• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.3
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• pp.218-225
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• 2015

This study used sodium fluorescein to improve imaging diagnostic ability by increasing the fluorescence difference between sound enamel and caries lesions. It also made it easier to discriminate between stain and caries lesions using quantitative light-induced fluorescence (QLF). Half of the specimen surface was covered with nail varnish as a control. Specimens were divided randomly in six decalcification groups and decalcified for different lengths of time. Then, ${\Delta}F$ was measured using QLF-D. After applying 0.075% sodium fluorescein, we measured ${\Delta}F$ again and compared it with the initial value. After cutting the central portion of the specimen, we measured the lesion depth using scanning electron microscopy. The lesion surfaces observed with QLF were darker than normal enamel, whereas they were lighter than normal enamel after applying fluorescein. Longer decalcification time was associated with greater fluorescent dye penetration. The ${\Delta}F$ measured after applying fluorescein was higher than the initial value (p < 0.05). Due to QLF measurement using fluorescein being more sensitive for diagnosing early decalcification, this approach will enable early diagnosis of dental caries before the cavity formation stage, allowing the treatment of early caries lesions. With QLF and sodium fluorescein, we can easily discriminate between stain and caries lesions.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.5
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• pp.102-111
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• 2013

In this paper, we proposed a $4{\times}4$ block parallel architecture of interpolation for high-performance H.264/AVC Motion Compensation in 4K UHD($3840{\times}2160$) video real time processing. To improve throughput, we design $4{\times}4$ block parallel interpolation. For supplying the $9{\times}9$ reference data for interpolation, we design 2D cache buffer which consists of the $9{\times}9$ memory arrays. We minimize redundant storage of the reference pixel by applying the Search Area Stripe Reuse scheme(SASR), and implement high-speed plane interpolator with 3-stage pipeline(Horizontal Vertical 1/2 interpolation, Diagonal 1/2 interpolation, 1/4 interpolation). The proposed architecture was simulated in 0.13um standard cell library. The maximum operation frequency is 150MHz. The gate count is 161Kgates. The proposed H.264/AVC Motion Compensation can support 4K UHD at 72 frames per second by running at 150MHz.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.2 s.314
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• pp.116-125
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• 2007

In this paper, we propose a illumination environment adaptive real-time surveillance system for security of important area such as military bases, prisons, and strategic infra structures. The proposed system recognizes movement of objects on the bright environments as well as in dark illumination. The procedure of proposed system may be summarized as follows. First, the system discriminates between bright and dark with input image distribution. Then, if the input image is dark, the system has a pre-processing. The Multi-scale Retinex Color Restoration(MSRCR) is processed to enhance the contrast of image captured in dark environments. Secondly, the enhanced input image is subtracted with the revised background image. And then, we take a morphology image processing to obtain objects correctly. Finally, each bounding box enclosing each objects are tracked. The center point of each bounding box obtained by the proposed algorithm provides more accurate tracking information. Experimental results show that the proposed system provides good performance even though an object moves very fast and the background is quite dark.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.04a
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• pp.51-55
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• 2003

본 연구는 조사대상지역인 전라남도 해남군 전역에 대해 현장조사된 지질 및 지하수 양수량 자료등과 같은 수리정보를 종합적으로 분석하고 이를 Landsat 영상자료과의 영상융합 과정을 통해 지하수 부존가능성에 대한 수리 지질 지표정보로 추출함으로서 지하수 특성정보를 위성영상정보와 연계하여 효과적으로 도시하고자 하였다. 현장조사시 획득된 자료는 해남지역을 11개 소유역으로 구분한 후 각 구역에 대한 2000여개 관점에서 측정된 양수량과 안정지하수위를 이용하여 산출한 비용출량 자료(groundwater specific capacity)와 각 소 유역 (unit watershed)에 대한 선구조 분석자료, 지질별 분포, 정밀고도자료를 추출하여 산출한 고도, 경사도 분포, 수계패턴과 수계밀도로서 이를 통합적으로 분석하여 해남지역에 대한 지하수 특성을 파악하고자 하였다. 위성영상자료의 처리과정은 Landsat 5 TM 영상자료는 '86. 12. 11 및 '98. 12. 28에 촬영된 WRS(World Reference System) Row-Path116-36로서, 1986년 영상은 12년 차이의 해남의 변화지역을 탐지하기 위한 영상자료로서 활용하였으며 98년 영상을 주요 분석 자료로 이용하였으며 지표 이용정보 추출은 크게 수역추출, 식생분포추출, 지표분류도, 변화탐지영역추출로 구분된다. 본 연구방법은 크게 위성영상분석을 통해 추출된 정보와 지표조사를 통해 획득된 선구조 및 지하수 정보를 Data fusion 방식으로 이용되고 있는 IHS 변환 기법을 통해 본 역에 대한 지하수 정보 및 간척지 등에 의한 지표 개발에 따른 지하수 부존 가능성을 탐색하기 위한 현황을 효과적인 자료로 표현하고자 하였다.및 스페클 잡영 제거 정도에 있어 다른 필터들과 큰 차이가 없지만 경계선보존지수는 다른 필터들에 비하여 가장 우수함을 확인할 수 있었다.rbon 탐식효율을 조사한 결과 B, D 및 E 분획에서 유의적인 효과를 나타내었다. 이상의 결과를 종합해볼 때, ${\beta}$-glucan은 고용량일 때 직접적으로 또는 $IFN-{\gamma}$ 존재시에는 저용량에서도 복강 큰 포식세로를 활성화시킬 뿐 아니라, 탐식효율도 높임으로써 면역기능을 증진 시키는 것으로 나타났고, 그 효과는 crude ${\beta}$-glucan의 추출조건에 따라 달라지는 것을 알 수 있었다.eveloped. Design concepts and control methods of a new crane will be introduced in this paper.and momentum balance was applied to the fluid field of bundle. while the movement of′ individual material was taken into account. The constitutive model relating the surface force and the deformation of bundle was introduced by considering a representative prodedure that stands for the bundle movement. Then a fundamental equations system could be simplified considering a steady state of the process. On th

• Journal of the Korean Society of Radiology
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• v.82 no.1
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• pp.237-243
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• 2021

This is a rare case of a 73-year-old male patient who presented with hematochezia and was treated using transcatheter arterial embolization following upper gastrointestinal bleeding in the third portion of the duodenum. The cause of the bleeding was not found on gastrointestinal endoscopy and CT. On the third day of hospitalization, the hemoglobin level continued to decrease. A technetium-99m-labeled red blood cell scan revealed suspicious bleeding in the diverticulum of the third portion of the duodenum. Superior mesenteric artery angiography showed active bleeding from the posteroinferior pancreaticoduodenal artery, which was embolized with N-butyl cyanoacrylate. The patient was discharged on the seventh day after embolization without re-bleeding or complication. We report a rare case of a patient with active bleeding from a duodenal diverticulum that was difficult to diagnose using routine modalities. Herein, we report a rare case of a patient with active bleeding from a duodenal diverticulum that was difficult to diagnose using routine modalities. We also conducted a relavant literature review.

• Korean Journal of Digital Imaging in Medicine
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• v.9 no.1
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• pp.31-35
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• 2007

외부 데이터가 진료병원 Server에 저장됨에 있어서 판독을 의뢰하지 않을 경우, 대부분의 병원이 무상으로 이루어 지고 있는 상황이며 이에 외부 데이터 단순 import의 효율적인 관리를 위한 수가 적용 여부를 검토하였다. 2007년 3월부터 4월까지 서울 경기 지역의 PACS가 도입 된지 1년 이상, 병상 수 500Bed 이상의 종합 대학병원 25곳에 근무하는 각 병원의 PACS 운영실 및 PACS 관리자를 대상으로 하였다. 외부 데이터에 관한 10가지 항목의 설문지를 작성하여 각 병원의 PASC 담당자 및 관리자를 대상으로 E-mail을 이용한 자기 기입 방식, 전화를 통한 질의응답 방식으로 조사하였다. 조사된 25개의 종합 대학병원의 96%이상이 외부 데이터 단순 import를 지원하고 있었으며, 그 중 92%의 병원은 무상으로 이루어지고 있었다. 이와 같이 진행 되는 부분에 대하여 각 병원의 PACS 담당자 70% 이상이 단순 import에 대한 수가 적용의 필요성을 느끼고 있으며, 현재 많은 병원에서 단순 import의 무상 지원으로 인한 문제점을 인식하고 있었다. K병원을 기준으로 단순 import에 년간 H/W 소요 비용은 336만원이고, 년간 인건비 소요비용은 421만원이다. 또한 단순 import 한 건당 평균 데이터 size는 48MB 정도로 조사되었다. 환자 입장에서 진료에 참고자료로 사용 될 외부 데이터의 정확한 저장과 정당한 PACS 사용을 위해서는 그에 상응하는 수가가 적용 되어야 할 것이다. 보험심사평가원 급여기준에 따라 수가적용이 인정되어 의료영상 디지털화로 인한 초기의 고액 투자비용 보장과 회수를 위해 단순 Import의 수가 적용이 반드시 필요하다고 사료 된다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.151-159
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• 2018

Recently, stereoscopic technology has become a potential for blue ocean as a new growth power industry, and interest in it has been steadily increasing with the development of virtual and augmented reality technologies. Various methods such as binocular parallax and polarized glasses have been developed and used for stereoscopic image expression, but they have limitations such as eye damage, headache, crosstalk and resolution degradation. In this paper, we present a new method of stereoscopic image representation that can overcome the limitations and verify its applicability through basic experiments for object extraction and real - time image representation.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.181-186
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• 2006

An imaging method of seismic sources using time-reversal wave propagation is presented. The method is based on the time-reversal invariance and the spatial reciprocity of the wave equation. Time-reversal wave propagation has been used to image anomalous features of a midium in medical imaging, non destructive testing and waveform tomography. Seismogram is the record whose energy is propagated from the seismic source. If time-reversed seismogram propagates back into the medium, seismic energy is concentrated at the origin time of the event and at the source location. In this work, a staggered-grid finite-difference method of the elastic wave equation is parallelized for 3-D wave propagation simulation. With numerical experiments, we show that the time-reversal imaging will enable us to explore the spatio-temporal history of complex earthquake.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.3
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• pp.103-114
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• 2004

This paper deals with a system that is capable of recognizing hand-signals in 3-dimensional space. The system uses 2 color cameras as input devices. Vision-based gesture recognition system is known to be user-friendly because of its contact-free characteristic. But as with other applications using a camera as an input device, there are difficulties under complex background and varying illumination. In order to detect hand region robustly from a input image under various conditions without any special gloves or markers, the paper uses previous position information and adaptive hand color model. The paper defines a hand-signal as a combination of two basic elements such as 'hand pose' and 'hand trajectory'. As an extensive classification method for hand pose, the paper proposes 2-stage classification method by using 'small group concept'. Also, the paper suggests a complementary feature selection method from images from two color cameras. We verified our method with a hand-signal application to our driving simulator.

• The Journal of the Acoustical Society of Korea
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• v.35 no.2
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• pp.125-133
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• 2016

In order to obtain high-resolution seafloor images, research on SA (Synthetic Aperture) processing and the development of related underwater systems have been performed in many countries. Recently the SA processing is also recognized as an important technique in Korea and researchers started related basic study. However, most previous studies ignored the Doppler effect by a moving receiver array. In this paper reconstructed SAS (Synthetic Aperture Sonar) images and position errors are analyzed according to the speed of a moving array for understanding its moving effect on the SAS images. In the analysis the spatial frequency domain interpolation algorithm is used. The results show that as the moving speed of the array increases the estimated position error also increases and image distortion gets worse when we do not consider the array motion. However, if the compensated receiver signals considering the array motion are used the position error and image distortion can be eliminated. In conclusion a signal processing scheme which compensates the Doppler effect is necessary especially in the condition where the array speed is over 1 m/s.