• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.522-523
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• 2008

This paper presents an LED lighting which can control its color temperature. It consists of a power factor correction (PFC) circuit, an LED driver, and an LED color control circuit. The proposed system can adjusts the light intensity to obtain a desired color with independently changeable illuminance. The power factor of the PFC circuit is 98%. The LED driver has 90% efficiency at 300mA output current. The output power of the experimented LED lighting is 150 W. The achieved color temperature range was from 3000K to 7500K, and the illumination one was from 500 lux to 1500 lux.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.129-132
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• 2009

공항내 설치된 보안등의 운용실태를 조사하고 인적경비에 맞춘 보안등 설계에서 첨단의 CCTV 카메라 및 주변기기를 이용한 과학화된 경비체제에 맞는 안정된 보안등 설계가 요구되어진다. 본 논문에서는 과학화된 보안시스템에 맞는 조명 설계을 위하여 단방향 투사용 LED 램프를 이용한 등기구와 2.5m 높이의 폴로 현장에 이동 배치하여 적용하였으며, 기존 시설된 고압나트륨과 시범 설치원 LED 광원의 조도 및 눈부심을 비교하여 최상의 CCTV 감시 화면의 특성파악 및 정확한 물체를 식별 할 수 있는 조도을 유지하여 안정된 보안등의 조명설비를 제시하고자 한다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.133-137
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• 2006

In iris recognition, iris segmentation plays a very important role because its accuracy affects directly to the performance of the whole system. This paper proposes a new approach for segmenting iris that is fast, accurate and especially robust to occlusion and illumination. In this method, a circular filter is used for detecting the center of the inner circle. Then, a technique to linearize the limbus is applied and the limbus is detected using a linear filter. Experimental results show that the proposed method has promising performance for improving the iris recognition accuracy.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.7
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• pp.1126-1132
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• 2002

In this paper, we propose a new scheme of motion tracking based on fuzzy inference (Fl) and wavelet transform (WT) from image sequences. First, we present a WT to segment a feature extraction of dynamic image . The coefficient matrix for 2-level DWT tent to be clustered around the location of Important features in the images, such as edge discontinuities, peaks, and corners. But these features are time varying owing to the environment conditions. Second, to reduce the spatio-temperal error, We develop a fuzzy inference algorithm. Some experiments are performed 0 testify the validity and applicability of the proposed system As a result, proposed method is relatively simple compared with the traditional space domain method. It is also well suited for motion tracking under the conditions of variation of illumination.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.3
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• pp.178-182
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• 2014

This paper investigates the lighting environment of railway system which are mainly used in KTX, Saemaul and Mugunghwa. When lighting used in KTX such as fluorescent lamp and incandescence is being replaced with LED lamp, illumination load of each railroad vehicle has been compared. The comparison result shows that the reduction of power consumption is 43.34% before and after the change. Also it has been performed the economic evaluation.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.3
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• pp.36-40
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• 2013

Recently, electronic equipments become smaller, more functional, and more complex than before. As these trends, MLC(multi-layer ceramic) circuit has been emerged to a promising technology in semiconductor inspection industry. Especially, multi-layer ceramic which is consisted of many fine-pitch multi-hole is used to produce a semiconductor inspection unit. The hole is processed by UV laser. But, working conditions are changed all the time. Therefore real time measurement of fine-pitch multi-hole is very important method for ensuring performance. In this paper we found the best method for illuminating and auto focusing. And, we verified our equipment.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1294-1298
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• 2007

Welding process monitoring is advantageous for maintaining weld quality and numerous sensing techniques have been developed for laser welding. Coaxial image monitoring enables direct monitoring of the weld pool shape and keyhole behavior, but requires the complex optical system and the image processing technique. In this study, we coaxially acquired the weld pool images during laser lap welding by using the camera and special illumination. The welding characteristics - pool width and length, keyhole shape, etc - were extracted by using image processing and the relationship between these characteristics and the penetration depth were investigated.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.59-60
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• 2011

요즘 스마트 디바이스의 보급으로 스마트 디바이스를 통한 다양한 정보제공 서비스 또한 빠르게 증가하고 있다. 본 논문에서는 GPS(Global Positioning System) 센서 이용이 제한적인 실내와 같은 좁은 공간에서 스마트 디바이스 통한 내비게이션시 다양한 정보를 제공할 수 있는 실내 조명변화에 강한 마커 인식 방법을 제안한다. 제안 방법은 형태가 비슷한 실내 공간과 조명이 제한적이거나 급격하게 변하는 상황에서 견고하고 정밀한 위치 추적을 통해 정확한 서비스를 제공할 수 있게 해 줄 것이다.

• The Journal of Korea Robotics Society
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• v.6 no.1
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• pp.18-26
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• 2011

This paper presents a method, Exposure Controlled Temporal Filtering (ECF), applied to visual motion tracking, that can cancel the temporal aliasing of periodic vibrations of cameras and fluctuations in illumination through the control of exposure time. We first present a theoretical analysis of the exposure induced image time integration process and how it samples sensor impingent light that is periodically fluctuating. Based on this analysis we develop a simple method to cancel high frequency vibrations that are temporally aliased onto sampled image sequences and thus to subsequent motion tracking measurements. Simulations and experiments using the 'Center of Gravity' and Normalized Cross-Correlation motion tracking methods were performed on a microscopic motion tracking system to validate the analytical predictions.

• Proceedings of the Korea Contents Association Conference
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• 2015.05a
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• pp.427-428
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• 2015

정보통신 기술의 발전으로 교육 패러다임이 스마트 디바이스를 이용하는 스마트 러닝으로 변화하고 있다. 특히 에듀테인먼트 시스템들은 암묵적 지식습득률 향상을 위하여 증강현실 기술을 도입한 다양한 시스템들이 도입되고 있다. 그러나 이와 같이 증강현실을 이용한 시스템들은 실환경의 조명과 가상환경의 조명환경의 부조화로 인하여 영상 합성시 실감성이 낮은 문제점을 가지고 있다. 따라서 본 논문에서는 증강 객체, 웹캠을 통해 입력된 영상, 가상의 배경 영역으로 구성된 단일 레이어를 3차원 조명환경 정보를 포함한 블록 레이어로 변환하고 변환된 블록 레이어를 합성하는 에듀테인먼트를 위한 증강현실 시스템을 설계한다.