• Title/Summary/Keyword: Resonance scattering theory

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

  • Jung, Yong-Hwa;Jeon, Sang-Bong;Ahn, Chang-Hoi
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.3
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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.

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

  • 이희남;박영진
    • Journal of KSNVE
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    • v.9 no.2
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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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Elastic Wave Resonance Scattering from a Fluid-filled Cylindrical Cavity (유체가 채워진 실린더형 공동에 의한 탄성파 공명 산란 해석)

  • Huinam Rhee;Park, Youngjin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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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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ELASTIC WAVE RESONANCE SCATTERING FROM AN ELASTIC CYLINDER (탄성체로 인한 탄성파의 공명산란)

  • 이희남
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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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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    • v.30 no.4
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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.

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

  • 정용화;안창회;최명선
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.1
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    • pp.87-93
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    • 2002
  • The previous RST postulates that the scattering field, within each modal partial wave, comprise of the resonance and the background components. 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 portions. In the scattering problems of acoustic waves, the moduli and phase of the resonance coefficient are obtained correctly by 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 extended to the 2-dimensional scattering problem of electromagnetic waves for a homogeneous dielectric cylinder, and the numerical results are compared with the previous RST.

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

  • 이희남;박영진
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1998.04a
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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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Background Coefficients in Resonance Scattering Theory for Spherical Dielectric Objects (투과성 구형 산란체에 대한 전자기파 공진산란이론의 배경성분)

  • Jung Younghwa;Jeon Sangbong;Ahn Chang-Hoi
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.54 no.8
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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.

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

  • Jung, Yong-Hwa;Jeon, Sang-Bong;Ahn, Chang-Hoi;Choi, Myoung-Seon
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • v.2 no.1
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    • pp.63-70
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    • 2003
  • Resonance Scattering Theory (RST) offers us an interpretation of the resonance phenomena in the scattered field. It is shown 1.hat the scattered field consists of the resonance and background components in the RST. The suitable background is necessary in order to obtain the resonance component. In this study, the background coefficients are investigated to obtain resonance components from electromagnetic scattering field for cylindrical object with different permittivities. We show some valid results valid for two models; cavity and dielectric cylinder.

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

  • 정용화;안창희;최명선
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2001.11a
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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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