• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.235-236
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• 2007

CCD(Charge-Coupled Device) 혹은 CMOS (Complementary Metal Oxide Semiconductor)와 같은 소자를 이용하여 빛을 전기적 신호인 Image로 재구성하는 촬상소자(Color Capture Device)는 촬영환경이 어두워지면 Dynamic Range가 작아지고, Noise가 상대적으로 심해진다[1][2]. 본 논문에서는 촬영 환경이 어두울 때, Resolution을 Preserving하는 Pixel Pitch가 큰 촬상 소자와 Motion Blur를 억제하는 Exposure Time이 긴 촬상 소자의 조합을 신호처리로 구현하여, 신호의 Power를 향상시켜 Dynamic Range를 키우고 Noise의 Boost-up을 억제하여 SNR(Signal to Noise Ratio)을 향상시키는 방식으로, 촬상 장치의 감도를 향상시켜 화질을 개선하는 방법을 제안한다.

• Proceedings of the Optical Society of Korea Conference
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• 2008.07a
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• pp.169-171
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• 2008

마이켈슨 간섭계 시스템에 두 개의 Convex Lens를 추가함으로서 평면파 참조광을 유지 시키며, 물체에 조사되는 물체광의 조사면적을 변화시킬 수 있는 새로운 형태의 마이켈슨 간섭계를 제작 하였다. 새로운 형태의 마이켈슨 간섭계를 반사형 디지털 홀로그래피 현미경 시스템(Digital Holography Microscope System)에 적용하여 촬상소자(CCD: Charge Couple Device)에 홀로그램 기록 시 기록 가능한 CCD의 유효 영역과 재생 가능 영역에 대해 연구를 하였다

• Korean Journal of Optics and Photonics
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• v.34 no.2
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• pp.66-71
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• 2023

Zoom lenses are now starting to be applied to mobile-phone cameras as well. A zoom lens applied to a mobile-phone camera is mainly used to capture images in the telephoto range. Such an optical system has a long focal length, similar to that of a high-magnification zoom optical system, so the position of the imaging device also shifts significantly, due to manufacturing errors of the lenses and mechanical parts. In the past, the positional shift of the imaging device was corrected by moving the first lens group and the total optical system, but this paper confirms that the position of the imaging device can be corrected by selecting any two moving lens groups. However, it is found that more distance must be secured in the front and rear of a moving lens group for this purpose.

• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.228-229
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• 2000

Buried channel JET-X CCDs (Joint European X-ray Telescope Charge Coupled Devices: EEV CCD12) with a deep depletion have been analyzed to provide an optimized condition for a charge storage and transfer. A maximum charge capacity has been found for the supplementary narrow channel by considering the potential distribution as a function of a mobile charge. Analysis for the depletion edges of JET-X CCDs have been successfully performed, showing good agreement with the depths estimated from X-ray detection efficiency measurements [1]. (omitted)

• Information and Communications Magazine
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• v.28 no.6
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• pp.31-38
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• 2011

본고에서는 홀로그래피 기술을 알아본다. 홀로그래피 기술은 파동 광학에 기초하여 빛의 크기뿐만이 아니라 위상까지 촬영하고 재생할 수 있는 기술이다. 특히 최근 촬상 소자와 광변조소자의 발달로 홀로그래피의 디지털 방식으로의 촬영, 처리, 재생이 가능해 지면서 이를 응용한 다양한 홀로그래피 기술들이 개발되고 있다. 본 고에서는 이 중에서 3차원 촬영 및 3차원 디스플레이에 응용되고 있는 홀로그래피 기술을 중심으로 알아본다.

• Journal of Welding and Joining
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• v.14 no.1
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• pp.99-106
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• 1996

Development of an automatic TIG welding system incorporating a vision sensor and torch control mechanism leads to an improved welding quality and greater production efficiency. The automatic welding system should be greatly restricted in its size and weight for the LNG(Liquefied Natural Gas) storage tank and also provide a unique torch rotating mechanism which keeps the torch tip in the constant position while the angle is changed continuously to maintain the welding torch substantially perpendicular to the weld line. The developed system is driven by two translation axes X, Z and one rotational axis. A moving line window method is adopted to the image recognition of the corrugated membranes with specular reflection. This method decides original laser stripe patterns in image which is affected by multi-reflection. A self-teaching algorithm, which guides the automatic welding machine with the information provided by the CCD camera without any previous learning of a reference trajectory, was developed for tracking the corrugated membrane of the LNG tank along the weld line.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.12 no.2
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• pp.8-17
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• 2008

Objectives: For the traditional pulse diagnosis in Oriental Medicine, not only the pulse shape in time domain, but the width, length and depth of arterial pulse also should be measured. However, conventional pulse diagnostic systems have failed to measure the spatial parameters of the arterial pulse e.g. effective length of arterial pulse in the wrist. In fact, there are many ways to measure that kind of spatial features in arterial pulsation, but among them, the method using image sensor provides relatively cheap and simple way, therefore I tested feasibility of measuring 2-dimensional pressure distribution by imaging devices. Methods: Using widely used PC cameras and dotted balloons, the subtle oscillation of skin over the radial artery was recorded continuously, and then the displacement of every dot was calculated. Consequently, the time course of that displacements shows arterial pulse wave. Results: By the proposed method I could get pressure distribution map with 30Hz sampling rate, 21steps quantization resolution, and approximately 1mm spatial resolution. With reduced quantization resolution, $3cm{\times}4cm$ view angle could be achieved. Conclusion: Although this method has some limitations, it would be useful method for detecting 2-dimensional features of arterial pulse, and accordingly, this method provides a novel way to detect 'narrow pulse', 'wide pulse', 'long pulse', 'short pulse', and their derivatives.

• Korean Journal of Optics and Photonics
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• v.33 no.6
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• pp.303-309
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• 2022

Since the pixel size of the image sensor used in optical systems is gradually decreasing, the resolution specification of the optical system should be inevitably higher. If aberration change according to the eccentricity of a specific lens group occurs, only the amount of eccentricity of a specific lens group may be calculated with the traditional resolution adjustment method so that the aberration of the optical system is minimized to a certain extent. As a result, it is possible to increase the resolution of the optical system and to respond to a sensor with a large number of pixels. However, in the traditional method, there should be no change in specific aberration due to the eccentricity of a specific lens group. In this paper, we propose a new method to eliminate such a limitation of the traditional method in a camera optical system with a floating system, which is to choose and control the arbitrary two lens groups to easily minimize the eccentricity of the optical system in order to obtain an optical system with high resolution.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.07a
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• pp.441-443
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• 2015

디지털 홀로그래픽 TV 시스템을 구현하려면 홀로그래픽 정보 획득 장치가 필요한데, 해상도 한계 때문에 홀로그램의 프린지 패턴을 상용 촬상 소자로는 직접 기록할 수 없다. 이를 극복하는 방법으로는 컬러 영상과 거리영상 정보를 얻은 후에 압축을 거쳐 수신 디스플레이단에 전송하고 이 정보로부터 3차원 모델을 형성한 후에 컴퓨터 생성 홀로그램을 생성하고 이를 회절소자를 이용하여 디스플레이하는 방법이 현재로서는 현실적인 방법이 될 것이다. 홀로그래픽 디스플레이에서는 회절소자인 공간광변조기 성능의 한계 때문에 기존 2DTV와 같은 수준의 디스플레이 구현은 매우 어렵다. 기존 공간광변조기는 픽셀피치가 커서 시야각이 매우 좁으나, 픽셀 크기를 작게 하는 동시에 공간광변조기 면적을 크게 하기에는 기술적인 어려움이 많다. 본 논문에서는 홀로그래픽 TV를 구현하는데 있어서 기술적으로 극복하고 고려해야 할 주요 요소에 대하여 분석한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.356-359
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• 2017

According to the plan of operation of the Ministry of Education, IWB (Interactive White Board) was distributed to one or two classrooms per school. Therefore, instead of the overhead projector (OHP) and the screen, the visual presenter and the IWB replaced the role. However, the development speed of the imaging device and the display device could not keep up, and the utilization was often lowered. In this study, we study to obtain a high resolution image using the camera of smartphone. It uses WiGig(Wireless Gigabit) technology to transmit the acquired high-resolution images to IWB or large-screen TV without delay in wireless communication. In addition, while the smartphone camera is equipped with a lens of a wide field of view(FOV), the microscope lens can be used to magnify and magnify a specific portion of a smartphone 400 times. As s result of this study it will be used as active material for real-time 400 times magnification in education and research field.