• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 추계학술대회
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• pp.757-758
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• 2010

진료 및 수술 집도 시 조명용 광원으로 할로겐램프와 플라즈마램프가 주로 사용되고 있다. 두 광원은 램프의 수명 및 과도한 발열로 인한 다양한 문제점을 야기할 뿐 아니라 냉각기로 인하여 부피 또한 매우 크다는 단점이 있다. 따라서 본 연구에서는 의료용 신조명 부품으로 주목받고 있는 고휘도 LED를 사용하여 진료실 및 수술실에서 환자의 환부에 대한 국소 무영 촬영이 가능하도록 링라이트를 설계 개발하였다. 개발에 적용한 LED는 환부 근접 무영 촬영시 피사체 고유의 Tone에 대한 섬세한 표현력과 강한 하이라이트, 간결한 쉐도우, 그리고 입체감을 부각시키기 위하여 다양한 색상 구현과 광량 조절이 가능하고 백색광을 얻을 수 있는 FULL COLOR용 고휘도 3색 LED를 사용하였다.

• 한국식품영양학회지
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• 제11권3호
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• pp.267-271
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• 1998

Seyferth 시약인 phenyl(tribromomethyl) mercury 및 diazomethane의 식품보존제인 dehydroacetic acid 및 coumarin과의 발암성과 그 반응기작을 분자 구조적 관점에서 알아보기 위하여 UV/vis 조건과 laser flash photolysis 시켰을 때의 결과는 다음과 같다. 1. Diazomethane과 Phenyl(tribromomethyl) mercury와 dehydroacetic acid와 diazomethane과의 반응은 광화학적 분해 반응에서 생성된 : CBr2와 : CH2 카르벤 중간체의 이탈기 효과에 따라 발암성이 크게 나타났다. 2. laser flash photolysis 상에서 반응시켰을 때 식품보존제의 발암성이 UV/vis 상에서의 photolysis 때보다 크게 나타났다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 E
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• pp.1871-1873
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• 1997

The conventional current transformers are often take faults and out of order that for detect to over current of electric power lines because electromagnetic interference. But, it is possible to implement protection relay of high reliability using optical magnetic field sensor which are immunity and small size. The optical magnetic field sensor is possible to rapidly detect to over current and recover when electric power line have fault. And it is not necessary to make with capacitance of electric power lines as optical magnetic field sensor is have linearity from 0 to about 20kA. In this study, we designed and constructed compensative feedback circuit in order to minimize of optical power intensity variation with environ- mental variations(temperature, drive current) of light source. And this system have highest optical advantages and reliability.

• 정보저장시스템학회논문집
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• 제2권1호
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• pp.1-6
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• 2006

An optical ROM card system which using an optical probe array generated by Talbot effect was proposed as new robust storage solution. To improve the optical density and to decrease the power consumption of the system, it is very important to make the spot sizes of optical probes smaller as well as to increase the optical efficiency from the light source to optical probes. In this study, a microlens illuminated aperture array for generating high efficiency optical probe away with small beam spot was designed and fabricated using monolithic lithography integration method. The maximum intensity of optical probes of microlens illuminated aperture array increased about 12 times of that of aperture array, and the full width half maximum of the optical probe at Talbot plane generated by microlens illuminated aperture array was $0.77{\mu}m$.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권1호
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• pp.166-179
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• 2021

Recently, with the development of technology, computer vision research based on the human visual system has been actively conducted. Saliency maps have been used to highlight areas that are visually interesting within the image, but they can suffer from low performance due to external factors, such as an indistinct background or light source. In this study, existing color, brightness, and contrast feature maps are subjected to multiple shape and orientation filters and then connected to a fully connected layer to determine pixel intensities within the image based on location-based weights. The proposed method demonstrates better performance in separating the background from the area of interest in terms of color and brightness in the presence of external elements and noise. Location-based weight normalization is also effective in removing pixels with high intensity that are outside of the image or in non-interest regions. Our proposed method also demonstrates that multi-filter normalization can be processed faster using parallel processing.

• 한국전자통신학회논문지
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• 제12권4호
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• pp.585-590
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• 2017

본 논문에서는 고휘도의 광원에 의한 눈부심 방지와 야간 교통사고예방을 위해 LED와 조도 센서를 이용한 디밍 기술을 사용하여 저 전력 안전지향 보도블록을 구현하였다. 본 논문의 디밍 시스템은 눈부심을 방지하기 위하여 눈에 피로도가 적은 전구색을 사용하였고, 6.10Wh 전력이 소모되었다. 또한, 기존 시스템과 비교하였을 때 약 56.9%의 전력이 절감되는 것을 확인하였다.

• 한국안전학회지
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• 제16권3호
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• pp.68-75
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• 2001

Photopolymerization, the utilization of electromagnetic radiation(or light) as the energy source for polymerization of functional monomers, oligomers is the basis of important commercial processes with broad applicability, including photoimaging and RV curing of coatings and inks. The objective of this study is to investigate the characteristics of environmental fraternitive photopolymerization of methyl methacrylate(MMA). This work is the first step to continue further research about alkyl methacrylate. The experiment was done in aqueous solution under the influence of photo-initiator concentration(0.05-0.25mol/l), light intensity (5000-9000 ${\mu}J/cm^2$) and monomer concentration(2-6mol/l). Methyl methacrylate was polymerized to high conversion ratio using hydrogen peroxide($H_2O_2$) and the kinetics model we have obtained is as follows. $R_p=k_p[S]^{0.41}[M]^{0.62}[L]^{2.45} exp(53.64/RT$). The differential method of thermogravimetric analysis(Friedman method) was used to obtain value of activation energy on decomposition reaction. The average value of it res 45.4Kca1/mol.

• Journal of the Optical Society of Korea
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• 제11권3호
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• pp.138-141
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• 2007

We suggest that supercontinuum can be used for absorption spectroscopy to observe the exciton levels of a semiconductor nano-structure. Exciton absorption spectrum of a GaAs/AlGaAs quantum well was observed using supercontinuum generated by a microstructrured fiber pumped by a femtosecond (fs) pulsed laser. Significantly narrower peaks were observed in the absorption spectrum from 11 K up to room temperature than photoluminescence (PL) spectrum peaks. Because supercontinuum is coherent light and can readily provide high enough intensity, this method can provide a coherent ultra-broad band light source to identify exciton levels in semiconductors, and be applicable to coherent nonlinear spectroscopy such as electromagnetically induced transparency (EIT), lasing without inversion (LWI) and coherent photon control in semiconductor quantum structures.

• Nuclear Engineering and Technology
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• 제50권5호
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• pp.801-805
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• 2018

In this study, an underwater radiation detector was built using a GAGG(Ce) scintillator and silicon photomultiplier to establish an underwater radiation exposure monitoring system. The GAGG(Ce) scintillator is suitable for small radiation detectors as it strongly absorbs gamma rays and has a high light emission rate with no deliquescent properties. Additionally, the silicon photomultiplier is a light sensor with characteristics such as small size and low applied voltage. Further, a program and mobile app were developed to monitor the radiation coefficient values generated from the detector. According to the results of the evaluation of the characteristics of the underwater radiation monitoring system, when tested for its responsiveness to radiation intensity and reactivity, the system exhibited a coefficient of determination of at least 0.99 with respect to the radiation source distance. Additionally, when tested for its underwater environmental temperature dependence, the monitoring system exhibited an increase in the count rate up to a certain temperature because of the increasing dark current and a decrease in the count rate because of decreasing overvoltage. Extended studies based on the results of this study are expected to greatly contribute to immediate and continuing evaluation of the degree of radioactive contamination in underwater environments.

• 한국산학기술학회논문지
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• 제21권3호
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• pp.304-311
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• 2020

본 연구는 식물공장 요소 기술의 표준화를 위하여 LED 광원의 광강도에 따른 식물의 성장변화와 최적 LED 광강도 범위를 확인하였다. 1400 lx와 1600 lx 영역에서 비교적 안정적인 성장을 확인하였고 광강도 증가에 따라 성장과 둔화가 반복되며 성장을 지속하지만, 잎의 성장이 없으면 웃자라는 현상과 함께 성장은 둔화하는 것이 확인되었다. 400 lx에서 800 lx까지의 성장 특징은 실험 기간 어느 정도 성장이 지속하였지만, 웃자라는 현상은 7일까지 유지되었고, 잎이 성장하지 않아 일간 평균 성장차가 현저히 낮아진다는 것을 확인하였다. 1,000 lx에서 1,400 lx까지의 성장은 광강도가 높아짐에 따라 잎의 성장과 일별 성장이 확인되었고 성장증가와 성장둔화가 반복되는 것이 확인되었다. 1,600 lx와 1,800 lx는 1,400 lx 영역과 유사한 성장을 보였지만, 잎의 성장은 높았다. 그러나 1,800 lx에서는 1,400 lx보다 높은 성장을 보였고, 시간 경과에 따라 성장이 둔화하는 것이 확인되었다. 또한, 광강도가 강할수록 광원으로부터 발산되는 열로 인하여 식물 주변의 온도상승이 수반되어 잎의 열화현상이 발생한다. 이러한 실험 결과를 토대로 식물의 성장에 따른 재배 트레이의 공간설정과 재배용 광원과의 거리 조절이 필요하며, 광원의 최대강도 사용에 따른 재배공간의 능동적인 공기조화 계획이 필요하다.