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    Please use this identifier to cite or link to this item: http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/35872


    Title: 利用基因法則及TE極化波照射重建二維非完全導體之研究
    Other Titles: Electromagnetic transverse electric wave inverse scattering of a two-dimensional imperfectly conducting cylinder by genetic algorithm
    Authors: 蔡明峯;Tasi, Ming-feng
    Contributors: 淡江大學電機工程學系碩士班
    丘建青;Chiu, Chien-ching
    Date: 2005
    Issue Date: 2010-01-11 07:15:33 (UTC+8)
    Abstract: 本論文針對TE極化波入射的情況下,對於非完全導體的電磁成像問題進行探討。
    對於非完全導體而言,我們利用非完全導體表面阻抗的觀念再加上表面電流的觀念,在物體的邊界上,可導出非線性積分方程式,繼而利用動差法求得正散射公式。經由推導出的正散射公式,我們可以得到散射場的相關資料。在於逆散射部分,我們使用了基因法則(Genetic Algorithm),經由適當地選取參數,同時結合所推導的散射公式,我們可以由觀測點所測得的散射場值,經由基因法則的運算,來反求得物體的形狀函數。
    就整體而言不論初始的猜測值如何,基因法則總會收歛到整體的極值(global extreme),因此,在數值模擬中,即使最初的猜測值與實際值相距甚遠,我們仍可求得準確的數值解,成功的重建出物體形狀函數與導電率。而且量測的散射場即使加入高斯分佈的雜訊存在,依然可以得到良好的重建結果。此外我們也對於形狀函數跟導電率的雜訊容忍量予以比較。
    This paper presents a computational approach to the transverse electric (TE) wave imaging of an imperfectly conducting cylinder. An imperfectly conducting cylinder of unknown shape and conductivity scatters the incident wave in the free space, and the scattered field is recorded outside the object. Based on the boundary condition and measured scattered field, a set of nonlinear integral equations is derived and the imaging problem is reformulated into an optimization one that solved by Genetic Algorithm. Numerical results demonstrated that, the even when the initial guess is far away from the exact one, good reconstruction for shape and conductivity of the object can be obtained and the object’s conductivity also can be reconstruction excellent, In addition, the effect of noise is also be investigated.
    Appears in Collections:[電機工程學系暨研究所] 學位論文

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