Browsing by Subject "Approximation techniques"

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    Fast and accurate solutions of extremely large scattering problems involving three-dimensional canonical and complicated objects
    (IEEE, 2009-07) Ergül, Özgür; Gürel, Levent
    We present fast and accurate solutions of extremely large scattering problems involving three-dimensional metallic objects discretized with hundreds of millions of unknowns. Solutions are performed by the multilevel fast multipole algorithm, which is parallelized efficiently via a hierarchical partition strategy. Various examples involving canonical and complicated objects are presented in order to demonstrate the feasibility of accurately solving large-scale problems on relatively inexpensive computing platforms without resorting to approximation techniques. ©2009 IEEE.
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    Hybridizing physical optics with MLFMA for efficient scattering computations of three-dimensional complex targets
    (IEEE, 2009-07) Manyas, Alp; Ergül, Özgür; Gürel, Levent
    The multilevel fast multipole algorithm (MLFMA) provides accurate and efficient solutions of electromagnetic scattering problems involving large and complicated structures. On the other hand, whenever applicable, accelerations provided by approximation techniques can be useful to further improve the efficiency of solutions. In this paper, we present a hybrid technique, which combines the physical-optics (PO) method and MLFMA for efficient scattering computations of three-dimensional objects. We show that, with a careful choice of MLFMA and PO regions on the structure, the number of unknowns can be reduced and solutions can be accelerated significantly, without sacrificing the accuracy. The proposed hybrid technique is easy to implement by modifying existing MLFMA codes. ©2009 IEEE.