• Journal of Korean Society for Quality Management
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• v.44 no.3
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• pp.601-616
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• 2016

Purpose: The purposes of this study are (1) to examine why users commit to M-SNG and (2) to understand what factors impact M-SNG users' enjoyment, motivation and commitment. Methods: We use a questionnaire survey to collect 190 data on users' perception on M-SNG. we also use a structural equation modeling method with Smart PLS 3.0 Results: Playfulness, design aesthetics, competition and social identity are found to be statistically significant factors affecting enjoyment and motivation. Also, enjoyment and motivation are found to be statistically significant factors affecting commitment. Conclusion: We suggest three points of view as game factors, socio-game factors, and social factors. Game factors are more important than other factors. Also, enjoyment is a more powerful factor than motivation in affecting user's commitment to using M-SNG.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.6
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• pp.592-595
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• 2009

Juvenile dermatomyositis is a common inflammatory muscle disease of childhood, characterized by weakness in proximal muscles and specific skin rash. In case of juvenile dermatomyositis without characteristic clinical features, non-invasive imaging tools such as $^{99m}Tc$-HDP three-phase bone scan are very helpful in diagnostic workup of myopathies. We report a case of 13-year old female with juvenile dermatomyositis, in which $^{99m}Tc$-HDP three-phase bone scan was useful in diagnosis and assessing therapy response.

• The Korean Journal of Nuclear Medicine
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• v.20 no.1
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• pp.17-24
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• 1986

Authors enumerate various malignant and benign cases which showed soft tissue uptake of $^{99m}Tc-MDP$. We hope it might be a help in understanding and interpreting bone scans. Among 10,361 $^{99m}Tc-MDP$ bone scans underwent from April, 1981 to March, 1986, 344 (3.3%) showed abnormal soft tissue uptake, which included 126 malignancies, 5 benign tumors, and 153 nontumorous diseases. Neuroblastoma(23.3%) and malignant fibrous histiocytoma(22.2%) showed highest positive uptake rate among various malignancies. We also illustrated typical cases according to possible mechanisms.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.262-264
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• 2018

Many of users play Mobil Social Network Games (M-SNG). M-SNGs are played through social network, and typically features multiplayer and asynchronous gameplay mechanics. It is most often implemented as mobile devices with mobile instant messenger app. Kakaotalk provids mobile game platform. The purpose of this study is to find significant factors that have effects on the commitment of M-SNGs. We also conduct multi-group comparison test to study the difference in factors of models between time t and time t1. Time t is October, 2012 and time t1 is April, 2016. This study is to empirically test the research model using data collected from M-SNGs' users. We survey two different groups of time t and time t1 people with the same model. We use structural equation model analysis with AMOS 18.0 and compare two models of different times. This study is to give academicians and practitioners insight about its effects and implications

• Journal of Radiation Protection and Research
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• v.48 no.1
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• pp.28-43
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• 2023

Background: High-fidelity meteorological data is a prerequisite for the realistic simulation of atmospheric dispersion of radioactive materials near nuclear power plants (NPPs). However, many meteorological models frequently overestimate near-surface wind speeds, failing to represent local meteorological conditions near NPPs. This study presents a new high-resolution (approximately 1 km) meteorological downscaling method for modeling short-range (< 100 km) atmospheric dispersion of accidental NPP plumes. Materials and Methods: Six considerations from literature reviews have been suggested for a new dynamic downscaling method. The dynamic downscaling method is developed based on the Weather Research and Forecasting (WRF) model version 3.6.1, applying high-resolution land-use and topography data. In addition, a new subgrid-scale topographic drag parameterization has been implemented for a realistic representation of the atmospheric surface-layer momentum transfer. Finally, a year-long simulation for the Kori and Wolsong NPPs, located in southeastern coastal areas, has been made for 2016 and evaluated against operational surface meteorological measurements and the NPPs' on-site weather stations. Results and Discussion: The new dynamic downscaling method can represent multiscale atmospheric motions from the synoptic to the boundary-layer scales and produce three-dimensional local meteorological fields near the NPPs with a 1.2 km grid resolution. Comparing the year-long simulation against the measurements showed a salient improvement in simulating near-surface wind fields by reducing the root mean square error of approximately 1 m/s. Furthermore, the improved wind field simulation led to a better agreement in the Eulerian estimate of the local atmospheric dispersion. The new subgrid-scale topographic drag parameterization was essential for improved performance, suggesting the importance of the subgrid-scale momentum interactions in the atmospheric surface layer. Conclusion: A new dynamic downscaling method has been developed to produce high-resolution local meteorological fields around the Kori and Wolsong NPPs, which can be used in short-range atmospheric dispersion modeling near the NPPs.

• Korean Journal of Materials Research
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• v.19 no.12
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• pp.667-673
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• 2009

The electrocatalytic characteristics of oxygen reduction reaction of the $PtxM_{(1-x)}$ (M = Co, Cu, Ni) supported on multi-walled carbon nanotubes (MWNTs) have been evaluated in a Polymer Electrolyte Membrane Fuel Cell (PEMFC). The $Pt_xM_{(1-x)}$/MWNTs catalysts with a Pt : M atomic ratio of about 3 : 1 were synthesized and applied to the cathode of PEMFC. The crystalline structure and morphology images of the $Pt_xM_{(1-x)}$ particles were characterized by X-ray diffraction and transmission electron microscopy, respectively. The results showed that the crystalline structure of the Pt alloy particles in Pt/MWNTs and $Pt_xM_{(1-x)}$/MWNTs catalysts are seen as FCC, and synthesized $Pt_xM_{(1-x)}$ crystals have lattice parameters smaller than the pure Pt crystal. According to the electrochemical surface area (ESA) calculated with cyclic voltammetry analysis, $Pt_{0.77}Co_{0.23}$/MWNTs catalyst has higher ESA than the other catalysts. The evaluation of a unit cell test using Pt/MWNTs or $Pt_xM_{(1-x)}$/MWNTs as the cathode catalysts demonstrated higher cell performance than did a commercial Pt/C catalyst. Among the MWNTs-supported Pt and $Pt_xM_{(1-x)}$ (M = Co, Cu, Ni) catalysts, the $Pt_{0.77}Co_{0.23}$/MWNTs shows the highest performance with the cathode catalyst of PEMFC because they had the largest ESA.

• The Korean Journal of Nuclear Medicine
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• v.34 no.4
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• pp.366-369
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• 2000

We report a case of a patient with cystic subdural hygroma who underwent pre-operative Tc-99m DTPA cistrenoscintigraphy to determine the course of operation. A 68-year-old female was admitted to the department of neurosurgery because of acute subarachnoid hemorrhage. After emergency ventricular drainage, the hydrocephalus and cystic subdural hygroma in the right fronto-temporal area developed. She underwent Tc-99m DTPA cisternoscintigraphy to evaluate the type of hydrocephalus, which revealed obstructive communicating hydrocephalus and the communication between the subdural hygroma and the subarachnoid space. As a result of these findings, she underwent the ventriculo-peritoneal shunt operation without removal of the subdural hygroma. Post-operative brain CT showed nearly normalized shape and size of the right ventricle and disappearance of subdural hygroma. We recommend the pre-operative cisternoscintigraphy in patients with complex hygroma to evaluate the communication between subdural hygroma and the subarachnoid space.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.587-590
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• 2005

We investigated the input impedance characteristics of UHF-band RFID tag chip for increased reading range. A voltage multiplier designed using 0.4 ${\mu}m$ $zero-V_T$ MOSFET showed that DC output voltage of 2 V can be obtained using standard CMOS process. The input impedance of the voltage multiplier was examined to achieve impedance level for maximum reading distance using analytical and numerical approaches. The input impedance of the voltage multiplier could be varied in a wide range by selecting the size of MOSFET and the number of multiplying stages of the voltage multiplier, and thus, the impedance level required for the tag antenna can be obtained in presence of other tag circuit blocks.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.700-703
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• 2017

안전 필수 소프트웨어란, 소프트웨어의 결함으로 인해 사고가 일어났을 경우 사용자에게 치명적인 위해를 야기하는 소프트웨어를 의미한다. 안전 필수 소프트웨어는 다양한 산업에서 보편화 되고 있기 때문에 안전성이 확보된 소프트웨어를 사용자에게 제공해야하며, 잠재적인 결함이 사고로 이어질 수 있기에 안전 요소들에 대한 충분한 분석이 필요하다. 요구사항으로부터 위험 요소를 분석할 때에는 결함의 결과만을 보고 위험 등급을 부여하는 한계가 있다. 결함의 결과가 비록 같더라도 각기 다른 원인에 의해서 각기 다른 위험 수준을 갖기 때문이다. 본 논문에서는 각각의 기능들에 대해 안전성을 부여하고 우선순위를 선정하여 위험도가 높은 기능들에 대해서 우선적으로 분석할 수 있는 기법에 대해서 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.1200-1202
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• 2021

어플을 사용하여 사용자 등록과 휴대폰 카메라를 사용하여 얼굴을 등록하고, 파이카메라에 촬영된 얼굴 이미지를 바탕으로 OpenCV를 이용하여 출입하는 인원의 식별과 열화상 카메라를 통해 체온 측정을 수행하여 사용자의 출입 기록을 저장한다. 기존의 QR코드 인식과 체온 측정을 동시에 수행하여 출입 시스템의 간소화를 기대할 수 있다.