• 제목/요약/키워드: resonance scattering theory

검색결과 32건 처리시간 0.023초

공진산란이론을 이용한 원통형 산란체에 대한 전자기파문제의 역산란 이론 (Solution of the Inverse Electromagnetic Scattering Problem for Cylindrical Objects by Using the Resonance Scattering Ttheory)

  • 정용화;전상봉;안창회
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제55권3호
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    • pp.142-148
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    • 2006
  • The resonances that contain the information on the properties of the scattering target can be used for target reconstruction approaches. The inverse scattering theory for the resonances has been applied to the problems of the scattering for a spherical, cylindrical dielectric objects and dielectrically coated conductors, shown reasonable results. Though by using this method the thickness and the dielectric constants of the target can be obtained from a determination of the spacing and of the widths of the scattering resonances, the radius of the target should be given. In this paper, we suggest the improved inverse theory combined with the resonance scattering theory to obtain the radius in addition to the dielectric constant of the target. The applications of this method for scattering problems of electromagnetic waves from cylindrical targets were accomplished, and it shows its validity.

음향파 공명 산란의 새로운 해석방법 (A New Method for Extracting Resonance Information in Acoustic Wave Resonance Scattering)

  • 이희남;박영진
    • 소음진동
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    • 제9권2호
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    • pp.409-417
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    • 1999
  • A new method is proposed for the isolation of resonances from scattered waves for the isolaton of resonances from scattered waves for acoustic wave resonance scattering problems. The resonance scattering function consisting purely of resonance information is defined. Acoustic wave scattering from a variety of submerged bodies is numerically analyzed. The classical resonance scattering theory (RST) and the new method compute identical magnitudes of the resonances from each partial wave, however, the phases are significantly different. The exact $\pi$-radians phase shifts through the resonance and anti-resonance frequencies show that the proposed method properly extracts the vibrational resonance information of the scatterer. Due to the differences in phases of the resonances from each partial wave, the new method and RST generate different total resonance spectra.

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유체가 채워진 실린더형 공동에 의한 탄성파 공명 산란 해석 (Elastic Wave Resonance Scattering from a Fluid-filled Cylindrical Cavity)

  • Huinam Rhee;Park, Youngjin
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 춘계학술대회논문집
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    • pp.208-213
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    • 2002
  • A new method is presented for the isolation of resonances from scattered waves for elastic wave resonance scattering problems. The resonance scattering function consisting purely of resonance information is defined. Elastic wave resonance scattering from a water-filled cylindrical cavity imbedded in an aluminum matrix is numerically analyzed. The classical resonance scattering theory and the new method compute different magnitudes and phases of the resonances from each partial wave, and therefore. their total resonance spectra are quite different. The exact $\pi$ - radians phase shifts through the resonance and anti-resonance frequencies show that the proposed method properly extracts the vibrational resonance information of the scatterer compared to resonance scattering theory.

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탄성체로 인한 탄성파의 공명산란 (ELASTIC WAVE RESONANCE SCATTERING FROM AN ELASTIC CYLINDER)

  • 이희남
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2003년도 춘계학술대회논문집
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    • pp.833-838
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    • 2003
  • The problem of elastic wave resonance scattering from elastic targets is studied in this paper. A new resonance formalism to extract the elastic resonance information of the target from scattered elastic waves is introduced. The proposed resonance formalism is an extension of the works developed for acoustic wave scattering problems by the author. The classical resonance scattering theory computes reasonable magnitude information of the resonances in each partial wave, but the phase behaves in somewhat irregular way, therefore, is not clearly explainable. The proposed method is developed to obtain physically meaningful magnitude and phase of the resonances. As an example problem, elastic wave scattering from an infinitely-long elastic cylinder was analyzed by the proposed method and compared to the results by RST. In case of no mode conversion, both methods generate identical magnitude. However, the new method computes exact $\pi$ radian phase shills through resonances and anti-resonances while RST produces physically unexplainable phases. In case of mode conversion, in addition to the phase even magnitudes are different. The phase shifts through resonances and antiresonances obtained by the proposed method are not exactly $\pi$ radians due to energy leak by mode conversion. But, the phases by the proposed method show reasonable and intuitively correct behavior compared to those by RST.

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Decoupling of Background and Resonance Scatterings in Multichannel Quantum Defect Theory and Extraction of Dynamic Parameters from Lu-Fano Plot

  • Lee, Chun-Woo
    • Bulletin of the Korean Chemical Society
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    • 제30권4호
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    • pp.891-896
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    • 2009
  • Giusti-Suzor and Fano introduced translations of the scales of Lu-Fano plots by phase renormalization in order to decouple the intra- and inter-channel couplings in multichannel quantum defect theory (MQDT). Their theory was further developed by others to deal with systems involving a larger number of channels. In different directions, MQDT was reformulated into forms with a one-to-one correspondence to those in Fano's configuration mixing theory of resonance for photofragmentation processes involving one closed and many open channels. In this study, the theory was further developed to fully reveal the coupling nature, decoupling of the background and resonance scattering in physical scattering matrices as well as to further extract the dynamic parameters undiscovered by Fano and his colleagues. This theory was applied to the photoabsorption spectrum of $H_2$ observed by Herzberg's group.

원통형 유전체에 대한 전자기파의 새로운 공진산란 이론 (New Resonance Scattering Theory of Electromagnetic Waves for a Homogeneous Dielectric Cylinder)

  • 정용화;안창회;최명선
    • 한국전자파학회논문지
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    • 제13권1호
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    • pp.87-93
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    • 2002
  • 기존의 공진산란이론에서는 하나의 모드에 대한 부분파 산란장이 주파수에 대하여 급격히 변하는 공진성분과 서서히 변하는 배경성분의 합으로 이루어졌다고 가정하고 적당한 배경성분을 제거하여 공진성분을 추출했다. 최근에 음향학 분야에서 산란 5-함수의 곱셈전개에 근거를 둔 새로운 공진 산란이론이 개발되어 왔다. 산란장이 공진성분과 배경성분 이외에 이들의 상호간섭성분으로 구성되어 있다고 제안한 이 이론은 공진성분의 크기뿐만 아니라 위상스펙트럼을 정확하게 얻게 해 주었다. 전자기파 분야에서는 유전체로 코팅된 도체 구 혹은 원통의 산란문제에 이 이론이 성공적으로 적용되었다. 본 논문에서는 유전체 실린더의 전자기파의 산란문제로 이 이론을 확장하고 수치계산으로 그 유효성을 검증했다.

음향파 공명 산란의 새로운 해석방법 (A new method for extracting resonance information in acoustic wave resonance scattering)

  • 이희남;박영진
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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    • pp.504-509
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    • 1998
  • A new method is proposed for the isolation of resonances from scattered waves for acoustic wave resonance scattering problems. The resonance scattering function consisting purely of resonance information is defined. Acoustic wave scattering from a variety of submerged bodies is numerically analyzed. The classical resonance scattering theory (RST) and the new method compute identical magnitude of the resonance from each scattered partial wave, however, the phases are significantly different. The exact .pi.-radians phase shifts through the resonance and anti-resonance show that the proposed method properly extracts the vibrational resonance information of the scatterer. Due to the difference in the phase of each, partial wave, the new method and RST generate different total resonance spectra.

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투과성 구형 산란체에 대한 전자기파 공진산란이론의 배경성분 (Background Coefficients in Resonance Scattering Theory for Spherical Dielectric Objects)

  • 정용화;전상봉;안창회
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제54권8호
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    • pp.384-389
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    • 2005
  • The Resonance Scattering Theory(RST) provides the physical explanation of the scattered field that appears in the vicinity of the resonance frequency. The theory suggests that the amplitude of each Partial-wave mode can be divided into two components : resonance and non-resonant background. The long-standing difficulty in the application of RST is that it always requires background components. We have applied the RST to the electromagnetic scattering problems by a penetrable spherical scatterer and a cavity. In this paper, we show some numerical results, and validate background coefficients.

원통형 유전체와 공동에 대한 전자기파 공진산란이론의 배경성분 (Background coefficients of the scattering from dielectric cylinder and cavity in the Resonance scattering theory)

  • 정용화;전상봉;안창회;최명선
    • 정보통신설비학회논문지
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    • 제2권1호
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    • pp.63-70
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    • 2003
  • 공진산란이론은 산란장의 공진현상을 물리적으로 해석해주는 이론으로, 산란장은 공진성분과 비공진성분 즉 배경성분으로 구성되어 있다고 가정한다. 따라서 공진 성분을 산란장으로부터 추출하기 위해서는 정확한 배경성분을 구하는 과정이 필요한데, 본 연구에서는 원통형 유전체와 공동에 의한 산란장으로부터 공진성분을 얻기 위한 배경성분을 제시하고, 수치 계산을 수행하여 타당성을 확인하였다.

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원통형 유전체에 대한 전자기파의 새로운 공진산란 이론 (New Resonance Scattering Theory of Electromagnetic Waves for a Homogeneous Dielectric Cylinder)

  • 정용화;안창희;최명선
    • 한국전자파학회:학술대회논문집
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    • 한국전자파학회 2001년도 종합학술발표회 논문집 Vol.11 No.1
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    • pp.332-336
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    • 2001
  • The new RST is recently developed by the product expansion of the scattering functions in the field of acoustics. The new formulation suggests that the scattering coefficients consist of resonance, non-resonance, and their interactional components. In the scattering problems of acoustic waves, the moduli and phase of the resonance coefficient are obtained the appropriate results through the new RST. In our recent works the new RST was successfully applied to the scattering problem of electromagnetic waves for coated conducting cylinder and sphere. In this paper, the new RST is applied to the 2-dimensional scattering problem of electromagnetic waves for a homogeneous dielectric cylinder, and the numerical results are compared with the previous RST.

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