• Journal of the Optical Society of Korea
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• 제15권2호
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• pp.196-201
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• 2011

Near-field properties of light emanated from a subwavelength double slit of finite length in a thin metal film, which is essential for understanding fundamental physical mechanisms for near-field optical beam manipulations and various potential nanophotonic device applications, is investigated by using a three-dimensional finite-difference time-domain method. Near-field intensity distribution along the propagation direction of light after passing through the slit has been obtained from the phase relation of transverse electric and magnetic fields and the wave impedance. It is found that the near field of emerged light from the both slits is evanescent, that is consistent with conventional surface plasmon localization near the metal surface. Due to the finite of the slit, the amplitude of this evanescent field does not monotonically approach to than of the infinite slit as the slit length increases, i.e. the near-field of the longer slit along the center line can be weaker than that of the shorter one.

• 한국광학회:학술대회논문집
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• 한국광학회 2001년도 제12회 정기총회 및 01년도 동계학술발표회
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• pp.122-123
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• 2001

본 연구에서는 주사 근접장 광학 현미경(Near-field Scanning Optical Microscope, 이하 NSOM이라 한다)을 이용하여 빛이 전파되고 있는 광 도파로 주변에 형성되는 evanescent field를 측정함으로써 광도파로 내부에서의 빛의 전파특성을 알아보았다. 광소자의 설계에 있어서 광도파로 내부에서의 빛이 어떻게 전파되어지는 가는 매우 중요한 인자가 된다. (중략)

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.460-463
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• 2003

We report the microwave reflection coefficient $S_{11}$ of copper(II)-phthalocyanine(CuPc) using a near-field microwave microscope(NSMM) in order to understand the intrinsic electromagnetic properties of organic materials. For a NSMM system, a high-quility microstip resonator coupled with a dielectric resonator was used. The reflection coefficient $S_{11}$ was changed by the preparation conditions of CuPc thin films. We compared the reflection coefficient with crystal phase, surface morphology, UV absorption spectra and x-ray diffraction results.

• 한국재료학회지
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• 제3권5호
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• pp.482-496
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• 1993

Radiation damage and contamination of silicons etched in the $CF_4+H_2$ and $CHF_3$ magnetron discharges have been characterized using Schottky diode characteristics, TEM, AES, and SIMS as a function of applied magnetic field strength. It turned out that, as the magnetic field strength increased, the radiation damage measured by cross sectional TEM and by leakage current of Schottky diodes decreased colse to that of wet dtched samples especially for $CF_4$ plasma etched samples, For $CF_4+H_2$and $CHF_3$ etched samples, hydrogen from the plasmas introduced extended defects to the silicon and this caused increased leakage current to the samples etched at low magnetic field strength conditions by hydrogen passivation. The thickness of polymer with the increasing magnetic field strength and showed the minimum polymer residue thickness near the 100Gauss where the silicon etch rate was maximum. Also, other contaminants such as target material were found to be minimum on the etched silicon surface near the highest etch rate condition.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 추계학술대회논문집; 한국과학기술회관, 8 Nov. 1996
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• pp.91-97
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• 1996

We have all heard sounds that did not sound "right" while riding in an automobile. Objectionable sounds are difficult to find and understand because the sound field is complex and dynamic in the near field of an automobile. Many different noise sources and transmission paths must be understood before an engineering change can be recommended. This paper reviews the fundamental characterization of sound and chscusses the Sound Intensity measurement technique. Sound intensity measurements locate sources and sinks of acoustic energy. Used with narrowband analysis equipment, acoustic noise sources can be identified. Sound intensity measurements are made -in-situ and do not require specmi anechoic facilities. The measurement results in a vector representation of the near field sound field and can discriminate between multiple sound sources.d sources.

• Journal of electromagnetic engineering and science
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• 제10권1호
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• pp.18-24
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• 2010

A Ka-band microstrip array antenna for wide-range detection of moving targets is analyzed through a photonicassisted reactive-near-field characterization technique. The antenna array employs a 3-dB-tapered feed network to suppress the sidelobe level while retaining a wide azimuth beamwidth for a wide detection range. The relative nearelectric field patterns of the array and its 3-dB-tapered feed lines have been measured using an electro-optic fieldmapping technique for minimally invasive millimeter-wave sensing. A number of typical limitations on the technique, involving bandwidth, low signal-modulation depth, and high laser-induced noise in high-frequency applications, have been overcome by suppressing the carrier portion of the optical interrogation beam.

• Earthquakes and Structures
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• 제3권2호
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• pp.117-140
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• 2012

The proposed research includes a comprehensive study on the seismic vulnerability assessment of typical building types, representative of the structural materials, the seismic codes and the construction techniques of Southern Europe. A damage database is created after the elaboration of the results of the observational data obtained from post-earthquake surveys carried out in the area struck by the September 7, 1999 Athens earthquake, a near field seismic event in an extended urban region. The observational database comprises 180.945 buildings which developed damage of varying degree, type and extent. The dataset is elaborated in order to gather useful information about the structural parameters influence on the seismic vulnerability and their correlation to the type and degree of building damages in near field earthquakes. The damage calibration of the observational data was based on label - damage provided by Earthquake Planning and Protection Organization (EPPO) in Greece and referred to the qualitative characterization for the recording of damage in post-earthquake surveys. Important conclusions are drawn on the parameters that influence the seismic response based on the wide homogeneous database which adds to the reliability of the collected information and reduces the scatter on the produced results.

• 대한기계학회논문집A
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• 제25권6호
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• pp.959-964
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• 2001

An experimental investigation on the near-field electromagnetic loss of thin copper layers has been presented using microfabricated microwave transceivers for applications to multi-chip microsystems. Copper layers in the thickness range of 0.2$\mu$m∼200$\mu$m have been electroplated on the Pyrex glass substrates. Microwave transceivers have been fabricated using the 3.5mm$\times$3.5mm nickel microloop antennas, electroformed on the silicon substrates. Electromagnetic radiation loss of the copper layers placed between the microloop transceivers has been measured as 10dB∼40dB for the wave frequency range of 100MHz∼1GHz. The 0.2$\mu$m-thick copper layer provides a shield loss of 20dB at the frequencies higher than 300MHz, whereas showing a predominant decreases of shield loss to 10dB at lower frequencies. No substantial increase of the shield effectiveness has been found for the copper shield layers thicker that 2 $\mu$m.

• 방사성폐기물학회지
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• 제21권1호
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• pp.23-41
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• 2023

Coupled thermo-hydraulic-mechanical (THM) processes are essential for the long-term performance of deep geological disposal of high-level radioactive waste. In this study, a numerical sensitivity analysis was performed to analyze the effect of rock properties on THM responses after the execution of the heater test at the Kamaishi mine in Japan. The TOUGH-FLAC simulator was applied for the numerical simulation assuming a continuum model for coupled THM analysis. The rock properties included in the sensitivity study were the Young's modulus, permeability, thermal conductivity, and thermal expansion coefficients of crystalline rock, rock salt, and clay. The responses, i.e., temperature, water content, displacement, and stress, were measured at monitoring points in the buffer and near-field rock mass during the simulations. The thermal conductivity had an overarching impact on THM responses. The influence of Young's modulus was evident in the mechanical behavior, whereas that of permeability was noticed through the change in the temperature and water content. The difference in the THM responses of the three rock type models implies the importance of the appropriate characterization of rock mass properties with regard to the performance assessment of the deep geological disposal of high-level radioactive waste.

• 한국광학회지
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• 제13권4호
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• pp.301-307
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• 2002

광 도파로를 따라 전파하는 빛의 특성을 측정하기 위해 근접장 주사 광학현미경(Near-field scanning optical microscope, NSOM)으로 광 도파로의 표면에 형성된 에바네슨트 파 evanescent wave)의 분포를 측정하였다. 사용된 NSOM은 photon scanning tunneling microscope방식으로 본 연구의 목적에 적합하도록 직접 제작한 것이다. 광원 파장 1550㎚에서 단일 모드 다중 모드 채널형 광 도파로에 대해 도파로 표면에 형성된 에바네슨트 파의 분포를 측정하였으며, 3차원 빔전파방법(Beam Propagation Method)으로 계산된 수치 해석 결과와 두 모드 간의 간섭 형상을 직접적으로 확인할 수 있었다.