• The Journal of the Korea Contents Association
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• v.9 no.10
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• pp.110-121
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• 2009

In this paper, we propose the new method that offer detailed-information through relax the system memory limitation about 3D model to user. That method based on making LOD(Level of Detail) model from huge 3D data of structure cultural assets. In our method as transformed AOSP algorithm, first of all it create the hierarchical structure space about 3D data, and create the LOD model by surface simplification. Then it extract the ROI(Region of Interest) of user in simplified LOD model, and then do rendering by original model and same surface detailed-information after process the local detailed in extracted region. To evaluate the proposed method, we have some experiment by using the precise 3D scan data of structure cultural assets. Our method can offer the detailed-information same as exist method, and moreover 45% reduced consumption of memory experimentally by forming mesh structure same as ROI of simplified LOD model. So we can check the huge structure cultural assets particularly in general computer environment.

• Journal of the Korea Convergence Society
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• v.11 no.7
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• pp.157-162
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• 2020

In recent years, laser induced graphene process have been intensively studied for eco-friendly electronic device such as flexible electronics or thin film based energy storage devices because of its simple and effective process. In order to increase the performance and efficiency of an electronic device using such a graphene patterned structure, it is essential to study an optimized laser patterning condition as small as possible linewidth while maintaining the graphene-specific 2-dimensional characteristics. In this study, we analyzed to find the optimal line pattern by using a Ti:sapphire femtosecond laser based photo-thermal reduction process. we tuned intensity and scanning speed of laser spot for generating effective graphene characteristic and minimum thermal effect. As a result, we demonstrated the reduced graphene pattern of 30㎛ in linewidth by using a focused laser beam of 18㎛ in diameter.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.1
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• pp.102-107
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• 2011

The current blood control system is using barcode and scanning one by one to manage blood bags. To have better management and accuracy, an RFID BIS (blood information system) is implemented with an UHF RFID tag antenna using a reflecter for a blood bag has been used.. The UHF RFID tag for blood bag, attached on the high permittivity blood, is designed and fabricated. The tag antenna is optimized and fabricated with the simulation tests such as the existence and nonexistence of the reflector, various distance between the reflector and the dipole tag, the different widths of the reflector and the existence and nonexistence of the T-matching structure. The characteristics and the reading range patterns of the tag antennas are measured. The BIS is implemented with the new tag design.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• fall
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• pp.331-334
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• 2021

기존의 택배 배송시스템은 수령인 본인이 아니더라도 주소, 전화번호와 같은 개인정보를 쉽게 확인할 수 있다. 코로나 19로 인해 언택트(Untact) 주문 및 배달, 배송 서비스가 급격히 늘어나면서 택배 배송 관련 사업은 거대한 시장으로 성장하고 있으며 이와 함께 노출된 개인정보가 범죄에 악용될 수 있다는 우려도 증가하고 있다. 더불어 여러 택배 및 배송물이 도착했을 때, 수신자는 택배 상자를 뜯지 않고 배송물의 오도착 여부를 확인하기 어려우며 원하는 물품이 담긴 택배가 정확히 어떤 것인지 알기 힘들다.본 프로젝트에서는 다단계 인증이 가능한 QR code를 활용해 송수신자의 주소, 제품 종류, 명칭 등을 포함한 여러 정보를 배송기사, 수령인 등에 따라 선택적으로 접근한다. 같은 QR code를 스캔하더라도 수령인의 경우 모든 정보를 확인할 수 있고, 배달원은 일부의 정보를 확인할 수 있지만, 권한이 없는 사람은 어떠한 정보도 확인할 수 없다. 기존의 택배 배송시스템처럼 정보를 맨눈으로 인식할 수도 없으므로 개인정보 노출의 한계를 극복할 수 있다. 이때 송장 정보는 텍스트 형태뿐 아니라 주문한 내용물의 종류 및 모양 등을 그대로 구현한 AR(augmented reality) 형태로도 확인할 수 있어 포장된 상태 그대로 배송물의 오도착 여부를 확인하거나 다량의 택배를 보다 효율적으로 구분할 수 있다. 이처럼 같은 QR code로 서로 다른 정보를 제공하는 SQRC(Security/Secure QR code)의 원리를 이용해 정보를 안전하게 보호하는 것에 그치지 않고, 비디오나 이미지와 같은 멀티미디어 서비스를 추가로 제공해 실감 미디어의 적용 범위를 넓힐 수 있다.

• Journal of the Korea Computer Graphics Society
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• v.17 no.1
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• pp.9-16
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• 2011

In this paper, we describe the development of a system for generating a 3-dimensional human face and predicting it's appearance as it ages over subsequent years using 3D scanned facial data and photo images. It is composed of 3-dimensional texture mapping functions, a facial definition parameter input tool, and 3-dimensional facial prediction algorithms. With the texture mapping functions, we can generate a new model of a given face at a specified age using a scanned facial model and photo images. The texture mapping is done using three photo images - a front and two side images of a face. The facial definition parameter input tool is a user interface necessary for texture mapping and used for matching facial feature points between photo images and a 3D scanned facial model in order to obtain material values in high resolution. We have calculated material values for future facial models and predicted future facial models in high resolution with a statistical analysis using 100 scanned facial models.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.109-110
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• 2014

주사전자현미경(Scanning Electron Microscopy: SEM)은 고체상태에서 미세조직과 형상을 관찰하는 데에 가장 다양하게 쓰이는 분석기기로서 최근에 판매되고 있는 고분해능 SEM은 수 나노미터의 분해능을 가지고 있다. 그리고 SEM의 초점심도가 크기 때문에 3차원적인 영상의 관찰이 용이해서 곡면 혹은 울퉁불퉁한 표면의 영상을 육안으로 관찰하는 것처럼 보여준다. 활용도도 매우 다양해서 금속파면, 광물과 화석, 반도체 소자와 회로망의 품질검사, 고분자 및 유기물, 생체시료 nnnnnnnnn와 유가공 제품 등 모든 산업영역에 걸쳐 있다(Fig. 1). 입사된 전자빔이 시료의 원자와 탄성, 비탄성 충돌을 할 때 2차 전자(secondary electron)외에 후방산란전자(back scattered electron), X선, 음극형광 등이 발생하게 되는 이것을 통하여 topography (시료의 표면 형상), morphology(시료의 구성입자의 형상), composition(시료의 구성원소), crystallography (시료의 원자배열상태)등의 정보를 얻을 수 있다. SEM은 2차 전자를 이용하여 시료의 표면형상을 측정하고 그 외에는 SEM을 플랫폼으로 하여 EDS (Energy Dispersive X-ray Spectroscopy), WDS (Wave Dispersive X-ray Spectroscope), EPMA (Electron Probe X-ray Micro Analyzer), FIB (Focus Ion Beam), EBIC (Electron Beam Induced Current), EBSD (Electron Backscatter Diffraction), PBMS (Particle Beam Mass Spectrometer) 등의 많은 분석장치들이 SEM에 부가적으로 장착되어 다양한 시료의 측정이 이루어진다. 이 중 결정구조, 조성분석을 쉽고 효과적으로 할 수 있게 하는 X선 분석장치인 EDS를 SEM에 일체화시킨 장비와 EDS 및 PBMS를 SEM에 장착하여 반도체 공정 중 발생하는 나노입자의 형상, 성분, 크기분포를 측정하는 PCDS(Particle Characteristic Diagnosis System)에 대해 소개하고자 한다. - EDS와 통합된 SEM 시스템 기본적으로 SEM과 EDS는 상호보완적인 기능을 통하여 매우 밀접하게 사용되고 있으나 제조사와 기술적 근간의 차이로 인해 전혀 다른 방식으로 운영되고 있다. 일반적으로 SEM과 EDS는 별개의 시스템으로 스캔회로와 이미지 프로세싱 회로가 개별적으로 구현되어 있지만 로렌츠힘에 의해 발생하는 전자빔의 왜곡을 보정을 위해 EDS 시스템은 SEM 시스템과 연동되어 운영될 수 밖에 없다. 따라서, 각각의 시스템에서는 필요하지만 전체 시스템에서 보면 중복된 기능을 가지는 전자회로들이 존재하게 되고 이로 인해 SEM과 EDS에서 보는 시료의 이미지의 차이로 인한 측정오차가 발생한다(Fig. 2). EDS와 통합된 SEM 시스템은 중복된 기능인 스캔을 담당하는 scanning generation circuit과 이미지 프로세싱을 담당하는 FPGA circuit 및 응용프로그램을 SEM의 회로와 프로그램을 사용하게 함으로 SEM과 EDS가 보는 시료의 이미지가 정확히 일치함으로 이미지 캘리브레이션이 필요없고 측정오차가 제거된 EDS 측정이 가능하다. - PCDS 공정 중 발생하는 입자는 반도체 생산 수율에 가장 큰 영향을 끼치는 원인으로 파악되고 있으며, 생산수율을 저하시키는 원인 중 70% 가량이 이와 관련된 것으로 알려져 있다. 현재 반도체 공정 중이나 반도체 공정 장비에서 발생하는 입자는 제어가 되고 있지 않은 실정이며 대부분의 반도체 공정은 저압환경에서 이루어지기에 이 때 발생하는 입자를 제어하기 위해서는 저압환경에서 측정할 수 있는 측정시스템이 필요하다. 최근 국내에서는 CVD (Chemical Vapor Deposition) 시스템 내 파이프내벽에서의 오염입자 침착은 심각한 문제점으로 인식되고 있다(Fig. 3). PCDS (Particle Characteristic Diagnosis System)는 오염입자의 형상을 측정할 수 있는 SEM, 오염입자의 성분을 측정할 수 있는 EDS, 저압환경에서 기체에 포함된 입자를 빔 형태로 집속, 가속, 포화상태에 이르게 대전시켜 오염입자의 크기분포를 측정할 수 있는 PBMS가 일체화 되어 반도체 공정 중 발생하는 나노입자 대해 실시간으로 대처와 조치가 가능하게 한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.10
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• pp.1089-1097
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• 2002

In this paper, the novel shipboard Active Phased Array Antenna(APAA) system for maritime mobile satellite communications is introduced. The antenna uses novel technologies like wide range hybrid tracking, single antenna elements with both of Rx and Tx, asymmetrical array structure, interference isolation between Rx and Tx, and error correction method from frequency scan effect. The antenna has single aperture for both of Rx and Tx with 32 $\times$ 4 two-dimensional array. The antenna has two beams. Its frequencies are 7.25 ~ 7.75 GHz for Rx and 7.9 ~ 8.4 GHz for Tx. The antenna gains are 35.4 dBi for Rx and 35.7 dBi for Tx, those are 54 % of efficiency. The electrically steering ranges are $\pm$35$^{\circ}$ of elevation direction and $\pm$4$^{\circ}$ of azimuth direction. The mechanical control ranges at hybrid tracking capability are continuous 360$^{\circ}$ of azimuth direction and $\pm$10$^{\circ}$ of elevation direction. The antenna has 2.2$^{\circ}$ of 3 dB beamwidth, -14 dB of sidelobe level, and 21 dB of cross-pol suppression. The antenna performance was measured by near field measurement set. Its system performance was tested on the ship motion simulator and with the satellite transponder simulator. The test result showed that its tracking error was within -3 dB from its peak gain under motion condition. The antenna system was tested by real modulated Direct Broadcasting Satellite(DBS) signals to check its communication processing function.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.3
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• pp.301-315
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• 2010

Recently, competition between companies has intensified and so has the necessity of creating a new business value inventions has increased. A numbers of Business organizations are beginning to realize the importance of business process management. Processes however can often not go the way they were initially designed or non-efficient performance process model could be designed. This can be due to a lack of cooperation and understanding between business analysts and system developers. To solve this problem, business process mining which can be used as the basis of the business process re-engineering has been recognized to an important concept. Current process mining research has only focused their attention on extracting workflow-based process model from competed process logs. Thus there have a limitations in expressing various forms of business processes. The disadvantage in this method is process discovering time and log scanning time in itself take a considerable amount of time. This is due to the re-scanning of the process logs with each new update. In this paper, we will presents a modified FP-Tree algorithm for FP-Tree based business processes, which are used for association analysis in data mining. Our modified algorithm supports the discovery of the appropriate level of process model according to the user's need without re-scanning the entire process logs during updated.

• Childhood Kidney Diseases
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• v.14 no.1
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• pp.71-78
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• 2010

Purpose : Hydronephrosis is found about 30% of children with urinary tract infection (UTI). It can be caused by various conditions, although most childhood hydronephrosis is congenital. This study was performed to investigate the relationship between febrile UTI and hydronephrosis. Methods : We retrospectively reviewed the medical charts of 183 patients diagnosed as UTI between January 2007 and May 2009 at Korea University Guro Hospital. Inclusion criteria were as followings; 1) fever more than $37.5^{\circ}C$ measured in the axilla, 2) positive urine culture, 3) no history of urinary tract anomaly on antenatal sonography and urinary tract infection. We classified the enrolled children into two groups of patients with hydronephrosis (HN) and those without hydronephrosis (NHN). Results : The 80 patients were HN and 103 patients NHN. Hydronephrosis was found in 58 patients with left kidney, 8 right and 14 both kidneys. Most of hydronephrosis were of low grade. Compared with NHN group, initial renal cortical defects on DMSA scan significantly increased in HN group (HN 37.5%, NHN 16.5%, P<0.05). The incidence of VUR was not different between the two groups (HN 22%, NHN 12.1%). White blood cell counts and C-reactive protein were not different between the two groups. Follow-up DMSA scan (about 6 months later after UTI) showed no difference of renal scarring in both two groups. Conclusion : Our data suggests that hydronephrosis in febrile UTI patients is clinically useful for detecting renal cortical defects, but is not associated with follow-up renal scar.

• The Korean Journal of Nuclear Medicine
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• v.33 no.4
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• pp.381-387
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• 1999

Purpose: The International Labor Organization (ILO) has established an international standard for chest X-ray diagnosis of pneumoconiosis since 1980. However, there is a need for improved diagnosis and staging in occupational disease. We evaluated Ga-67 citrate scintigraphy quantitatively and correlated the scintigraphic findings with pulmonary function tests and chest X-ray results. Materials and Methods: Twenty-five patients underwent whole body scintigraphy with additional chest and abdomen images 48 hrs after intravenous injection of 185 MBq of Ga-67 citrate. Ten normal controls were also studied. Regions of interest (ROI) were drawn on the posterior image to measure counts from the liver and lungs (Lung/Liver Ratio). Results: L/L ratio according to the stages of chest X-ray classification were as follows; stage 0 (normal, n=10): $0.3948{\pm}0.0692$, stage 1 (n=10): $0.5763{\pm}0.1537$, stage 2 (n=11), $0.6849{\pm}0.1459$, stage 3 (n=4) $0.9913{\pm}0.0712$. There was a significant correlation between the scintigraphic L/L ratio and the X-ray stage (r=0.618, p<0.05). However, no significant correlation between L/L ratio and pulmonary function tests were observed (p>0.05). Conclusion: Quantitative Ga-67 scintigraphy can be a useful method for staging of silicosis. However, it is not a method to assess pulmonary functional impairment.