36 results about "Propagation equation" patented technology

An apparatus and method for monitoring a process involve development and application of a statistically qualified neuro-analytic (SQNA) model to accurately and reliably identify process change. The development of the SQNA model is accomplished in two stages: deterministic model adaption and stochastic model modification of the deterministic model adaptation. Deterministic model adaption involves formulating an analytic model of the process representing known process characteristics, augmenting the analytic model with a neural network that captures unknown process characteristics, and training the resulting neuro-analytic model by adjusting the neural network weights according to a unique scaled equation error minimization technique. Stochastic model modification involves qualifying any remaining uncertainty in the trained neuro-analytic model by formulating a likelihood function, given an error propagation equation, for computing the probability that the neuro-analytic model generates measured process output. Preferably, the developed SQNA model is validated using known sequential probability ratio tests and applied to the process as an on-line monitoring system. Illustrative of the method and apparatus, the method is applied to a peristaltic pump system.

The invention relates to a 3D anisotropic micro seismic interference inverse positioning method and a 3D anisotropic micro seismic interference inverse positioning system. The method comprises the following steps: (1) building a medium model, and performing grid discretization of the medium model to get multiple grid points; (2) calculating a seismic source function, and calculating the pressure value of each grid point according to the seismic source function; (3) converting a 3D anisotropic elastic wave equation into a propagation equation, and substituting the pressure value of each grid point into the propagation equation for calculation to get the wave field value at each moment; (4) performing interference imaging of all the obtained wave field values to obtain an imaging result; and (5) analyzing the imaging result, and determining the point with the maximum wave field value as the location of the seismic source. Micro seismic positioning is carried out by use of a wave equation-based positioning method which has the advantages of high positioning accuracy and reliability and the like. By adoption of GPU acceleration 3D anisotropic micro seismic inverse positioning, the computation speed is greatly improved, and the computation efficiency is improved.

A method for detecting isotropic material surface Young modulus by using surface acoustic wave technology. The method is as below: exciting broadband surface acoustic wave in an isotropic specimen surface to obtain a dispersion curve on a surface acoustic wave propagation direction; fitting the actual phase velocity data to obtain a closest truth-value phase velocity and a phase velocity fluctuation section; establishing a Cartesian coordinate geometry model to obtain a surface wave basic propagation equation containing unknown medium Young modulus, Poisson ratio, direction cosine of the propagation direction, amplitude attenuation coefficient given according to experience value, wave number and wave velocity; calculating assumption corresponding relation between wave velocity and wave number in the Cartesian coordinate geometry model and simultaneous theoretical relationship, to obtain mutual relationship of velocity, frequency and Young modulus under ideal conditions; and conducting reverse calculation to obtain the Young modulus in medium according to the mutual relationship of velocity, frequency and Young modulus under ideal conditions and the dispersion curve under actual conditions. The invention realizes effective measurement of isotropic material surface young modulus.

The invention relates to a three-dimensional anisotropy elastic wave numerical simulation method and system. The method comprises the following steps: 1, a medium model is established to carry out grid discretization on the medium model to obtain a plurality of grid points; 2, a seismic source function is calculated, and a pressure value at each grid point is calculated according to the seismic source function; 3, a three-dimensional anisotropy elastic wave equation is converted into a propagation equation, and the pressure value at each grid point is taken into the propagation equation as substitutes to conduct calculating to obtain a wave field value at each moment; and 4, according to the wave field value, a calculating area of each grid point is determined; area division is carried out; and data exchange is carried out on divided area boundary data to complete elastic wave numerical simulation. According to the invention, acceleration of three-dimensional elastic wave numerical simulation under a complex medium is realized through utilization of a GPU; a realization scheme of accelerating data transmission through utilization of GPU Direct technology is realized; a large amount of data copying from a CPU to the GPU and from the GPU to the CPU is avoided; and communication bottleneck optimization is realized.

A system for determining a position of location of a tag includes, in an embodiment: a plurality of routers each including at least one antenna; and a location engine to: (a) determine for at least one router, from signals sent by the one router and at least part of which are received by the at least one antenna of each of at least one other of the routers, an average path loss of signal strength; (b) optimize, for at least the one router, multipath parameters in a radio-frequency signal propagation equation using the average path loss for each of the at least one other of the routers and known distance between the router and each of the at least one other of the routers; and (c) determine the position of location of the tag using at least the optimized multipath parameters.

The invention discloses a particle filter multi-crack growth prediction method based on dynamic crack number, belonging to the technical field of fault prediction and health management. The inventionadopts the on-line guided wave structure health monitoring method to on-line monitor the initiation and expansion of cracks in the structure, when the new crack initiation is detected, the crack component and the crack propagation equation number in the multi-crack propagation state equation are updated, the crack propagation law under the multi-crack coupling is constructed, and the particle setis updated. Combined with the on-line observations obtained from guided wave structure health monitoring method, the posterior probability density function of multi-crack propagation state vector is estimated on-line by regularized particle filter. The crack propagation model is updated by posterior estimation of model parameters, and the crack propagation trajectories at future time are predictedby posterior estimation of crack length. The invention can effectively realize on-line monitoring and prediction of multiple cracks in a structure, and has wide application prospect in prediction ofmultiple cracks in a structure.

The invention discloses an underwater sound field numerical simulation method and system based on a Chebyshev polynomial spectrum and a medium. The method comprises the following steps: establishing asimplified control equation of an acoustic propagation Helmholtz equation under a cylindrical coordinate system; completing independent variable transformation from a z coordinate to an x coordinateby using the simplified control equation; implementing Chebyshev forward transformation on the simplified control equation, and mapping a physical space to a spectral space to form a discretized linear equation set in the spectral space; solving the discretized linear equation set in the spectral space to obtain a solution in the spectral space; implementing Chebyshev inverse transformation on thesolution in the spectral space, and mapping the solution in the spectral space back to the physical space; completing independent variable inverse transformation from an x coordinate to a z coordinate to obtain u (r, z), and solving a sound pressure field p; calculating propagation losses. The method is suitable for obtaining higher calculation precision under the condition that few discrete gridpoints are used, the calculation performance of a hardware platform can be brought into full play, and the speed of numerical simulation is remarkably increased.

The invention discloses a method for detecting piezoelectric material surface layer Young modulus based on a laser acoustic surface wave technology. The method comprises the steps of utilizing a pulse laser for exciting high frequency acoustic surface waves on the surface layer of a piezoelectric test piece, picking up acoustic surface wave signals with the propagation distance ranging from 1 cm to 2 cm for processing, fitting dispersion curves, and obtaining the phase velocity approaching a true value; establishing a laminated piezoelectric material model under an ideal condition, uniting a wave equation and an electromagnetic wave equation of the acoustic surface waves on piezoelectric media, and obtaining a basic propagation equation of the surface waves; calculating the corresponding relation between the wave velocity and the wave number in combination with boundary conditions of the piezoelectric media; obtaining the relation among the wave velocity, the frequency and the Young modulus under the ideal condition, conducting analysis and comparison on the dispersion curves fitted through tests, and obtaining the absolute Young modules E<->, the minimum Young modulus E and the maximum Young modules E of the tested piece. By means of the method, the reliability and anti-interference property of a detection result can be improved, a detection device is transformed toward miniaturization, confidentiality and the like, and application of the technology to theoretical research and practical application is promoted.

The invention discloses a method for calculating cable interference in an infinite shielding layer with holes in a point source radiation field, is applied to the field of electromagnetic interference, and has the advantages of simple algorithm, accurate result, high efficiency and the like. In that method, the aisle of the voltage wave on the cable and the propagation aisle of the space electromagnetic field are represented by signal pipelines, the position with the energy reflection is represented by nodes, a signal flow graph reflecting the electromagnetic energy flow of the system is established, the propagation equation of the whole system signal pipeline and the scattering equation on all the nodes are established by using the magnetic flow element radiation instead of the small holetransmission, the extended BLT (Baum-Liu-Tesche) equation of the system electromagnetic interference is obtained, and the interference intensity on the cable is obtained by solving the extended BLT equation. The method realizes the accurate calculation of the electromagnetic interference of the point source radiation field in the infinite shielding layer with holes and is coupled to the transmission line, and the method effectively reduces the dependence on the computing resources and improves the efficiency.

Poor BSE estimation accuracy resulting from conventional Extended Kalman Filtering (EKF) approaches using RF OI sensors mounted on the ground as a remote bullet tracking sensor motivated the design and development of the present disclosure. The observer based BSE removes EKF process noise (state noise) and measurement noise (OI sensor noise) covariance matrices selection and tuning which have been long recognized by the estimation community as a time consuming process during the design stage; requires no consideration of interactions when having the control input signal as part of the state propagation equation; and provides a significant improvement in velocity estimation accuracy, in some cases to less than 1 m / s errors in all axes, thereby meeting the miss distance requirement with amble margin.

The invention relates to the field of coal mine gas safety and provides a seam wave airy phase identification tectonic coal method based on a transmission method. According to a seam wave group velocity frequency propagation equation, a relationship between an airy phase velocity and a coal seam shear wave velocity is fitted out through utilization of the airy phase velocity obtained from inversion and combinations with coal seam and surrounding rock velocity parameters. When a surrounding rock shear wave velocity is constant, the airy phase velocity is proportional to the coal seam shear wavevelocity, coal beam shear wave velocity distribution can be obtained, and then tectonic coal distribution can be predicted.

The invention belongs to the technical field of wireless communication, and discloses a channel characteristic analysis method and system, a medium, equipment and a processing terminal.The channel characteristic analysis method comprises the steps that a deterministic channel model is constructed based on geometric information and electromagnetic information of a specific propagation environment, and a channel characteristic analysis result is obtained by solving a Maxwell equation or an approximate propagation equation; calculating a multi-dimensional channel parameter at the predicted receiving point; proposing a wireless channel characteristic analysis method based on a simulation result of the deterministic channel model; aiming at a propagation scene, systematized and planned parameter extraction and characteristic analysis are carried out on typical channel parameters; on the basis of a K-means algorithm, a multipath parameter is added as a weight measurement, selection of a centroid is optimized, and a channel clustering algorithm is improved. Based on a reverse ray tracing algorithm, accurate electromagnetic wave path prediction and multi-dimensional channel parameter calculation are carried out, a channel characteristic analysis method of the system is defined, and an accurate theoretical basis is provided for wireless communication system design and network planning.

The invention discloses a level set topological optimization method, system and equipment and a medium, and belongs to the field of structural design topological optimizing. The method comprises the steps that a design area corresponding to a to-be-optimized object is divided into a plurality of finite element units, and a level set function and a boundary propagation equation of the finite element units are established; the strain energy density of each finite element unit is sequentially subjected to space smooth filtering and time smooth filtering, the value of a Lagrange multiplier in the boundary propagation equation is updated to be the Nsth small strain energy density after filtering, and Ns is the number of solid finite element units needing to be removed currently; topological optimization is performed based on the updated boundary propagation equation and the level set function to reduce the flexibility of the design area; and the calculation, filtering, updating and optimization operations are repeatedly executed until the flexibility of the optimized design area is converged to the minimum. A parameter-free method is proposed to determine the Lagrange multiplier, so that the problems of inaccurate volume constraint, low calculation efficiency, unstable convergence and the like in the existing method can be effectively solved.

The invention provides a noise prediction and layout optimization method for a flat terrain wind power plant. The noise prediction and optimization layout method for the flat terrain wind power plantcomprises the following steps that 1, on the basis of a wind power plant engineering wake flow model, generating the incoming flow wind speed of each wind turbine in the wind power plant, and calculating the aerodynamic noise source of each wind turbine; 2, simplifying the three-dimensional PE parabolic equation, and calculating a wind turbine noise propagation database based on a two-dimensionalnoise propagation equation of a single wind turbine; Step 3, according to the wind turbine noise propagation database obtained in the step 2, carrying out wind power plant noise numerical simulation calculation by using a wind power plant noise propagation multidimensional interpolation formula; And 4, optimizing the optimized layout of the wind power plant meeting the sound pressure level contourline by adopting a maximum sound pressure boundary value taking method.

The invention provides an elastic wave least squares inverse time migration method based on an acoustic-elastic coupling equation. The method comprises the steps of: firstly, inputting an initial longitudinal and horizontal wave velocity and a density initial model, synthesizing a shot end forward propagation wave field and a detection end reverse propagation wave field by using an acoustic-elastic coupling propagation equation and an accompanying equation thereof, and figuring out a multi-parameter image according to the imaging conditions of the longitudinal and horizontal wave velocity anddensity; then, synthesizing reflected wave data by back migration according to a first-order Bonn scattering equation of the acoustic-elastic coupling equation; and evaluating the imaging result according to a four-component waveform residual objective function, if the imaging result is not satisfied, iteratively updating the longitudinal and horizontal wave velocity and density imaging results byusing a CGLS algorithm of a diagonal Hessian precondition, until the condition is satisfied, and returning a final result.

The embodiment of the invention provides a target classification method for double-path coupling deep learning based on a sound wave propagation equation. A category to which the to-be-classified target belongs is determined by adopting a preset deep neural network classification model; the hidden layer has a two-way coupling structure and a cross-layer jump connection structure, the SWTNN classification model can have the double-path coupling capacity and the jumping connection capacity between layers at the same time, the problem of gradient disappearance can be solved, the training precision and the classification precision of the SWTNN classification model are improved, and then the efficiency and the accuracy of determining the category to which the to-be-classified target belongs are greatly improved. Moreover, the SWTNN classification model adopted in the embodiment of the invention is constructed based on a frequency domain first-order sound wave propagation equation and a finite difference algorithm, has clear physical and mathematical significance, is an interpretable deep neural network classification model, is another important technical breakthrough, and has very high innovativeness.

The invention provides an inertial navigation method, electronic equipment, a storage medium and a computer program product. The method comprises the following steps: acquiring acceleration and angular velocity output by an inertial measurement unit, and generating a state propagation equation of extended Kalman filtering based on a kinematic model of the inertial measurement unit; based on the state propagation equation, performing state prediction on the target equipment deployed with the inertial measurement unit to obtain a state prediction value; inputting the acceleration and the angular velocity into a target prediction model, performing observation noise covariance prediction, and obtaining an observation noise covariance output by the target prediction model; and constructing a state updating equation of extended Kalman filtering based on the observation noise covariance, and updating the state prediction value based on the state updating equation to obtain a state optimization value for navigation positioning. According to the method, the accuracy of Kalman filtering can be improved through deep learning, so that the more accurate observation noise covariance is obtained, and the positioning precision of the inertial measurement unit is improved.

The invention relates to a three-dimensional reconstruction method and system based on a photogrammetric photometric stereo model. The method comprises the following steps: reading an internal orientation attitude, an external orientation attitude parameter and an incident light vector of a camera; substituting the parameters into a photogrammetry collinear equation and an error propagation equation to calculate a normal vector of an object space coordinate; according to the normal vector and the incident light vector, solving a cosine function of a light incident angle, an emergent angle anda phase angle; establishing a radiation equation of the image according to the incident angle, the emergent angle and the phase angle of the light; according to the radiation equation of the image, performing iterative solution to obtain gradient values of the elevation in the x and y directions of the image space coordinates; according to the gradient values of the image space coordinates in thex direction and the y direction, obtaining the relative elevation value of each point through least square solution, and therefore a reconstructed three-dimensional model is obtained. The limitation that three attitudes of a camera in a traditional photometric stereo are all 0 degree can be effectively broken through, the application range of the photometric stereo in close-range photogrammetry isexpanded, and the relative elevation value of an object is recovered.

The invention discloses an airborne / vehicle-mounted laser point cloud precision estimation method based on Monte Carlo simulation, and the method comprises the steps: generating an original laser point cloud, and carrying out the calculation of a POS track line; generating Monte Carlo simulation laser point cloud; performing laser point cloud rapid association based on a timestamp; carrying out airborne / vehicle-mounted laser point cloud precision estimation analysis, carrying out statistical analysis on the basis of the aligned original laser point cloud and n groups of attitude angle Monte Carlo simulation laser point clouds, and realizing analysis of spatial distribution characteristics and laws of laser point cloud coordinates and prediction and evaluation of the overall precision by considering a median error of an antenna phase center position on the basis of the statistical analysis of the aligned original laser point clouds and n groups of attitude angle Monte Carlo simulation laser point clouds. The method is suitable for the point cloud obtained by any laser scanning device, is suitable for any terrain, does not need to establish an error propagation equation and condition assumption, can provide an effective basis for point cloud precision estimation and device type selection in an airborne laser scanning engineering project, is beneficial to guarantee the engineering data quality, and has remarkable social and economic benefits.

The invention relates to an aviation network sweep effect inference method based on two-stage regression, belongs to the technical field of flight delay prediction, and solves the problem that an existing delay propagation analysis model is solidified and established based on idealized hypothesis. Comprising the following steps: constructing an adjacent matrix among all airports in each time slice, and generating a delay state vector of each airport; constructing a flight delay model according to the dynamic function library and the adjacent matrix; according to the delay state vector, fitting a flight delay model through an LASSO regression method to obtain a preliminary fitting equation; sampling from all airports to obtain a plurality of airport combinations, optimizing the preliminary fitting equation corresponding to each airport combination by adopting a weighted akaike information criterion to obtain an optimization equation corresponding to each airport combination, and obtaining a delay propagation equation based on each optimization equation; and obtaining delay time of all airports in corresponding time slices according to the delay propagation equation, and taking the delay time as an inference result of the aviation network sweep effect. And accurate prediction of the aviation network sweep effect is realized.

The invention provides a noise prediction and layout optimization method for a flat terrain wind power plant. The noise prediction and optimization layout method for the flat terrain wind power plantcomprises the following steps that 1, on the basis of a wind power plant engineering wake flow model, generating the incoming flow wind speed of each wind turbine in the wind power plant, and calculating the aerodynamic noise source of each wind turbine; 2, simplifying the three-dimensional PE parabolic equation, and calculating a wind turbine noise propagation database based on a two-dimensionalnoise propagation equation of a single wind turbine; Step 3, according to the wind turbine noise propagation database obtained in the step 2, carrying out wind power plant noise numerical simulation calculation by using a wind power plant noise propagation multidimensional interpolation formula; And 4, optimizing the optimized layout of the wind power plant meeting the sound pressure level contourline by adopting a maximum sound pressure boundary value taking method.

The invention discloses a level set topology optimization method, system, equipment and medium, belonging to the field of structure design topology optimization. and the boundary propagation equation; respectively perform spatial smoothing filtering and time smoothing filtering on the strain energy density of each finite element element, and update the value of the Lagrange multiplier in the boundary propagation equation to the Nth after filtering s A small strain energy density, N s is the number of solid finite element elements to be removed at present; topology optimization is performed based on the updated boundary propagation equation and level set function to reduce the flexibility of the design area; the above calculation, filtering, updating and optimization operations are repeated until the optimization is completed. The flexibility of the design region converges to a minimum. A parameter-free method is proposed to determine Lagrange multipliers, which can effectively solve the problems of inaccurate volume constraints, low computational efficiency and unstable convergence of existing methods.

The invention provides an anti-dispersion seismic wave forward modeling method, system and device and a medium. The method comprises the following steps of obtaining an underground medium velocity field and a forward modeling wavelet dominant frequency, and setting a first projection relation according to the underground medium velocity field and the forward modeling wavelet dominant frequency, re-sampling in the depth direction according to the first projection relation to generate a second velocity field, and according to the second velocity field, performing seismic wave field forward modeling through a wave field propagation equation. The method realizes longitudinal frequency dispersion suppression, can balance efficiency and data quality to carry out seismic wave forward modeling, realizes relatively good balance of calculation cost, geologic structure characteristics and data quality, and can be widely applied to the technical field of seismic exploration.

The invention discloses a seismic data processing method for suppressing exogenous interference waves and a storage medium. The seismic data processing method for suppressing the exogenous interference waves comprises the following steps of: inputting initial seismic data; preprocessing the initial seismic data to obtain seismic data to be processed; obtaining coordinates of at least four points of the event of the exogenous interference wave and corresponding travel time; based on the propagation equation of the exogenous interference waves, utilizing the coordinates of the at least four points and the corresponding travel time to construct an equation set; solving the equation set formed by the at least four equations of the at least four points to obtain the coordinates of the exogenousinterference waves and the propagation speed of the exogenous interference waves; and processing the seismic data to be processed according to the coordinates of the exogenous interference waves andthe propagation speed of the exogenous interference waves so as to suppress the exogenous interference waves. According to the seismic data processing method for suppressing the exogenous interferencewaves and the storage medium, the source point position of the exogenous interference waves can be automatically obtained, and the suppression effect of the exogenous interference waves can be betterimproved.

The invention discloses a particle filter multi-crack propagation prediction method based on the number of dynamic cracks, which belongs to the technical field of fault prediction and health management. The invention adopts the online guided wave structure health monitoring method to monitor the initiation and propagation of cracks in the structure online. When a new crack initiation is detected, the crack components and the number of crack propagation equations in the multi-crack propagation state equation are updated, and the cracks under multi-crack coupling are constructed. Extend the law, and update the particle set. Combined with the online observations obtained by the guided wave structural health monitoring method, the posterior probability density function of the multi-crack propagation state vector is estimated online by regularized particle filter. The crack growth model is updated by the posterior estimation of the model parameters, and the trajectory of each crack growth in the future is predicted from the posterior estimation of the crack length. The invention can effectively realize the on-line monitoring and prediction of multiple cracks in the structure, and has wide application prospects in the prediction of the expansion of multiple cracks in the structure.

The invention relates to a multilayer medium photoacoustic tomography method. The multilayer medium photoacoustic tomography method comprises the following steps of: illuminating a multilayer medium to be imaged by using pulsed light, receiving acoustic signals generated by the multilayer medium from different positions at multiple angles by using a plurality of transducers arranged in an outer layer medium, and performing Fourier transform on the signals received by each transducer, forming a sound pressure spectrum; according to a resolution requirement of required imaging, carrying out discretization grid division on the multilayer medium based on geometric parameters of the multilayer medium; according to a frequency domain sound propagation equation, selecting a certain number of discrete frequency points, and constructing a model matrix; combining the model matrix with the sound pressure spectrums corresponding to a certain number of discrete frequency points, and constructing a linear equation set; and solving and optimizing the linear equation set. According to the photoacoustic tomography method, the quality of the photoacoustic tomography image in the multilayer heterogeneous medium can be remarkably improved, accurate initial sound pressure distribution is obtained, and high-resolution and high-precision imaging can be completed by automatically setting image resolution according to actual needs.

The invention relates to the field of coal mine gas safety and provides a seam wave airy phase identification tectonic coal method based on a transmission method. According to a seam wave group velocity frequency propagation equation, a relationship between an airy phase velocity and a coal seam shear wave velocity is fitted out through utilization of the airy phase velocity obtained from inversion and combinations with coal seam and surrounding rock velocity parameters. When a surrounding rock shear wave velocity is constant, the airy phase velocity is proportional to the coal seam shear wavevelocity, coal beam shear wave velocity distribution can be obtained, and then tectonic coal distribution can be predicted.

The invention relates to a spacecraft robust rendezvous trajectory design method considering uncertain factors. With utilization of the characteristic of constructing an uncertain factor propagation equation rapidly and precisely according to a covariance analysis method, influences on a nominal track by uncertain factors are analyzed. A robust optimization problem is constructed by using the analysis results as the constraints of the optimization problem. Calculation is carried out based on a genetic algorithm to realize the robust rendezvous trajectory design. Therefore, the traditional optimal system rendezvous determination problem is transformed into a robust rendezvous problem considering uncertain factors; and calculation is carried out based on the genetic algorithm, so that an objective of the robust rendezvous trajectory design is achieved.

The invention discloses a method for calculating the interference of a point source radiation field on a cable in an infinitely large shielding layer with a hole. It is applied to the field of electromagnetic interference and has the advantages of simple algorithm, accurate results, and high efficiency. The invention uses the voltage on the cable The wave propagation channel and the space electromagnetic field propagation channel are represented by signal pipes, and the positions with energy reflection are represented by nodes, and the signal flow diagram reflecting the electromagnetic energy flow of the system is established, and the magnetic flow element radiation is used instead of the small hole transmission to establish the whole The propagation equation on the signal pipeline of the system and the scattering equation on all nodes are synthesized to obtain the extended BLT (Baum‑Liu‑Tesche) equation of the system electromagnetic interference, and the extended BLT equation is solved to obtain the interference intensity on the cable to achieve point-to-point The accurate calculation of the electromagnetic interference that the source radiation field couples to the transmission line through the infinite shielding layer with holes effectively reduces the dependence on computing resources and improves the efficiency.