80 results about "Conjugate gradient method" patented technology

The invention discloses a semiconductor film performance cooperative control method and system based on multi-parameter coupling, and belongs to the technical field of semiconductor material manufacturing, and the method specifically comprises the steps: determining a control parameter set containing plasma power density and other parameters, and building a multi-parameter coupling response model; generating sample points by using Latin hypercube sampling, quantifying a parameter interaction effect, and forming a dynamic weight matrix in combination with a graph model; monitoring data such as plasma emission spectrum intensity ratio in real time, comparing the data with a model predicted value, and correcting the model; a multi-objective optimization problem is constructed based on the correction model and the dynamic weight matrix, and optimal parameter configuration is solved by using a conjugate gradient method; alternately applying a high-frequency pulse and a relaxation stage according to the optimal configuration, and modulating the pulse frequency according to a Fibonacci sequence; and finally, based on the substrate temperature, planning a temperature rise path by using an S-shaped curve, superimposing cosine modulation, and introducing oscillation compensation gas to compensate the reactant concentration deviation, thereby realizing accurate optimization of the material preparation process.

The invention discloses a least square reverse time migration method and device for a three-dimensional anisotropic medium, and the method comprises the steps: building a forward equation of the three-dimensional anisotropic medium for a seismic block to be subjected to reverse time migration, and obtaining a background wave field under the three-dimensional anisotropic medium through regional forward modeling; determining a three-dimensional anisotropic medium adjoint wave field by using a pre-established wave equation of the adjoint wave field; according to the adjoint wave field and the background wave field, determining an initial gradient by using a pre-established least square reverse time migration cross-correlation equation, and obtaining a migration result according to the initial gradient; and updating an imaging result through a conjugate gradient method according to the offset result to obtain a reflected wave record.

The invention discloses a main lobe gain maximization method for an analog-digital hybrid array of a radar communication system. According to the method, the ratio of the maximum minimum main lobe level to the peak side lobe level is used as a target function, and under the main lobe ripple constraint, the simulation weight constant modulus constraint and the digital weight power constraint, the ADMM (Alternating Direction of Multiplexing) is used for carrying out joint design on the simulation weight and the digital weight. In the ADMM framework, a Riemann conjugate gradient method is adopted to solve a simulation weight subproblem with constant modulus constraint; and solving a digital weight by adopting a Lagrange multiplier method. A numerical result shows that the method can generate better main lobe ripples and lower peak side lobe level, and has good beam directional diagram accurate control performance.

The invention discloses a large-scale MIMO multi-satellite positioning and direction estimation method and system based on angle information. The method comprises the following steps: firstly, obtaining channel matrix estimation between each satellite and a user by sending a pilot signal; then, obtaining estimated values of channel parameters by using a tensor-ESPRIT algorithm, wherein the estimated values comprise an angle of departure and an angle of arrival; according to the estimated departure angles, direction vectors between the user and all satellites are obtained, an optimization problem on spherical manifold is established, altitude constraints are considered, and a Riemann conjugate gradient method is used for solving and obtaining a user position estimation value; and finally, according to the estimated user position and arrival angle, establishing an optimization problem on the SO (3) manifold, and solving by using a Riemannian gradient descent method to obtain an estimated value of a user array rotation matrix. According to the method, positioning and direction estimation are performed by combining channel information between a plurality of satellites and users, and altitude constraints are considered during positioning, so that compared with single-satellite and non-constraint conditions, the positioning performance can be remarkably improved, and meanwhile, the method has good direction estimation performance.

The invention relates to the technical field of interface thermal resistance calculation, and discloses a method for measuring and calculating interface thermal resistance based on an infrared imaging technology, which comprises the following steps: fixing and aligning paired upper and lower test pieces to form a to-be-measured contact interface, respectively preheating to a preset initial temperature difference and stabilizing, and monitoring and recording temperature change and test piece thermophysical parameters; enabling the test piece to be in contact, starting infrared imaging equipment to record full-field transient temperature data in a temperature equalization process, and forming a three-dimensional data matrix; building a thermal resistance correlation model, constructing a heat conduction equation in combination with the parameters to solve a simulated temperature field, and inverting related heat conduction coefficients by using a conjugate gradient method; and calculating microscopic and total contact thermal resistance according to the inversion coefficient and the geometric parameters, and deducing macroscopic thermal resistance. According to the method, non-intrusive transient infrared temperature measurement is combined with a reverse heat transfer algorithm, so that the microscopic thermal resistance, the macroscopic thermal resistance and the total contact thermal resistance are accurately distinguished and quantified.

The invention discloses a power transmission line three-dimensional meteorological field reconstruction method and system considering terrain influence, and the method comprises the steps: constructing a physical constraint projection function according to a terrain normal vector and an actual measurement value of each station in a power transmission line; constructing a computational physical operator system oriented to sparse sites; constructing a variational optimization objective function of each station according to the physical constraint projection function and the computational physical operator system; constructing a POD basis matrix according to historical data, and performing iterative solution by adopting a preprocessing conjugate gradient method according to the POD basis matrix to obtain a modal coefficient vector enabling the variational optimization objective function to be optimal, namely an optimal modal coefficient vector; and reconstructing a three-dimensional field according to the optimal modal coefficient vector, and synchronously calculating a space gradient. Reconstruction accuracy, physical consistency and reliability can be improved, and the requirements for a high-precision three-dimensional meteorological field in multiple aspects such as severe convection weather monitoring and early warning of a power transmission line and weather forecast verification can be met.

The present application relates to a kind of based on position dynamics adaptive anisotropic cloth simulation method, system, electronic equipment and storage medium, belong to computer graphics physics simulation field.The method includes setting cloth grid;Topology relationship of grid is calculated, and the set of point edge surface is formed;According to Newton's law, the linear system of external force is constructed, and change coordinate is solved using conjugate gradient method;Using graph coloring method, data dependence is decoupled to grid, using the method of position dynamics, strain constraint iteration parallel computing is carried out to change coordinate, and the coordinate correction amount after cloth motion deformation is obtained;According to the revised coordinate, grid tensor field is calculated, grid dynamic refinement and coarsening are carried out, and non-uniform anisotropic cloth grid is formed.The present application uses position dynamics method to calculate dynamic non-uniform grid, simulates the anisotropy of cloth deformation, retains the dynamic behavior of cloth wrinkle under fine scale, is quickly solved on the basis of not losing simulation details, satisfies real-time.

This invention discloses an online super-resolution imaging method for scanning radar based on the minimization criterion. By establishing an azimuth echo convolution model and discretizing it, the super-resolution problem is transformed. Under a regularization framework, the minimization criterion is used to construct an analytically optimizeable cost function containing sparse prior information, transforming the forward-looking imaging resolution improvement problem into an optimization estimation problem. By dividing the antenna measurement matrix into rows and blocks, matrix operations are degraded into the continuous accumulation of vector operations, enabling real-time online updates of targets in the forward-looking region. Finally, the conjugate gradient method is used to degrade and invert the matrix, outputting the super-resolution result. This method can achieve rapid imaging with limited system memory through an online conjugate gradient super-resolution algorithm based on the minimization criterion. Compared with existing batch processing regularization methods, it eliminates false targets, significantly reduces computational complexity, and is beneficial for rapid imaging of scanning radar.

The invention discloses a constant modulus waveform design method based on a penalty flow pattern optimization strategy, which relates to the technical field of radars, and comprises the following steps: for the problem of joint design of a constant modulus waveform and a filter of local fuzzy function shaping in single-input single-output radar system modeling, designing a constant modulus waveform and a filter; solving the problem of joint design of modeling based on a flow pattern accurate penalty method, and constructing an accurate penalty mechanism item for performing penalty optimization on a spectrum constraint condition; a plurality of inequality constraints are constructed into subitems of a target function through an accurate penalty function to eliminate the inequality constraints, and then a problem is projected to a CCM to obtain an equivalent complex quaternary unconstrained problem; the complex quaternary unconstrained problem is solved through a conjugate gradient method in a flow pattern space. The method provided by the invention shows better practicability in the aspects of radio frequency interference resistance, spectrum utilization, target detection and the like.

The invention provides a super-large-scale MIMO system beam focusing method based on an adaptive time delay-phase structure, and relates to the technical field of radio communication, comprising the following steps: constructing an adaptive time delay-phase structure suitable for a super-large-scale MIMO system, and establishing a near-field beam focusing joint optimization mathematical model; solving an all-digital optimal beam focusing matrix through maximum ratio transmission; a switch matrix optimization problem is converted into a bipartite graph matching problem, and an optimal matching matrix is solved by using a Hungary algorithm; solving a phase shift matrix through a Riemann spectrum conjugate gradient method; optimizing the time delay matrix by using a gradient descent method; optimizing the digital precoding matrix by using a least square method; and giving a base station beam focusing matrix through alternate iteration, and completing beam focusing of the super-large-scale MIMO system. According to the structure provided by the invention, dynamic sharing with the antenna array elements can be realized by utilizing the switching network, so that the adaptive capacity of hybrid precoding to a channel environment is effectively enhanced.

The invention relates to a magnetic resonance spectrum reconstruction method based on a structured matrix null space, and belongs to the field of undersampling and reconstruction of magnetic resonance spectrums. The method comprises the following steps: acquiring calibration data from a full sampling region of a non-uniform sampling time-domain magnetic resonance spectrum signal to be reconstructed; rearranging and constructing a structured matrix on the calibration data through a sliding window; calculating a null space based on singular value decomposition of the structured matrix; constructing a magnetic resonance spectrum reconstruction model containing a data consistency item and a null space constraint item; and solving a signal to be reconstructed by adopting a conjugate gradient method. According to the method, the null-space constraint relation is constructed by using the low-rank characteristic of the time-domain magnetic resonance spectrum signal under the structured matrix, so that rapid and high-precision magnetic resonance spectrum reconstruction is realized at a low sampling rate. The method is excellent in effect and can be applied to one-dimensional, two-dimensional and higher-dimensional undersampled magnetic resonance spectrum reconstruction.

The invention discloses a non-intrusive transient contact numerical calculation method based on a penalty function and a conjugate gradient, and relates to the field of structural impact dynamics numerical simulation, and the method comprises the steps: for a current calculation time step, estimating a displacement prediction value based on the motion state parameters of two collision objects in a previous calculation time step, and calculating the displacement prediction value; determining a contact gap prediction value of the current calculation time step; a penalty function method is adopted to carry out contact initial calculation to obtain a contact force estimated value, and a contact gap is updated; when the updated contact gap does not meet the non-intrusion condition, a preprocessed conjugate gradient method is adopted to carry out contact secondary calculation to obtain a contact force correction value; and determining the contact force of the current calculation time step based on the contact force estimated value and the contact force corrected value, and entering the next calculation time step after updating the motion state parameters. According to the method, interface non-intrusive calculation is achieved, and meanwhile high convergence and calculation efficiency are achieved.

The invention discloses a radiotherapy plan automatic optimization design method based on machine learning, and relates to the technical field of radiotherapy, and the method comprises the steps: firstly collecting and preprocessing radiotherapy core data to generate a training set, training feature extraction, dose prediction and optimization adjustment of a model; processing to-be-processed data through a feature extraction model, screening three optimal similar cases in combination with cosine similarity, and extracting effective features; based on the feature vectors and the effective features, outputting an initial dose plan, constraint parameters and a deposition matrix by a dose prediction model; and finally, constructing a target function, and iteratively optimizing the radiation field parameters and the photon flux by adopting an improved ant colony algorithm and a conjugate gradient method. According to the method, clinical experience and individual differences are fused, the radiotherapy plan is efficiently and accurately generated, and the quality stability and clinical suitability of the plan are improved.

This application provides a bridge dynamic weighing algorithm based on maximum entropy regularization. The steps include: First, obtain the measured response M of the bridge when the vehicle crosses the bridge m and the influence line matrix IL; Second, use M m and IL to calculate the initial value A of the axle weight 0 , and define the initial value r of the regularization parameter i=1 , where i represents the number of times of the main loop; Third, enter the sub-loop, substitute r i and A 0 into the iterative formula of the non-linear conjugate gradient method for calculation until the axle weight converges, and the absolute value of the difference between the axle weights obtained from the previous and the current iterations is less than e, that is: |A i k - A i k‑1 | < e. Assign the axle weight A i k at the k-th iteration after the convergence of the sub-loop to A i ; Fourth, substitute A i into the Regińska formula to obtain the parameter V, and calculate the next regularization parameter r i+1 ; Fifth, judge whether i is greater than 10. If not, substitute r i=i+1 into step three, and repeat the calculation process of steps three to five; If so, draw the r-V curve; Sixth, observe whether there is a minimum value in the curve. If not, substitute r i=i+1 into step three, and repeat the calculation process of steps three to five; If there is, output the axle weight corresponding to the minimum value and use it as the axle weight identification result.

The application provides a kind of based on adaptive time delay-phase structure's super large scale MIMO system beam focusing method, it is related to radio communication technical field, including the following steps: constructing adaptive time delay-phase structure suitable for super large scale MIMO system, and establishing near-field beam focusing joint optimization mathematical model;Through maximum ratio transmission solving all digital optimal beam focusing matrix;Switch matrix optimization problem is converted into two-part graph matching problem, and optimal matching matrix is solved using hungarian algorithm;Through riemann spectrum conjugate gradient method solving phase shift matrix;Utilize gradient descent method to optimize time delay matrix;Least square method is used to optimize digital precoding matrix;Through alternate iteration, base station beam focusing matrix is given, and the beam focusing of super large scale MIMO system is completed.The structure provided in the application can be realized with switch network and the dynamic sharing of antenna array element, so as to effectively enhance the adaptive ability of hybrid precoding to channel environment.

This invention discloses a method and system for reconstructing a three-dimensional meteorological field for transmission lines considering the influence of terrain. The method includes: constructing a physically constrained projection function based on the terrain normal vectors and measured values ​​of each station in the transmission line; constructing a computational physics operator system for sparse stations; constructing a variational optimization objective function for each station based on the physically constrained projection function and the computational physics operator system; constructing a POD basis matrix based on historical data, and iteratively solving the POD basis matrix using the preprocessed conjugate gradient method to obtain the modal coefficient vector that optimizes the variational optimization objective function, i.e., the optimal modal coefficient vector; reconstructing the three-dimensional field based on the optimal modal coefficient vector, and simultaneously calculating the spatial gradient. This method can improve the accuracy, physical consistency, and reliability of the reconstruction, meeting the needs of high-precision three-dimensional meteorological fields in various aspects such as monitoring and early warning of severe convective weather along transmission lines and verifying meteorological forecasts.

The invention provides a water-cooled wall temperature field reconstruction method based on a tube panel heat transfer network model, which comprises the following steps of: obtaining a geometric structure of a water-cooled wall tube panel, and mapping the water-cooled wall tube panel into a two-dimensional regular grid according to computational nodes; establishing a heat balance equation corresponding to the node according to the heat transfer data and the equivalent heat resistance; synthesizing the heat balance equations corresponding to the computational nodes of the upper actual installation measuring points of the water wall tube panel into linear equations, and representing the linear equations as a solution matrix; temperature measurement data are used as boundary conditions to be implanted into the solution matrix; solving the solving matrix according to a preprocessing conjugate gradient method; and mapping the temperature values in the vectors obtained by solving back to the geometric structure of the water-cooled wall tube panel according to node coordinates, and outputting a temperature field data set of the water-cooled wall tube panel. According to the method, the physical structure of the water wall tube panel is abstracted into the regular heat transfer network, the node-level linear equation is established based on the heat balance principle, and the whole-field temperature distribution of the water wall is reconstructed only through existing sparse measuring points.

The invention discloses an IGBT device junction temperature distribution inversion method and system based on a shell temperature actual measurement method and a conjugate gradient method, and belongs to the field of power electronic devices. According to the method, a transient heat conduction final control equation and an inversion parameter objective function are constructed by obtaining environment temperature, material parameters, geometric structure parameters and shell bottom plate temperature measurement values; the inversion parameter objective function is iteratively solved by using a conjugate gradient method to obtain an inversion parameter, and then the internal junction temperature distribution of the IGBT device is deduced through inversion without any change or interference to the interior of the device, so that the integrity and normal operation of the device are ensured, the interference of internal elements of the device is avoided, and the reliability of the device is improved. The accuracy of monitoring the junction temperature distribution in the IGBT device is improved, and the problem that the monitoring of the junction temperature of the IGBT device is inaccurate due to the fact that an intrusive junction temperature measuring method in the prior art is easily interfered by elements in the device is solved.

The application discloses a large-scale space random variation characteristic generation method based on grid pseudo-point approximation, and belongs to the field of non-homogeneous material space variation characteristic generation. The method utilizes pseudo-points to reduce the size of a covariance matrix, simultaneously utilizes a linear conjugate gradient method to solve a self-covariance matrix of the grid pseudo-points, reduces the operation amount of self-covariance matrix inversion and the calculation amount of self-covariance matrix decomposition in a simulation process, and can greatly improve the generation efficiency of a Gaussian random field. The large-scale non-homogeneous material space variation characteristic generation model of the Gaussian random field based on grid pseudo-point approximation constructed by the method can realize the generation of a large-scale Gaussian random field based on grid pseudo-points, utilizes an equivalent self-covariance function of a sparse power expectation propagation method to derive a Gaussian random field posterior mean function and a self-covariance function based on grid pseudo-point approximation, adopts Kronecker operation to realize fast decomposition of a posterior self-covariance matrix, and greatly improves the generation efficiency of a multi-dimensional large-scale random field.

The application relates to the technical field of bone imaging, and provides an ultrasonic cancellous bone imaging method based on full-wave inversion, which comprises the following steps: S1: setting an imaged bone phantom model, emitting an ultrasonic pulse signal, recording the ultrasonic pulse signal passing through the model, and sampling the signal as a simulation experiment wave field signal; S2: establishing a simulation wave field, setting an initial sound velocity model as a current sound velocity model; S3: based on the current sound velocity model, carrying out forward modeling on the simulation wave field, carrying out incremental extrapolation of the forward wave field signal along the propagation direction of the ultrasonic pulse signal, recording the simulation wave field signal after completing one round of emission-reception; S4: constructing a loss function, solving the loss function by using a conjugate gradient method, and updating the current sound velocity model; and S5: judging whether the loss function converges or not, and outputting the current sound velocity model if the loss function converges. High-resolution ultrasonic imaging of bone and microstructure is realized, and the demand of bone medical treatment and diagnosis with high precision requirements is met.

The application discloses a complex ground surface ground penetrating radar amplitude-preserving imaging method based on an orthogonal skin mesh, and comprises the following steps: 1) constructing a ground surface model according to ground fluctuation data; constructing an electromagnetic wave underground propagation speed model according to geological exploration data; 2) generating an orthogonal skin mesh by using a Ryskin-Leal method; 3) discretizing the orthogonal skin mesh by using a finite difference time domain method; 4) performing reverse extrapolation on the received ground penetrating radar signal, and reversely propagating the electromagnetic wave field to an initial time; in the reverse extrapolation process, the spatial position of a reflection interface is calculated through a cross-correlation imaging condition, and an underground imaging profile is obtained; 5) calculating a target function gradient, and solving an inversion problem by using a conjugate gradient method to iteratively update the electromagnetic wave underground propagation speed model; and 6) generating an imaging profile of an underground structure according to the iteratively converged electromagnetic wave underground propagation speed model. The application significantly improves the precision, stability and anti-noise performance of underground imaging.

The invention relates to an MIMO-DFRC waveform design method based on angle estimation CRB optimization. The method comprises the following steps: establishing a signal model; deriving an angle estimation CRB; establishing a communication CI constraint; establishing a constant modulus constraint; an MIMO radar communication integrated waveform design problem based on angle estimation CRB optimization is established; converting inequality constraints by adopting a barrier function thought; and a Riemann conjugate gradient method is adopted for efficient solution. According to the method, the thought of a barrier function in an interior point method is adopted to process inequality constraints, it is ensured that the optimization result can strictly meet the established communication service quality requirement, and the method is more suitable and robust in an actual radar communication integrated scene; according to the method, the Riemann conjugate gradient method is adopted to carry out integrated waveform optimization solution, and compared with an existing ADMM algorithm, the calculation efficiency is higher, the real-time emission capability of MIMO radar communication integrated waveforms is improved, and the method has more advantages in engineering application.

The invention relates to the technical field of mountain exploration, in particular to a mountain three-dimensional seismic data processing and correcting method based on micro-logging, which comprises the following steps of: 1, acquiring and calibrating micro-logging data; step 2, constructing a micro-logging constraint initial velocity model; step 3, accurately calculating a chromatography static correction value; and step 4, result verification and dynamic optimization. According to the method, micro-logging data are collected and calibrated through grid point distribution and key point encryption, a three-dimensional initial velocity model is constructed by adopting a Kriging interpolation method with the micro-logging data as hard constraint, after the model is optimized through iteration inversion based on a conjugate gradient method, the total static correction value containing elevation, a low speed reduction zone and a phreatic reservoir additional item is calculated through a ray tracing method, and the static correction value is calculated. And dynamic optimization is carried out through double-index verification. According to the method, the speed error of the key stratum is controlled within 5%, the static correction error of the development area of the phreatic reservoir is reduced within 15 ms, the data processing efficiency is improved by 40% or above, and the signal-to-noise ratio is improved by 50%-70%.

The invention discloses a spectrum optimization-based double-layer medium wide spectrum parameter simultaneous reconstruction method, relates to the technical field of spectral imaging, and aims to solve the problems that when wide optical parameter reconstruction is carried out based on a multi-layer medium model in the prior art, detection radiation optical signals are limited by a traditional contact type measurement mode, and the reconstruction precision is low. On the basis of a traditional participating medium optical parameter measurement and reconstruction method, a light field camera is introduced to more accurately detect a reflected radiation measurement signal of a medium boundary; a reconstruction optimization algorithm of searching an initial point by a steepest descent method and searching an optimal solution by a conjugate gradient method is combined, so that the efficiency of accurate reconstruction of the double-layer medium is greatly improved, the limitation of a traditional contact measurement mode is broken through, and the reconstruction precision is improved; in view of the problem that a radiation measurement signal is extremely low in sensitivity to a reduced scattering coefficient of a bottom-layer medium, prior information of a spectrum dimension is introduced, reconstruction results of an absorption coefficient and a reduced scattering coefficient of a double-layer medium, especially the bottom-layer medium, are improved, and simultaneous reconstruction of a double-layer medium absorption spectrum and a reduced scattering spectrum is realized.

The application provides a stratum absorption compensation method and system based on a seismic signal space, and the compensation method comprises the following steps: acquiring a seismic signal; determining a coherent direction of the seismic signal by using a dip angle scanning method, and designing a spatial prediction error filter with signal identification capability; constructing a non-steady filter representing an absorption effect of the seismic signal; establishing a target functional for non-steady inversion of the seismic signal after absorption compensation, and introducing spatial coherence of the seismic signal into a regularization condition of an inversion system; and performing inversion on the target functional by using a conjugate gradient method to obtain the seismic record after absorption compensation. The method is simple to operate, stable to run, and obvious in effect, effectively suppresses the influence of noise interference on absorption compensation, and improves the compensation precision of the seismic signal.

The application provides a global sparse texture filtering method based on edge structure preservation, including introducing a texture inhibition function in a penalty term, and constraining the gradient of an output image, the texture inhibition function inhibits texture, noise and unnecessary detail information in the image by setting two threshold values, then using the inhibited gradient as the input of the denominator of the penalty term, so that the penalty term can sufficiently distinguish texture and structure; sparse regular L1 norm is used to constrain the penalty term, non-convex optimization is converted into a convex optimization problem by introducing a sub-gradient, and an alternating direction multiplier method is used for iterative solution, so that better edge preservation is achieved; sparse L p Norm is used to constrain the penalty term and a preconditioned conjugate gradient method is used to accelerate and improve the calculation efficiency, so that more robust and sparse image smoothing effect is achieved. The application can improve the robustness of the algorithm in distinguishing texture and structure, retain better semantic information, and achieve better edge structure preservation and smoothing performance.

The application discloses a distributed signal reconstruction method and system of an M-channel oversampling graph filter bank, the method converts a signal reconstruction problem into a set of a series of local optimization problems through a truncation operator matrix, then solves the local optimization problems by using a distributed conjugate gradient method, obtains a local step value and a local increment value, and performs data fusion to update a reconstructed graph signal vector, a residual error vector and a search direction vector; finally, the method reduces errors through an iteration process to obtain an optimal solution of the reconstructed signal; each node on the network in the system has independent computing and communication capabilities, and all the nodes participate in system analysis and processing of a signal task. The method avoids a problem of computing a matrix inverse, and distributes calculation of the step value and the increment value in the conjugate gradient iteration, so that the signal reconstruction process of the filter bank can be realized in a completely distributed manner on the distributed system, the calculation complexity is effectively reduced, the robustness of the system is enhanced, and the method is suitable for analysis and processing of a large-scale node graph signal on the network.

The application provides a wave equation full-wave Q tomography method, which comprises the following steps: performing FFT transformation on existing seismic records to determine the frequency of a Ricker wavelet; performing forward simulation using the frequency of the Ricker wavelet determined in step 1 to obtain seismic correlation data; converting the seismic correlation data to a local domain and performing FFT on the data in the local domain to obtain the frequency of a single seismic event; obtaining the peak frequency shift of each seismic event in the local domain according to the frequency of the single seismic event; obtaining a companion source according to the peak frequency shift; performing wave field continuation calculation according to the companion source to obtain a back-propagating wave field; obtaining a gradient using the back-propagating wave field; and performing iterative updating using a conjugate gradient method according to the gradient to finally obtain an updated Q model. The method provided by the application can be simulated to obtain a relatively accurate Q model.

The invention relates to the technical field of numerical simulation and ultra-precision machining, and particularly discloses a laser-assisted cutting tool wear simulation test method and device, and the method comprises the following steps: S1, building a tool material model through an LAMMPS language; s2, setting system boundary conditions, ensuring unification of physical quantity units and the boundary conditions, and ensuring simulation accuracy and comparability; s2, establishing an ionic group model right above the tool material model established in S1, setting an interaction potential function between atoms, and ensuring that a simulation result accords with an actual physical process; s3, layering the initial model set in the S1, setting an integral time step length and total relaxation time, and enabling the relaxation system model to reach a stable state through a conjugate gradient method and an isothermal isometric system; and S4, setting an incident angle and a speed of the ionic group, outputting an atomic parameter, a thermodynamic parameter and a visual image in the process of bombarding the tool material by the ionic group, and carrying out subsequent analysis and result verification.

The application provides a large-span crossing water area conductor dismantling and releasing process construction calculation method, and belongs to the technical field of power transmission line construction simulation. The method first acquires tower position, materials, environment, construction control and other engineering basic data, and establishes a three-dimensional finite element model of the conductor composed of eight-node three-dimensional entity units; then constructs a global stiffness equation, and applies external loads such as self-weight, hydrodynamic load and constraints such as releasing end and riverbed contact in combination with construction stages and spatial positions; the precondition conjugate gradient method is used to solve the equation to obtain node displacement, and then the mechanical parameters of the unit are calculated and the conductor cracking and shearing states are identified; finally, the conductor geometric shape is updated, and the releasing and collecting process simulation is iteratively completed. The application realizes continuous simulation of the whole construction process, comprehensively considers the coupling effect of multiple loads, improves the stress deformation analysis accuracy, can output multiple construction evaluation indexes, is suitable for construction simulation of various types of slender flexible components, and has good engineering popularization.