• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.4
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• pp.143-154
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• 2004

The researchers, who seek geological and environmental information, depend on the remote sensing and aerial photographic datum from various commercial satellites and aircraft. However, the adverse weather conditions and the expensive equipment can restrict that the researcher can collect their data anywhere and any time. To allow for better flexibility, we have developed a compact, a multi-spectral automatic Aerial photographic system(PKNU 2). This system's Multi-spectral camera can catch the visible(RGB) and infrared(NIR) bands($3032{\times}2008$ pixels) image. Visible and infrared bands images were obtained from each camera respectively and produced Color-infrared composite images to be analyzed in the purpose of the environment monitor but that was not very good data. Moreover, it has a demerit that the stereoscopic overlap area is not satisfied with 60% due to the 12s storage time of each data, while it was possible that PKNU 2 system photographed photos of great capacity. Therefore, we have been developing the advanced PKNU 2(PKNU 3) that consists of color-infrared spectral camera can photograph the visible and near infrared bands data using one sensor at once, thermal infrared camera, two of 40 G computers to store images, and MPEG board to compress and transfer data to the computer at the real time and can attach and detach itself to a helicopter. Verification and calibration of each sensor(REDLAKE MS 4000, Raytheon IRPro) were conducted before we took the aerial photographs for obtaining more valuable data. Corrections for the spectral characteristics and radial lens distortions of sensor were carried out.

• Journal of Radiation Protection and Research
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• v.30 no.1
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• pp.9-15
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• 2005

This study was conducted to investigate the patient exposure dose during a CT examination and the present position in utilization of the CT equipments. To this end Questionnaire were sent out to 278 medical facilities registered at Korea Hospital Association and replies of 161 medical facilities were analyzed. The results were as follows ; 1) The distribution of CT examination was. Brain 40.7%, Abdomen 27.8%, Chest 15.7%, Spine 4.8%, Pelvis 4.1%, PNS 3.2%, Facial bone 2.5% and Extremity 1.1% respectively. 2) The statistics for dose index according to each part of examination were Brain 38.0mGy, Abdomen 12.0mGy for adults : Brain 13.6mGy, Abdomen 6.2mGy for infant. Our surveyed dose index appeared lower than the IAEA recommends. 3) Most medical facilities have selected the parameters for radiographic exposure in the range of $100{\sim}120kVp,\;100{\sim}250mA\;and\;1{\sim}2$ seconds.

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.523-530
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• 2019

The purpose of this study was to obtain the K-edge images using a spectral CT system based on a photon-counting detector and implement the 3D fusion imaging using the conventional and spectral CT images. Also, we evaluated the clinical feasibility of the 3D fusion images though the quantitative analysis of image quality. A spectral CT system based on a CdTe photon-counting detector was used to obtain K-edge images. A pork phantom was manufactured with the six tubes including diluted iodine and gadolinium solutions. The K-edge images were obtained by the low-energy thresholds of 35 and 52 keV for iodine and gadolinium imaging with the X-ray spectrum, which was generated at a tube voltage of 100 kVp with a tube current of $500{\mu}A$. We implemented 3D fusion imaging by combining the iodine and gadolinium K-edge images with the conventional CT images. The results showed that the CNRs of the 3D fusion images were 6.76-14.9 times higher than those of the conventional CT images. Also, the 3D fusion images was able to provide the maps of target materials. Therefore, the technique proposed in this study can improve the quality of CT images and the diagnostic efficiency through the additional information of target materials.

• 순환기질환의공학회:학술대회논문집
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• 2006.10a
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• pp.44-45
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• 2006

• Journal of the Korean Society for information Management
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• v.8 no.2
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• pp.108-124
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• 1991

정보량이 많은 사진과 같은 화상 정보는 대용량을 갖고 있는 광 디스크에 축적시켜 DB를 구축하고 이는 컴퓨터를 이용해 고속 검색할 수 있다. 사진 DB 구축은 사진의 양, 구 축 목적, 이용 대상, 활용 방법 등에 따라 방법을 달리할 수 있으며 이의 검색 요소에는 촬 영 행위, 촬영 조건, 표제, 주제의 4가지 요소가 있고 그 중 가장 중요시되는 주제 요소에는 감각 정보, 주제 분류, 키워드가 있다.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.251-254
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• 2004

최근 인공위성 영상자료의 해상도가 높아짐에 따라 영상을 통해 얻을 있는 정보의 양이 증가하고 있다. 영상의 식별력이 증가함으로써 영상에서 얻을 수 있는 정보량이 증가하지만 그와 함께 정보의 질이 향상되었다고 판단하기는 어렵기 때문에 지형과 영상의 정밀보정은 매우 중요하다 특히, 광학센서 기반의 인공위성 자료는 영상자료의 공간해상도 뿐만 아니라 촬영시기, 지형형태 둥 많은 내ㆍ외부 조건에 따른 특성을 가지고 있다. 이러한 특성은 표고가 높은 지형에서 더욱 크게 영향 받는다. 이에 본 연구에서는 Kompsat EOC 및 Spot-5 등 다양한 광학위성 센서에 대한 지형효과 특성을 위성의 기하정보 등록방법에 따라 분석함으로써 자료 이용의 효용성 제고에 기여하고자 한다.

• Proceedings of the KAIS Fall Conference
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• 2004.11a
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• pp.93-95
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• 2004

가공방법에 따라 금형의 성능과 수명에 영향을 준다. 이와 같은 원인을 규명하기 위한 기초 연구를 수행하였다. 재료로는 프레스 금형 제작에 주로 사용되는 STD11을 선정하였다. 가공방법을 WEDM, WEDM후 템퍼링 등 2개 조건으로 하였다. 2개의 가공방법에 의해 제작된 시편을 전자주사현미경으로 표면, 단면조직사진을 촬영하였고, EDS를 하여 표면성분의 변화량을 측정하였다.

• Journal of radiological science and technology
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• v.3 no.1
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• pp.29-35
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• 1980

The tube voltage in radiographic technique factors of the extremities was studied to use the acryl phantom and aluminum step wedge. It was the proper tube voltage that was over 55-60kV in the finger, over 65kV in the forearm and over 75kV in the knee joint.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.06a
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• pp.288-290
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• 2019

본 논문에서는 블록체인 및 암호화폐(토큰)를 이용해 미디어사물인터넷 내 카메라로부터의 비디오 스트리밍 서비스를 제공하는 시스템을 제안한다. 사용자가 분산형 애플리케이션을 통해 블록체인 상에 작성되어 있는 스마트 컨트랙트의 계약조건에 따라 토큰을 지불하고, 토큰을 지불 받은 IP 카메라는 촬영하고 있는 동영상을 실시간으로 사용자에게 스트리밍하는 시나리오를 구성하였다. 블록체인 카메라 스트리밍 서비스의 가능성을 알아보기 위해, 이더리움 기반의 블록체인 위에 스트리밍 서비스를 위한 스마트 컨트랙트를 업로드하고, 거래에 필요한 ERC20 토큰을 제작하여 시스템을 구현하였다.

• Journal of the Korean Geotechnical Society
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• v.15 no.4
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• pp.167-173
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• 1999

In this paper the failure behavior of the reinforced earth retaining wall structures according to the deformed types of the face was studied by model test using carbon rods. In model test the behavior of the face for the model of the reinforced earth wall was divided into three cases : the displacement of the top part(case 1), the lateral displacement(case 2) and the displacement of the lower part (case 3). The photographic method was applied to examine the failure line of the deformed wall with the naked eye. The failure line shows a parabolic shape for case 1, a large circular arc for case 2 and a logarithmic spiral for case 3 in the experimental results. The design failure line for the coherent gravity structure hypothesis was most similar to the failure line for the case of the lower part displacement.