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22 results about "Geometric analysis" patented technology

Geometric analysis is a mathematical discipline where tools from differential equations, especially elliptic partial differential equations are used to establish new results in differential geometry and differential topology. The use of linear elliptic PDEs dates at least as far back as Hodge theory. More recently, it refers largely to the use of nonlinear partial differential equations to study geometric and topological properties of spaces, such as submanifolds of Euclidean space, Riemannian manifolds, and symplectic manifolds. This approach dates back to the work by Tibor Radó and Jesse Douglas on minimal surfaces, John Forbes Nash Jr. on isometric embeddings of Riemannian manifolds into Euclidean space, work by Louis Nirenberg on the Minkowski problem and the Weyl problem, and work by Aleksandr Danilovich Aleksandrov and Aleksei Pogorelov on convex hypersurfaces. In the 1980's fundamental contributions by Karen Uhlenbeck, Clifford Taubes, Shing Tung Yau, Richard Schoen, and Richard Hamilton launched a particularly exciting and productive era of geometric analysis that continues to this day. A celebrated achievement was the solution to the Poincaré conjecture by Grigori Perelman, completing a program initiated and largely carried out by Richard Hamilton.

Power load prediction method and device

The invention provides a power load prediction method and device, and belongs to the technical field of power load prediction.The method comprises the steps that current waveform data are obtained, and fundamental wave and harmonic components in the current waveform data are extracted; carrying out waveform spatial form geometric analysis to obtain a real-time load characteristic sequence, and then carrying out segmentation processing; the current effective value sequence of each time window is converted into a time-frequency domain energy distribution vector, and then a three-level feature library is constructed; constructing a three-dimensional tensor model through equipment start-stop event identification, inputting the three-dimensional tensor model into a multi-target optimizer to evolve feature weights, and filtering abnormal samples to obtain a feature cluster; performing random masking processing on the time sequence data of the feature cluster to generate a mask sequence, inputting the mask sequence into an encoder to reconstruct masking data, comparing, learning and judging abnormal output correction data, and inputting the corrected data into a prediction network to generate a feedback signal flow; and analyzing the feedback signal flow to update the prediction network weight. Based on the method, the invention also provides power load prediction equipment. According to the invention, the precision of power load prediction is obviously improved.
Owner:山东华科信息技术有限公司 +6

Three-dimensional modeling method for correlation of coal permeability and pore and fracture evolution

The invention provides a three-dimensional modeling method for correlation of coal permeability and pore fracture evolution, and relates to the technical field of three-dimensional modeling of a coal structure. Gray standardization, classification marking and spatial structure unit identification are carried out on all voxels at each moment, and voxel-level parameter statistics and geometric analysis are combined, so that the three-dimensional modeling method for correlation of coal permeability and pore fracture evolution is realized. According to the method, the porosity, the fracture width, the fracture connectivity and other structural characteristic parameters can be extracted and are dynamically paired with synchronously acquired physical field parameters, so that the physical accuracy and the time sequence response capability of the parameters are ensured, the accurate assignment of voxel-level parameters is also realized, the coal body heterogeneity and the dynamic evolution process are meticulously quantified, and the coal body quality is improved. The voxel scale permeability calculation method is adopted, the permeability value of each voxel can be calculated at each moment according to the voxel characteristic parameters and the physical field parameters, permeability distribution in a three-dimensional space is generated, and the structural evolution process of a coal rock core sample can be comprehensively captured.
Owner:INFORMATION RES INST OF EMERGENCY MANAGEMENT DEPT

Spraying method for surface of vacuum cup

PendingCN120861361ALiquid surface applicatorsImage analysisPoint cloudFirst order derivative
The invention relates to the technical field of spraying of surfaces of vacuum cups, and discloses a spraying method for the surfaces of vacuum cups. The method comprises the following steps: establishing a space coordinate system, collecting a structured light three-dimensional point cloud, mapping the point cloud to a two-dimensional parameter domain, calculating a first-order derivative and a normal vector, further calculating a second-order derivative and a basic form coefficient, extracting a Gaussian curvature and an average absolute curvature, generating a spray point spacing function according to the curvature, generating spray points in the parameter domain, and mapping the spray points into three-dimensional coordinates. And finally, path planning and spraying instruction output are carried out. According to the method, through high-precision non-contact modeling and differential geometric analysis, the geometric change of the curved surface is accurately recognized, self-adaptive adjustment of the spraying point density is guided, the spraying efficiency and uniformity are improved through path optimization, the bottlenecks of a traditional manual or mechanical path setting method in the aspects of spraying uniformity and consistency are broken through, and the method is suitable for large-scale popularization and application. And the device is particularly suitable for intelligent and high-precision spraying operation of personalized products and complex structure surfaces.
Owner:NINGBO XIMATE NEW MATERIAL CO LTD

Two-dimensional seepage simulation method based on geometric analysis of fixed grid and like

The invention is suitable for the technical field of efficient numerical simulation of a seepage field, and relates to a two-dimensional seepage simulation method based on geometric analysis of a fixed grid, which is characterized in that a control equation is derived based on the Darcy theorem and the mass conservation theorem, and a target soil body is discretized by adopting the fixed grid; a nonlinear permeability coefficient is introduced to realize updating of material parameters on a Gaussian integral point level, and fine solving of a two-dimensional seepage problem without grid iteration is realized; an NURBS primary function is adopted to carry out interpolation approximation on a seepage field and a geometrical shape of a target soil body, and accurate calculation of physical quantities such as water head pressure and flow velocity of any point in the two-dimensional seepage problem soil body is realized by utilizing high-order continuity of the NURBS primary function and accurate representation of a complex shape; in addition, determination of seepage fields in the stratified soil bodies in longitudinal arrangement and transverse arrangement can be achieved. The whole method is low in cost and high in calculation precision and calculation efficiency.
Owner:ZHENGZHOU UNIV +2

Gas ultrasonic gas flowmeter and measurement method thereof

ActiveCN122108287BFeature extractionPhase space
This invention relates to the field of flow measurement and industrial process control technology, specifically to a gas ultrasonic flow meter and its measurement method; it includes a measurement pipe section, signal acquisition, phase space reconstruction, symplectic geometric analysis, and adaptive solution modules; the system acquires the original acoustic time-series signal and maps it into a high-dimensional state trajectory matrix; its core is to use symplectic geometric transformation to extract dynamic invariants such as the maximum Lyapunov exponent, determine the flow field distribution correction coefficient, and compensate the basic flow velocity to generate a standard flow rate; this invention transforms a complex inverse fluid mechanics problem into a geometric topology feature extraction problem, eliminating the need for massive model training, significantly reducing computational power consumption, and solving the computational deadlock problem.
Owner:NINGBO LIQING ULTRASONIC TECH CO LTD

Double-arc ball screw raceway section error identification method

The invention discloses a biarc ball screw raceway section error identification method, which comprises the following steps of: acquiring normal section two-dimensional original data of a raceway, fitting the original data through a sliding window to screen outer diameter section data, and completing clamping inclination error correction through least square fitting and coordinate transformation; in combination with a contourgraph hardware measurement parameter, continuously compensating a displacement coupling error to obtain new two-dimensional data; screening out raceway contour data from the new two-dimensional data, dividing the raceway contour data into segments containing complete left and right raceways, and fitting radiuses and circle centers of left and right arcs of each segment; preferentially adopting a geometric analysis method to solve the circle center of the ball for each segment, and switching a grid constraint centering algorithm to carry out iterative positioning in case of failure; and calculating a comparison design value of the contact angle and the nominal lead. Through a dual error correction mechanism and a dual-path circle center solving strategy, the problem of measurement errors caused by clamping inclination and displacement coupling of a contourgraph lever structure in the existing measurement technology is solved, and the measurement precision and the data processing efficiency are both considered.
Owner:XIAN UNIV OF TECH

Underground granary heat insulation performance simulation method based on axisymmetric isogeometric analysis

The invention is suitable for the technical field of heat conduction analysis, and relates to an underground granary heat insulation performance simulation method based on axisymmetric geometric analysis, which utilizes a non-uniform rational B-spline (NURBS) primary function to accurately represent a geometric shape and approximate a physical field, realizes the unification of modeling and analysis data, and improves the heat insulation performance of an underground granary. The axisymmetric characteristics and boundary conditions of the granary are fully utilized, geometric analysis system equations and solving formats such as the axisymmetric heat conduction problem are deduced in a cylindrical coordinate system from an axisymmetric steady-state heat conduction problem control equation on the basis of the variational principle, and a general three-dimensional problem is reduced into a two-dimensional problem; efficient utilization of the degree of freedom of calculation is achieved, then temperature field and heat flux density distribution characteristics of a granary body-soil body system are analyzed, the influence rule of different conditions on underground granary heat conduction is revealed through parameterization research, and a high-order continuous interpolation basis function is introduced to obtain a high-order continuous interpolation basis function; the calculation precision and calculation efficiency of underground granary temperature field analysis are effectively improved.
Owner:ZHENGZHOU UNIV +2

Image navigation and precise positioning system for gynecological minimally invasive surgery

The invention relates to the technical field of medical equipment, in particular to a gynecological minimally invasive surgery image navigation and precise positioning system which comprises a navigation tracking module, an image reconstruction module, a medical image registration module, an identification module, a path planning module and a display module. Comprising a feature characterization unit, a topology analysis unit and a self-adaptive registration unit, and by extracting differential curvature features of an anatomical structure, constructing a multi-scale geometric analysis framework, calculating persistent coherence features, analyzing branch structure features and executing geodesic line optimization registration on a Riemannian manifold, a geodesic line is obtained. The navigation tracking module integrates electromagnetic positioning and optical positioning technologies and provides a dual verification mechanism, and the path planning module plans an optimal operation path based on an identification result, avoids the key anatomical structures, performs accurate registration on a preoperative CT / MRI image and an intraoperative real-time endoscope image, and performs accurate registration on the preoperative CT / MRI image and the intraoperative real-time endoscope image. And the registration precision reaches a submillimeter level.
Owner:GENERAL HOSPITAL OF THE NORTHERN WAR ZONE OF THE CHINESE PEOPLES LIBERATION ARMY

Three-dimensional tangent point-passing route planning method based on hierarchical projection and sliding window geometric analysis

The invention discloses a three-dimensional tangent point-passing route planning method based on hierarchical projection and sliding window geometric analysis. The method comprises the following steps: S1, unifying and initializing a coordinate system; s2, a three-element sliding window geometric solution algorithm is adopted to generate a two-dimensional optimal smooth path composed of straight line segments and arc segments; s3, converting the two-dimensional optimal smooth path to a three-dimensional geographic space; and S4, outputting the three-dimensional coordinate information of all the path points to an external visualization module. The method has the beneficial effects that a complicated three-dimensional problem is decomposed into low-dimensional two-dimensional geometric solution and height mapping by adopting a layering strategy of two-dimensional first and three-dimensional second, and a three-element sliding window is utilized to carry out iterative analysis on local elements, so that global large-scale optimization solution is avoided, the algorithm complexity is remarkably reduced, and the algorithm efficiency is improved. The planning process has high calculation efficiency, and the real-time or quasi-real-time route planning requirement can be met.
Owner:CHENGDU BOOSTOR TECH

A structural thermo-mechanical coupling method and apparatus considering isogeometric analysis

This invention discloses a structural thermo-mechanical coupling method and apparatus considering isogeometric analysis, belonging to the field of thermodynamics. The method includes: S1. Establishing an isogeometric NURBS model: providing the basis for expressing geometric and physical fields for thermo-mechanical coupling analysis, achieving seamless integration of CAD and CAE; S2. Calculating the transient temperature field based on the central difference method: obtaining the temperature distribution of the structure at different times, providing temperature input for subsequent thermo-mechanical coupling; S3. Transforming the temperature field into equivalent temperature loads: converting the thermal effects caused by temperature changes into equivalent loads identifiable by structural mechanics analysis; S4. Solving the stiffness equation of the structure under the combined action of external forces and temperature: obtaining the displacement matrix of the structural control points; S5. Solving the structural coupling field based on the displacement matrix: obtaining all key physical quantities in the thermo-mechanical coupling field, completing the coupling analysis. This invention can verify the feasibility of applying isogeometric analysis in coupled fields.
Owner:TIANJIN UNIV

An isogeometric analysis simulation method based on volumetric subdivision of a hyperelastic material model

The application discloses an isogeometric analysis simulation method of a hyperelastic material model based on body subdivision. The isogeometric analysis adopts the division of a spline model parameter domain and the mapping of the parameter domain to a physical model, avoids the time consumption of mesh division in a finite element, and realizes an integrated process from modeling to simulation in combination with a CC subdivision method. The application comprises the following steps: converting a CC subdivision body into a spline body model, and establishing a mapping relationship of control points of the subdivision body and the spline body; establishing a hyperelastic material constitutive model according to geometric boundary conditions and material parameters; establishing a discrete balance equation of the model according to an isogeometric method; in combination with the balance equation, establishing a model motion equation and a nonlinear solving system; using a Newton iteration method to solve the nonlinear system, obtaining displacement solutions at each time step, and mapping the displacement solutions back to the subdivision body, so as to realize deformation simulation of the subdivision body.
Owner:HANGZHOU DIANZI UNIV

Method, device and medium for analyzing static stability boundary of alternating current line based on phasor geometry

The application discloses an alternating current line static stability boundary analysis method and device based on a phasor geometry, and a medium, and relates to the technical field of alternating current line static stability. The method is based on a line impedance model of a reference system of a first-end voltage, and a voltage phasor triangle composed of the first-end voltage, a last-end voltage and a line voltage drop is constructed. By analyzing the trajectory of the vertex of the triangle moving along the corresponding circumcircle arc when the last-end complex power changes, a core relationship that the apparent power is proportional to the area of the triangle is found. It is proved that when the triangle is an isosceles triangle, the apparent power reaches the maximum value and is a line static stability critical point. Therefore, the application proposes that the isosceles of the voltage phasor triangle is used as a geometric condition for judging the static stability boundary, and power, voltage, power angle and impedance boundaries of the line static stability are derived. The application converts the traditional complex nonlinear algebraic problem into clear geometric analysis, the physical concept is clear, and the solving process is significantly simplified.
Owner:CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY

Security constraint method of heterogeneous multi-agent pursuit game in multi-obstacle environment

The invention relates to a security constraint method for a heterogeneous multi-agent pursuit game in a multi-obstacle environment, and the method comprises the steps: carrying out heterogeneous modeling: constructing a first-order differential system model and a second-order differential system model for a pursuer and an escaper, and depicting the dynamic difference of the first-order differential system model and the second-order differential system model; according to the hierarchical control strategy, pursuing, surrounding and obstacle avoidance subtasks are divided based on motion priorities, a surrounding area is generated through a dynamic Aeronoius circle, and multi-target cooperation is achieved through revenue function optimization; according to the safety constraint mechanism, double safety boundaries of obstacle collision prevention and intelligent agent collision prevention are designed, and the system safety is guaranteed through a geometric analysis and potential field fusion method; and carrying out adversarial strategy expansion: constructing an escaper anti-hunting dynamic game model, and converting a control strategy into actual physical driving force through inverse dynamic mapping. The method has the advantages that the calculation complexity is reduced through heterogeneous modeling and hierarchical task decomposition; according to the method for generating the surrounding area based on the dynamic Apollonius circle, the multi-obstacle environment adaptability is improved; the invention discloses a lightweight control framework integrating geometric constraint and revenue function optimization.
Owner:ANHUI SCI & TECH UNIV

Gas ultrasonic gas flowmeter and measurement method thereof

The present application relates to the technical field of flow measurement and industrial process control, in particular to a kind of gas ultrasonic gas flowmeter and its measuring method;It contains measurement pipe section, signal acquisition, phase space reconstruction, symplectic geometry analysis and adaptive solution module;System through the acquisition original sound wave time sequence signal, mapping is high-dimensional state trajectory matrix;Its core is to use symplectic geometry transformation to extract maximum Lyapunov exponent and other dynamic invariants, determine flow field distribution correction coefficient, and compensate the basic flow rate to generate standard flow;The present application converts complex fluid mechanics inverse problem into geometric topology feature extraction problem, without mass model training, significantly reduces the operation power consumption and solves the computing deadlock problem.
Owner:NINGBO LIQING ULTRASONIC TECH CO LTD

Multi-arc-segment symmetric structural member measurement system, method and device and storage medium

The invention relates to a multi-arc-segment symmetric structural member measurement system, method and device and a storage medium. The system comprises an OCT image acquisition device, a contour extraction module, a curve analysis module and a circle fitting module, the OCT image acquisition device is used for acquiring an original tomographic image of a to-be-detected sample by utilizing an OCT imaging technology, and the contour extraction module is used for extracting surface contour features of the preprocessed image by adopting morphology and a connected region processing algorithm; the curve analysis module is used for performing curvature analysis and segmental arc identification on the surface contour features based on a differential geometry principle and a multi-scale analysis method, and the circle fitting module is used for performing geometric analysis on segmental arc segmentation results by combining algebraic fitting and geometric fitting algorithms, judging the opening direction of each segmental arc and generating circle fitting parameters. According to the invention, an end-to-end automatic measurement process is formed by using an integrated design, the operation cost and time consumption are reduced, and the measurement precision, efficiency and reliability are improved.
Owner:JIHUA LAB

A self-adaptive loop subdivision surface equal geometric analysis model establishment method

PendingCN122413500AAlgorithmThresholding
This invention discloses a method for establishing a geometric analysis model for NURBS surfaces using adaptive Loop subdivision, comprising the following steps: (1) setting curvature threshold parameters and a maximum number of samplings; (2) performing initial uniform sampling on the NURBS parameter domain; (3) calculating the curvature threshold and the average curvature of the point set based on the average curvature of the surface, identifying feature regions, and performing Delaunay triangulation on the current point set; (4) marking parameter points based on the curvature threshold, and inserting the marked parameter points into new parameter points based on the Delaunay triangulation relationship, with the new parameter points included in the point set; (5) repeating steps (3)-(4) until the maximum number of samplings is set, thereby capturing geometric details; (6) constructing a Delaunay triangulation on the latest point set; (7) applying Loop subdivision rules to generate a surface representation suitable for isogeometric analysis. The method of this invention is applicable to arbitrary topological structures, requires no multi-patch splicing, and provides a new solution for the accurate mechanical analysis of complex plate and shell structures.
Owner:GUANGXI UNIV

Efficient fatigue topology optimization method for isogeometric analysis

The application provides an efficient fatigue topology optimization method for isogeometric analysis, and belongs to the technical field of geometric analysis, and mainly comprises the following steps: constructing a fatigue problem model, dividing multiple layers of grid methods according to the design domain requirement, and generating the lowest level isogeometric node vector by using h insertion; assembling each level interpolation operator and continuation operator of the multi-grid method according to the isogeometric node vector; decomposing and storing independent load components in a load spectrum, and solving the combination weight of each independent load component; assembling the overall stress spectrum according to the weight; evaluating the fatigue constraint of the unit fatigue damage; expressing the fatigue constraint topology optimization problem by using the augmented Lagrange method; performing the update iteration of the isogeometric analysis design variable until the fatigue constraint topology optimization problem converges according to the design variable change amount. The scheme improves the simplified calculation and counting problem of the multi-cycle general fatigue load spectrum, and reduces the solving cost.
Owner:HUAZHONG UNIV OF SCI & TECH

Three-dimensional modeling method for correlating coal permeability with pore and fracture evolution

The present application provides a kind of coal body permeability and pore fissure evolution associated three-dimensional modeling method, it is related to coal body structure three-dimensional modeling technical field, the present application is by to each time all voxel gray standardization, classification mark and space structure unit identification, combine voxel level parameter statistics and geometric analysis, can extract porosity, fracture width and fracture connectivity and other structure characteristic parameters, and with the physical field parameter dynamic pairing of synchronous acquisition, not only guarantee the physical accuracy and time sequence response ability of parameter, also realize the accurate assignment of voxel level parameter, so that coal body heterogeneity and dynamic evolution process can be carefully quantified, using voxel scale permeability calculation method, can calculate the permeability value of each voxel according to voxel characteristic parameters and physical field parameters at each time, generate the permeability distribution in three-dimensional space, can fully capture the structural evolution process of coal core sample.
Owner:INFORMATION RES INST OF EMERGENCY MANAGEMENT DEPT

A transfer orbit fast optimization method based on spatial conic splicing

The application discloses a transfer orbit fast optimization method based on spatial conic curve splicing, and belongs to the field of deep space exploration. The application expands the plane conic curve splicing method to the optimization of spatial earth-moon transfer orbit on the basis of the plane conic curve splicing method used for orbit transfer, by using coordinate conversion and geometric analysis method to increase the azimuth angle parameters theta and psi used for describing the spatial orientation of the earth-centered launch orbit plane; the application can improve the orbit analysis and optimization efficiency by using the two-body orbit theory to deduce the two-body model and based on the double two-body model splicing with analytical characteristics; the application can realize the fast optimization and solution of the transfer orbit based on the spatial conic curve splicing by establishing the penalty function iterative optimization of four independent optimization quantities, i.e., the earth-moon transfer launch speed increment, the moon influence ball entry point phase, the azimuth angle parameters theta and psi, according to the orbit inclination and the perigee height constraints. The application has the advantages of good convergence, high optimization efficiency and wide application range. The application is suitable for various earth-moon transfer missions and moon flyby orbit optimization.
Owner:BEIJING INST OF TECH

Control method of energy-saving and efficient heat exchanger and heat exchanger thereof

The invention discloses a control method of an energy-saving and efficient heat exchanger and the heat exchanger thereof, and relates to the field of heat exchangers, the control method comprises the following steps: S1, generating a preset periodic flow disturbance signal; s2, total flow and total pressure drop data of a main fluid in the operation process of the heat exchanger are collected; s3, constructing a dynamic pressure drop response curved surface of the heat exchanger; s4, carrying out differential geometric analysis on the dynamic voltage drop response curved surface, and calculating a local Gaussian curvature value and a distribution characteristic of each point on the curved surface; s5, whether asymmetric blockage exists in the heat exchanger or not is judged; and S6, if asymmetric blockage occurs, generating a self-adaptive control instruction. According to the method, high-precision non-inductive identification of asymmetric degradation can be realized without arranging a sensor in each loop, and the consistency of MPC model prediction and actual working conditions is ensured, so that the control precision, the operation efficiency and the energy consumption optimization capability of a heat exchanger system are improved.
Owner:SICHUAN UNIV

Electric charge notice structuring method combining geometric analysis and multi-level verification

The invention discloses an electric charge notice structuring method combining geometric analysis and multi-level verification, and relates to the technical field of document information processing.The method comprises the steps that firstly, an electric charge notice document is analyzed, and the text and geometric coordinates of the text are extracted; intelligently inferring a logic layout structure of the document through spatial clustering and alignment analysis based on the coordinates; extracting information based on the structural model to form structured data; verifying the data by using a multi-level rule engine; and when verification fails and a layout understanding error is identified, triggering a geometric model correction process, rechecking a coordinate relationship, optimizing a structure model, and performing iterative execution until data passes verification. According to the method, accurate geometric attributes of the electronic document are fully utilized, and layout analysis self-optimization is driven through business verification feedback; and high-precision and high-reliability structured information extraction of the searchable electric charge notice is realized.
Owner:SINOPEC SALES CO LTD GUANGDONG PETROLEUM BRANCH +1

Alternating current line static stability boundary analysis method and device based on phasor geometry and medium

The invention discloses an AC line static stability boundary analysis method and device based on phasor geometry and a medium, and relates to the technical field of AC line static stability. The method comprises the following steps: constructing a voltage phasor triangle formed by head end voltage, tail end voltage and line voltage drop based on a line impedance model of a head end voltage reference system; the core relation that the apparent power is in direct proportion to the area of the triangle is found by analyzing the moving track of the vertex of the triangle along the arc of the corresponding circumcircle when the complex power at the tail end changes. Therefore, when the triangle is an isosceles triangle, the apparent power reaches the maximum value and is a line static stability critical point. Therefore, according to the method, the voltage phasor triangular isosceles is used as a geometric condition for judging the static stability boundary, and the static stability power, voltage, power angle and impedance boundary of the line are deduced. According to the method, a traditional complex nonlinear algebraic problem is converted into clear geometric analysis, the physical concept is clear, and the solving process is remarkably simplified.
Owner:CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY