• Horticulture, Environment, and Biotechnology : HEB
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• v.59 no.6
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• pp.827-833
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• 2018

Plasma lighting systems have been engineered to simulate sunlight. The objective of this study was to determine the effects of plasma lighting on tomato plant growth, photosynthetic characteristics, flowering rate, and physiological disorders. Tomato plants were grown in growth chambers at air temperatures of $25/23^{\circ}C$ (light/dark period), in a $16h\;day^{-1}$ light period provided by four different light sources: 1 kW and 700 W sulfur plasma lights (1 SPL and 0.7 SPL), 1 kW indium bromide plasma light, and 700 W high pressure sodium lamp (0.7 HPS) as a control. The totaldry weight and leaf area at 0.7 SPL were approximately 1.2 and 1.3 times greater, respectively, than that of 0.7 HPS at the 62 days after sowing (DAS). The maximum light assimilation rate was observed at 1 SPL at the 73 DAS. In addition, the light compensation and saturation points of the plants treated with plasma lighting were 98.5% higher compared with HPS. Those differences appeared to be related to more efficient light interception, provided by the SPL spectrum. The percentage of flowering at 0.7 SPL was 30.5%, which was higher than that at 0.7 HPS; however, there were some instances of severe blossom end rot. Results indicate that plasma lighting promotes tomato growth, flowering, and photosynthesis. Therefore, a plasma lighting system may be a valuable supplemental light source in a greenhouse or plant factory.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.11
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• pp.14-25
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• 2011

Full-Color LED lighting system requires efficient control of the lighting color in order to easily achieve various color effects. In this paper, we present not only a portable color scanner using color sensors which can control lighting color directly from detected color but also methods to convert detected color to a complementary color, similar colors and so on. In addition, we propose a compensation method for measured sensor color to reduce measurement errors more than 50[%] in detected color. The developed color scanner is applied to control full-color LED ceiling light for emotional lighting.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.436-442
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• 2015

In this paper, we develop an indoor localization device which embeds localization information into indoor light-emitting-diodes (LED) lighting systems. The key idea of our device is the use of the newly proposed "bit stuffing method". Through the use of stuff bits, our device is able to measure signal strengths even in transient states, which prohibits interference between lighting signals. The stuff bits also scatter the parts of the signal where the LED is turned on, thus provides quality indoor lighting. Additionally, for the indoor localization system based on RSSI and TDM to be practical, we propose methods for the control of LED lamps and compensation of received signals. The effectiveness of the proposed scheme is validated through experiments with a low-cost implementation including an indoor navigation task.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1649-1651
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• 2008

A novel configured S-IPS LCD has been developed introducing a new compensation film with an anti-reflective layer. This new technology provides wide viewing characteristics as well as excellent visibility under bright indoor lighting or natural lighting.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.3
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• pp.16-25
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• 2013

Now it's a trend to install a series of white fluorescent light and orange high pressure sodium lamps because tunnel lighting should be opaque to the safety of drivers from soot, dust, humidity, and fog. Also fluorescent lighting is replaced to LED due to the fact that it improves amenity and object recognition and LED lighting has gradually been improved its nature. In this paper, we have implemented the circuits of the yellow series of high-pressure sodium lamps and white series of LED lights at one board to improve the transparency and recognition of objects. It is possible for inductive high-pressure sodium lamps and the capacitive LED drivers to circuit without power factor compensation. Two circuit parts share only a small number of parts, so low cost LED drivers compared to conventional ones are possible. Therefore, the implementation of the hybrid lighting with high-pressure sodium lamps and LED lights that can be driven at the same time by one driving circuit is possible. The LED capacitive power factor was 0.91 while individually implemented the sodium lamp power factor was 0.98. It shows not only the 2% improvement of hybrid forms but also the efficiency and THD.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.364-368
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• 2009

자궁경부암은 다른 암과 달리 전암(前癌) 단계가 존재하므로 조기에 발견할 경우 생존율이 높다. 그러나 검체 적정성의 부족과 검체 체취의 오류로 인해 질병이 있음에도 음성으로 나타나는 위음성률이 높다. 따라서 본 논문에서는 세포 도말검사에서 사용되는 자궁 경부진 세포에서 암종 세포를 추출하는 방법을 제안한다. 영상의 배경 그리고 핵과 세포질 영역의 구분이 중요하기 때문에 조기 자궁 경부 세포진 영상에서 핵의 추출은 Lighting Compensation을 적용하여 영상을 보정하고, 명암도 분포가 가장 작은 B 채널과 명암도 분포가 높은 R채널과의 OR 연산을 적용한 후, $3{\times}3$마스크를 이용하여 잡음을 제거한다. 잡음이 제거된 영상을 이진화하고 Grassfire 알고리즘을 이용하여 암종 세포의 후보 객체를 추출한다. 추출된 세포 객체에서 핵의 크기, 핵의 면적과 핵의 외곽의 방향성 정보를 이용하여 백혈구와 잡음으로 구성된 객체를 제거한다. 세포 도말검사 과정에서 겹쳐진 부분은 거리 함수와 명암도를 이용하여 마커를 추출하고 추출된 마커 정보와 워터쉐드 알고리즘을 적용하여 겹쳐진 암종 세포를 분리한다. 자궁경부 편평 세포진 400 배율 영상과 자궁 경부 상피내 종양 400 배율 영상을 대상으로 실험한 결과, 기존의 자궁 경부진 암종 세포 추출 방법보다 효과적으로 암종 세포 영역이 추출되는 것을 확인하였다.

• Journal of Internet Computing and Services
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• v.7 no.3
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• pp.143-153
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• 2006

Facial feature detection is a basic technology in applications such as human computer interface, face recognition, face tracking and image database management. The speed of feature detection algorithm is one of the main issues for facial feature detection in real-time environment. Primary factors like a variation by lighting effect, location, rotation and complex background give an effect to decrease a detection ratio. A facial feature detection algorithm is proposed to improve the detection ratio and the detection speed. The proposed algorithm detects skin regions over the entire image improved by CLAHE, an algorithm for light compensation against varying lighting conditions. To extract facial feature points on detected skin regions, it uses appearance-based geometrical characteristics of a face. Since the method shows fast detection speed as well as efficient face-detection ratio, it can be applied in real-time application to face tracking and face recognition.

• Journal of Broadcast Engineering
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• v.11 no.4 s.33
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• pp.396-406
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• 2006

This paper proposes an omni-directional image generation algorithm with parametric image compensation. The algorithm generates an omni-directional image by transforming each planar image to the spherical image on spherical coordinate. Parametric image compensation method is presented in order to compensate vignetting and illumination distortions caused by properties of a camera system and lighting condition. The proposed algorithm can generates realistic and seamless omni-directional video and synthesize any point of view from the stitched omni-directional image on the spherical image. Experimental results show that the proposed omni-directional system with vignetting and illumination compensation is approximately $1{\sim}4dB$ better than that which does not consider the said effects.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.9
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• pp.1181-1187
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• 1995

In video camera, an automatic video quality compensation method using the dynamic range transform is proposed. The histogram is used to decide the nonuniformness of picture brightness by nonuniform lighting. The gray level is divided four regions, and the histogram is obtained per one field. We introduce a new parameter, nonuniformness, defined by the cumulative difference between its CDF and LCDF. We also propose the decision function of the dynamic range transform constant versus its nonuniformness, and compensate the quality of video automatically.

• Journal of Bio-Environment Control
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• v.17 no.2
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• pp.132-137
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• 2008

This experiment was conducted to investigate the effect of supplemental lighting of low light intensities on growth and yield of rose 'Vital' in a forcing culture. Metal halide lamp (MH), High pressure sodium lamp (HSP), and MH+HSP were used as the light sources, and they were set up at a $310\;cm{\times}450\;cm$ interval and at 120cm above the culture beds. Light intensity at 1m point distance from supplemental lighting sources was $32{\sim}34\;{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Days to the 1st and 2nd harvests decreased by $5{\sim}8$ and $3{\sim}5$days, respectively in supplemental lighting treatment as compared to the control. Days to harvesting was the shortest in MH+HPS treatment, followed by BPS and MH, although there was no significant difference between HPS and MH treatments. The growth was better and incidence of blind shooting decreased by $5{\sim}7%$ in supplemental lighting treatments than the control, increasing marketable cut flowers. The incidence of blind shoot was the lowest in MH+BPS treatment, and there were no significant difference between MH and BPS treatments. In conclusion, supplemental lighting of low light intensities was effective in reducing days to flowering and reduced occurrence of blind shoots.