• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.317-318
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• 2022

해상환경에 설치된 광파표지는 정기적으로 광학특성 검사를 수행하지만, 사람이 접근하기 힘든 지역에 위치한 표지는 측정선을 활용하여 측정한다. 이러한 측정방법은 비용문제, 안전문제, 측정오차 등의 문제가 있어 새로운 측정방법이 필요한 상황이다. 또한, 항만배후광의 영향으로 인한 항로표지 시인성 저하 문제를 분석하기 위해 휘도계 장비를 사용하지만, 환경적 제약으로 정확한 측정과 분석이 어려운 상황이다. 본 논문은 항로표지와 항만배후광의 광휘도 분석을 위한 측정방법과 알고리즘 설계에 관한 내용이다.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.2
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• pp.11-16
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• 2001

The polariscope to measure :he stress in lens was made up quarter-wave plate polarizer and we analyzed two components of light's wave $E_1$ and $E_2$ following the steps. It is clear that the principal-stress difference ${\sigma}_1-{\sigma}_2$ can be determined in 2-D model if fringe order N is measured each point in sample moreover. the optical axes of sample coincide with the principal-stress directions. The birefringence acted to a light wave and a phase retardation were in proportioned to the principal-stressed difference (${\sigma}_1-{\sigma}_2$) and the intensity of final light wave was proportioned to $sin^2({\Delta}/2)$, when ${\Delta}/2=n^{\pi}$ (n=0, 1, 2, ...) and the extinction occurs. As a experimental result, the extinction band shifted owing to a magnitude of lens' external stress.

• 한국IT서비스학회:학술대회논문집
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• 2010.05a
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• pp.162-165
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• 2010

우리나라 대형 건설시장의 하나인 터널 시공은 계획 대비 많은 물량과 자재의 소모로 인해 이들 정보의 지속적 관리를 통한 정확한 물량 및 자재 산출 정보 예측에 대한 관심이 꾸준히 요구되고 있는 실정이다. 대부분의 시공현장에서는 굴진의 정확도 검측을 위해 광파기를 사용하고 있다. 광파기는 공사 초기 시부터 유지된 원점으로부터의 정확한 좌표를 사용하고 있어 취득된 정보는 신뢰할 수 있으나, 몇 개의 기준점을 측량하여 굴진방향 및 공사의 진척도를 평가하는 방식이므로, 전체적인 면을 측정하지 못한다는 단점이 있다. 이에 반하여 3차원 스캐너는 제원에 따른 반경 내의 모든 점들을 계측하여 그 정보를 선이 아닌 면으로써 파악하지만 위치에 대한 정확도를 포함할 수 없다. 이러한 문제점을 보완하기 위하여, 광파기와 3차원 스캐너를 동시 활용하는 본 시스템은 현장에서 소모된 자원의 정확한 양을 체크하여 굴진정도를 파악하여 공사의 전반적인 진도를 관리할 수 있다. 또한 여굴의 발생 여부를 직접 확인하고 계획대비 소모된 물량정보를 통해 자재관리를 할 수 있게 된다. 마지막으로 추후 발생할 수 있는 하자에 대한 정확한 근거를 제시하여 균열 및 누수 등에 대한 정확한 원인 파악을 제공할 수 있다는 장점들을 제공한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.10a
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• pp.365-367
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• 2012

해양교통시설 측정선 "한빛호"는 우리나라 전 해역의 광파표지(유 무인등대), 전파표지(GNSS, DGNSS, Loran-C 등), 음파표지(무신호기) 성능 측정 및 분석을 담당하는 국내 유일의 선박으로 그 중 전파표지의 GNSS와 DGNSS 측정된 수신테이터 분석을 통해 항법성능 요구조건 충족 여부와 전파 관련 유관기관에 참고자료로 활용하는데 기여하고자 합니다.

• Progress in Medical Physics
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• v.9 no.2
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• pp.115-121
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• 1998

In this paper, basic study of diagnostic device development for early detection of cancer, we present the optical property measurements of 12 histologically classified biological tissue and blood specimens in order to determine whether significant optical contrast exists for detection of disease(cancer). In vitro, optical properties of each 630nm, 660nm, 780n, 880nm and 940nm shows consistent changes in effective absorbtion coefficients, ${\mu}$$\_$${\alpha}$/ with tissue classification of pig an chicken and human blood according to the 27.3%, 35.4%, 45.6% and 59.1% of HCT. We found differences in optical properties at each of specific wavelengths and histologically classified biological tissue.

• Korean Journal of Optics and Photonics
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• v.10 no.4
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• pp.328-334
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• 1999

Methylene blue-sensitized photopolymerizable material based on acrylamide is investigated with two-wave energy coupling experiments. Differently from other studies, self-diffraction oscillations are observed and the grating phase is determined without applying external electric fields, moving nonlinear materials, and phase shifting one of two writing beams. The phase grating showed a phase shift of $\pm$50$^{\circ}$ with respect to the intensity grating. Modified Kogelnik's coupled wave equation considering the mixed gratings of phase and absorption gratings and nonzero spatial phase shifts of the gratings with respect to the intensity interference patterns formed during the two-wave energy coupling is discussed in detail to understand these phenomenon.

• The Journal of Engineering Geology
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• v.17 no.4
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• pp.567-576
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• 2007

In order to assess the on-site applicability of 3D absolute displacement monitoring of tunnel using digital photogrammetry, the displacement of the optical target placed at the measurement section was investigated, as planned in the OO tunnel construction site. The targets on 3 measurement lines only were considered for each point of measurement for the reconstruction of 3D cubic model for the digital vision monitoring. For each 3D model, 3 or more images have to be obtained at each point. On the last 2 measurement lines, 6 targets (crown, left and right walls) were continuously overlapped to construct 3D models so that 6 or more apices can be shared by 2 3D models. In order to compare the measurement methods of 3D absolute displacements in tunnel excavation, i. e, total station and digital image measurement, both the digital image measurement and optical measurement were conducted for 10 times in the same work section. The time and measurement results of both methods were compared.

• Proceedings of the Optical Society of Korea Conference
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• 2004.07a
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• pp.76-77
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• 2004

• Korean Journal of Optics and Photonics
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• v.10 no.6
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• pp.507-511
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• 1999

A 10 GHz timing extracted signal which is phase-locked to a 10 Gbit/s mode-locked optical fiber laser pulse train is obtained using a tour-wave-mixing signal in semiconductor optical amplifier. The phase-locked loop wm, demonstrated ~Llccessful1y over 8 hours and found to have the lock-in frequency range of 30 KHz. 0 KHz.

• Korean Journal of Optics and Photonics
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• v.4 no.1
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• pp.73-83
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• 1993

The temporal differential equation describing the build-up of the space-charge field in the presence of square and sinusoidal alternating field in photorefractive materials is solved analytically. We also measured the average two-wave mixing gain and the full temopral gain variations in a B$i_{12}$Si$O_{20}$ crystal with applied fields of up to 7 KV/cm amplitude and 1 KHz repetition rate. It has been found that the experimental measurements agree well with the theoretical results.