• Korean Journal of Crystallography
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• v.20 no.1
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• pp.9-14
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• 2009

직충돌 이온산란 분광법(ICISS: Impact Collision Ion Scattering Spectroscopy)을 이용한 고체표면 해석의 마지막 개설로서 금속 표면에 대한 연구를 소개하기로 한다. 금속은 도체이기 때문에 전하 축적을 방지하려는 별도의 장치가 필요 없다. 또한 결정구조가 간단하여 금속재료 자체보다는 표면의 흡착구조 및 반응, 박막 구조 등과 같은 분야에서 ISS를 이용하고 있다. 세라믹이나 반도체와 구별되는 응용 분야로서는 첫째 금속의 높은 표면 반응성을 이용하는 촉매와 같은 분야에 있어서 표면에서 일어나는 반응을 추적하기 위한 수단으로 사용된다. 둘째 표면 용융 현상을 표면 원자의 위치 결정을 통하여 연구할 수 있다. 마지막으로 자성재료의 표면 자성 특성을 스핀분극 ISS를 이용하여 접근할 수 있다. 이상과 같은 금속 표면물성 분야에 대하여 ICISS를 적용한 연구 사례를 소개하고자 한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.6
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• pp.571-579
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• 1987

The integral equations used in electromagnetic fields theory can be used for scattering problems. We can obtain various characteristics of scatterer. Ie, power pattern, scattered field, by finding current distribution on the scatterer. In this paper, current distribution on polygonal cylinder is obtained using integral equations in 2 dimension. For numerical aualysis, the moment method is used with pulse function as a basis function and integral equation is used with extrapolation method, which saves cpu time.

• 한국초전도학회:학술대회논문집
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• 2009.07a
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• pp.4-4
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• 2009

• Journal of the Korean Vacuum Society
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• v.2 no.2
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• pp.171-180
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• 1993

X-ray photoelectron diffraction (XPD) is used to characterize the crystallographically cleaved GaAs(110) surface. By using polar and azimuthal scans of the usual angle-resolved x-ray photoelectron spectroscopy, we get the reconstruction geometry of the clean GaAs(110) surface from the intensity ratio of Ga 3d core-level peaks. The reconstruction parameters are determined by fitting the diffraction pattern with the single scattering cluster (SSC) model, and the results show similar tendencies to those obtained by other techniques.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.6
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• pp.650-655
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• 2011

Analysis of two-dimensional Rayleigh wave scattering pattern by a surface defect is studied through modified boundary element method. BEM proposed in this paper has special treatment at each end of boundary which should have the Rayleigh wave go away without any generation of virtual reflections. It is shown that treatment for truncated boundary which is used to model two-dimensional Rayleigh waves' behavior in an elastic half-space is successfully implemented. To check numerical results' accuracy, time domain IFFT signal of the displacements is presented. Improvement on getting rid of unwanted influence of truncated boundary induced by 2-D Rayleigh waves on a flat surface of an elastic half-infinite medium is shown. As a final goal, the numerical results of Rayleigh wave scattering trend are plotted and they are compared with theoretical curves to prove its accuracy.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.2
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• pp.242-251
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• 2000

Design of wireless link in Ka and mm-wave bands is critically affected by rain attenuation. In this paper, we compared and analyzed the main distributions of rain drop size to estimate the rain attenuation which can be used in domestic environment. Mie scattering theory was checked to agree with Rayleigh theory in its low frequency limit and agree with optical scattering theory in its high frequency limit. We intended to provide more specific criteria to estimate rain attenuation with a generalized approach.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.1
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• pp.41-46
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• 2004

In this paper, we present a new combined field integral equation (CFIE) formulation for the analysis of electromagnetic scattering from arbitrarily shaped three-dimensional perfectly conducting and piecewise homogeneous dielectric composite body. The conducting/dielectric structures are approximated by planar triangular patches, which have the ability to conform to any geometrical surface. The surface covering the conducting body is replaced by an equivalent surface electric current and the surface of the dielectric by equivalent electric and magnetic currents. The all equivalent currents are approximated in terms of RWG (Rao, Wilton, Glisson) functions. The objective of this paper is to illustrate that the CFIE is a valid methodology in removing defects, which occur at a frequency corresponding to an internal resonance of the structure. Numerical results are presented and compared with solutions obtained using other formulations.

• Journal of the Korea Society for Simulation
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• v.9 no.3
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• pp.1-11
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• 2000

This paper proposes the practical echo-signal synthesis models - UTAHID (Underwater TArget by Highlight Distribution) & M-UTAHID(Modified UTAHID) - of underwater target for active sonar engineering At high frequencies all the echo components that are the specular reflected waves and various elastic scattering wave scan be regarded the summation of individual echo from some equivalent scattering centers, so the underwater target is characterized by highlights distributed in spatial target structure. Proposed models are compared with characteristics of random distributed model & equivalent interval highlight model, and analyzed target strength, echo-elongation effect, target time spread loss and so on. Thus these can be efficiently used in various real systems related to underwater target echo-signal synthesis on active sonar and acoustic countermeasure.

• Bulletin of the Korean Chemical Society
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• v.29 no.9
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• pp.1761-1764
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• 2008

The adsorption structure and binding of maleimide (MI) and succinimide (SI) on silver nanocolloidal surfaces have been comparatively investigated by means of pH-varied surface-enhanced Raman scattering (SERS). The two molecules appeared not to adsorb onto Ag surfaces at pH values below 5. The appearance of a ring ν (CH) band at ~3100 $cm^{-1}$ denoted the standing geometry of MI’s aromatic ring on Ag. The absence or weakness of in-plane vibrational modes of MI and SI also supported a perpendicular orientation of MI and SI on Ag from the electromagnetic selection rule. Density functional theory (DFT) calculations were employed to examine the vibrational frequencies of MI’s and SI’s neutral and anionic states.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.2
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• pp.144-148
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• 2013

In this paper, the ultra water-repellent thin films were prepared by RF PECVD. On the basis of surface morphology, chemical bonding states and plasma diagnostics, a formation model of clusters for the ultra water-repellent films was discussed from considerations of formation process and laser scattering results. Moreover, using laser scattering method, the relative change of quantity of nano-clusters or size of agglomerates could be confirmed. From the results, the films were deposited with nano-clusters and those of agglomerates, which formed in organosilicon plasma, and formation of agglomerates were depended on the deposition time.