• Journal of the Institute of Electronics Engineers of Korea TE
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• v.39 no.2
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• pp.11-16
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• 2002

In this paper, single-layer white organic light emitting device was fabricated on ITO glass substrate using PVK as host, Bu-PBD as electron transport layer, Nile Red, Coumarin 6, TPB as red, green, blue color fluorescent dyes. The red, green, blue organic light emitting devices were fabricated respectively. After the characteristic analysis of each color device, the white organic light emitting device was fabricated with optimized condition of each color device by spin coating method. we obtained white emission CIE coordination of (0.32, 0.34) and luminescence of 785cd/$m^2$ at driving voltage of 20V with condition of PVK(70wt%), Bu-PBD(30wt%), Nile Red(0.015mol%), Coumarin 6(0.04mol%), TPB(3mol%). 

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.367-372
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• 2017

LED illumination has been developed from simple illumination to human oriented multi-functional system depending on the IT convergence trends. Thus, the convergence of IT technology such as various types of sensor and communication functions with application software can make saving of energy, and there are also several needs about the tailor-made illuminations requirements for the diverse users who want to take their own colors, strengths of the light. For the adaption of these kinds of intelligent system illumination, user oriented sensor and control should be possible. The LED lighting control system transmits and receives data via the Bluetooth mesh network and provides functions such as LED lighting control, LED lighting condition monitoring, energy usage monitoring, and energy peak point management. Therefore, in this paper, we suggest wireless communication platform and control system for the LED illumination control. We can expect life extension of LED illumination, and energy saving through this suggested system.

• The Transactions of the Korea Information Processing Society
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• v.6 no.12
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• pp.3683-3693
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• 1999

Most recognition methods of car licence plate have difficulties concerning plate recognition rates and system stability in that restricted car images are used and good image capture environment is required. To overcome these difficulties, I proposed a new recognition method of car licence plates, in which both intensity variation and color information are used. For a captured car image, multiple candidate plate-bands are extracted based on the number of intensity variation. To have an equal performance on abnormally dark and bright Images. plate lightness is calculated and adjusted based on the brightness of plate background. Candidate plate regions are extracted using contour following on plate color pixels in oath plate band. A candidate region is decided as a real plate region after extracting character regions and then recognizing them. I recognize characters using template matching since total number of possible characters is small and they art machine printed. To show the efficiency of the proposed method, I tested it on 200 car images and found that the method shows good performance.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.455-455
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• 2016

최근 기후변화로 빈번하게 발생하는 국지성 집중호우로 인해 홍수 피해가 증가하고 있으며, 이에 따라 유량 계측 자료의 필요성이 더욱 증대되고 있다. 현재까지 하천의 홍수 유량측정은 대부분 부자법에 의해 수행되어 왔지만, 측정 작업의 위험성이나 측정 정확도에 대해 여러 문제점이 지적되고 있다. 이에 비접촉식 측정 방법으로 안전하고 측정방식이 간편하며 높은 정확도를 갖춘 표면영상유속측정법(Surface Image Velocimetry, SIV)에 대한 연구가 활발하게 진행되고 있다. 다만 표면영상유속측정법의 경우 질 좋은 영상 촬영을 위해 밝은 빛이 필요하고, 일반적으로 매우 작은 규모의 하천을 제외하고는 영상 획득이 어렵다는 한계가 있다. 이와 같은 문제들을 해결하기 위해 최근 류권규 등(2015)은 영상 획득 장비로 원적외선 카메라의 적용성을 검토한 바 있다. 원적외선 카메라의 경우 별도의 조명을 필요로 하지 않기 때문에 주야간 구분 없이 사용 가능하다는 장점이 있으며 실제 하천에서 홍수와 함께 발생하는 안개의 영향 또한 받지 않아 고정식으로 설치하여 하천 유량측정 시스템을 구성하는 좋은 대안이 될 수 있음을 강조하였다. 다만, 원적외선 카메라는 야간에 적용시 주간과 비교하여 수표면의 움직임이 느리게 분석되는 경향이 있다고 하였다. 실험 결과를 보면, 소형 프로펠러 유속계로 측정한 수표면의 유속값에 비교하여 일반 캠코더 영상으로 산정한 유속 산정 결과의 상대오차는 최대 -10%인 반면, 원적외선 카메라 영상으로 산정한 유속 산정 결과의 오차는 -9%에서 -19%(주간), -10% 에서 -23%까지의 오차 범위를 나타내는 등 일반 캠코더에 비해 원적외선 카메라의 정확도가 다소 떨어지는 결과를 나타냈으며, 이러한 문제를 해결하기 위해서는 원적외선 영상의 명암값 분포 차이를 해결하기 위해 영상 처리 기법에 대한 추가적인 연구가 필요할 것이라고 하였다. 이에 본 연구에서는 원적외선 영상에 대한 다양한 영상 개선을 통해 표면영상유속계의 유속 측정 정확도를 높이고자 하였다. 이를 위해 우선, 적정 해상도와 시간간격을 제시하였으며, 영상의 색 보정과 영상 강화 등의 영상 개선을 통해 원적외선 영상을 이용한 유속 산정 정확도를 향상하였고, 마지막으로 다양한 야간 하천 흐름 조건에 적용하여 원적외선 영상을 활용한 표면영상유속계의 유속 측정 정확도를 높이고자 하였다.

• Journal of the Korea Society of Computer and Information
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• v.13 no.5
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• pp.77-84
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• 2008

This paper proposes a new approach to eliminate the reflectance component for the localization of text in natural scene images. Natural scene images normally have an illumination component as well as a reflectance component. It is well known that a reflectance component usually obstructs the task of detecting and recognizing objects like texts in the scene, since it blurs out an overall image. We have developed an approach that efficiently removes reflectance components while Preserving illumination components. We decided whether an input image hits Normal or Polarized for determining the light environment, using the histogram which consisted of a red component. In the normal image, we acquired the text region without additional processing. Otherwise we removed light reflecting from the object using homomorphic filtering in the polarized image. And then this decided the each text region based on the color merging technique and the Saliency Map. Finally, we localized text region on these two candidate regions.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.2
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• pp.84-88
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• 2021

The change of the photoluminescence properties of La2O3-CaF2-Al2O3-SiO2 glass-ceramics doped with rare earth material, that is used as laser and optical sensors, was analyzed according to heat treatment temperature. The heat treatment conditions for fabricating glass-ceramics were obtained through non-isothermal thermal analysis, and X-ray diffraction analysis was performed to determine the degree of crystal growth and kinds of crystal phases generated according to the heat treatment temperature. Using Scherrer's equation, it was predicted that crystals with a size of 25~40 nm would be generated inside the glass-ceramics. Photoluminescence (PL) analysis showed that the specimens heat-treated at 660℃ to 670℃ for 1 hour had the highest PL intensity. Also, from the CIE color coordinate analysis, all glass-ceramics specimens emitted red-orange light regardless of the heat treatment condition.

• Food Engineering Progress
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• v.14 no.3
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• pp.263-270
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• 2010

An alkalophilic microorganism named DK-2386, which produces xylanase, was isolated from soil of Taejo-mountain, Cheonan-si, Chungnam, Korea. The isolated strain was characterized as Gram-positive, with size of 0.4${\times}$2.5 ${\mu}$m, spore forming, anaerobic, catalase positive, possessed with hydrolysis abilities of casein, starch, sodium carboxy methyl cellulose, and xylan, reduction of nitrate to nitrite, resistant against lysozyme, urease positive, and motility positive. The color of culture broth was reddish yellow. The strain DK-2386 was identified as Bacillus agaradhaerens by whole cell fatty-acid composition analysis and 16S rDNA sequence analysis. However, it was not identical to Bacillus agaradhaerens 40952 obtained from the Korean Culture Center of Microorganism in its colour of culture broth. Therefore, we have named the newly isolated strain as Bacillus agaradhaerens DK-2386.

• Journal of the Korean Applied Science and Technology
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• v.38 no.1
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• pp.126-135
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• 2021

Stimuli-responsive hydrogels are being extensively studied to alter their physiochemical properties in response to external changes such as temperature, pH, light and mechanical stress. This study reports multi-responsive hydrogel having optical change response to external stress. First, we synthesized a novel spiropyran cross-linker successfully by grafting poly(ethylene glycol) diacrylate (PEGDA) on both side of spiropyran and introduced to hydrogel. In the results, the yellow spriopyran structure was conversed to purple merocyaine structure by internal stress during swelling of the hydrogels cross-linked with the SP-PEGDAs. Also, the hydrogel could be visualized the swelling and deswelling process in response to pH, by converting MC and prontonated MC structure.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.4
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• pp.383-390
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• 2020

Blue light is a blue-based light existing at a wavelength between 380 and 450 nm, and it has been reported that it induces active oxygen and causes aging, and accordingly, interest in the blue light blocking effect is increasing. In this study, the effects of the polarity of oil, viscosity of the formulation, type of emulsifier, emulsified particles, and inorganic UV blocking agents on the blue light blocking effect in UV blocking products were investigated. As a result, it was confirmed that the blue light blocking rate increased as the polarity of the oil became similar to that of the organic UV blocker, and the higher the viscosity of the formulation, the higher the blue light blocking rate. The types of emulsifiers and emulsified particles had little effect on the blue light blocking effect, and the presence of inorganic UV blocking agents was found to be one of the factors that greatly influenced the blue light blocking rate. These results can effectively increase the efficiency of blocking blue light, and may be used in the development of blue light blocking products and formulation research in the future.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.5
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• pp.9-16
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• 2005

The purpose of this research is to acquire emotional data on luminous source by measuring and evaluating human emotional response to the change of the optical feature of luminous environment Luminous sources used in actual architectural space were selected with the optical feature of luminous soured then to measure and analysis human emotional response on Luminous Source. As a result of that 1) In the result of performance measurement by the item of the clear vision of an optic function the fluorescent lamp of daylight indicated the most excellent Performance. 2) In the item of fatigue and stress, the metal halide lamp and mercury lamp showed the most 3) In $\ulcorner$ suitable in light$\lrcorner$, $\ulcorner$a similar with daylight$\lrcorner$ adjective of the amenity item the fluorescent lamp of daylight which color temperature was high turned up to be high also, in $\ulcorner$brilliant$\lrcorner$, adjective, the metal halide lamp and mercury lamp turned up to be low. 4) In the result of factor analysis, three factors $\ulcorner$activity$\lrcorner$, $\ulcorner$potency$\lrcorner$, $\ulcorner$evaluation$\lrcorner$ were abstracted and $\ulcorner$activity$\lrcorner$ factor has the most influential on evaluating the mood of interior space. 5) For the affection in the mood evaluation by each luminous sources, $\ulcorner$activity$\lrcorner$ factor was the most influential by metal halide lamp and fluorescent lamp of daylight, $\ulcorner$potency$\lrcorner$ factor was most influential by kind of incandescent lamp, $\ulcorner$evaluation$\lrcorner$ factor was most influential by fluorescent lamp of low color temperature.