3,796 research outputs found

    A Novel Eigenvalue Algorithm for the Complex Band Structure and Eigenmodes of Plasmonic Crystals

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    Optimized operator-splitting methods in numerical integration of Maxwell's equations

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    Optimized operator splitting methods for numerical integration of the time domain Maxwell's equations in computational electromagnetics (CEM) are proposed for the first time. The methods are based on splitting the time domain evolution operator of Maxwell's equations into suboperators, and corresponding time coefficients are obtained by reducing the norm of truncation terms to a minimum. The general high-order staggered finite difference is introduced for discretizing the three-dimensional curl operator in the spatial domain. The detail of the schemes and explicit iterated formulas are also included. Furthermore, new high-order Padé approximations are adopted to improve the efficiency of the proposed methods. Theoretical proof of the stability is also included. Numerical results are presented to demonstrate the effectiveness and efficiency of the schemes. It is found that the optimized schemes with coarse discretized grid and large Courant-Friedrichs-Lewy (CFL) number can obtain satisfactory numerical results, which in turn proves to be a promising method, with advantages of high accuracy, low computational resources and facility of large domain and long-time simulation. In addition, due to the generality, our optimized schemes can be extended to other science and engineering areas directly. © 2012 Z. X. Huang et al.published_or_final_versio

    Fast computation of radar cross-section by fast multipole method in conjunction with lifting wavelet-like transform

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    The fast multipole method (FMM) in conjunction with the lifting wavelet-like transform scheme is proposed for the scattering analysis of differently shaped three-dimensional perfectly electrical conducting objects. As a flexible and efficient matrix compression technique, the proposed method can sparsify the aggregation matrix and disaggregation matrix in real time with compression ratio about 30%. The computational complexity and choice of proper wavelet are also discussed. Numerical simulation and complexity analysis have shown that the proposed method can speed up the aggregation and disaggregation steps of the FMM with lower memory requirements. © 2010 The Institution of Engineering and Technology.postprin

    Adaptive frequency sweep analysis for electromagnetic problems using the Thiele interpolating continued fractions

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    A direct rational approximation method based on Thiele interpolating continued fractions theory is proposed for fast frequency sweep analysis of electromagnetic problems. And an adaptive algorithm is also formed. Compared with the conventional rational approximation method, the proposed method can get a rational approximation directly without a great number of matrix inverse computations and doesn't need to allocate much memory for high derivatives of the dense impedance matrix. Meanwhile, the computation of surface currents by continued fractions can be sped up as compared with the traditional rational approximation. Numerical simulations for broad band scattering analysis of different shaped objects are discussed to shown the effectiveness of the present method. © 2010 IEEE.published_or_final_versionThe 2nd International Conference on Education Technology and Computer (ICETC 2010), Shanghai, China, 22-24 June 2010. In Proceedings of 2nd ICETC, 2010, v. 5, p. 126-12

    多天线GPS软件系统

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    Author name used in this publication: 黄丁发, HUANG Ding-faAuthor name used in this publication: 丁晓利, DING Xiao-liAuthor name used in this publication: 陈永奇Title in Traditional Chinese: 多天線GPS軟體系統Journal title in Traditional Chinese: 科學通報2000-2001 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    ERS-2 SAR反演海洋风矢量的研究

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    Author name used in this publication: 陈艳玲Author name used in this publication: 丁晓利, DING Xiao-liAuthor name used in this publication: 李志伟Title in Traditional Chinese: ERS-2 SAR反演海洋風矢量的研究Journal title in Traditional Chinese: 地球物理學報2007-2008 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    虚拟参考站技术中对流层误差建模方法研究

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    Author name used in this publication: 黄丁发Author name used in this publication: 丁晓利, DING Xiao-liAuthor name used in this publication: 殷海涛Title in Traditional Chinese: 虛擬參考站技術中對流層誤差建模方法研究Journal title in Traditional Chinese: 測繪學報2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Quantum Rotor Engines

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    This chapter presents autonomous quantum engines that generate work in the form of directed motion for a rotor. We first formulate a prototypical clock-driven model in a time-dependent framework and demonstrate how it can be translated into an autonomous engine with the introduction of a planar rotor degree of freedom. The rotor plays both the roles of internal engine clock and of work repository. Using the example of a single-qubit piston engine, the thermodynamic performance is then reviewed. We evaluate the extractable work in terms of ergotropy, the kinetic energy associated to net directed rotation, as well as the intrinsic work based on the exerted torque under autonomous operation; and we compare them with the actual energy output to an external dissipative load. The chapter closes with a quantum-classical comparison of the engine's dynamics. For the single-qubit piston example, we propose two alternative representations of the qubit in an entirely classical framework: (i) a coin flip model and (ii) a classical magnet moment, showing subtle differences between the quantum and classical descriptions.Comment: Chapter of the upcoming book "Thermodynamics in the Quantum Regime - Recent Progress and Outlook
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