• Proceedings of the Korean Society of Broadcast Engineers Conference
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• fall
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• pp.9-12
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• 2021

드론 Photogrammetry는 높은 기술적 활용가치가 있는 기술로서, 결과물로 생성하는 3D 디지털 공간정보 모델이 시설물의 비육안 안전점검 및 진단에 활용될 수 있을 뿐만 아니라 디지털 트윈 구축을 위한 가장 기초적이고 핵심적인 수치 데이터를 제공하기 때문이다. 본 연구에서는 드론 Photogrammetry의 적정 품질을 구현하기 위한 임무비행의 다양한 영향인자에 대해 고찰하였다. K-water연구원 누수탐사실습장을 대상으로 드론 사진 촬영 시 비행고도, 비행속도, 중첩도, 카메라 Pitch각의 영향에 대해 연구를 수행하였다. 본 연구에서 비행시간에 영향을 미치는 인자로서 비행고도, 중첩도, 비행속도의 순으로 중요도가 있음을 알 수 있었다. 드론 임무 비행 시 후처리 결과에 가장 큰 영향을 미치는 인자는 중첩도로 나타났다. 중첩도 60% 임무비행은 3D 모델의 geometry 왜곡이 큰 편으로 나타났다. 비행 고도는 GSD (Ground Sampling Distance)와 직접 연계되므로 중요하며, 낮은 고도일수록 높은 품질의 모델링이 가능하다. April Tag를 통한 지상기준점 자동 패턴 인식 기능은 후처리 과정에서 시간 절약이 가능하여 유용하였다. 비행속도에 의한 결과물의 품질은 큰 차이가 없었으나, 수직 구조물의 모서리 부분에 다소 차이가 있었다. 짐벌 Pitch각도에 의한 정사영상 품질의 차이는 크지 않았으나 수직구조물과 평면적 구조물에 따라 각기 다른 촬영각도를 적용하는 것이 바람직하다. 본 연구성과는 향후 보다 다양한 환경에서의 데이터 수집을 통해 최적 디지털 현실 모델링에 기여할 것으로 판단된다.

• Proceedings of the Korean Society of Radiological Science
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• 2005.04a
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• pp.152.3-153
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• 2005

• Journal of The Korean Radiological Technologist Association
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• v.29 no.1
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• pp.94-94
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• 2003

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.755-757
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• 2022

최근 온라인 수업, 동영상 수업의 수요가 많아짐에 따라 강의촬영을 하는 경우가 증가하는 추세다. 혼자서 강의를 촬영하는 경우도 늘어났지만 혼자서 강의를 촬영할 경우 실시간으로 카메라 각도 조절하기 불편한 점이 있다. 자동으로 강사를 추적하며 강의 촬영할 수 있는 저가의 카메라를 개발 및 연구를 진행하였다.

• Korean Journal of Bronchoesophagology
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• v.2 no.1
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• pp.71-81
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• 1996

The normal larynx locates to the front of the neck symmetrically and the thyroid notch lies in the center of the neck, but practically the larynx is not symmetric in all people. From a clinical point of views, there are vague cases to decide whether a disordered laryngeal structure is within normal variations or a pathologic condition. The purpose of this study is to investigate the anatomy of the laryngeal framework in normal population. Authors investigate various measures of normal laryngeal framework, such as symmetry and length of the larynx, levels of the hyoid bone and vocal cord and angle of thyroid cartilage by using calipers and protractor on 45 cases of neck CT. The results are summerized as follows. 1. The laryngeal framework was asymmetric to a greater or lesser extent in most cases with directional preponderance to the right side. The degree of asymmetry did not differ among different age groups and between seres. 2. The level of the hyoid bone ranged from C2-C3 vertebrae to C5-C6 intervertebral space with most frequent level of C5. 3. The level of the vocal cord ranged from 01 vertebra to C6-C7 intervertebral space with most frequent level of C5. 4. The angle of thyroid cartilage ranged from 58 degree to 100 degree with average of 81.5 and mean angle between both thyroid alae were 77.24 degree in male and 87.88 degree in female.

• Journal of radiological science and technology
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• v.26 no.1
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• pp.63-70
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• 2003

SMAS(Superior Mesenteric Artery Syndrome) is a disease caused by a chronic obstruction of the duodenum(transverse portion), which is hardly detectable. However, it is known that when the superior mesenteric artery and abdominal aorta form a narrow angle, that the transverse portion of the duodenum is pressed down between the superior mesenteric artery and the abdominal aorta, and that this can lead to obstruction of the duodenum. Measuring this angle is a complicated job using conventional angiography, and results often turns out to be inaccurate. In addition, no attempt has been made to determine the value of this angle in Koreans. In this study, we conducted abdominal CT angiography using MIP(maximum intensity projection) on patients with no clinical evidence of SMAS in order to determine the angle at which the superior mesenteric artery branches from the abdominal aorta by using PC based software(Rapidia ver. 1.2) for the image reconstruction. Accordingly, we found that the mean angle between the abdominal aorta and the superior mesenteric artery was $50.05{\pm}15.87^{\circ}$ on average, and that the angle in men($53.64{\pm}16.57^{\circ}$) is higher than in women($46.46{\pm}14.98^{\circ}$). We hope that the angles determined by our study will serve as an important indicator for detecting SMAS.

• Journal of radiological science and technology
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• v.28 no.3
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• pp.203-209
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• 2005

Objective True lateral scapular image was very important to diagnosis the scapular fracture and dislocation induced by traumatic injury. The aim of this study was to know the patient rotation angle to be showing the scapular true lateral in Korean. Subjects and Materials Thirty patients(22men, 8 women, mean ages 53.4)with scapular pain, had supine anteroposterior projection taken with $32^{\circ}$, $37^{\circ}$, $42^{\circ}$ trunk rotation angle changing the manual angulation material. Radiographs were evaluated independently by 5 experienced observers(1 orthopedics surgery specialist, 1 diagnostic radiology specialist, 3 radiological technologist) They assessed overlab of vertebral border and axillary border of scapular as follows; Totally overlapping of vertebral border and axillary border is 4, partially overlapping is 3, not overlapping is 2 and oblique location with two borders is 1. All observers scored using by PACS monitor. Results $32^{\circ}$ trunk rotation was scored $1.53{\pm}0.39$, $37^{\circ}$ trunk rotation was scored $3.83{\pm}0.15$ and $42^{\circ}$trunk rotation was scored $2.17{\pm}0.43$. There was no difference(p<0.05) between group of more than 100cm of the girth of the chest and group of less than 100cm. Similarly, men and women group showed no difference(p<0.05) with trunk rotation statistically. Conclusions There was no result of trunk rotation angle to radiograph the true scapular lateral image up to date. This studies were summarized as follows; Adaptation of $37^{\circ}$ trunk rotation was the best to show the true scapular lateral image in Korean. Our results were very useful to get the true scapular lateral images in clinic.

• Journal of the Korean Society of Radiology
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• v.17 no.4
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• pp.607-614
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• 2023

Clear overlapping of the bilateral epicondyle and proper separation of the elbow joint are crucial for obtaining accurate lateral general radiographs of the elbow. However, due to the complex anatomical structure of the elbow, achieving optimal positioning is challenging, leading to the need for repeated x-ray examinations. Therefore, the purpose of this study was to investigate the angle of the forearm in patients where accurate lateral images of the elbow joint can't be obtained after vertical incidence using a styrofoam device during elbow joint lateral x-ray imaging. Twenty patients were enrolled in our study following the established protocol. First, a vertical x-ray at an angle of 0° between the forearm and the table was taken (control group). Here, if the lateral image of the elbow joint was deemed inadequate, the forearm angle was adjusted using custom-made styrofoam supports with 5° and 10° inclinations (experimental groups). For the evaluation method, two assessors utilized a 5-point Likert scale to assess the images. The reliability of the assessments was analyzed using Cronbach's alpha coefficient. As a result, patients with inadequate overlap of the bilateral epicondyle and separation of the elbow joint in the initial examination (control group) were able to obtain the best images when setting a 10° angle between the forearm and the table. The subjective evaluation was 1.6 ± 0.8 points at 0°, 2.7 ± 0.8 points at 5°, and 4.4 ± 1.3 points at 10°, respectively. The reliability analysis for the angles of 0°, 5°, and 10° yielded Cronbach's alpha values of 0.867, 0.697, and 0.922, respectively. In conclusion, when it is not possible to obtain accurate images using the conventional position and X-ray beam direction, it is considered that by initially acquiring images with an angle of 10° between the forearm and the table, and gradually decreasing the angle while obtaining images, it would be possible to achieve the optimal image while reducing the number of repeat examinations.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.499-505
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• 2022

Recently, the metaverse has been receiving a lot of attention. Metaverse means a virtual space, and various events can be held in this space. In particular, 360-degree video, a format optimized for the metaverse space, is attracting attention. A 360-degree video image is created by stitching images taken with multiple cameras or lenses in all 360-degree directions. When shooting a 360-degree video, a variety of shooting equipment, including a shooting staff to take a picture of a subject in front of the camera, is displayed on the video. Therefore, when shooting a 360-degree video, you have to hide everything except the subject around the camera. There are several problems with this shooting method. Among them, lighting is the biggest problem. This is because it is very difficult to install a fixture that focuses on the subject from behind the camera as in conventional image shooting. This study is an experimental study to find the optimal angle for 360-degree images by adjusting the angle of indoor lighting. We propose a method to record 360-degree video without installing additional lighting. Based on the results of this study, it is expected that experiments will be conducted through more various shooting angles in the future, and furthermore, it is expected that it will be helpful when using 360-degree images in the metaverse space.

• Journal of the Korean Society of Radiology
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• v.10 no.6
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• pp.435-442
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• 2016

This study was an investigation of the anode heel effect caused by changing the angle of the x-ray tube. We established the following conditions for experimental measurements: 70 kV, 30 mAs, focus-detector distance of 100cm, and a collimator setting of $35{\times}43cm^2$. The measurement points were set up at the center of the collimator and extended to each side in intervals of 3.5cm, with points A1, A2, A3, A4, A5, A6 on the anode side and points C1, C2, C3, C4, C5, C6 on the cathode side. We measured the entrance surface dose from point A6 to point C6 with each point perpendicular to an x-ray tube. And we did the same when measuring different angles of the x-ray tube from 15 to 30 degrees for every point on the anode and cathode sides. Using perpendicular x-ray tube, we found that the entrance surface dose of the A5 point was three times higher than that of the C5 point. Thus, we conclude that if the anode side is placed near highly radiosensitive organs, then there will be less radiation exposure when using a perpendicular x-ray tube. When imaging using x-ray tube angles, an angle to the cathode side can reduce the gap of the entrance surface dose on both the anode and cathode sides. When imaging areas where there are differences in thickness between the upper and lower sides, the angle to the cathode side that is closer to the thicker area can reduce the gap of the entrance surface dose and capture a higher quality image.