49 results about "Conjugate gradient method" patented technology

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 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 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 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 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 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 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 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.

The invention provides a fast multi-group genome prediction method based on Fast-Ridge, and the fast multi-group genome prediction method is an efficient Ridge regression solution method (FAST-Ridge-MP) oriented to multi-group genome prediction. Through collaborative design algorithm architecture innovation and hyper-parameter adaptive tuning, the complexity of a traditional algorithm is reduced from > to > by an efficient sparse matrix solver based on a conjugate gradient method (CG), and the large-scale data processing capacity is greatly improved; a parallel Bayesian optimization (PBO) framework is innovatively proposed, a Pearson's correlation coefficient (PCC) is adopted as an evaluation index, and regularization parameters and group weights are intelligently and collaboratively optimized; the function of improving the efficiency and precision of genome prediction is achieved. According to the method, a grading performance verification system is established, the method is suitable for genome prediction of complex quantitative characters in animal and plant breeding, and the accuracy and calculation efficiency of cross-population prediction are improved.

The invention discloses a full-wave simulation method and device of a strip line structure, electronic equipment and a storage medium. The full-wave simulation method for the strip line structure comprises the following steps: modeling an interconnection condition of the strip line structure through a full-wave layered interconnection solution method, and solving an electromagnetic field Green function of a layered interconnection structure; filling in reaction matrix elements generated by a moment method; solving a moment method reaction matrix by adopting a conjugate gradient method, wherein the moment method reaction matrix is a sparse matrix generated in the modeling process; and on the basis of the obtained matrix solution and the model, performing result description on the strip line structure, which is expressed as an S parameter, near-end crosstalk and far-end crosstalk of the strip line structure. According to the full-wave simulation method of the strip line structure provided by the embodiment of the invention, the calculation process in the simulation process is simplified, the data processing amount and the calculation amount are greatly reduced, the time consumption of the whole simulation process is shortened, and the full-wave simulation efficiency of the strip line structure is improved.

The application relates to a MIMO-DFRC waveform design method based on angle estimation CRB optimization, and the method comprises the following steps: establishing a signal model; deducing angle estimation CRB; establishing a communication CI constraint; establishing a constant modulus constraint; establishing a MIMO radar communication integrated waveform design problem based on angle estimation CRB optimization; converting inequality constraints by adopting the idea of barrier function; and efficiently solving by adopting the Riemann conjugate gradient method. The method adopts the idea of barrier function in the interior point method to process inequality constraints, ensures that the optimization result can strictly meet the established communication service quality requirement, is more applicable and stable in the actual radar communication integrated scene, adopts the Riemann conjugate gradient method to solve the integrated waveform optimization, is higher in calculation efficiency compared with the existing ADMM algorithm, improves the real-time transmission capability of the MIMO radar communication integrated waveform, and is more advantageous in engineering application.

This application relates to a method and system for solving conjugate gradient finite element models based on sparse convolution preprocessing. The method includes establishing a structural finite element model, generating a structural stiffness matrix A and a load vector b, and constructing a linear equation system Ax=b, where A is a sparse symmetric positive definite matrix. A preprocessing sub-generator is constructed by training different structures using a sparse convolutional neural network. The stiffness matrix A is input into the preprocessing sub-generator to obtain a preprocessing factor. A symmetric positive definite preprocessor is constructed based on the preprocessing factor. The linear equation system Ax=b is solved using the preprocessed conjugate gradient method to obtain the displacement response vector x. This application optimizes the condition number of the preprocessed matrix to improve convergence speed and reduce solution time. It adapts the sparse convolutional U-net structure to large-scale sparse matrices, improving training efficiency and forming a unified and scalable preprocessing framework for structural engineering, providing a general and efficient preprocessing strategy for large-scale finite element model analysis.

The invention discloses an earth and rockfill dam hidden danger full-waveform inversion method based on a simulated inter-well observation system, and the method comprises the steps: laying excitation points and detection points at a dam crest and upstream and downstream dam slopes along the cross section of an earth and rockfill dam, and constructing the simulated inter-well observation system to collect seismic data; establishing a hidden-danger-free initial model, performing forward modeling as a current model, and constructing a target function based on observation and simulation records; when the target function value does not reach the preset threshold value, performing wave field back-stepping through the residual record, and calculating the physical property parameter gradient of the current model in combination with the forward modeling wave field; processing by adopting a conjugate gradient method to obtain a conjugate gradient, and then constructing a precondition operator for suppressing surface wave interference and accelerating deep updating in a dam body to correct the precondition operator; and obtaining an optimal inversion step length through step length search, updating the model, and carrying out iteration until an objective function is converged, so as to obtain a physical property parameter model reflecting the earth and rockfill dam hidden danger. According to the invention, the accuracy and inversion efficiency of earth and rockfill dam hidden danger detection can be effectively improved.

The application discloses a kind of large-scale MIMO multi-star positioning and direction estimation method and system based on angle information.The application first obtains the channel matrix estimation between each satellite and user by sending pilot signal;Then the estimated value of channel parameter is obtained using tensor-ESPRIT algorithm, including angle of departure and angle of arrival;According to the estimated angle of departure, the direction vector between user and each satellite is obtained, the optimization problem on spherical surface is established, considering the altitude constraint, the user position estimation value is obtained by using Riemann conjugate gradient method;Finally, according to the estimated user position and angle of arrival, the optimization problem on SO (3) manifold is established, and the estimated value of user array rotation matrix is obtained by using Riemann gradient descent method.The application combines the channel information between multiple satellites and users for positioning and direction estimation, and considers the altitude constraint during positioning, compared with single satellite and unconstrained case, can significantly improve the positioning performance, while having good direction estimation performance.

The invention provides an insulation aging mechanism analysis method and system for an extra-high voltage converter transformer valve side outgoing line device. The method comprises the following steps: pretreating an insulating material, preparing an experimental sample, and collecting a near infrared spectrum of the experimental sample; constructing an insulation paper cellulose model, optimizing an atomic position through a conjugate gradient method, and optimizing a model structure through a simulated annealing algorithm; carrying out molecular dynamics simulation on the optimized model, simulating temperature by adopting a Nose temperature control method, calculating dipole moment and analyzing dielectric constant and system energy change; applying a strong electric field as external disturbance, observing chemical bond change in combination with a near infrared spectrum, and finally summarizing an aging related data rule. According to the method, the problems of insufficient molecular dynamics simulation accuracy and low aging mechanism model prediction precision and reliability are effectively solved, and the accuracy of insulating material aging state evaluation is improved.

The invention relates to a pushing type rotary guiding pushing force control method and system based on higher harmonics. The method comprises the steps that vector decomposition is conducted on sidewall contact type rotary guiding lateral force, and sidewall contact force corresponding to a hydraulic device is obtained; based on the pushing force of the corresponding hydraulic device, designing a pushing force higher harmonic expression of the corresponding hydraulic device; according to the designed pushing force higher harmonic expression, extreme value solving is conducted on the higher harmonic signals through a conjugate ladder method, the pushing force extreme value of the corresponding hydraulic device is obtained, and a pushing force signal coefficient is obtained based on the pushing force extreme value; and obtaining a pushing force expression of the corresponding hydraulic device based on the obtained pushing force signal coefficient. The control method and system are simple, the pushing force can be changed gently, the design difficulty of an execution mechanism of the control system is reduced, good engineering application value is achieved, and the conjugate gradient method is small in storage amount needed for solving the extreme value, has step convergence and high stability and does not need any external parameter.

A kind of static calculation method for prefabricated dam, based on finite element method and contact element method, a large number of joints in prefabricated dam are simulated, the properties of contact element are superimposed into the overall stiffness matrix using traditional finite element integration rule, to ensure that the overall stiffness matrix of prefabricated dam is a symmetric positive definite matrix, the linear equations are solved using Cholesky decomposition, and the iterative convergence speed is improved using preconditioned conjugate gradient method, to ensure the calculation efficiency. C# and FORTRAN programming language are used to write programs to obtain model information file and contact element information file, to complete the heavy pre-processing work of prefabricated dam performance analysis, and programs are written to convert the calculation result file into post-processing file; in addition to the calculation efficiency of the method itself, the whole process of the application is almost completed by program, which greatly improves the performance analysis efficiency of prefabricated dam.

This invention discloses a method for maximizing the main lobe gain of a hybrid analog-digital array used in radar communication systems. The invention investigates a method for jointly designing analog and digital weights using an alternating direction method of multipliers (ADMM) framework, with the objective function being the maximization of the ratio of the minimum main lobe level to the peak sidelobe level. Under constraints of main lobe ripple, constant modulus constraint on analog weights, and power constraint on digital weights, the Riemann conjugate gradient method is used to solve the analog weight subproblem with constant modulus constraint; the Lagrange multiplier method is used to solve the digital weights. Numerical results show that the method of this invention can produce good main lobe ripple and low peak sidelobe levels, exhibiting excellent beam pattern control performance.

The application discloses a large-scale structure reanalysis method and system based on a separation-reconstruction framework, which comprises the following steps: dividing a truss structure into multiple subdomains and constructing an extraction matrix; constructing a flexibility matrix corresponding to the subdomains according to a total stiffness matrix and the extraction matrix, and modifying the stiffness of the corresponding subdomains according to structure design modification, thereby constructing a dimension-reduced modification equation of the subdomains; iteratively solving the dimension-reduced modification equation of the subdomains according to a stable double-conjugate gradient method to obtain displacement modification amounts of the subdomains; mapping the displacement modification amounts of the subdomains to the whole structure to reconstruct a displacement response vector of the whole structure; calculating an internal and external force residual vector of the displacement response vector, and judging whether the internal and external force residual vector meets a preset convergence condition; and if yes, outputting a structure reanalysis result. The local modification structure reanalysis method based on dimension reduction iteration, in combination with a high-dimensional model representation method and a residual modification mechanism, can improve the reanalysis efficiency of large-scale or whole modified structures.