• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.928-931
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• 2003

In order to realize full color display, two approaches were used. The first method is the patterning of red, green, and blue emitters using a selective deposition. Another approach is based on a white-emitting diode, from which the three primary colors could be obtained by micro-patterned color filters. White-light-emitting organic light emitting devices (OLEDs) are attracting much attention recently due to potential applications such as backlights in liquid crystal displays (LCDs) or other illumination purposes. In order for the white OLEDs to be used as backlights in LCDs, the light emission should be bright and have Commission Internationale d'Eclairage (CIE) chromaticity coordinates of (0.33, 0.33). For obtaining white emission from OLEDs, different colours should be mixed with proper balances even though there are a few different methods for mixing colors. In this study, we will report a white organic electroluminescent device using exciton diffusion length concept.

• 한국정밀공학회지
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• 제31권7호
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• pp.605-613
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• 2014

Scanning white-light interferometry is an important measurement option for many surfaces. However, serious profile measurement errors can be present when measuring free-form surfaces being highly curved or tilted. When the object surface slope is not zero, the object and reference rays are no longer common path and optical aberrations impact the measurement. Aberrations mainly occur at the beam splitter in the interference objective and from misalignment in the optical system. Both effects distort the white-light interference signal when the surface slope is not zero. In this paper, we describe a modified version of white-light interferometry for eliminating these measurement errors and improving the accuracy of white-light interferometry. Moreover, we report systematic errors that are caused by optical aberrations when the object is not flat, and compare our proposed method with the conventional processing algorithm using the random ball test.

• 한국전기전자재료학회논문지
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• 제16권7호
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• pp.616-621
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• 2003

The white-light-emitting organic LED with two-wavelength was fabricated using blue emitting material(DPVBi) and a series of orange color fluorescent dye(Rubrene) by vacuum evaporation processes. The basic structure of white-light-emitting OLED was ITO/NPB(150$\AA$)/DPVBi(150$\AA$)/Alq$_3$:Rubrene(150$\AA$)/BCP(100$\AA$)/Alq$_3$(150$\AA$)/Al(600$\AA$). The changes of the CIE coordiante strongly depended on the doping concentration of Rubrene and the thickness of NPB layer. We obtained the white-light-emitting OLED close to the pure white color light and the CIE coordinate of the device was (0.315, 0.330) at applied voltage of 13V when the doping concentration of Rubrene was 0.5wt% and the thickness of NPB layer is 200$\AA$. At a current of 100mA/$\textrm{cm}^2$, the quantum efficiency was 0.35%.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.411-412
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• 2007

EL (electro luminescent) is generally studied as a large size plane light emitting device and flexible light source because of it's simple manufacturing process. In this experiment, we manufactured flexible white emitting light source using Ni-foil with blue phosphor and color change materials. With increasing the thickness of color change material, the luminance of white emission is increased and the color coordinate of white color was shifted to pure white of (0.317,0.328) by strong emission of color change materials excited by blue excitation spectra. Also the luminance level was 30% higher in white emitting light device than blue only light source.

• 한국컴퓨터그래픽스학회논문지
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• 제16권2호
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• pp.39-45
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• 2010

물체의 색은 모양과 더불어 사람이 바깥세상의 사물을 알아보는데 중요한 역할을 한다. 이런 색상을 인식하는 것은 태양과 같은 빛이 존재하기 때문이다. 빛은 여러 파장들로 구성되어 있으며, 눈에 보이지 않는 적외선, 자외선의 영역과 색을 인식시켜 줄 수 있는 눈에 보이는 가시광선 영역 등으로 이루어져 있다. 이러한 모든 파장의 빛이 균등하게 혼합되면 그 빛은 흰 색을 띄게 되며, 이를 백색광이라고 한다. 백색광이 굴절이 이루어지면 그 구성되어져 있는 가시광선 영역이 여러 가지 색으로 갈라지는데 이것을 분산현상이라 한다. 본 논문에서는, 백색광을 무지개의 대표적인 일곱 가지 색상으로 구성하고 자연의 분상현상을 시뮬레이션하기 위해 N색 분산 포톤 매핑 방법을 제안하였다.

• 한국환경과학회지
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• 제5권5호
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• pp.643-656
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• 1996

백색광 및 여러 파장의 광선 (적색, 청색, 그리고 녹색광)이 녹화중인 귀리 유식물의 엽록소 함량 변화 및 엽록소-단백질 복합체 형성에 미치는 효과를 조사하였다. 높은 광도의 백색광은 낮은 광도의 백색광에 비하여 귀리 유식물의 전체 엽록소 함량 및 엽록소 a/b 비율의 증가에 효과적이었다. 또한 엽록소-단백질 복합체의 형성에 있어서 높은 광도의 백색광은 낮은 광도의 백색광에 비하여 PSI, CCI, 및 CCII의 형성을 효과적으로 촉진하였다. 한편, 여러 파장의 광선하에서 생장한 귀리 유식물은 유사한 광도를 가진 백색 광하에서 생장한 유식물에 비하여 엽록소의 축적 및 엽록소 a/b 비율에 큰 영향을 받지 않았다. 적색광은 귀리 유식물의 엽록소-단백질 복합체의 형성에 있어서 백색광에 비하여 LHCII trimer형성에 효과적이지 못하였으나, 청색광은 백색광과 유사한 효과를 나타내었다. 청색광과 적색광을 비교하였을 때, 청색광은 적색광보다 LHCII monomer의 형성에 효과적이었다. 이와 같은 결과에서 엽록체의 발달과정동안 광도의 효과가 광질의 효과보다 엽록소 축적 및 엽록소 a/b비율의 증가에 중요한 인자로 작용하며, 여러 파장의 광선은 엽록체-단백질 복합체의 조성을 조절하는데 중요한 인자인 것으로 사료된다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 추계국제학술대회
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• pp.62-62
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• 2020

Ginseng is a shade-plant cultivated using shading facilities. However, at too low light levels, root growth is poor, and at high light levels, the destruction of chlorophyll reduces the photosynthesis efficiency due to leaf burn and early fall leaves. The ginseng has a lightsaturation point of 12,000~15,000 lux when grown at 15 to 20℃ and 9,500 lux at 25℃. This study was conducted to select the optimal light intensity of 3-year-old ginseng grown in blue-white film plastic house. The seeds were planted in the blue-white film plastic house with different light receiving rate (March 17, 2020). Between April and September, the average air temperature in the house was 20.4-20.7℃. Average soil temperature was 18.3℃-18.5℃. The chemical properties of the test soil was as follows. The pH level was 7.0-7.4, EC was 0.5-0.6 dS/m, OM was at the levels of 33.6-37.7 g/kg, P₂O₅ was 513.0-590.8 mg/kg, slightly higher than the allowable 400 mg/kg. The amount of light intensity, illuminance, and solar radiation in the blue-white film house was increased as the light-receiving rate increased and the amount of light intensity was found to be 9-14% compared to the open field, 8-13% illuminance and 9-14% solar irradiation respectively. The photosynthesis rate was the lowest at 3.1 µmolCO²/m²/s in the 9% light blue-white plastic house and 4.2 and 4.0 µmolCO²/m²/s in the 12% and 14% light blue-white plastic house, respectively. These results generally indicate that the photosynthesis of plants increases with the amount of light, but the ginseng has a lower light saturation point at high temperatures, and the higher the amount of light, the lower the photosynthetic efficiency. The SPAD (chlorophyll content) value decreased as the increase of light-receiving rate, and was the highest at 32.7 in 9% light blue-white plastic house. Ginseng germination started on April 11 and took 13-15 days to germinate. The overall germination rate was 82.9-85.8%. The plant height and length of stem were long in the 9% light-receiving plastic house. The diameter of stem was thick in the 12-14% light-receiving plastic house. In the 12% and 14% light-receiving plastic house, the length and diameter of taproot was long and thick, so the fresh weight of root per plant was 20 g or more, which was heavier than 16.9 g of the 9% light-receiving plastic house. The disease incidence (Alternaria blight, Gray mold and Damping-off etc.) rate were 0.9-2.7%. The incidence of Sclerotinia rot disease was 7.5-8.4%, and root rot was 0-20.0%. The incidence ratio of rusty root ginseng was 34.4-38.7% level, which was an increase from the previous year's 15% level.

• 한국수산과학회지
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• 제39권6호
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• pp.480-486
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• 2006

The radiation characteristics of a high-luminance light-emitting diode (LED) light source were studied to evaluate its potential as an energy-saving light source for fishing lamps. The angle of the LED light source with 50% illuminance was $8-15^{\circ}$, and it had strong directional characteristics. The wavelengths at which the radiance and irradiance were maxima were 709, 613, 473, 501, 525, and 465 nm for red, orange, blue, peacock blue, green, and white light, respectively. The underwater transmission characteristics of the LED light source were superior in the order blue, white, peacock blue, and green in optical water type I: blue, peacock blue, white, and green in optical water type II; and blue, peacock blue, green, and white in optical water type III. Setting the underwater transmission characteristics of the LED light source in optical water type I at 100%, the transmission of water types II and III decreased to 67 and 17%, respectively. Based on the underwater transmission characteristics calculated in optical water types I-III, the blue and peacock blue LED light sources can be used as an energy-saving light source for fishing lamps.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1559-1560
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• 2007

BGR mixture phosphor pumped by 400 nm is developed for white-light-emitting diode of liquid crystal display backlight. White-emitting phosphor is prepared by mixing $Ba_2SiO_4:Eu^{2+}$ and $(Ba,Sr)_3MgSi_2O_8:Eu^{2+},Mn^{2+}$ phosphors.

• Journal of the Optical Society of Korea
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• 제16권3호
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• pp.203-209
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• 2012

Visible light communications (VLC) use modern solid-state light-emitting diodes (LEDs) to broadcast information. Emerging white-light LEDs allow the combination of lighting and optical wireless communication in one optical source. In this paper, a new LED lighting design using one-chip-type white LEDs is proposed for efficient illumination and optical wireless communications under the existence of several obstacles. Lighting and communication performance are analyzed to show the effectiveness of the proposed LED lighting. Specifically, the signal-to-noise ratio considering intersymbol interference and the bit-error rate of variable pulse position modulation (VPPM) with dimming control are considered.