Patents
Literature
Patsnap Copilot is an intelligent assistant for R&D personnel, combined with Patent DNA, to facilitate innovative research.
Patsnap Copilot

1844 results about "Coefficient matrix" patented technology

In linear algebra, a coefficient matrix is a matrix consisting of the coefficients of the variables in a set of linear equations. The matrix is used in solving systems of linear equations.

Method for acquiring fine distribution of reactor core three dimensional neutron flux density of reactor

A method for acquiring fine distribution of the reactor core three dimensional neutron flux density of a reactor comprises the following steps: 1, carrying out geometric modeling to a reactor core, dividing computational domain, dispersing angle space, generating characteristic line, appointing materials for all computing regions, obtaining macroscopic section parameters and setting initial values for neutron flux density flux of a computed region, terminal condition of reactor and characteristic value; 2, calculating coefficient matrix required by the matrix method of each sub region and a part which is positioned at the right end and cannot be changed with the iterative computation; 3, seeking the density of thicknet neutron flux and correcting the density of one-dimensional and two dimensional thinnet neutron flux; 4, seeking the density of one-dimensional neutron flux of each lattice cell; 5, iterative solution of the density of the two dimensional thinnet neutron flux of each layer; and 6, updating three dimensional thicknet parameters, judging whether a characteristic value and the density of a three dimensional neutron flux are in convergence or not, if in convergence, turning to the step 3 for continuous iteration under convergence is achieved, namely, fine distribution of three dimensional neutron flux density can be obtained; and the fine distribution of the reactor core three dimensional neutron flux density of a reactor can be obtained quickly.
Owner:XI AN JIAOTONG UNIV

Apparatus for detecting foreign matter with high selectivity and high sensitivity by image processing

PCT No. PCT/JP96/03778 Sec. 371 Date Apr. 17, 1998 Sec. 102(e) Date Apr. 17, 1998 PCT Filed Dec. 25, 1996 PCT Pub. No. WO98/11456 PCT Pub. Date Mar. 19, 1998This invention provides a contaminant-detecting apparatus having high selectivity and high sensitivity against a contaminant. A product (1) is conveyed to a point where it is irradiated by x-rays from source (3). An x-ray detector (4), having a predetermined detection unit width in a direction perpendicularly intersecting the conveying direction, then detects the x-rays transmitted through the product. A storage unit (5) stores a two-dimensional distribution of x-ray intensity detected by the x-ray detector as a transmission image in units of pixels. An average calculation unit (7) performs a sum-or-product operation of a kernel, which is equal to or larger than 7x7 pixels, (9x9 or 11x11), and equal to or smaller than (a pixel count corresponding to +E,fra 1/2+EE the predetermined x-ray detection unit width)x(pixel count corresponding to +E,fra 1/2+EE the predetermined x-ray detection unit width), and includes a target pixel, in units of pixels of the transmission image stored in the storage unit by using a predetermined coefficient matrix, thereby calculating the weighted average over the kernel. A difference calculation unit (8) calculates the difference between the x-ray intensity of the target pixel of the transmission image stored in the storage unit and the weighted average over the kernel of the target pixel which is calculated by the difference calculation unit. A determination unit (9) compares the difference calculated by the difference calculation unit with predetermined criteria, thereby determining presence/absence of a contaminant in the product to be tested.
Owner:ANRITSU SANKI SYSTEM CO LTD

Calibration compensation method for triaxial vector sensor and biaxial vector sensor

The invention relates to error correction of a vector sensor, in particular to a calibration compensation method for a triaxial vector sensor and a biaxial vector sensor, and solves the problems that the calibration compensation method of the existing multi-axial vector sensor fails to take all factors causing measurement error into account and the like. In the method, an error correction mathematical model of the vector sensor is built according to the relation of actually measured output Sm and theoretical output Se of the vector sensor, i.e. Sm=KSe + S0 and according to an error coefficient matrix K=K1K2, wherein, K1 and K2 are respectively a sensitivity error coefficient matrix of the triaxial vector sensor and a non-orthogonal error coefficient matrix among three measured axes; and an effective method is utilized to obtain correct zero-offset S0 and a correction coefficient matrix K-1 in the error correction mathematical model, and finally the error correction mathematical model of the measured vector sensor is obtained to carry out calibration compensation on the measuring result of the vector sensor. The method achieves calibration compensation taking into account of all the factors causing the measurement error of the multi-axial sensor, thus improving the accuracy of measuring results; and the method has concise and convenient process and no excessively high requirements on hardware equipment, thus being suitable for various vector sensors.
Owner:ZHONGBEI UNIV

Method for comprehensively evaluating electric energy quality

The invention discloses a method for comprehensively evaluating the electric energy quality by applying a TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) of a grey correlation coefficient matrix, which comprises the following steps of: taking electric energy quality data at all time intervals and standard data at all grades as an original decision matrix; determining subjective weights through an improved AHP (Analytic Hierarchy Process); determining objective weights through an entropy method; establishing a least square method decision model to obtain a comprehensive weight, so that the deviation of decision results under the subjective weights and the objective weights of all indexes is the least; carrying out standardization and weighted standardization on the decision matrix and obtaining the grey correction coefficient matrix by utilizing the grey theory; taking the grey correction coefficient matrix as a decision matrix of the TOPSIS to obtain the distance between positive ideal solutions and negative ideal solutions of all schemes and the relative closeness of the positive ideal solutions and the negative ideal solutions; and comparing the electric energy quality closeness at all the time intervals with the standard closeness at all the electric energy quality grades to finally obtain the electric energy quality grades at all the time intervals. With the adoption of the method, the electric energy quality evaluation result can be objectively and reasonably obtained under the situation of poor information, so that the practicability and the feasibility are stronger.
Owner:SOUTHEAST UNIV

Living body human face detection method based on gray scale symbiosis matrixes and wavelet analysis

The invention discloses a living body human face detection method based on gray scale symbiosis matrixes and wavelet analysis. The method comprises: first of all, converting an RGB image comprising a human face area, which is obtained from a camera, into a gray scale image, compressing a gray scale grade to 16 grades, then respectively calculating four gray scale symbiosis matrixes (taking a distance of 1, and angles of 0 degree, 45 degrees, 90 degrees and 13 degrees respectively ), then extracting four texture characteristic quantities including energy, entropy, moment of inertia and correlation on the basis of the gray scale symbiosis matrixes, and respectively obtaining a mean value and a variance for the four texture characteristic quantities of the four gray scale symbiosis matrixes; at the same time, performing secondary decomposition on an original image by use of a Haar small wavelet base, extracting the coefficient matrixes of sub-bands HH1 and HH2 and obtaining a mean value and a variance; and finally sending all characteristic values as samples to be detected to a trained support vector machine for detection, and performing classification identification on real or counterfeit face images. The method provided by the invention has the advantages of reduced calculating complexity and improved detection accuracy.
Owner:BEIJING UNIV OF TECH

Method based on linear programming for locating near-field targets and system thereof

The invention provides a method based on linear programming for locating near-field targets and a system thereof, particularly a method for locating near-field targets on the basis of the compressivesensing theory. The method comprises the following steps: selecting a reference array element under the condition that the signal form is unknown, allowing the reference array element to work at the normal sampling frequency, and the other array elements to work at far below the Nyquist sampling frequency; taking the output signal of the reference array element as the reference target signal, to acquire the sample data of all the array elements; generating a time-delay table and a sparse basis array; generating a random mapping array and obtaining a coefficient array; obtaining a sparse vectorby linear programming solution; and acquiring the location information of the near-field target from the predetermined location-distance collection on the basis of the acquired estimation results ofthe sparse vector. According to the invention, the sensor does not need to work beyond the Nyquist sampling frequency, thereby greatly reducing the sampling rate, reducing the operating energy consumption of the sensor and improving the resource utilization rate of the system; and the method has no limits to the target bandwidth, so that the method is applicable to the target location of both narrowband and wideband, and the method is further applicable to non-Gaussian target location.
Owner:INST OF ACOUSTICS CHINESE ACAD OF SCI

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

Single-phase earth fault line selection method based on transient state high-frequency component correlation analysis

ActiveCN108663599AOvercome the problem of not being able to select the correct lineImprove reliabilityFault location by conductor typesCapacitanceEngineering
The invention dislcoses a single-phase earth fault line selection method based on transient state high-frequency component correlation analysis. The method comprises the steps that whether or not a single-phase earth fault happens is judged according to the magnitude of a busbar zero-mode voltage instantaneous value, db10 wavelets are adopted for performing five-layer wavelet packet decompositionon zero-mode current of two work frequency periods after each feeder line fault, after the minimum frequency band is removed, node wavelet packet deposition coeffiences are reconstructed and summeredto obtain a fault transient high-frequency capacitance-current component, and a correlation coeefient matrix M between every two feeder lines is obtained; Si is set as a correlation accumulation coefficient for the ith feeder line fault transient high-freuqency capacitance-current component, when rho ij is larger than rho set, Si is equal to 1, 1 is subtracted from Si, and a correlation accumulation coefficient matrix S can be obtained; if Si is larger than 0 constantly, the busbar breaks down; if Si of only one feeder line is smaller than 0, the circuit is a fault circuit; if Si is smaller than 0 constantly, the circuit with the maximum high-frequency-band wavelet packet energy sum is determined as the fault circuit. According to RTDS simulation experimental verification, the method has the good accuracy, adaptability and the like.
Owner:TAIYUAN UNIV OF TECH

Multi-target distribution and flight path planning method for multiple rescue helicopters

The invention discloses a multi-target distribution and flight path planning method for multiple rescue helicopters, which relates to the technical field of aviation emergency rescue. The method comprises the steps of evaluating aviation rescue task execution feasibility, conducting disaster area map image processing, obtaining a feasibility matrix through the evaluation of the rescue task execution feasibility, taking the feasibility matrix as a coefficient matrix for a solution matrix Xij, solving distribution results according to tasks of different quantities of the rescue helicopters and target points through a Hungary algorithm, obtaining a flight path solution space by extracting a safety zone topological structure by adopting an image processing method and morphological characteristics, obtaining the shortest path in the flight path solution space by a heuristic A* search algorithm, combining the results of multi-target distribution for multiple rescue helicopters, forming an emergency plan for rescue task execution of the helicopters, and calling a Google Earth flight simulation API (Application Program Interface) to demonstrate the emergency rescue plan and making preflight preparation, so as to improve the efficiency and safety of the aviation emergency rescue. The method is simple, the time complexity is low, the flight path planning process is visual, and the result is distinct.
Owner:CIVIL AVIATION FLIGHT UNIV OF CHINA

Non-reference image quality assessment method based on information entropy characters

InactiveCN103475898AHigh subjective consistencySmall time complexityTelevision systemsImaging qualityTime complexity
The invention relates to an image quality assessment method, in particular to a non-reference image quality assessment method based on information entropy characters, and belongs to the field of image analyzing. The method comprises the first step of carrying out Contourlet conversion on a distorted image to obtain N*M conversion sub-bands, the second step of dividing each conversion sub-band and the unconverted original distorted image, the third step of calculating null domain information entropy and frequency domain information entropy on each block coefficient matrix, and the fourth step of screening the blocking characters and calculating a mean value to obtain the quality character value of each conversion sub-band. The method of a support vector machine and the method of non-reference image quality assessment are utilized for testing on a test set, and quality prediction and assessment are carried out through quality character vectors corresponding to a disaggregated model, an evaluation model and the test set all of which are obtained through training. The non-reference image quality assessment method has the advantages of being high in subjective consistency, small in time complexity and good in university, can be embedded into application systems related to image quality, and has very high application value.
Owner:BEIJING INSTITUTE OF TECHNOLOGYGY

Fast decoupled flow calculation method for power systems

The invention discloses a fast decoupled flow calculation method for power systems, which comprises the following steps of: inputting original data and initializing voltage; forming an admittance matrix; forming correction equation coefficient matrixes B' and B'' and performing factor table decomposition; performing P-theta iteration, and correcting a voltage phase angle; performing Q-V iteration, and correcting voltage amplitude; judging whether the iteration is converged; and calculating node power and branch power. The method requires that the P-theta iteration and the Q-V iteration are all converged in the same iteration and the iteration process is finished, so that the algorithm frame is simpler, and the flow is clearer. The sparse matrix technology is not adopted, so the matrix elements are convenient to access and calculate, and the programming is simple; the correction equation coefficient matrixes are stored according to n order, number change of nodes is avoided, and the programming difficulty is reduced; and the calculation amount is reduced through reasonable logic judgment, the calculation speed is obviously improved and the requirement of scientific research can be completely met. The fast decoupled flow calculation method also can process power systems with a plurality of balance nodes.
Owner:DALIAN MARITIME UNIVERSITY

Multiple time phase remote sensing image registration method based on edge and spectral reflectivity curve

The invention discloses a multiple time phase remote sensing image registration method based on an edge and spectral reflectivity curve. The multiple time phase remote sensing image registration method based on the edge and spectral reflectivity curve mainly solves the problems that stability is insufficient and accuracy is low when registration is conducted on two time phases of multiple spectral image sets with variation regions and whole luminance difference in the prior art. The multiple time phase remote sensing image registration method based on the edge and spectral reflectivity curve comprises the following steps: small wave high frequency coefficient matrixes are added and divided, the small wave high frequency coefficient matrixes are added simultaneously, the input two time phases of the multiple spectral image sets are preprocessed, and thus two time phases of strong edge images are acquired; registration parameters of edge alignment metric of the two time phases of the strong edge images are calculated to register the two time phases of image sets and acquire coarse registration image sets; the coarse registration image sets are converted into opposite object spectral reflectance image sets, small wave high frequency coefficients of time phases 1 of the object spectral reflectance image sets are reconstructed to acquire coarse registration edge images, and the coarse registration edge images conduct local matching on opposite object spectral reflectance images of the time phases 1 and time phases 2 to acquire a final registration image set. The multiple time phase remote sensing image registration method based on the edge and spectral reflectivity curve can be used for change detection, integrating and embedding.
Owner:XIDIAN UNIV

Standard dot matrix light source and image point correction method of LED display screen

The invention discloses a standard dot matrix light source and an image point correction method of a light-emitting diode (LED) display screen. The method comprises the following steps of: A, constructing the standard dot matrix light source, and calibrating the brightness and the chroma of the standard dot matrix light source; B, acquiring image data of the LED display screen, and the brightness and the chroma of the standard dot matrix light source; C, comparing the acquired brightness and chroma of the standard dot matrix light source with a stored value to obtain an error compensation matrix, and converting the image data of the LED display screen from a relative value into an absolute value; D, analyzing the converted image data of the LED display screen to generate a data correction coefficient matrix; and E, outputting the data correction coefficient matrix to an image point correction processor to perform image data correction processing so as to obtain corrected image data according to the data correction coefficient matrix, and finally outputting the corrected image data to an LED large screen display system. The standard dot matrix light source and the image point correction method can overcome adverse effects caused by working condition drifting of a camera to ensure that the LED display screen has better light-color consistence and white balance after performing the image point correction; and an additional light colorimeter is not needed, and a plurality of times of tests are not performed any more.
Owner:GTEK GRP LTD

Face recognition method based on weighted diagnostic sparseness constraint nonnegative matrix decomposition

ActiveCN105469034AOvercome the problem of weak expression ability of facial featuresOvercoming the problem of poor occlusion robustnessCharacter and pattern recognitionMatrix decompositionIdentity recognition
The invention discloses a face recognition method based on weighted diagnostic sparseness constraint nonnegative matrix decomposition, and mainly aims to solve the problem that the method in the prior art is not robust to an obscured face and is of low recognition rate. According to the technical scheme, the method comprises the following steps: (1) constructing a nonnegative weight matrix according to the obscured area of a test image; (2) introducing the weight matrix into a general KL divergence objective function, applying a sparseness constraint to a basis matrix, and applying intra-class and inter-class divergence constraints to a coefficient matrix to get a weighted diagnostic sparseness constraint nonnegative matrix decomposition objective function; (3) solving the objective function, and decomposition-training a data matrix to get a basis matrix and a coefficient matrix; (4) projecting a test data matrix on the basis matrix to get a corresponding low-dimensional representation set, and taking the low-dimensional representation set as final test data; and (5) using a nearest neighbor classifier to classify the test data by taking the coefficient matrix as training data, and outputting the result. By using the method, the effect of obscured face recognition is improved. The method can be used in identity recognition and information security.
Owner:XIDIAN UNIV

Image encryption method and image decryption method with visual security and data security based on compressed sensing

ActiveCN106600518AIncrease spaceEnhanced resistance to brute force attacksImage data processing detailsChosen-plaintext attackHash function
The invention relates to an image encryption method and an image decryption method with visual security and data security based on compressed sensing. The image encryption method comprises the steps of: firstly, utilizing an SHA 256 hash function to obtain a 256-bit hash value of a plaintext image as an image secret key, and calculating initial numerical values of one-dimensional skew tent chaotic mapping and zigzag scrambling; carrying out sparse processing on the plaintext image, and carrying out zigzag scrambling on a coefficient matrix; and then utilizing the one-dimensional skew tent chaotic mapping to generate a measurement matrix, measuring and quantifying a scrambling matrix to obtain a compressed and encrypted image, and embedding the image into a carrier image with visual significance to obtain a final ciphertext image with visual significance. The image encryption method realizes the visual security and data security of the plaintext image, has large secret key space, is highly sensitive to plaintext, has higher capacity of resisting brute-force attack, chosen-plaintext attack and known-plaintext attack, does not need an additional storage space, and can transmit and store the ciphertext image quickly and effectively.
Owner:HENAN UNIVERSITY
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products