaluation index function is established, and a comprehensive evaluation result of a development and construction level of a smart power grid is given; and at the step 6, a principal component factor load matrix is established, and the cluster analysis is carried out to comprehensive evaluation indexes of the smart power grid. The comprehensive evaluation method of the smart power grid construction based on the principal component cluster analysis provided by the invention combines principal component analysis and the cluster analysis in order to simplify and reconstruct the evaluation index system of the smart power grid construction and provides suggestions for the smart power grid construction is laggard areas.
Owner:STATE GRID TIANJIN ELECTRIC POWER +1

Method for acquiring steady-state equivalent wind speed and generated power in wind power station based on correlation analysis

InactiveCN101661530AHigh precisionSolve the problem of large measurement errorWind motor combinationsMachines/enginesElectric power systemCorrelation analysis
The invention provides a method for acquiring steady-state equivalent wind speed and generated power in wind power station based on correlation analysis, belonging to the technical field of wind powergeneration. The method comprises the following steps: preprocessing the operational data in the wind power station; acquiring the steady-state equivalent wind speed in the wind power station by a correlation analysis method; forming a wind speed matrix, calculating correlated matrix of all unit wind speed in the wind power station, acquiring a characteristic value and a characteristic vector of the correlated matrix to obtain the equivalent wind speed finally; and acquiring the generated power in the wind power station, and the like. The method can accurately acquire the equivalent wind speedand generated power in the wind power station, and has the characteristics of high precision, simple method, convenient operation, and the like. The method has wide application range, and can be usedfor equivalent modeling of the wind power station, confirmation of the maximum penetration power of the wind power station, technique and system for predicating the generated power in the wind powerstation, reliability and economy application of the wind power station, analysis of influence of a wind power access network to the power system, and the like, and has great application value for planning and designing a wind power station access system.
Owner:NORTH CHINA ELECTRIC POWER UNIV (BAODING)

Large-scale time-lag electric system characteristic value calculation method based on EIGD

Te invention discloses a large-scale time-lag electric system characteristic value calculation method based on EIGD. The method includes the steps of establishing a time-lag electric system model, converting the formula of the time-lag electric system model into the abstract cauchy problem, converting the characteristic value of the time-lag electric system model into the characteristic value of an infinitesimal generator of the calculated and converted formula, conducting discretization on the infinitesimal generator to obtain an approximate matrix of the infinitesimal generator, obtaining the approximate matrix where displacement processing is conducted by conducting displacement processing on the approximate matrix, obtaining an inverse matrix after inverse conversion is conducted on the approximate matrix where displacement processing is conducted, converting the partial characteristic value required to be calculated into the partial characteristic value with the maximum module value, calculating the partial characteristic value, with the maximum module value, of the inverse matrix through the Arnoldi algorithm, and obtaining the characteristic value lambda of the approximate matrix. Verification is conducted through the Newton iteration method, and the accurate characteristic value and the accurate characteristic vector of a time-lag electric system are obtained through calculation.
Owner:SHANDONG UNIV

Pavement crack detection method and apparatus based on deep learning and principle component analysis

The invention provides a pavement crack detection method based on deep learning and principle component analysis. The method comprises the following steps: acquiring pavement images; performing gray-scale processing on the pavement images; then cutting each pavement image into W*V subimages each with a size of K*N pixels; manually selecting subimages comprising cracks and subimages not comprising cracks respectively as positive samples and negative samples which are taken together as a training set for training a convolutional neural network; establishing the convolutional neural network, training the convolutional neural network by use of the training set, detecting preprocessed pavement images to be analyzed by use of the trained convolutional neural network, and automatically extracting the subimages comprising the cracks; and performing crack type analysis, i.e., solving feature values and feature vectors by performing PCA calculation on distribution of the crack subimages, and determining crack types. According to the invention, automatic crack extraction is carried out on the pavement images by use of the convolutional neural network, pavement crack detection and crack type determination are realized, and a determining basis is provided for subsequent detection of the road crack types.
Owner:WUHAN KOTEI TECH CORP

Intermediate-voltage distribution operation state fuzzy integrated evaluation method based on principle component analysis method and entropy weight method

InactiveCN105719048AConsider relevanceTake ambiguity into accountResourcesEntropy weight methodPrincipal component analysis
The invention discloses an intermediate-voltage distribution operation state fuzzy integrated evaluation method based on a principle component analysis method and an entropy weight method. Major information in source data can be reserved by use of the principle component analysis method, a power supply capability, power supply quality and economic indexes are taken as the source data representing an operation state of a distribution network, through solving a feature value and a feature vector of a correlation coefficient matrix, principle components of operation of the distribution network are determined, and an evaluation system with weak correlation yet large envelope information content is formed. Given fuzziness existing in index evaluation, new evaluation indexes are objectively endowed with weights by use of the entropy weight method in the system, and a fuzzy integrated evaluation system of a 10kV distribution network operation mode is finally formed. According to the invention, the fuzziness of the evaluation indexes is taken into consideration, qualitative analysis and quantitative determination are realized, and the method provided by the invention is reasonable and scientific to a certain degree.
Owner:SHANGHAI MUNICIPAL ELECTRIC POWER CO +1

CPU+GPU heterogeneous parallel computing based natural frequency characteristic analysis method for turbomachinery blade

The invention provides a CPU+GPU heterogeneous parallel computing based natural frequency characteristic analysis method for a turbomachinery blade. The method comprises the steps of firstly, establishing a finite element model according to a three-dimensional model and material parameters of a to-be-analyzed turbomachinery blade, and performing pre-stress analysis on the blade; secondly, performing blade grid data preprocessing, simultaneously calculating a rigidity matrix and a mass matrix of each unit in a CPU and a GPU, and assembling the rigidity matrix and the mass matrix into total rigidity and mass matrixes; setting constraint conditions of the blade and a rim, wherein the setting process comprises constraint of rigid and elastic displacement of a boundary, contact coupling of a blade root and the rim or contact coupling of connecting pieces and correction of the total rigidity matrix; thirdly, extracting generalized eigenvalues and eigenvectors of the total rigidity and mass matrixes by using a CPU+GPU heterogeneous parallel algorithm; fourthly, converting the eigenvalues and eigenvectors into a frequency and a vibration mode of the blade, and performing output; and finally, judging a vibration type of a natural vibration mode, and drawing frequency curve distribution, a vibration safety graph or a Campbell chart of the blade according to the vibration type.
Owner:XI AN JIAOTONG UNIV

Ground PM2.5 concentration feature vector spatial filter value modeling method based on remote sensing data

The present invention provides a ground PM2.5 concentration feature vector spatial filter value modeling method based on remote sensing data. The method comprises: obtaining data, selecting a model variable, carrying out data processing and matching, constructing a spatial adjacency matrix from the location of the national control point of a study area, carrying out centralization, calculating thematrix eigenvalues and eigenvectors, and extracting the appropriate eigenvectors from the vector group as the spatial influence factor of the PM2.5 concentration; and obtaining an eigenvector spatialfilter regression model of the PM2.5 concentration, interpolating the extracted eigenvectors raster images with the same spatial resolution as the AOD, and bringing the raster images into the eigenvector spatial filter regression model for raster calculation to obtain the continuous spatial distribution model of the PM2.5 concentration in the study area. According to the method provided by the present invention, for the problem that the number of ground control points is small and the ground control points are unevenly distributed, the remote sensing data with high resolution and continuous distribution is selected to perform the inversion of the ground PM2.5 concentration for study on a wide range of PM2.5 spatiotemporal features.
Owner:WUHAN UNIV

Method for calculating rotor dynamics performance of multi-parallel-axis system

The invention relates to a method for calculating rotor dynamics performance of a multi-parallel-axis system. The method comprises the steps specifically as follows: step (1), selecting an analysis object and a calculation type, inputting parameters of a bearing-rotor system, finishing pre-processing operations like discretization of the rotor system; step (2), calling a bearing calculation program, calculating dynamic and static characteristic parameters of each bearing, forming a rotor dynamics equation of a parallel axis system which gives consideration to gear engagement according to the selected analysis object and calculation type; and step (3), calling a solving function to calculate a feature value and a feature vector of a dynamics differential equation, converting the feature value and the feature vector into dynamics characteristic result data through dimension so as to finish calculation and analysis of system stability, critical rotation speed, forced vibration response and vibration mode. According to the method disclosed by the invention, calculation and analysis means for dynamics performance of the multi-parallel-axis system, which can be applied to actual engineering, are developed on the basis of solid theoretical research; the calculated rotor system comprises supports of various types; therefore, combination of bearing calculation and rotor system dynamics analysis is implemented better.
Owner:XI AN JIAOTONG UNIV

Low frequency oscillation identification method for accessing of wind power to power grid

The present invention discloses a low frequency oscillation identification method for accessing of wind power to a power grid in the technical field of wind power integration monitoring. The low frequency oscillation identification method comprises the steps that the system-wide linearized state matrix of a power system without a winder turbine generator is corrected, and a corrected system-wide linearized state matrix is obtained; eigenvalues and eigenvectors of the corrected system-wide linearized state matrix are figured out; the frequency, attenuation damping ratio and electromechanical circuit correlation ratio of the eigenvalues are worked out according to the eigenvalues and eigenvectors; and the eigenvalues are analyzed according to the frequency, attenuation damping ratio and the electromechanical circuit correlation ratio of the eigenvalues, and the low frequency oscillation mode of the accessing of the wind power to the power grid is determined. The low frequency oscillation identification method for the accessing of the wind power to the power grid solves the problems that an existing low frequency oscillation identification method does not take large-scale wind power accessing into consideration and cannot identity the system-leaded oscillation mode automatically.
Owner:STATE GRID CORP OF CHINA +2

Penicillin fermentation process failure monitoring method based on recursive kernel principal component analysis

The invention relates to a penicillin fermentation process failure monitoring method based on recursive kernel principal component analysis (RKPCA), which belongs to the technical field of failure monitoring and diagnosis. The method comprises the following steps: acquiring the ventilation rate, stirrer power, substrate feed rate, substrate feed temperature, generated heat quantity, concentrationof dissolved oxygen, pH value and concentration of carbon dioxide; and establishing an initial monitoring model by using the first N numbered standardized samples, updating the model by a RKPCA method, and computing the characteristic vectors to detect and diagnose the failure in the process of continuous annealing, wherein when the T2 statistics and SPE statistics exceed the respective control limit, judging that a failure exists, and otherwise, judging that the whole process is normal. The method mainly solves the problems of data nonlinearity and time variability; and the RKPCA method is used for updating the model by carrying out recursive computation on the characteristic values and characteristic vectors of the training data covariance. The result indicates that the method can greatly reduce the false alarm rate and enhance the failure detection accuracy.
Owner:NORTHEASTERN UNIV

Drilling strain data anomaly extraction method based on principal component analysis

The present invention relates to a drilling strain data anomaly extraction method based on principal component analysis. The method comprises: performing strain conversion of drilling strain data sequence of the same station, and performing preprocessing of the converted data; constructing a matrix through adoption of the drilling strain data after preprocessing; performing principal component analysis of the everyday matrix to obtain the feature value and the feature vector of each matrix; and corresponding the obtained feature value and the calculated feature vector angle and an earthquake event to obtain an abnormal detection result. The drilling strain data anomaly extraction method based on principal component analysis effectively employs the method of the principal component analysis to perform analysis of the drilling strain data, and performs extraction of possible earthquake precursor anomaly according to the correlation of each measurement item of drilling strain. The drilling strain data anomaly extraction method based on principal component analysis employs the feature values in the principal component analysis and the feature vector angle to represent the weak change of an earth crust so as to realize the accurate extraction of the drilling strain data anomaly in the condition having strong background interference.
Owner:JILIN UNIV

High-order cumulant based bistatic MIMO (Multiple Input Multiple Output) radar parameter estimation method

The invention discloses a high-order cumulant based bistatic MIMO (Multiple Input Multiple Output) radar parameter estimation method. A joint estimation method of DOD (Direction of Departure), DOA (Direction of Arrival) and Doppler frequency of targets under a gauss color noise background is given out according to bistatic MIMO radar echo signal characteristics through a characteristic that high-order cumulant is insensitive to gauss color noise. The high-order cumulant based bistatic MIMO radar parameter estimation method comprises constructing two opposite angle section matrixes of cross-fourth-order cumulant of output signals of adjacent matched filters through airspace and time domain information of the bistatic MIMO radar; decomposing a singular value of the opposite angle section matrixes of the four-order cumulant, estimating the number of targets, reducing dimensions through eigenvalues and eigenvectors and constructing a new matrix; obtaining joint estimation of the Doppler frequency, the DOD and the DOA of the targets through the eigenvalues and eigenvectors of the novel matrix. According to the high-order cumulant based bistatic MIMO radar parameter estimation method which is an effective bistatic MIMO radar parameter estimation method, a target parameter estimation process has no specific requirements for the number of transmission array elements and receiving array elements.
Owner:HOHAI UNIV

Self-adaption mixed filtering method of GPS/SINS (Global Positioning System/Strapdown Inertial Navigation System) super-compact integrated navigation system

The invention relates to a self-adaption mixed filtering method of a GPS/SINS (Global Positioning System/Strapdown Inertial Navigation System) super-compact integrated navigation system. The self-adaption mixed filtering method is characterized by comprising the following steps: step 1. establishing a GPS/SINS super-compact integrated navigation system error model; step 2. carrying out data fusion by adopting a Kalman filtering method to obtain an optimal estimation value of a system state and an estimation error equation array P; step 3. carrying out output correction on navigation positioning information output to an SINS by utilizing the obtained optimal estimation value of the system state; step 4. carrying out an observability analyzing method by adopting a characteristic value and a characteristic vector of an error variance array; solving observability information of all the states by using the estimation error equation array P obtained in the step 2; and step 5. carrying out feedback correction on parameters of a GPS and the SINS by taking the observability information of the system state in the step 4 as a feedback factor and taking a product of the feedback factor and the optimal estimation value of the system state in the step 2 as a feedback amount.
Owner:HARBIN ENG UNIV

Method for reconstructing interval transit time curve by virtue of multiple logging curves

The invention relates to a method for reconstructing an interval transit time curve by virtue of multiple logging curves. The method mainly comprises the steps of selecting a plurality of logging curves obvious in response to reservoir characteristics by performing reservoir sensitivity and correlation analysis on the logging curves; performing discrete wavelet decomposition on the logging curves together with a sonic wave curve to form 8 decomposition layers; enabling all the layers of high-frequency decomposition results of other logging curves except the sonic curve to form matrices respectively, obtaining the corresponding characteristic values and characteristic vectors of the matrices; taking the characteristic vectors corresponding to different characteristic values as new components, which, at the moment, have orthogonality (correlation ); performing multivariate regression analysis on the high-frequency components of the corresponding layer of wavelet decomposition of the sonic curve by utilizing characteristic vectors of each layer, calculating a weighting coefficient corresponding to each vector, returning a regression significance analysis result and determining the quality of regression; next, determining the number of layers of the sonic high-frequency components to be reconstructed by virtue of the characteristic vectors according to the regression significance analysis result, selecting multiple regression results as the high-frequency components for a part having more layers than selected layers, and remaining the high-frequency decomposition results of the sonic logging curves for a part having less layers than the selected layer, and then carrying out curve reconstruction by using the low-frequency components of the sonic logging curves and the high-frequency components obtained through regression so as to obtain a final sonic reconstructed curve.
Owner:BEIJING NORMAL UNIVERSITY
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