• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 춘계학술대회 논문집
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• pp.371-376
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• 1995

Computer vision is applicated to measure the position and orientation of the SMD on 8mm Camcoder PCB and advanced image processing algorithms for high accuracy and real time processing are proposed. Illumination conditions are optimized for the best image formation and a set of LEDs is used as economic illuminator, which is regarded as a summation of many point sources. Conctete optical system is constructed and the performance of the proposed algorithm is verified by several experiments.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 1997년도 강연회 및 연구개발 발표회 논문집
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• pp.188-195
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• 1997

The application of PIV to the studies of fluid-machines, especially focused on turbo-machinery is reviewed by scrutinizing the previous investigation. Owing to the inevitable high-speed analysis of turbo-machinery consisting of rotating impellers, the importance of optical setups to cope with illumination problem is frequently mentioned as main ingredient affecting the PIV performance. And the acquisition of the relative velocity and absolute velocity is determined mainly by the optical recording conditions. A few studies cast satisfactory extension of the PIV data to quantitative pressure estimation and related noise assessment.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 춘계학술대회 논문집
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• pp.230-234
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• 2009

무대조명의 조도 시뮬레이션을 수행하여 얻은 결과치와 실제로 스튜디오 상에서 설치 후 조도값을 실측한 결과를 비교하여 발생하는 오차에 대하여 비교 연구 하였다.

• 대한소아치과학회지
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• 제34권2호
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• pp.183-191
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• 2007

본 연구는 Digital Imaging Fiber-Optic Trans-Illumination(DIFOTI)이나 Laser Fluorescence(LF)를 이용한 방법이 평활면 법랑질 초기우식증의 재광화 정도를 정확하게 monitoring 할 수 있는지의 여부를 평가하기 위하여 진행되었다. 우치 법랑질로부터 얻어진 인공 우식 절편을 특별히 제작된 의치에 식립한 다음, 10명의 실험 참가자들이 구강 내에 장착하고 3주 동안 불소 양치용액을 사용하도록 한 다음 Confocal Laser Scanning Microscopy(CLSM)로 측정된 병소 깊이를 gold standard로 사용하여 DIFOTI와 LF로 측정 된 우식 절편의 재광화 정도를 비교 평가한 후 다음과 같은 결론을 얻었다. 1. DIFOTI에 측정된 광도 백분율이 재광화 기간이 지남에 따라 증가하였으며, CLSM에서 측정된 병소 깊이와 유의한 역상관관계를 보였다(r=-0.683, p<0.01). 2. LF 측정치는 재광화 기간이 경과함에 따라 증가하였으며 CLSM에서 측정된 병소 깊이와 유의한 상관관계를 보였다(p<0.05). 3. CLSM 촬영 결과 500 ppm 불소 양치군이 0 ppm 불소 양치군보다 빠른 속도로 병소 깊이가 감소하는 양상을 보여 주었다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제34권3호
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• pp.255-265
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• 2007

본 논문은 지능형 자동차 개발을 위한 주간 및 야간 환경에서 차량 운전 시 발생할 수 있는 다양한 조명을 극복하고 운전자 졸음 상태를 단일 CCD(Charge Coupled Device) 카메라를 통해 감시하는 시스템을 제안한다. 운전 중 운전자 눈을 감시하여 졸음 상태를 판단하는 시스템에서 눈 검출 및 눈꺼풀 움직임 측정은 선행되어야 할 중요한 과정이다. 따라서 비전기반 시스템의 가장 큰 단점인 조명변화를 극복하며 눈 검출 성능을 높이고 실시간 처리가 가능한 간단한 조명 보정 알고리즘을 제안하였으며 또한 신뢰성 있는 졸음 판단을 위해 효율적인 눈꺼풀 움직임 측정 방법을 제안한다. 이러한 시스템은 실시간으로 처리되어야 하며 이를 위해 제안한 방법과 더불어 효율적인 눈 검증 방법으로 단계적 SVM(Cascaded Support Vector Machine)을 적용하였다. 한편, 제안한 알고리즘의 성능 측정을 위해 주간 및 야간의 다 양한 조명 변화 속에서 주행 중 수집된 운전자 동영상을 사용하였으며 자체 수집된 동영상에 대해 98% 이상의 눈 검출 성능 및 신뢰성 있는 눈꺼풀 움직임을 측정하였다. 최종 졸음판단 결과는 수집된 각각의 동 영상에 대한 PERCLOS(The percentage of eye-closed time during a period)를 비교함으로써 제안한 시스템의 성능 및 우수성을 보였다.

• 대한기계학회논문집B
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• 제22권8호
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• pp.1152-1163
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• 1998

In the present work, the image processing technique for measurement of drop sizes has been improved. Firstly, the local processing concept was adopted in addition to the global processing technique to take account of non-uniformity of the illumination intensity ; thereby, basically, the measurement error can be reduced. Also, the unfocussed image of drops can be eliminated more precisely since the elimination process is based on the local normalized contrast. Secondly the algorithms to process the partially detected or overlapped drop images and the non-spherical drop images were developed. Finally, the improved algorithm was tested by using an artificially prepared image-frame, where the partial or overlapped particles and the non-spherical particles are mixed with the normal spherical ones (with their true size-distributions known a priori). The results showed that both the recognition rate of the number of particles and the measurement accuracy were improved prominently.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2004년도 Proceedings of 2004 Korea-Japan Joint Seminar on Particle Image Velocimetry
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• pp.65-74
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• 2004

Measurement of concentration distributions of suspended particles in a micro-channel is out of the most crucial necessities in the area of Lab-on-a-chip to be used for various bio-chemical applications. One most feasible way to measure the concentration field in the micro-channel is using micro-LIF(Laser Induced Fluorescence) method. However, an accurate concentration field at a given cross plane in a micro-channel has not been successfully achieved so far due to various limitations in the light illumination and fluorescence signal detection. The present study demonstrates a novel method to provide an ultra thin laser sheet beam having five(5) microns thickness by use of a micro focus laser line generator. The laser sheet beam illuminates an exact plane of concentration measurement field to increase the signal to noise ratio and considerably reduce the depth uncertainty. Nile Blue A was used as fluorescent dye for the present LIF measurement. The enhancement of the fluorescent intensity signals was performed by a solvent mixture of water $(95\%)$ and ethanol (EtOH)/methanol (MeOH) $(5\%)$ mixture. To reduce the rms errors resulted from the CCD electronic noise and other sources, an expansion of grid size was attempted from $1\times1\;to\;3\times3\;or\;5\times5$ pixel data windows and the pertinent signal-to-noise level has been noticeably increased accordingly.

• 한국전기전자재료학회논문지
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• 제23권9호
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• pp.708-713
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• 2010

In this research a ring light was developed so that a partial shadowless shooting for the patient's affected area at the medical treatment room and surgical operation room using high luminance light emitting diode (LED) for which attention is being paid as new lighting parts for medical purpose. LED which was applied to the development used high luminance three color LED for full color for which various color materialization and the adjustment of radiation intensity are possible and we can get white light in order to emphasize the delicate expression for generic tone of shooting object, strong highlight, simple shadow and three dimensional effect at the time of close-up shadowless shooting of the affected area. And at the time of design of ring light, the characteristics of LED and the loss of light at the time of penetrating light diffusion PC were considered so that intensity of illumination for over 150 lx can be obtained. The result of measurement of the intensity of illumination of the ring light that was developed revealed that maximum intensity of illumination of 225.7 lx was obtained, while smoke index was measured to be maximum 78 Ra in the case of Red(50%) Green(100%) and Blue LED(60%). We could confirm that response speed was also very fast as 1.72 ms.

• 조명전기설비학회논문지
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• 제23권2호
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• pp.27-35
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• 2009

본 연구에서는 먼저 도시적 특성의 분석을 토대로 안양시를 6개 지역으로 구분하였으며 지역별 구분에 따른 야간의 조도 휘도의 실측조사 및 야간이용자 패턴 조사를 통하여 야간경관의 문제점을 도출하였다. 야간경관 연출개념으로는 지역별 문제점 분석에 따른 개선방안과 예술적 가치를 창출하는 개념을 적용하여 예술도시로서의 안양의 이미지를 고양시키고자 하였으며 야간조명의 괌형과 통일성 확보를 위해 지역별 점진적 변화를 빛의 조닝의 개념으로 선정하였다. 특히, 건축물의 높이에 따른 건축물 기준선을 통해 주변 건축물과 조화된 단계적인 스카이라인을 연출하여 자연경관 등과 조화로운 조망권을 확보하도록 하였으며 지역 특성에 따라 가로등 및 가로시설물의 조도, 높이, 램프형태, 배열방식 등의 야간 조명환경의 개선방향을 추가로 제시하였다.

• 한국기계가공학회지
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• 제21권1호
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• pp.95-101
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• 2022

This paper proposes a method to process the shape of an optical transmission road and attempts to determine the most suitable single processing method for an acrylic plate optical transmission road. In addition, by manufacturing an automatic pattern processing device to generate certain shapes on the acrylic plate at regular intervals, and measuring the illuminance of the patterned acrylic plate optical transmission road, the measured illuminance was confirmed to fall under the KS illuminance values presented in Table 1. In conclusion, when an incident light of approximately 20,000 lx is applied, the transmission illumination is approximately 200 lx, which represents a transmission rate of approximately 1% for incident light and corresponds to the KS illumination criterion F. Additionally, the right-angle triangular pyramid base size (A) processed at a temperature of 350 ℃ for one second was 2 mm, exhibiting the largest transmission illumination of 280 lx. When the transparent acrylic plate was set to a constant size of 1.6 mm at the bottom of the right-angle triangular pyramid, the fastest response occurred at a processing tip temperature of 350 ℃ (0.04 s). On the other hand, it took 10 s to process the size of the bottom of the right-angled triangular pyramid at a temperature of 200 ℃ to 1.6 mm, and it was confirmed that the optical transmission efficiency was significantly reduced because of the burr that occurred at this time.