• 디지털산업정보학회논문지
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• 제13권4호
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• pp.41-48
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• 2017

It is necessary to develop an LED traffic light lens having a snow removal function capable of clearly providing a traffic signal to the driver even when a traffic light is blurred due to heavy snow and wind in the winter season. This study is focused on the research and development of the traffic light lens in the process of developing the LED traffic light with the snow removal function. In the developed traffic light lens, instead of attaching the film heater, the coated nichrome wire was wound into a coil shape and inserted directly into the groove in the lens. The developed heater system facilitates the insertion of the heating wire with high elasticity into a curved lens and can provide a sufficient heat without deformation of the PC lens. The proposed traffic lights were tested in various external environments and the test results showed that complete snow removal is possible without tunnel effect.

• 대한임베디드공학회논문지
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• 제9권3호
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• pp.145-150
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• 2014

This paper presents an effective vision based method for LED traffic light detection at the daytime. First, the proposed method calculates horizontal coordinates to set region of interest (ROI) on input sequence images. Second, the proposed uses color segmentation method to extract region of green and red traffic light. Next, to classify traffic light and another noise, shape filter and haar-like feature value are used. Finally, temporal delay filter with weight is applied to remove blinking effect of LED traffic light, and state and weight of traffic light detection are used to classify types of traffic light. For simulations, the proposed method is implemented through Intel Core CPU with 2.80 GHz and 4 GB RAM, and tested on the urban and rural road video. Average detection rate of traffic light is 94.50 % and average recognition rate of traffic type is 90.24 %. Average computing time of the proposed method is 11 ms.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.348-350
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• 2006

Currently the indication method of the traffic signal light which is established in our country displays each "red, yellow, green" using the brightness LED signal light. In this paper, one LED circular arrangement replaces the Current indication method of the traffic signal light using two color LED. Also the blinking signal function of present time uses the MCU of AVR series and it is embodied with magnification and abridgment of the circular arrangement for recognizing easily far away. The signal light indication method which is proposed will be able to substitute the signal light of 3 colors with 1 signal light with economic profit presented the reform measure of energy efficiency improvement together.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.476-481
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• 2009

In this paper, we propose a visible light road-to-vehicle communication system at intersection as one of ITS technique. In this system, the communication between vehicle and a LED traffic light is approached using LED traffic light as the transmitter, and on-vehicle high-speed camera as the receiver. The LEDs in the transmitter are emitted with 500Hz and those emitting LEDs are captured by a high-speed camera for making communication. The images from the high-speed camera are processed to get luminance value of each LED in the transmitter. For this purpose, first transmitter should be found, then it should be tracked for each frame, and the luminance value of each LED in the transmitter should be captured. In our previous work, transmitter was found by getting the subtraction of two consecutive frames. In this paper, we mainly introduce an algorithm to detect the found transmitter in consecutive frames. Experimental results using appropriate images showed the effectiveness of the proposal

• 방송공학회논문지
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• 제14권4호
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• pp.475-487
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• 2009

We propose a visible light road-to-vehicle communication system at intersection as one of ITS technique. In this system, the communication between vehicle and a LED traffic light is approached using LED traffic light as a transmitter, and on-vehicle high-speed camera as a receiver. The LEDs in the transmitter are emitted in 500Hz and those emitting LEDs are captured by a high-speed camera for making communication. Here, the luminance value of each LED in the transmitter should be found for consecutive frames to achieve effective communication. For this purpose, first the transmitter should be identified, then it should be tracked for consecutive frames while the vehicle is moving, by processing the images from the high-speed camera. In our previous work, the transmitter was identified by getting the subtraction of two consecutive frames. In this paper, we mainly introduce an algorithm to track the identified transmitter in consecutive frames. Experimental results using appropriate images showed the effectiveness of the proposal.

• 한국ITS학회:학술대회논문집
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• 한국ITS학회 2008년도 제7회 추계학술대회 및 정기총회
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• pp.565-569
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• 2008

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2009년도 공동학술대회
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• pp.538-539
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• 2009

해양교통안전시설인 등대 불빛은 지금까지 백열전구를 사용한 필라멘트를 이용하여 열을 빛으로 바꾸는 광원을 사용하고 있으며, 점차적으로 저전력 소비 및 장수명의 장점을 가진 고휘도 LED(Light Emitting Diode)을 이용한 LED 도등, LED 등명기, LED 등대 표체 경관조명, LED로 만든 전등 국내 개발 등 차세대 광원 "발광다이오드"는 수년내에 시장을 평정할 것으로 전망된다.

• 한국통신학회논문지
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• 제37A권10호
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• pp.834-840
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• 2012

The use of ranging sensors on automobiles is becoming common with the desire of traffic safety by providing drivers the information of the relative distance between the vehicles. In this paper, the LED visible light ranging system different from the conventional ranging systems using the RF signal is investigated. For such a system, we propose a novel ranging algorithm which combines the time-of-flight (TOF) with the CDMA technology. Via the CDMA technology, the TOF ranging system can accurately distinguish the desired ranging signal from the visible light interferences of the neighbor vehicles. In addition, the proposed system can also overcome the light noise from other luminaries, i.e. sun-light, traffic-light, and so on. The simulation results show that the CDMA-based LED ranging system has a significant improvement for the ranging accuracy compared with the case without employing the CDMA.

• 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).

• 디지털융복합연구
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• 제12권7호
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• pp.247-252
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• 2014

교통의 연동시스템은 이웃한 교차로의 교통상황을 입력받아 해당 교차로 신호처리시 고려하는 시스템이다. 이웃 교차로의 통과차량수, 대기차량수,녹색신호등 주기 등을 감안하여 해당 교차로의 녹색신호등의 주기를 결정하는 형태이다. 해당교차로의 녹색신호등을 고려할 때는 자기 자신의 센서 입력들만 고려해서는 안되고 이웃 교차로의 센서 입력들을 받아 들여야 한다. 이러한 센서 노드들의 데이터 수집을 위해서 위험과 한계가 있는 곳에 센서 노드를 배치하여 데이터 수집을 하는 경향을 감안하여 사람이 인접할수 없는 곳이나 환경이 척박한곳에 센서들을 배치하여 센서들을 통한 정보 획득, 무선 네트워크를 통한 통신, 초저전력 소모를 실현할 수 있다.