共查询到11条相似文献,搜索用时 46 毫秒
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图形电磁计算方法是计算复杂目标高频区雷达散射截面(RCS)的有效方法之一。而复杂目标的电磁散射主要来源于面元以及棱边。针对传统图形电磁计算方法的特点及其不足之处,提出并实施了相应的改进措施,包括:对面元散射场的离散化计算公式进行了修正,对棱边散射场的计算引用新的等效电磁流边缘分量表达式。计算实例表明,改进后的方法与实验测量值吻合良好,具有更高的计算精度和准确性。该方法对隐身与反隐身技术及仿真技术的研究,具有一定的参考价值。 相似文献
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现今武器大多是利用非均匀有理B样条(non-uniform rational B-spline,NURBS)数学表述,在CAD/CAM系统下完成建模和重构.利用电磁计算软件运算武器模型的雷达散射截面(radar cross section,RCS)从而评估其隐身性能,就需要与CAD/CAM系统进行数据交互.通过对基本图形转换规范(initial graphics exchange specification,IGES)数据标准的分析,为电磁计算软件编译了IGES数据接口.该数据接口具备IGES文件数据导入和模型数据导出另存为IGES文件格式的功能,从而实现了自行开发的计算软件CRCS v1.2和CAD系统软件的数据交互,提高了软件处理复杂模型的能力进而使模型重构与计算趋于一体化. 相似文献
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基于Linux集群电磁散射并行计算实现 总被引:1,自引:0,他引:1
工业应用,特别是军事应用对计算电磁学(CEM)的需求提出挑战,解决电大尺寸电磁散射问题(物理尺寸/λ》1)的有效方法是采用并行计算技术.给出了MLFMA算法基于Linux集群技术的并行实现,并给出了电大尺寸目标电磁散射的计算实例.由于这种并行化方法只是充分利用已有的工作站,编程容易,所以是一种值得推广的并行化实现方法. 相似文献
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矩量法是广泛使用的高精度电磁数值算法之一。在仿真复杂电磁问题时,该算法需要处理大型复数稠密矩阵方程,这导致其面临内存需求高、计算时间长的问题。与传统基函数相比,本文采用的高阶多项式基函数能够在保证计算精度的前提下大幅度降低未知量,进而降低矩阵阶数。在此基础上,本文设计了基于分块矩阵的高效并行策略,在国内超级计算机平台开展了并行高阶矩量法的超级电磁计算研究,大幅度提升了矩量法的仿真能力。在国产神威蓝光超级计算机上,以机载天线阵列的辐射特性计算为例,对并行规模高达30720 CPU核时的算法性能进行了评估,测试结果表明算法在并行规模扩大20倍以上时仍可获得50%以上的并行效率。在当前排名世界第一的天河2号超级计算机上,以飞机散射特性计算为例,对并行规模高达201600 CPU核时的算法性能进行了评估,测试结果表明算法在并行规模扩大约8倍时可获得50%以上的并行效率。数值仿真结果表明并行高阶矩量法可以在不同架构的超级计算机上高效完成复杂电大目标的精确电磁计算。 相似文献
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陈亚瑞 《模式识别与人工智能》2012,25(5):775-782
提出基于均值场计算树的Ising图模型消息族传播算法。首先定义Ising图模型均值场计算树和均值场剪枝计算树概念来描述Ising图模型均值场推理方法的迭代计算过程。然后基于均值场计算树设计Ising图模型消息族传播算法,指出沿着计算树自底向上逐层进行消息族传播,可计算根节点变量的边缘概率分布族。同时证明基于均值场剪枝计算树的消息族传播算法可计算出变量边缘概率分布的界,即此时的边缘概率分布族包括边缘概率分布精确值。最后通过数值实验验证消息族传播算法的有效性和边缘概率分布界的紧致性。 相似文献
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Discontinuous Galerkin Approximations for Computing Electromagnetic Bloch Modes in Photonic Crystals
Zhongjie Lu A. Cesmelioglu J. J. W. Van der Vegt Yan Xu 《Journal of scientific computing》2017,70(2):922-964
We analyze discontinuous Galerkin finite element discretizations of the Maxwell equations with periodic coefficients. These equations are used to model the behavior of light in photonic crystals, which are materials containing a spatially periodic variation of the refractive index commensurate with the wavelength of light. Depending on the geometry, material properties and lattice structure these materials exhibit a photonic band gap in which light of certain frequencies is completely prohibited inside the photonic crystal. By Bloch/Floquet theory, this problem is equivalent to a modified Maxwell eigenvalue problem with periodic boundary conditions, which is discretized with a mixed discontinuous Galerkin (DG) formulation using modified Nédélec basis functions. We also investigate an alternative primal DG interior penalty formulation and compare this method with the mixed DG formulation. To guarantee the non-pollution of the numerical spectrum, we prove a discrete compactness property for the corresponding DG space. The convergence rate of the numerical eigenvalues is twice the minimum of the order of the polynomial basis functions and the regularity of the solution of the Maxwell equations. We present both 2D and 3D numerical examples to verify the convergence rate of the mixed DG method and demonstrate its application to computing the band structure of photonic crystals. 相似文献
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Wei-Yi Liu Kun Yue Jin Li Ning Song Li Ding 《Journal of Intelligent and Robotic Systems》2010,60(2):241-261
In this paper, an approach for reducing the graphical model and a genetic algorithm for computing the approximate Nash equilibrium
in a static multi-agent game is studied. In order to describe the relationship between strategies of various agents, the concepts
of the influence degree and the strategy dependency are presented. Based on these concepts, an approach for reducing a graphical
model is given. For discretized mixed strategies, the relationship between the discrete degree and the approximate degree
is developed. Based on the regret degree, a genetic algorithm for computing the approximate Nash equilibrium is given. Experimental
results indicate the genetic algorithm has high efficiency and few equilibrium errors. 相似文献