• Title/Summary/Keyword: Thales' Theorem

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Fast Analysis of Fractal Antenna by Using FMM (FMM에 의한 프랙탈 안테나 고속 해석)

  • Kim, Yo-Sik;Lee, Kwang-Jae;Kim, Kun-Woo;Oh, Kyung-Hyun;Lee, Taek-Kyung;Lee, Jae-Wook
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.2
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    • pp.121-129
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    • 2008
  • In this paper, we present a fast analysis of multilayer microstrip fractal structure by using the fast multipole method (FMM). In the analysis, accurate spatial green's functions from the real-axis integration method(RAIM) are employed to solve the mixed potential integral equation(MPIE) with FMM algorithm. MoM's iteration and memory requirement is $O(N^2)$ in case of calculation using the green function. the problem is the unknown number N can be extremely large for calculation of large scale objects and high accuracy. To improve these problem is fast algorithm FMM. FMM use the addition theorem of green function. So, it reduce the complexity of a matrix-vector multiplication and reduce the cost of calculation to the order of $O(N^{1.5})$, The efficiency is proved from comparing calculation results of the moment method and Fast algorithm.

Vanishing Points Detection in Indoor Scene Using Line Segment Classification (선분분류를 이용한 실내영상의 소실점 추출)

  • Ma, Chaoqing;Gwun, Oubong
    • The Journal of the Korea Contents Association
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    • v.13 no.8
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    • pp.1-10
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    • 2013
  • This paper proposes a method to detect vanishing points of an indoor scene using line segment classification. Two-stage vanishing points detection is carried out to detect vanishing point in indoor scene efficiently. In the first stage, the method examines whether the image composition is a one-point perspective projection or a two-point one. If it is a two-point perspective projection, a horizontal line through the detected vanishing point is found for line segment classification. In the second stage, the method detects two vanishing points exactly using line segment classification. The method is evaluated by synthetic images and an image DB. In the synthetic image which some noise is added in, vanishing point detection error is under 16 pixels until the percent of the noise to the image becomes 60%. Vanishing points detection ratio by A.Quattoni and A.Torralba's image DB is over 87%.