31results about How to "Reduce computing memory" patented technology

The invention provides an array antenna electromagnetic characteristic solving method based on finite element region decomposition, and aims to give consideration to the calculation precision, solvingcapability and efficiency of solving the electromagnetic characteristics of a large array antenna at the same time, and the method comprises the following specific steps: (1) creating a unit geometric model; (2) setting materials and boundary conditions; (3) generating unit grids; (4) translating and copying the unit grids; (5) replacing the material and boundary attributes of the non-structuralunit; (6) solving by adopting a finite element region decomposition method; and (7) calculating electromagnetic characteristics. According to the invention, a finite element region decomposition method is applied to electromagnetic characteristic solution of the array antenna, so that the difficulty in geometric modeling and mesh generation of the large array antenna is reduced, and both the solution precision and the solution efficiency are considered.

The invention discloses a method for controlling the attitude of a high-altitude aircraft by utilizing jet flow, and relates to the field of aircraft high-altitude attitude control, the method adopts local encryption in a speed space to simulate the interference effect of jet flow and hypersonic speed rarefied incoming flow, and by adopting the method, a jet flow amplification factor can be efficiently and accurately obtained; and the flight attitude of the aircraft can be efficiently and accurately controlled.

The invention discloses a method for acquiring broadband RCS of an electrically large target based on ACA and CAT. The method comprises the following steps: 1) subdividing the surface of the electrically large target; 2) defining an RWG primary function on the subdivided target surface; 3) grouping the RWG primary functions of the surface of the electrically large target; 4) dividing the impedance matrix into a near field block and a far field block; 5) determining a Chebyshev sampling point of the broadband; 6) respectively filling far-field blocks and near-field blocks of the impedance matrix at the sampling points; 7) filling excitation vectors of the sampling points with an incident wave electric field; 8) solving the surface induction current at each Chebyshev sampling point; 9) calculating the surface current of each frequency point in the broadband; and 10) obtaining the broadband radar scattering cross section of the electrically large-size target. On the basis of Chebyshev approximation, an adaptive crossover approximation algorithm is combined, so that the operation time is greatly shortened, and the memory demand is reduced.

The invention discloses a method for obtaining carrier platform broadband RCS based on SAIM and CAT. The method comprises the steps: segmenting a complex carrier platform target into a plurality of sub-regions, and reserving public virtual surfaces between the adjacent sub-regions ; adopting triangles to subdivide all closed sub-regions and establishing respective Cartesian grids for each sub-region; calculating a Chebyshev sampling point of the broadband RCS, and calculating an initial surface induction current of the sub-region at the Chebyshev sampling point by using AIM; imposing boundary condition updating excitation vectors on the virtual surfaces of the adjacent sub-regions, and updating the surface induction current of the sub-regions at Chebyshev sampling points until convergence; and improving the current precision by utilizing Meili approximation, and obtaining the broadband radar cross section of the complex carrier platform. According to the method, the calculation time is greatly shortened under the condition of ensuring the precision, and the convergence speed is improved.

The embodiment of this specification discloses a forward modeling method for acoustic seismic data in a viscous medium. By separating the amplitude attenuation item and the phase dispersion item, the present invention can conveniently realize the viscoacoustic reverse time migration imaging compared with the traditional forward modeling simulation of the viscoacoustic wave equation in which the attenuation item and the dispersion item are coupled together. Compared with traditional computing methods, it can greatly improve computing efficiency and reduce computing memory.

The invention provides a fast numerical simulation method of two-dimensional magnetotelluric field, which combines the finite element method and Fourier transform, and converts the two-dimensional partial differential problem into different wave numbers by performing Fourier transform along the horizontal direction One-dimensional ordinary differential problems that are independent of each other, with high parallelism, effectively reduce the calculation amount and improve the calculation efficiency; provide conditions for the refined numerical simulation of the magnetotelluric method under large-scale conditions; after verification, adopt the present invention The calculation result of the method is within the range of the error bars of the international public data included in the literature of Zhdanov et al.

The present invention provides a method and system for extracting azimuth gathers based on offset vector slices, comprising the following steps: dividing seismic data into several offset vector slices; calculating the ground azimuth of each offset vector slice; Perform three-dimensional Kirchhoff integral pre-stack time migration on the acquired seismic data to calculate the subsurface scattering azimuth and reflection angle; retain the subsurface scattering azimuth consistent with the ground azimuth angle; select several The x-axis, the x-axis is used to represent the angular change of the emission angle, the normal direction of the plane is the z-axis, and the z-axis is used to represent the change of the formation depth, and the obtained reflection angle is marked in the x-z coordinate system to obtain the reflection angle distribution map ; Obtain the azimuth angle gather according to the reflection angle distribution map. It effectively reduces the variation range of the scattering angle γ and the scattering azimuth angle, can greatly save memory and hard disk resources, and shorten the calculation cycle.

The invention relates to a method and system for self-adaptive subdivision of a polygonal unstructured grid of an integrated circuit layout. The method includes sequentially inserting eccentric points into the existing mesh according to the lost and eroded polygon edges to recover the lost and eliminated eroded polygon edges, determining the triangles to be subdivided according to the set ratio / minimum angle threshold, in order Insert the center of the eccentric circle of the triangle to be subdivided into the existing mesh to eliminate the triangle to be subdivided. The above restores the lost and eliminated the eroded polygon edges and eliminates the triangle to be subdivided. Interleaved until the integrated circuit layout polygonal unstructured network There are no missing and eroded polygon edges and triangles to be subdivided in the grid, and finally form a new unstructured grid of VLSI layout to solve the redundancy caused by newly inserted nodes in the prior art While solving the problem of excessively dense local grids, it improves grid division accuracy and numerical calculation efficiency, and reduces calculation memory.

The invention provides a fast numerical simulation method for a two-dimensional magnetotelluric field, which combines a finite element method with Fourier transform, transforms a two-dimensional partial differential problem into a mutually independent one-dimensional ordinary differential problem among different wave numbers by performing Fourier transform along the horizontal direction, is high in parallelism degree, effectively reduces the calculation amount, and improves the calculation efficiency. The calculation efficiency is improved; conditions are provided for refined numerical simulation of the magnetotelluric method under a large-scale condition; through verification, a result calculated by adopting the method disclosed by the invention is within an error rod range of international public data recorded in the Zhdanov et al.1997 literature, is close to a mean value, and meets a precision requirement.

A three-dimensional quasi-transport acceleration method for the uniform geometric variational nodal method, which eliminates the axial and radial cross-derivative terms in the second-order even-parity neutron transport equation through quasi-transport approximation; considering the In the actual pressurized water reactor, the axial inhomogeneity is relatively weak, and the present invention adopts diffusion approximation to the angular distribution of the odd neutron angular flux density on the axial surface in the Ritz discrete process; , taking advantage of the symmetry of the angular space, reduces the number of angular basis functions for the odd neutron angular flux density on the radial surface. The invention can greatly improve the calculation efficiency and reduce the calculation memory without significantly affecting the calculation accuracy, so as to be used for accurate and efficient neutronics simulation in nuclear reactor design.

The application provides a method for coordinating distributed power flow optimization of the main distribution network and related equipment, wherein the method of the application includes: according to the topological relationship of the distribution network system model, the distribution network system model is divided into a main network model and a distribution network model Model; according to the preset power flow optimization target threshold, the main distribution coordination power flow optimization model is established, and the main network ADMM iterative optimization model and the distribution network ADMM iterative optimization model are respectively established through the alternate direction multiplier calculation method according to the main distribution coordination power flow optimization model ; The main network ADMM iterative optimization model and the distribution network ADMM iterative optimization model are iteratively calculated to obtain the current main network optimization parameters and distribution network optimization parameters. This application is based on the target-synchronized alternating direction multiplier method of the master-coordinated distributed power flow optimization method, which does not require a unified upper-level optimization center, and solves the calculation and communication bottleneck problems of the existing centralized optimization degree method with a distributed calculation mode , which improves the power flow optimization efficiency of the main distribution coordination.

The invention discloses a seismic forward modeling method based on least square conjugate gradient iteration of a frequency domain. The method comprises the following steps: inputting a time-harmonic wave equation after Fourier transform to the frequency domain; setting corresponding forward modeling simulation parameters; and performing iterative solution on the time-harmonic wave equation through a least square conjugate gradient algorithm according to the forward modeling simulation parameters. Compared with a forward modeling method based on LU direct solution, the method provided by the invention can reduce memory consumption and improve calculation efficiency under the condition of keeping the same precision, and compared with a forward modeling method based on BI-CGSTAB iterative solution, the method provided by the invention can obtain more loose use conditions and better calculation stability under the condition of approximate calculation efficiency.

The invention discloses a self-adaptive two-dimensional finite element sparse and dense grid interface transition method which is applied to the field of engineering structure analysis. The method comprises the following steps: forcing displacement of finite element nodes in different sparse and dense grid sub-regions to be continuous through penalty factors in a least square manner, so as to obtain an interface transition element and system rigidity matrix according to the principle of minimum potential energy; introducing the rigidity matrix into commercial finite element software through a user unit subprogram interface; selecting the proper penalty factor only by setting the material attribute, the geometrical feature, the load and other properties of the unit by the user so as to realize the two-dimensional finite element grid interface transition. The method can effectively solve the local refinement problem when the finite element grids are divided and the remote docking problem of finite element models established in different regions, by different analysts and by adopting different types of finite element software, has self-adaptability, and is simple and practicable, high in computational accuracy, small in occupied internal storage and high in computation speed.

The invention relates to a large-scale integrated circuit layout unstructured grid eccentric midpoint generation method and system. According to the large-scale integrated circuit layout unstructuredgrid eccentric midpoint generation method and system, lost edges are recovered by an eccentric midpoint recovery method, and eroded edges are eliminated by an eccentric midpoint elimination method. Inthe recovery process of the lost edge, the elimination of the eroded edge is nested, and in the elimination process of the eroded edge, the recovery of the lost edge is nested, so that it is can be ensured that all the lost edges and the eroded edges are eliminated. Moreover, an included angle formed by eccentric midpoints generated for the lost edges and the eroded edges is just a preset triangle minimum angle threshold value for defining the quality of the triangle, so that grid nodes are reduced while the quality of the generated grid meets the requirements, and the calculation memory is reduced while the speed of numerical calculation is increased.

The invention discloses a method for controlling the attitude of high-altitude aircraft by using jet flow, which relates to the field of high-altitude attitude control of aircraft. The method adopts local encryption in velocity space to simulate the interference effect of jet flow and hypersonic thin incoming flow. The method can The jet amplification factor can be obtained efficiently and accurately, and then the flight attitude of the aircraft can be controlled efficiently and accurately.

The invention relates to a method and device for compressing nuclear magnetic resonance echo data, wherein the compression method comprises: acquiring nuclear magnetic resonance echo data to be analyzed; using the nuclear magnetic resonance echo data to obtain principal components of the nuclear magnetic resonance echo data; A compression matrix is ​​constructed by using the principal components of the nuclear magnetic resonance echo data; and the nuclear magnetic resonance echo data is compressed by using the compression matrix. This technical solution can effectively eliminate the information that has little contribution to the characterization of formation characteristics or even redundant information in the original echo data, can still ensure the characteristics of the original data under the condition of high compression ratio, and can effectively prevent the loss of accuracy. Improve inversion speed and reduce computational memory.