• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.352-354
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• 2022

Position measurement using a camera has been studied for a long time. This is being studied for distance recognition or object recognition in autonomous vehicles, and it is being studied in the field of indoor navigation, which is a limited space where GPS is difficult to apply. In general, in a method of measuring the distance using a camera, the distance is measured using a distance between the cameras using two stereo cameras and a value measured through a captured image or photo. In this paper, we propose a method of measuring the distance of an object using a single camera. The proposed method measures the distance by using the distance between cameras, such as a stereo camera, and the value measured by the photographed picture through the gap of the photographing time and the distance between photographing.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.11a
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• pp.354-357
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• 2020

최근 스포츠 경기나 차량 블랙박스 등에서 비디오를 이용한 판정이 점차 확대되고 있지만, 일반 카메라로 촬영된 비디오에서 정확한 판정을 하기 어려울 때가 빈번히 발생한다. 초고속 카메라로 촬영한 슬로우 모션 비디오를 이용할 수 있다면 판정의 정확성을 향상시킬 수 있을 것이다. 본 논문에서는 일반 카메라로 촬영한 비디오로부터 마치 초고속 카메라로 촬영한 것과 같은 슬로우 모션 비디오를 생성하여 제공하는 서비스를 제안한다. 제안 방법은 NVIDIA에서 개발한 Super Slomo 기술을 기반으로, 초당 30장의 표준 비디오를 초당 60장에서 240장까지의 고품질 슬로우 모션 비디오로 변환한다. 이 기술은 시간적으로 이웃한 두 영상을 입력하여 딥 러닝 기반으로 중간 프레임을 보간함으로써 프레임율을 향상시킨다. 또한 본 논문에서는 Super Slomo 기술에 FP16을 적용하여 처리속도를 향상 시켰으며, 웹 서버를 이용하여 비디오를 업로드하고 슬로우 모션으로 변환된 비디오를 다운로드 할 수 있는 사이트를 구현했다.

• The Journal of Korean Society for Radiation Therapy
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• v.21 no.2
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• pp.89-95
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• 2009

Purpose: The purpose is to evaluate efficiency of the CT simulator QA phantom manufactured for daily QA. Materials and Methods: We made holes ($1{\times}100{\times}1\;mm$) to verify accuracy between image and real measurement in polystyrene phantom and made 1 mm holes to verify table movement accuracy at superior and inferior 100 mm to the center of the phantom and inserted radiopacity material. To evaluate laser alignment, we made cross mark on the right and left side at phantom and to evaluate CT number accuracy we made 3 cylindrical holes and inserted equivalence material of bone, water, air in them. After CT scanning the phantom, We evaluated accuracy between image and real measurement, accuracy of table movement, laser, and CT number using exposed image. Results: It was measured that the accuracy between image and real measurement was ${\pm}0.3\;mm$, table movement accuracy was ${\pm}0.3\;mm$, laser accuracy was ${\pm}0.5\;mm$ from 7th January to 7th March in 2008 as within the reference point ${\pm}1\;mm$. In the CT number accuracy of bone was ${\pm}10\;HU$, air was ${\pm}5\;HU$, water was ${\pm}5\;HU$ as within the reference point is ${\pm}10\;HU$. Conclusion: We was able to perform CT simulator QA and laser equipment QA more conveniently and fast using manufactured phantom at the same time. We will be able to make more accurate treatment plan that added to QA procedures using images at previous daily QA.

• Journal of the Korean earth science society
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• v.34 no.3
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• pp.195-208
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• 2013

We employed electrical resistivity and optical borehole imaging methods to identify underground cavities and determine ground subsidence rate at the study area affected by land subsidence due to abandoned underground mines. At the study site 1, the anomalous zones of low resistivity ranging between 100 ohm-meter and 150 ohm-meter were observed and confirmed as an abandoned underground mine by subsequent borehole drilling and optical borehole imaging. Although the electrical resistivity survey was unavailable due to the paved surface of the study site 2, we were able to locate another abandoned underground mine with the collapsed mine shaft based on the distribution of the ore veins and confirmed it with borehole drilling. In addition, we measured vertical displacements of underground features indicating underground subsidence by conducting optical borehole imaging 6 times over a period of 43 days at the study site 2. The displacement magnitude at the deep segment caused by subsidence appeared to be 3 times larger than those at the shallow segment. Similarly, the displacement duration at the deep segment was 4 times longer than those at the shallow segment. Therefore, the combination of electrical resistivity and optical borehole imaging methods can be effectively applicable to detect and monitor ground subsidence caused by underground cavities.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.665-668
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• 2006

이동 물체 검출 및 추적은 과중한 연산량에 의해 초당 처리할 수 있는 프레임의 수가 적게 되거나 정합 과정이 단순하여 추적을 실패하는 문제점들이 있다. 본 논문에서는 동영상내에서 이동 물체를 검출하고 추적하는 새로운 접근 방법을 제안한다. 입력된 영상으로부터 배경과 물체를 분리하기 위해 background subtraction을 이용하였고, 분리된 물체들은 이진 연결 요소 분석을 통하여 세그먼트 된다. 그리고 물체의 추적을 위하여 Kalman filter를 사용하였다. 본 논문의 실험에서는 야외에서 촬영한 비디오 시퀀스를 이용하였으며, 물체 검출 및 추적이 조명 변화, 그림자에도 잘 적응함을 증명하였다.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.4
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• pp.39-44
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• 2009

Purpose: To design a mini optical system photographing the iris, which is used in the iridology. Methods: We designed a mini optical system photographing the iris by using the Sigma 2000 design program. Results: We designed a mini optical system photographing the iris, which is suitable in the CCD using a micro actuator for auto-focusing, of which characteristics have the TCL of 30 mm, a magnification of -0.65, about 8.0 mm distance from the 1st lens to the last lens, the max barrel diameter of 11 mm, and about 1 mm of the effective stop diameter. Also the resolution line width of this system is characterised by 92 lps/mm at the 30% MTF value criterion. Conclusions: By designing an optical system of which characteristics have the TCL of 30 mm, about 8.0 mm distance from the 1st lens to the last lens, the max barrel diameter of 11 mm, and the resolution line width of $5.4{\mu}m$ at the 30% MTF value criterion, we could miniaturize the iris photographing optical system.

• Archives of design research
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• v.19 no.2 s.64
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• pp.217-228
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• 2006

It is obvious that the characteristics of the media are related with the visual expression found in film and video shots. It can be assumed that there would be unavoidable distortion when the space and objects are being framed into an image by the camera and that unavoidable distortion can be utilized for creative expression. Therefore the relationship among the shape of filming zone, the structure of the image, and the strategies of disposition of camera, actors, and objects were studied in accordance with expressional attempts found in film and video images. The classified cases of the expressions found in film and video was studied from the view of the dispositions and movements of the physical elements such as camera, actors, and objects which made the designated expression possible. Finally the organization of method to arrange of the elements used for film within film zone was resulted as the expressional directing methods for filming. Later the usefulness of the method was tested by the application of the method in educational procedure and the evaluation of the analysis of the students' results.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.260-261
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• 2008

이동 물체 탐지(Object Detection) 기법은 대부분의 감시 시스템에서 가장 초기 단계로서, 이후에 물체 추적(Object Tracking) 및 물체 식별(Object Classification) 등의 지능 알고리듬에 입력으로 사용된다. 따라서 물체의 윤곽의 변화 없이 최대한 정교하게 이동 물체 영역 맵을 생성하는 것이 물체 탐지의 가장 중요한 요소가 된다. 카메라가 고정되어 있는 경우에는 현재 들어오는 영상에 대한 확률적 배경 모델을 생성할 수 있지만, 팬틸트 카메라와 같이 영상의 좌표가 변하는 환경에서는 배경 모델도 계속 변하기 때문에 기존의 배경 모델을 그대로 사용할 수 없다. 본 논문에서는 팬틸트 카메라와 같이 동적인 카메라에서 이동 물체 탐지를 위해, 국소 특징점(Local Feature)를 통해 카메라의 움직임을 판단하여 연속되는 영상간의 변환 행렬(Transformation Matrix)를 구하고 하고, 확률적 배경 모델링을 통한 이동 물체 탐지 기법을 제안한다. 자제 촬영한 이동 카메라 실험영상을 통해서 이 알고리듬이 동적 배경에서도 매우 강인하게 동작하는 것을 검증하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.2
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• pp.171-176
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• 2007

The tracking antenna must always point to track moving vehicle for data link. In this paper, we determine pointing angle from the geometric relationship of antenna and UAV(Unmaned Aerial Vehicle) to let an antenna be toward a moving vehicle. The pointing angle of antenna is set through GPS measurement data installed in antenna and UAV. We verify the performance of this system from the fixing a camcoder on the antenna.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2022.10a
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• pp.347-348
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• 2022

본 연구에서는 무인이동체를 활용한 철도교량의 외관조사 점검을 보다 효율적이고 객관성 있게 수행하기 위하여 무인이동체를 통해 촬영된 이미지를 딥러닝 기반 분석기술을 활용하여 손상 자동으로 분석 하기위한 기술을 연구하였다. 철도교량의 외관 손상 중 균열, 콘크리트 박리·박락, 누수, 철근노출에 대한 손상 이미지를 추출하여 딥러닝 분석 모델을 생성하고 학습한 분석 모델을 적용한 시스템을 실제 현장에 적용 테스트를 수행하였으며 학습 구현된 분석모델의 검측 재현율을 검토한 결과 평균 95%이상의 감지성능을 검토할 수 있었다. 개발 제안된 자동손상분석 기술은 기존 육안점검 결과 대비 보다 객관적이고 정밀한 손상 검측이 가능하며 철도 유지관리 분야에서 무인이동체를 활용한 외관조사 업무를 수행함에 있어 기존 대비 객관적인 결과도출과 소요시간, 비용저감이 가능할 것으로 기대된다.