• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.961-964
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• 2016

This paper describes the implementation of AUSV system for Sonar Image acquisition. The system be controlled by FF-PID algorithm for the thrusters using motion sensor and DGPS. As experimental results, the control performance is that the error distance from the destination positions are under 5m in total survey track of 1km, and the image deviation is under 12 pixel from the manned survey method, which the comparison with the total image quality is almost the same as the manned survey one. Thus the AUSV system is a new method of system can be utilized on the limited survey area as the surveyor should not be able to approach on sea surface.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1998.10a
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• pp.343-348
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• 1998

In this study, we extracted several terrain information using satellite and aerial images. We detected change of terrain using Landsat Thematic Mapper(TM) and aerial images which are multitemporal data. In change detection processing, we first classified satellite images by ISODATA algorithm which is an unsupervised learning algorithm, then performed change detection. By this method, we could obtain good result. Also we introduce sub-pixel concept to classify road and agriculture area in inaccessible area. In summary, in chang detection processing, we can find that the used method is efficient.

• Proceedings of the KSRS Conference
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• 2006.03a
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• pp.319-322
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• 2006

2002년 5월 촬영이 시작된 SPOTS 영상은 공간해상도가 2.5mX2.5m로 고해상도이면서도 촬영폭이 광역적이어서 다양한 활용이 가능하다. SPOT5영상을 보다 유용하게 활용하기 위해서는 단순 기하보정 보다는 높은 정확도를 얻을 수 있는 정사보정이 요구된다. 보정영상의 정확도에 영향을 미치는 요소로는 지형, GCP, DEM등이 있다. 본 연구에서는 다른 조건들은 동일하게 하고, 자료 구축에 많은 시간이 소요되는 DEM(수치표고모델)의 축척만을 달리하여 보정 영상의 정확도를 비교하였다. 그 결과 DEM의 축척 변화가 보정 영상에 미치는 영향은 미비한 것으로 나타났다. 따라서 작업의 효율성을 고려할 경우에 소축척의 DEM을 사용하는 것이 바람직하다.

• The Optical Journal
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• s.139
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• pp.67-72
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• 2012

아시아를 대표하는 사진영상축제인 '2012 서울국제사진영상기자재전'(이하 P&I 2012)이 지난 4월 26일부터 29까지 나흘간의 일정으로 서울 삼성동 소재 Coex 전시장 본관 1층 A홀에서 화려하게 펼쳐졌다. 올해로 21회를 맞이한 이번 전시회에서는 삼성을 비롯해 캐논, 니콘, 소니, 올림푸스, 파나소닉, 후지필름 등 디지털 카메라 제조사와 프린터 및 주변기기, 사진 액세서리 업체 등 세계 18개국 117개사가 참가해 최첨단 디지털 이미징 기술을 선보였으며 사진문화산업의 트렌드를 한눈에 볼 수 있는 다양한 영상기기와 응용 기자재도 출품하였다. 전시기간 동안에는 총 7만 4000여 명의 참관객이 다녀간 것으로 나타나 카메라를 비롯한 사진영상분야에 대한 소비자들의 뜨거운 관심도를 재확인할 수 있었다.

• Journal of Veterinary Clinics
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• v.31 no.5
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• pp.439-444
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• 2014

A 5-year-old, 2.7 kg female maltese dog was presented a local veterinary clinic with one week history of hindlimb lameness associated with patellar luxation. Reduction of bilateral medial patellar luxation was operated using trochlear resection and lateral reinforcement technique. Three weeks after the surgery, the dog showed bending spine with pain in thoracic and lumbar region, continuous ataxia and intermittent convulsion. Magnetic resonance imaging scanning revealed a hyperintense mass in right frontal lobe of brain and abnormal cavitation from cervical cord to third lumbar cord. Histopathologically, neoplasm in brain composed of meningothelial cells showed loosely reticular or lace-like morphology with numerous extracellular cystic spaces of variable size and shape. Neoplastic cells were positive for vimentin and negative for neuron specific enolase and glial fibrillary acidic protein. Irregular shaped enlarge central canal-like cavity was existed in cervical and lumbar cords. In our best knowledge, this report described the clinical findings, imaging and histopathologic characteristics of unusual intracranial microcystic meningioma with secondary syringomyelia in a dog.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.9 no.2
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• pp.103-113
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• 1991

The accuracy of input coordinates of ground control points and check points affects great influences to the results of ground coordinate computation in using SPOT digital image data. The original SPOT images displayed on CRT are not usually adequate for identifying the object features and determining the point positioning. Hence, appropriate image processing techniques such as contrast enhancement, subpixel interpolation, edge enhancement, and spatial filtering are needed. In this study, the principles of digital image processing needed for accurate three dimensional positioning and spectral characteristic analysis are investigated. The algorithms for the actual applications are developed and programmed. And using the developed image processing software, some SPOT P-mode and XS-mode images are merged into the SPOT P＋XS, the high-resolution color composite image.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.5
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• pp.1639-1644
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• 2014

SAR satellite can acquire clear imagery regardless of weather and the images are widely used for land management, natural hazard monitoring and many other applications. Automatic image matching technique is necessary for management of a huge amount of SAR data. Nevertheless, it is difficult to assure the accuracy of image matching due to the difference of image-capturing attitude and time. In this paper, we compared performances of MI method, FMT method and SIFT method by applying arbitrary displacement and rotation to TerraSAR-X images and changing resolution of the images. As a result, when the features having specific intensity were distributed well in SAR imagery, MI method could assure 0~2 pixels accuracy even if the images were captured in different geometry. But the accuracy of FMT method was significantly poor for the images having different spatial resolutions and the error was represented by tens or hundreds pixels. Moreover, the ratio of corresponding matching points for SIFT method was only 0~17% and it was difficult for SIFT method to apply to SAR images captured in different geometry.

• Journal of the Korean earth science society
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• v.23 no.8
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• pp.707-721
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• 2002

Seafloor acoustic image data using the side scan sonar system were gathered on the Sindu-ri offshore near the Taean peninsula, middle western Korea. The relationship between the back-scattering acoustic intensity and the sea-bottom sediment properties was studied. And these two data sets were compared and interpreted with the water depth, respectively. Most of sediment properties were correlated well to the acoustic intensity, however the distribution patterns of the sea-bottom sediment and the seafloor acoustic image were not similar to each other except the rocky bottom area. The water depth was not only influential on the distribution pattern of seafloor acoustic image but also showed a linear relation with the sediment properties distribution.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.39.4-40
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• 2018

KMTNet 광시야 망원경의 성능 개선을 위해 2017년에 이루어진 주요 작업으로 주경 배플(baffle) 설치, 주경 코팅, 돔 플랫(dome flat) 장치 설치에 대해 발표한다. 망원경 주경의 가장자리(turn down edge)는 경면 가공이나 코팅 상태가 균질하지 않을 수 있으며, 이로 인한 난반사는 밝은 별 주위에 넓은 wing profile과 여러 갈래의 방사상 빛줄기를 만든다. 이런 난반사를 제거하기 위해 주경면 바로 앞에 배플을 설치하였다. 주경의 광학 성능과 집광력이 최적이 되도록 배플 내부 직경 값을 1,580 mm로 조정하여 설치한 결과, 관측 영상에서 별의 영상이 크게 개선되었다. 호주 관측소는 상대적으로 습기가 높아서 망원경 주경의 반사율이 빨리 낮아졌으며, 이를 개선하기 위해 기존의 코팅(protected silver)을 제거하고 알루미늄으로 새로 코팅하였다. KMTNet 3개 관측소는 주경의 반사율과 코팅 면의 확대 영상을 정기적으로 모니터링하여 광학 성능의 변화를 추적하고 있다. 밤하늘 플랫(twilight sky flat) 영상을 보완하기 위해, 돔 인클로져에 플랫 스크린과 광원을 설치하여 돔 플랫 영상을 획득하였다. 마지막으로 KMNet 관측시스템을 운영하며 발생한 돔 회전 및 돔 셔터 구동부 문제 등에 대해 소개하고, 문제 발생 원인과 주기, 문제 해결 방안을 발표한다.

• Journal of the Korean Society of Radiology
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• v.81 no.5
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• pp.1204-1209
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• 2020

Cases of undifferentiated pleomorphic sarcoma of the thoracic aorta are rare, and usually present with embolic events, renovascular hypertension, or back pain. Mural-based undifferentiated pleomorphic sarcomas that present as ruptured saccular aneurysms are extremely rare and are difficult to differentiate from mycotic aneurysms or penetrating atherosclerotic ulcers. Herein, we report a case of histopathologically proven undifferentiated pleomorphic sarcoma arising from the wall of the descending thoracic aorta that manifested as a mass after thoracic endovascular aortic repair for the treatment of a ruptured saccular aneurysm. We present findings obtained by CT and PET to provide helpful information for the accurate diagnosis and appropriate treatment of future cases.