• 대한약리학회지
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• 제8권2호
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• pp.35-39
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• 1972

Previous studies on the effect of the visible lights on the organism have shown the possible influences on the nervous system. It was reported that the illumination of blue beam increased the sympathetic tone and that of red beam increased the parasympathetic tone. The pharmacological actions of the sympathomimetics were also known to be altered by various visible lights. But their modes and mechanisms of actions on the nervous system have not been clarified and is obscure. To elucidate the precise mechanism of action of the visible lights on the nervous system, present study was made to observe the survival time of the mole living in the dark environment, under the illumination of the various visible lights and influences of several drugs. The results are summerized as follows: 1. The illumination of the natural sun light caused the survival time of the mole to be shortened and visible monochromatic beams (red, blue and green) even more markedly shortened the survival time. No significant difference was noted depending on the wave length of the chromatic beam. 2. The shortened survival time caused by the visible monochromatic lights was prolonged by strychnine but not affected by morphine. 3. The survival time under the illumination of the visible monochromatic lights was prolonged by acetylcholine and physostigmine. 4. The shortened survival time under the illumination of the monochromatic visible lights was not affected by adrenaline but prolonged by priscoline. It is suggested that the shortened survival time of the mole by the illumination of the visible lights can be prolonged by the stimulation of central and parasympathetic nervous system and blocking of the sympathetic nervous system.

• 한국ITS학회 논문지
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• 제8권5호
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• pp.114-120
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• 2009

In outdoor visible light communication channels and LED road illumination communications for the intelligent transport systems (ITS), inter symbol interference (ISI) due to multipath propagation prevents high data rate transmission. Indoor wireless optical communication systems utilizing white LED lights and on the road illumination have been studying about it. Generally, plural lights are installed in room and considered to the traffic information system using existing LED traffic lights. Therefore, their optical path difference must be considered. In this paper, the influence of an optical path difference has been investigated and two approaches against this problem are introduced. One uses on-off keying, return-to-zero (OOK-RZ) coding and the other uses optical orthogonal frequency division multiplexing(OFDM).

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.7-11
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• 2008

Future electric lights will be composed of white LEDs (Light Emitting Diodes). Indoor wireless optical communication systems utilizing white LED lights have been studying about it. Generally, plural lights are installed in room. Therefore, their optical path difference must be considered. In this paper, the influence of an optical path difference has been investigated and two approaches against this problem are introduced. One uses OOK-RZ (On-Off Keying, Return-to-Zero) coding and the other uses optical OFDM (Orthogonal Frequency Division Multiplexing). From the results of computer simulations, we have found that these approaches are feasible for the wireless optical communication systems utilizing white LED lights.

• 대한안전경영과학회지
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• 제18권1호
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• pp.1-8
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• 2016

This study was conducted by survey and inspection of stair passage leading lights in shopping buildings which are more than 5 stories and have an underground parking lot located at Pyeongtaek-si and Seongnam-si. Number of shopping building for this study is 30 and of stair passage leading light inspected by two lights in each shopping building is 60. The result of this study is that the type of installed leading lights is LED(77%), and 60% of leading lights has problem such as no cleaning, scratch and discoloration, etc. The height of installed leading lights meets the fire law which is less than 1m from the floor. Visible condition of leading lights is good except some leading lights which have a little visible problem due to banner advertisement. 37% of standby power has flickered and went out. 93% of total leading lights meets the fire law which is more than 1lux from 0.5m distance, but cold cathode fluorescent lamps(CCFLs) have the problem which not meets proper brightness level based on fire law. In additional measurement result, zero lux of leading lights is 32%(from 1m distance), 68%(from 1.5m distance) and 98%(from 2m distance). Leading light is very important facility because it is eyes and guide when emergency. Therefore, proper fire facility operating function inspection and total detailed inspection are important to keep the good condition of leading light except simple visual check, and also improvement in law system of type approval, fire construction inspection and illumination level will be needed.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2017년도 제56차 하계학술대회논문집 25권2호
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• pp.135-136
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• 2017

When driving at night time environment, the whole body of transports does not visible to us. Due to lack of light conditions, there are only two options, which is clearly visible their taillights and break lights. To improve the recognition correctness of vehicle detection, we present an approach to vehicle detection and tracking using finding contour of the object on binary image at night time. Bilateral filtering is used to make more clearly on threshold part. To remove unexpected small noises used morphological opening. In verification stage, paired tail lights are tracked during their existence in the ROI. The accuracy of the test results for vehicle detection is about 93%.

• Fisheries and Aquatic Sciences
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• 제26권8호
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• pp.514-523
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• 2023

The visible threshold of Oreochromis niloticus responded to high light intensity under short wavelengths, whereas the response to low light intensity under long wavelengths was low, with a minimum visual threshold of 574 nm of LED lights. Movement distance of O. niloticus was dropped at 31℃ and increased abnormally at 37℃ under natural light. Comparing movement distance under red (622 nm) and green (518 nm) lights of LED, movement distance and swimming speed under red and green lights were higher than under natural light. However, the movement distance decreased rapidly at 31℃ under red light and lowest at 33℃ under green light. After that, there was a tendency to adapt to high water temperatures gradually. Consequently, red and green lights may be recommended for O. niloticus's aquaculture because the red and green lights have a positive effect on growth performance, survival rate, and metabolism, as shown in previous studies. It is necessary to control the water temperature below 32℃ because abnormal behavior above 32℃ revealed under red and green LED lights and natural light.

• 한국멀티미디어학회논문지
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• 제22권2호
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• pp.186-193
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• 2019

Visible light communication technology is being studied and developed in various ways due to advantages such as high transmission speed, excellent positioning and higher security. However, existing visible light communication systems have difficulties in entering the market because they use special transmitters and receivers. We will overcome the difficulty if we develope a VLC system that uses a conventional LED light as a transmitter and a smartphone camera as a receiver. What matters is that LED lights include a scatter filter to prevent glareness for human eyes, but the existing VLC(Visual Light Communication) method can not be applied. In this paper, we propose a method to encode data with On / Off patterns of LEDs in the lighting with $M{\times}N$ LEDs. We defined parameters like L-off-able and K-seperated to facilitate the recognition of On / Off patterns in the diffused Lights. We conducted experiments using an LED lighting and smart phones to determine the parameter values. Also, the maximum transmission rate of our encoding technique is mathematically presented. Our encoding scheme can be applied to indoor and outdoor positioning applications or settlement of commercial transactions.

• Journal of the Optical Society of Korea
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• 제19권6호
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• pp.586-591
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• 2015

In recent years, along with the rapid development of LED technology, indoor positioning systems based on visible light communication (VLC) have been researched. In this paper, we propose an accurate indoor positioning method using white-light LEDs and a dual image sensor. Indoor LED lights are located at the ceiling in a room and broadcast information on their positions using VLC technology. A mobile device with a dual image sensor receives LED position information by VLC and estimates its position and azimuth angle. Simulation and experimental results are given to show the performance of the proposed indoor positioning system.

• 한국광학회:학술대회논문집
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• 한국광학회 1999년도 제16회 광학 및 양자전자 학술발표회Proceedings of 16th Optics and Quantum Electronics Conference, 1999
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• pp.150-151
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• 1999

• 한국정보통신학회논문지
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• 제15권5호
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• pp.1045-1052
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• 2011

최근 복합 문화 시설이 증가하면서 지하 공간 활용이 확대됨에 따라, 사용자의 실내 위치에 따른 주변 정보만을 무선으로 제공해주는 맞춤형 서비스에 대한 요구도 확산되고 있다. LED 조명을 이용한 가시광 통신 방식의 경우, GPS를 사용할 수 없는 실내 공간에서 위치 기반 서비스를 구현하기에 적합하다. 이에 본 논문에서는 가시광 통신을 이용한 실내 위치 기반 서비스를 구현하기 위해 기준 위치를 구분하는 실험에 대해 다룬다. LED 조명의 특성을 고려하여 LED와 PD 간의 각도 및 거리에 따라 LED 조명별로 서로 다른 식별 패턴을 ASCII 코드로 전송한 결과 최대 1.75m의 거리까지 LED 조명의 식별자를 수신할 수 있음을 확인한다. 이러한 실험 결과를 통하여 LED 조명을 이용한 실내 네비게이션의 가능성을 확인해볼 수 있다.