共查询到20条相似文献,搜索用时 598 毫秒
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Xule Duan Hong Wei Yang Han Liu Li An 《Journal of Infrared, Millimeter and Terahertz Waves》2009,30(8):860-867
This paper introduces the peculiarity of a parallel ADE-FDTD method for plasma in dispersive media. We analyze the interaction
between the EM wave of various frequencies and plasma using parallel FDTD method. Then, we compare results calculated with
a serial and parallel FDTD implementations to obtain speed ratios, as well as validate the parallel implementaion. We conclude
that the parallel ADE method implementation has almost the same precision as the serial implementation. The parallel approach
facilitates using large memory, and reduces the CPU time. 相似文献
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结合IIR数字滤波器的基本结构,针对分布式算法中查找表规模过大的缺点,采用级联或并联结构,利用多块查找表使得硬件规模极大地减小,提出了并行和串行相结合的设计方案,并且实现了级联方式的10阶IIR低通滤波器。通过试验验证了该方法的有效性和实时性。 相似文献
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Liu Z.M. Mohan A.S. Aubrey T.A. Belcher W.R. 《Antennas and Propagation Magazine, IEEE》1995,37(5):64-71
In this paper, techniques for efficiently parallelizing the FDTD method for radiation problems are presented. Methods of parallelizing the core FDTD algorithm, PML ABC, Mur's ABCs, and the near-zone-to-far-zone transformation are discussed. A technique which makes the parallel FDTD more efficient can be applied to Berenger's PML in a straightforward manner, and apparently makes the code for PML ABC faster. Performance of the code is shown, and the computer-time usage for various parts of the code is given. On a 32 processor CM-5, the core FDTD algorithm is 100 times faster than an existing serial code, run on a SUN SPARC-2 workstation, and the calculation of the radiation patterns for two orthogonal planes is approximately 27 times faster. The techniques can easily be extended to other cases, not included in this paper, such as FDTD codes for magnetic materials, and non-uniform-mesh FDTD codes 相似文献
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Shaobin Liu Jinjun Mo Naichang Yuan 《Microwave and Wireless Components Letters, IEEE》2004,14(5):222-224
The piecewise linear current density recursive convolution (PLCDRC) finite-difference time-domain (FDTD) method for isotropic dispersive media greatly improves accuracy over recursive convolution (RC) and current density recursive convolution (CDRC) FDTD approaches but retains its speed and efficiency advantages. This letter extends this approach to anisotropic magnetoactive plasmas which incorporates both anisotropy and frequency dispersion at the same time, enabling the transient solutions of electromagnetic wave propagation in anisotropic magnetoactive plasmas. The high efficiency and accuracy of the method are confirmed by computing the reflection and transmission through a magnetized plasma layer, with the direction of propagation parallel to the direction of the biasing field. A comparison to frequency-domain analytic results and CDRC FDTD results is included. 相似文献
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目前,时域有限差分方法(Finite Difference Time Domain,FDTD)在电磁数值计算中已获得了广泛应用。对许多复杂电磁问题,FDTD 算法需要耗费巨大的计算机计算时间和存储空间,这成为FDTD 方法亟待解决的难题。本文提出了应用基于消息传递(Message Passing)方式实现FDTD 的并行算法。并对基于MPI 不同通信方式的并行FDTD 进行了效
率比较。采用MPI2.0 单边通信方式中的put 操作和主动对象同步(PSCW)方式,在一套16 个节点的Beowulf 型网络并行计算机系统上,实现了三维FDTD 并行程序,获得了较高的加速比和并行效率。 相似文献
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Shaobin Lui Jinjun Mo Naichang Yuan 《Journal of Infrared, Millimeter and Terahertz Waves》2002,23(12):1803-1815
A novel finite-difference time-domain (FDTD) methodology which incorporates both anisotropy and frequency dispersion at the same time is developed for electromagnetic wave propagation in anisotropic magnetoactive plasmas in this paper. The numerical verification of the method are confirmed by computing the reflection and transmission of right-handed/left-handed circularly polarized (RCP/LCP) wave through a magnetized plasma layer, with the direction of propagation parallel to the direction of the biasing field. And, the right-handed / left-handed polarized wave reflection coefficients for electromagnetic signals normally incident upon a conductive plane covered with a layer of magnetized plasma are computed using the new FDTD method. The parabolic electron-number density profile varies only in the direction perpendicular to the plane. The function dependence of reflection coefficients on the number density, collision frequency and external magnetic field is studied. 相似文献
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探讨了基于OpenMP的电磁场FDTD多核并行程序设计的方法,以期实现该方法在更复杂的算法中应用具有更理想的性能提升。针对一个一维电磁场FDTD算法问题,对其计算方法与过程做了简单描述。在Fortran语言环境中,采用OpenMP+~粒度并行的方式实现了并行化,即只对循环部分进行并行计算,并将该并行方法在一个三维瞬态场电偶极子辐射FDTD程序中进行了验证。该并行算法取得了较其他并行FDTD算法更快的加速比和更高的效率。结果表明基于OpenMP的电磁场FDTD并行算法具有非常好的加速比和效率。 相似文献
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一个基于并行时域Diakoptics的离散格林函数的新算法 总被引:1,自引:0,他引:1
本文介绍一个计算系统离散格林函数的新方法--并行时域Diakoptics法,将一个较简单的子域,用有时域差分法计算各子域的时域响应,用并行射iakoptics计算任意彼此相邻的两个子域间的电磁耦合,并最终得到整个系统的离散格林函数,与传统的模式匹配法和有限时域差分法(FDTD)比较,本方法可处理几何结构更为复杂的问题,并且具有较好的精度及计算效率。 相似文献
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Yil Suk Yang Jongdae Kim Tae Moon Roh Dae Woo Lee Jin Gun Koo Sang‐Gi Kim Il Yong Park Byoung Gon Yu 《ETRI Journal》2002,24(6):462-464
This paper presents a serial interface circuit that permits selection of the amount of data converted from serial‐to‐parallel and parallel‐to‐serial and overcomes the disadvantages of the conventional serial input/output interface. Based on the selected data length operating mode, 8 bit or 16 bit serial‐to‐parallel and 8 bit or 16 bit parallel‐to‐serial conversion takes place in data blocks of the selected data length. 相似文献
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分析了色散介质时域有限差分的模型,并针对非磁化等离子体给出了的分层线性递归卷积算法。介绍了OpenMP并行设计的基本模型,并将其应用于非磁化等离子体的计算当中。最终通过验证非磁化等离子体的透射电磁波,验证了将OpenMP并行设计应用于色散介质中的准确性,同时依据计算区域大小不同的3个算例验证了该算法具有较高的并行性能。 相似文献
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针对窄带、宽带及其临界情况时洛伦兹介质对应不同时域表达式而导致的递归卷积、Z变换等常用色散介质FDTD方法的更新公式无法通用问题,提出一种改进的移位算子FDTD方法,该方法保持了原方法概念简明、推导简单的优点,减少了内存占用,提高了计算速度,对窄带、宽带及其临界情况洛伦兹介质具有完全相同的更新公式。最后,通过具体算例验证了算法的有效性。 相似文献
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Over the past few years, a number of different finite-difference time-domain (FDTD) methods for modeling electromagnetic propagation in an isotropic cold plasma have been published. We have analyzed the accuracy and stability of these methods to determine which method provides the greatest accuracy for a given computation time. For completeness, two new FDTD methods for cold plasma, one of which is based on the concept of exponential fitting, are introduced and evaluated along with the existing methods. We also introduce the concept of cutoff modification which can be easily applied to most of the FDTD methods, and which we show can improve the accuracy of these methods with no additional computational cost. Von Neumann's stability analysis is used to evaluate the stability of the various methods, and their accuracy is determined from a straightforward time-and-space harmonic analysis of the dispersion and dissipation errors. Results of numerical experiments to verify the accuracy analysis are presented. It is found that for low-loss plasma, the piecewise linear recursive convolution method (PLRC) method is the most accurate, but the method of Young (see Radio Sci., vol.29, p.1513-22, 1994) can use less memory and is nearly as accurate. In this low-loss plasma regime, cutoff modification can significantly reduce the error near cutoff at the expense of slightly greater error at lower frequencies. For strongly collisional plasmas, the PLRC method also provides the most accurate solution 相似文献
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Yoon‐Jae So Hyoung‐Goo Jeon Young‐Hwan You Myung‐Sun Baek Hyoung‐Kyu Song 《ETRI Journal》2004,26(5):397-404
In this paper, we provide a new detection scheme for a pilot symbol assisted interference nulling and cancellation operation to reduce unexpected effects owing to parallel transmission in orthogonal frequency division multiplexing (OFDM)‐based spatial multiplexing systems. We have shown that the investigated OFDM vertical Bell laboratories layered space time (VBLAST) detection based on hybrid processing performs better than ordinary OFDM‐VBLAST detections based on serial processing and parallel processing, respectively. 相似文献
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Yuan Zhong-cai Shi Jia-ming 《Journal of Infrared, Millimeter and Terahertz Waves》2007,28(11):987-992
In a collisional plasma, the collision frequency between electrons and neutrals may be equal to or greater than incident electromagnetic wave frequency. The complex permittivity can not represent the dielectric property of the plasma perfectly used in the finite difference in time domain (FDTD). Drude model is adopted to characterize a collisional plasma. Using a commercial FDTD package, XFDTD 6.0, the electromagnetic scattering of plasma sphere is calculated. By comparison with Mie method, Drude mode is proven to be suitable. Radar cross-section (RCS) of nonuniform plasma spheres and conductor spheres coated by plasma layer are calculated. 相似文献