• Proceedings of the Korean Information Science Society Conference
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• 2007.10c
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• pp.239-242
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• 2007

본 논문에서는 다수의 저가형 웹캠(Web Cam)으로 촬영된 다각도의 다중 영상을 입력으로 받아 이들을 자연스럽게 연결하여 임의의 각도에서 물체의 모습을 관찰할 수 있도록 하는 ${\ulcorner}$다중 카메라 촬영 영상을 이용한 Object Movie 생성 기반 기술${\lrcorner}$을 제안한다. 기존 Object Movie 생성도구들이 다중의 이미지들을 스티칭(stiching)하기 위해 정확한 카메라의 위치와 방향을 요구하는 데 비해, 제안된 방법은 고가의 트랙장비를 사용하기 어려운 경우에 다수의 저가형 웹캠으로 촬영된 카메라의 위치와 방향을 보정하는 단계를 추가하여 트랙장비를 사용한 것과 같은 매끄러운 영상을 생성할 수 있도록 하였다.

• Journal of the Korean Society of Radiology
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• v.7 no.4
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• pp.277-284
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• 2013

This study aims to find out geometric parameters which practitioner adjustable to reduce dose in coronary angiography. We take fluoroscopy and cine exposure by use of phantom, and got dose use the dose-area product(DAP) meter of angiography device, than convert DAP to effective dose. As results, Cine exposure shows higher dose measurement about 6-7 times than fluoroscopy. Dose in frame per second(FPS) mode could be decrease down to 70%, as lower FPS. In view of X-ray tube angle, LAO $45^{\circ}$+Caudal $30^{\circ}$ shows highest dose measurement. More use of Collimator, lower dose measurement. Source-image intensifier distance(SID) get longer to 10cm, dose of each fluoroscopy and cine exposure increase up to 25-30%. Image magnification of field of view(FOV) could increase dose up to 1.21-2 times. Also table-image intensifier distance get longer to 10cm, dose increased 1.11-1.25 times. Practitioner can adjust several geometric parameters, as FPS mode, tube angle, Collimation, SID, table-image intensifier distance, FOV. And each factors can reduce radiation dose in coronary angiography.

• Journal of Digital Convergence
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• v.12 no.10
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• pp.345-351
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• 2014

The purpose of this study is to offer more accurate information in whole spine examination of 3 spot DR through the comparative study about image distortion as making the flat phantom and measuring horizontal, vertical ratio and cobb angle of the virtual. We produced $H(40cm){\times}V(116cm){\times}D(2.3cm)$ flat acrylic phantom with lattice type of lead plate. We took projection respectively 3 times, total 9 times in each equipments using manufactured phantom as changing OFD to 6, 12, 18 cm. We measured a horizontal and vertical length of lead lattice and calculated the ratio. As appointing arbitrary points in the phantom and we measured cobb angle. The results of horizontal, vertical ratio measured CR type 0.98~1.01, scan DR type 0.96~0.97 and 3 spot DR 0.99~1.01. Cobb angle measured $52.5{\sim}53.3^{\circ}$, $52.1{\sim}54.3^{\circ}$ and $52.8{\sim}53.2^{\circ}$. Finally we can say that 3 spot DR method is an accurate method without any distortion in whole spine radiography.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.1
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• pp.41-46
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• 2021

As data acquisition using unmanned aerial vehicles is widely used, as one of the ways to increase the accuracy of photogrammetry using unmanned aerial vehicles, a method of inputting both vertical and oblique images in bundle adjustment of aerial triangulation has been proposed. In this study, in order to find a suitable method for increasing the accuracy of photogrammetry, the accuracy of the case of adjusting the oblique images taken at different shooting angles and the case of adjusting the oblique images with different shooting angles at the same time with the vertical images were compared. As a result of the study, it was found that the error of the checkpoint decreases as the angle of the input oblique images increases. In particular, when the vertical images and oblique images are used together, the height error decreases significantly as the angle of the oblique images increases. The current 『Aerial Photogrammetry Work Regulation』 requires RMSE (Root Mean Square Error), which is the same as GSD (Ground Spatial Distance) of a vertical image. When using an oblique images with a shooting angle of 50°, a result close to this standard is obtained. If the vertical images and the 50° oblique images were adjusted at the same time, the work regulations could be satisfied. Using the results of this study, it is expected that photogrammetry using low-cost cameras mounted on unmanned aerial vehicles will become more active.

• Journal of Acupuncture Research
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• v.21 no.6
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• pp.195-207
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• 2004

목적 : 경추통에 대한 침구치료의 효과여부가 현재까지 시행된 무작위 대조군 시험의 검토에서 논란이 되고 있는데, 경추통에 대한 치료 효과의 검증에 최근 들어 경추 전만각도의 변화를 측정하는 것이 점차 많이 사용되고 있는 실정이다. 하지만 아직까지 변형된 형태의 경추 견인 등 몇몇 요소들이 경추전만을 변화시켰다는 보고는 있었으나, 침치료 중 深刺의 방법이 경추의 만곡을 변화시켰다는 보고는 없었다. 방법 : 자침의 방법 중 深刻(五刺法 중 合谷刺 또는 關刺)방법이 경추 전만의 변화를 주는가에 대하여 검증하기 위하여 심자 치료를 시행한 19명의 실험군과 치료를 시행하지 않고 단순히 방사선 촬영만 시행한 21명의 대조군의 단순 방사선 사진을 후향적 연구의 방법으로 비교하였으며, 아울러 심자 자침군에서는 VAS를 측정하여 통증의 정도의 변화를 함께 연구하였다. 결과 : 연구결과 자침을 시행하지 않은 대조군에서는 VAS와 경추 전만의 Cobb각도에서 유의성 있는 변화가 나타나지 않았으나, 심자의 방법으로 자침한 군에서는 치료 전후의 VAS가 유의한 차이를 나타내었고, 경추의 전만 각도에서도 경추 2번과 7번 사이의 Cobb의 각도에서 유의성 있는 변화를 나타내었다(p < 0.05). 결론 : 이러한 연구 결과들은 심자의 자침방법이 경주의 통증을 줄여줄 뿐만 아니라 경추의 구조적 변화를 일으킬 수 있음을 나타내 주는 것이다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.199-206
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• 2012

Attempt to use as a marker of natural objects directly in the real world, but there is a way to use the accelerometer of the smartphone, to convert the Frontal-View virtual, because it asks only the pitch of the camera, from the side there is a drawback that can not be converted to images. The proposed algorithm, to obtain the rotation matrix of axis 3 pitch, roll, yaw, we set the reference point of the yaw of the target image. Then, to compensate for the rotation matrix to determine Myon'inji any floor, wall, the ceiling of the target image. Finally, to obtain the homography matrix for obtaining the Frontal-View to account for the difference between the gyro sensor coordinate system and image coordinate system, so we can get the Frontal-View from the captured images through the projection transformation was designed. Was tested to convert Frontal-View the picture was taken in an environment smartphone environment surrounding floor, walls and ceiling in order to evaluate the conversion program Frontal-View has been implemented, in this paper, design and The conversion algorithm implementation, it was confirmed that to convert a regular basis Frontal-View footage taken from multiple angles.

• Journal of the Korea Computer Graphics Society
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• v.23 no.5
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• pp.9-17
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• 2017

Filming using multiple cameras is required for the production of the multi-screen content. It can fill the viewer's field of view (FOV) entirely to provide an increased sense of immersion. In such a filming scenario, it is very important to monitor how images captured by multiple cameras are displayed as a single content or how the content will be displayed in an actual theatre. Most recent studies on creating the content of special format have been focused on their own purposes, such as stereoscopic and panoramic images. There is no research on content creation optimized for theatres that use three screens that are spreading recently. In this paper, we propose a novel content production system with a rig that can control three cameras and monitoring software specialized for multi-screen content. The proposed rig can precisely control the angles between the cameras and capture wide angle of view with three cameras. It works with monitoring software via remote communication. The monitoring software automatically aligned the content in real time, and the alignment of the content is updated according to the angle of camera rig. Futher, the producion efficiency is greatly improved by making the alignment information available for post-production.

• Journal of the Korean Society of Radiology
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• v.9 no.4
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• pp.197-203
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• 2015

The Study on the patient is in a clinical researcher is not necessarily pose before after before after dwichim (Pronation) pose with neck-in-law (RAO, LAO) to chwalyoungbeop subjective evaluation experiment looked at objectively. Overview evaluation is a result of measuring the angle of the space between the vertebrae in PACS image $C_2{\sim}C_3$, $C_3{\sim}C_4$, $C_4{\sim}C_5$, $C_5{\sim}C_6$, $C_6{\sim}C_7$, in the angle of the $C_7{\sim}T_1$ $47.4^{\circ}{\pm}3.3$, $50.5^{\circ}{\pm}2.3$, $52.7^{\circ}{\pm}4.2$, $53.2^{\circ}{\pm}1.9$, $53.2^{\circ}{\pm}2.3$, $55.2^{\circ}{\pm}2.3$ was found to show increasing the angle between the ball and the median nerve in the lower neck sagittal grows. In a comparison of the measured angles in foraminal image was not significantly different (P>0.01). Subjective evaluation Recever Operation characteristic to the top, the upper neck hole (foramen) C2 ~ C3-up than conventional $45^{\circ}$ angle of the lower neck, $C_3{\sim}C_4$, were observed in the well $50^{\circ}$ $C_5{\sim}C_6$, $C_6{\sim}C_7$, the $C_7{\sim}T_1$ was observed at $55^{\circ}$ well observed experimental results video recession neck vertebrae son-in-law, son-in-law taken place in an objective evaluation, subjective evaluation of the upper neck after case could be observed at $50^{\circ}$, well in the lower neck $55^{\circ}$.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.2
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• pp.261-271
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• 2009

Due to the recent rise of a need for 3 dimensional geospatial information on urban areas, general interest in aerial multi-view cameras has been on an increase. The conventional geospatial information system depends solely upon vertical images, while the multi-view camera is capable of taking both vertical and oblique images taken from multiple directions, thus making it easier for the user to interpret the object. Through our research we developed a prototype of a multi-view camera system that includes a camera system, GPS/INS, a flight management system, and a control system. We also studied and experimented with the camera viewing angles, the synchronization of image capture, the exposure delay, the data storage that must be considered for the development of the multi-view camera system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.763-764
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• 2017

The use of barcodes in mobile phones has become generalized, and barcodes are widely used in security-sensitive applications, including mobile payment and personal identification. Generally, images photographed by a mobile phone generate geometric distortion due to the shooting angle, resulting in low quality images. Embedding watermark for low quality images makes it difficult to satisfy transparency. To solve such problem, this paper focuses on the technique of embedding barcode images in the image taken by mobile phone and proposes barcode watermarking for protecting mobile-based ownership. The barcode watermark embedded in the image can be used to prove ownership since it is readable by a machine such as illegal copy.