• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2002년도 가을학술발표대회 디자인학 연구
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• pp.6-7
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• 2002

• Genomics & Informatics
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• 제18권3호
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• pp.30.1-30.7
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• 2020

The novel coronavirus pandemic that has originated from China and spread throughout the world in three months. Genome of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) predecessor, severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) play an important role in understanding the concept of genetic variation. In this paper, the genomic data accessed from National Center for Biotechnology Information (NCBI) through Molecular Evolutionary Genetic Analysis (MEGA) for statistical analysis. Firstly, the Bayesian information criterion (BIC) and Akaike information criterion (AICc) are used to evaluate the best substitution pattern. Secondly, the maximum likelihood method used to estimate of transition/transversions (R) through Kimura-2, Tamura-3, Hasegawa-Kishino-Yano, and Tamura-Nei nucleotide substitutions model. Thirdly and finally nucleotide frequencies computed based on genomic data of NCBI. The results indicate that general times reversible model has the lowest BIC and AICc score 347,394 and 347,287, respectively. The transition/transversions bias for nucleotide substitutions models varies from 0.56 to 0.59 in MEGA output. The average nitrogenous bases frequency of U, C, A, and G are 31.74, 19.48, 28.04, and 20.74, respectively in percentages. Overall the genomic data analysis of SARS-CoV-2, SARS-CoV, and MERS-CoV highlights the close genetic relationship.

• 한국입자에어로졸학회지
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• 제4권1호
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• pp.1-7
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• 2008

Temporal trends of the PM10 and PM2.5 mass concentrations, and the concentrations of chemical species (sulfate, nitrate, ammonium, OC, and EC) in PM2.5 at Seoul are compared with the reported results from other mega cities in the world. The mass concentrations of PM10 and PM2.5 at Seoul show decreasing trend. However, the concentration levels are still higher than other cities except Beijing. The sulfate concentration at Seoul has decreased while those of nitrate and ammonium have increased. The concentrations of OC and EC show no apparent trend.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.7-9
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• 2007

If used to drive the minicar, the BLDC Motor has advantages of weightless, efficient, small-size and credibleness. In this paper at first the position detecting method for BLDC was introduced, secondly the simulation of control algorithm was done and at last the prototype controller based one chip processor MEGA48 was fabricated. The controller proposed has characteristic of cheap cost, reliable performance and totally meeting demands of minicar control.

• 한국전자통신학회논문지
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• 제7권5호
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• pp.999-1004
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• 2012

본 논문에서는 광각렌즈기반의 WDR(Wide Dynamic Range)인 2M(Mega)급 CMOS 이미지 센서를 통해 왜곡영상을 보정하는 카메라 모듈의 설계와 렌즈영상의 성능을 분석한다. 또한, 설계한 광각렌즈모듈의 광각렌즈($176^{\circ}$) 특성으로 인한 왜곡영상의 보정된 결과를 분석하였으며, 카메라 모듈의 스마트 NUX(Natural User eXprience) 활용방안을 제안하였다.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.1075-1080
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• 2015

A hybrid electric vehicle (HEV) powertrain has more than one energy source including a high-voltage electric battery. However, for a high voltage electric battery, the average current is relatively low for a given power level. Introduced to increase the voltage of a HEV battery, a compact, high-efficiency boost converter, sometimes called a step-up converter, is a dc-dc converter with an output voltage greater than its input voltage. The inductor occupies more than 30% of the total converter volume making it difficult to get high power density. The inductor should have the characteristics of good thermal stability, low weight, low losses and low EMI. In this paper, Mega Flux^® was selected as the core material among potential core candidates. Different structured inductors with Mega Flux^® were fabricated to compare the performance between the conventional air cooled and proposed potting structure. The proposed inductor has reduced the weight by 75% from 8.8kg to 2.18kg and the power density was increased from 15.6W/cc to 56.4W/cc compared with conventional inductor. To optimize the performance of proposed inductor, the potting materials with various thermal conductivities were investigated. Silicone with alumina was chosen as potting materials due to the high thermo-stable properties. The proposed inductors used potting material with thermal conductivities of 0.7W/m·K, 1.0W/m·K and 1.6W/m·K to analyze the thermal performance. Simulations of the proposed inductor were fulfilled in terms of magnetic flux saturation, leakage flux and temperature rise. The temperature rise and power efficiency were measured with the 40kW boost converter. Experimental results show that the proposed inductor reached the temperature saturation of 107℃ in 20 minutes. On the other hand, the temperature of conventional inductor rose by 138℃ without saturation. And the effect of thermal conductivity was verified as the highest thermal conductivity of potting materials leads to the lowest temperature saturations.

• Radiation Oncology Journal
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• 제36권3호
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• pp.235-240
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• 2018

Purpose: We describe the daily bladder volume change observed by mega-voltage computed tomography (MVCT) during pelvic radiotherapy with potential predictors of increased bladder volume variations. Materials and Methods: For 41 patients who received pelvic area irradiation, the volumes of bladder and pelvic body contour were measured twice a day with pre- and post-irradiation MVCT from the 1st to the 10th fraction. The median prescription dose was 20 Gy (range, 18 to 30 Gy) up to a 10th fraction. The upper and lower margin of MVCT scanning was consistent during the daily treatments. The median age was 69 years (range, 33 to 86 years) and 10 patients (24.4%) were treated postoperatively. Results: Overall bladder volume on planning computed tomography was 139.7 ± 92.8 mL. Generally, post-irradiation bladder volume (POSTBV) was larger than pre-irradiation bladder volume (PREBV) (p < 0.001). The mean PREBV and POSTBV was reduced after 10 fraction treatments by 21.3% (p = 0.028) and 25.4% (p = 0.007), respectively. The MVCT-scanned body contour volumes had a tendency to decrease as the treatment sessions progressed (p = 0.043 at the 8th fraction and p = 0.044 at the 10th fraction). There was a statistically significant correlation between bladder filling time and PREBV (p = 0.001). Conclusion: Daily MVCT-based bladder volume assessment was feasible both intra- and inter-fractionally.

• ALGAE
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• 제34권3호
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• pp.217-228
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• 2019

The marine brown algal genus Colpomenia has a worldwide distribution, with five species reported in Korea and Japan. However, no studies to date attempted to identify the number of species and geographical distribution of Colpomenia along Chinese coast. To fill the biodiversity knowledge gap, we analyzed 63 mitochondrial cox3 and 62 mitochondrial atp6 sequences of Colpomenia specimens collected from 30 localities along the Chinese coast. Maximum likelihood and Bayesian inference trees suggest the presence of at least three Colpomenia species (i.e., C. peregrina, C. claytoniae, and C. sinuosa) in China. C. peregrina and C. claytoniae are documented for the first time. C. sinuosa was only found in the South China Sea and its distribution didn't overlap with that of C. peregrina which was found in the Yellow-Bohai Sea and the East China Sea. C. claytoniae appears to be confined to three isolated islands in the East and the South China Sea, where it occurs in sympatry with, respectively, C. peregrina and C. sinuosa. Future study can focus on comparing eco-physiological differences of Colpomenia species in response to environmental variables and exploring possible genetic hybridization / introgression at inter-specific contact zones.

• Clinical and Experimental Pediatrics
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• 제45권2호
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• pp.247-255
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• 2002

목 적 : 태아 간세포는 면역학적으로 미숙하여 이식에 따른 거부반응이 잘 일어나지 않으므로 조혈모세포 이식, 특히 자궁내 이식의 좋은 공여세포로 이용할 수 있으나 아직 국내에서는 이를 위한 기초연구가 미미한 실정이다. 연구자는 태아 간 단핵세포를 이용하여 면역조직학적 염색과 체외배양 결과를 분석하여 태아 간의 거핵구 집락형성과 관련된 기초자료를 마련하고자 이 연구를 시행하였다. 방 법: 임신중절시 수집한 태아 간조직과 특발성 혈소판 감소성 자반증 및 범혈구 감소증 환아의 골수에서 단핵세포를 분리한 후 $MegaCult^{TM}-C$ 배지에서 12일간 배양 후 성장인자 첨가에 따른 거핵구 집락형성을 관찰하였고, 5일간의 Flask 배양 후 유세포 분석기를 이용하여 CD34, CD41 양성세포를 측정하였으며, methylcellulose 배지를 이용하여 $37^{\circ}C$ 5% $CO_2$ 배양기에서 배양한 후 제 7일과 14일에 성장인자 첨가에 따른 CFU-GM 집락 수를 조사하였다. 결 과 : 태아 간의 단핵세포 수는 재태주령 11주에 비해서 19주에서 더 많았으며 세포생존율은 $91.2{\pm}3.4%$였다. $MegaCult^{TM}-C$ kit를 이용하여 12일간 배양시 재태주령 11주의 태아 간이 19주에 비해서 거핵구 집락 수가 많았고, 4례 모두 성장인자의 첨가에 따른 집락증폭의 상승효과는 없었으며 배양 후 형성된 거핵구 집락 수는 태아 간, 특발성 혈소판 감소성 자반증 환아의 골수, 범혈구 감소증 환아의 골수 순이었다. 거핵구 집락 중 순수집락 수는 태아 간이 특발성 혈소판 감소성 자반증 및 범혈구 감소증 환아의 골수에 비해서 유의하게 높았으며, 순수집락 중 large CFU-Mk의 비율은 태아 간이 특발성 혈소판 감소성 자반증 및 범혈구 감소증 환아의 골수에 비해서 높았으나 유의성은 보이지 않았다. 태아 간 단핵세포를 5일간 flask 배양한 후 CD34 양성세포의 발현율은 증가하였으나 성장인자의 첨가에 따른 집락증폭의 상승효과는 TPO 투여군에서만 있었고, CD41 양성세포의 발현율 역시 배양 후 증가하였으나 성장인자 첨가군에 비해서 대조군의 발현율이 너무 높은 결과를 보였다. Methylcellulose 배지를 이용한 단핵세포 배양에서 CFU-GM 집락 수는 태아 간의 경우 배양 7일에 비하여 14일에 감소하였고, 성장인자의 첨가에 따른 집락증폭의 상승효과는 태아 간에서는 모든 군에서 보였으나 특발성 혈소판 감소성 자반증에서는 GM-CSF 투여군에서만 있었으며 범혈구 감소증 환아의 골수에서는 없었다. 결 론: $MegaCult^{TM}-C$ 배지를 이용하여 태아 간세포를 배양하고 면역조직학적 염색으로 거핵구 집락형성을 성공적으로 관찰하였으며, 태아 간에서 얻은 거핵구 집락이 특발성 혈소판 감소성 자반증 및 범혈구 감소증 환아의 골수에서 얻은 집락에 비하여 집락수나 순수집락의 분포, 집락의 크기 등에서 우수한 것으로 나타났으나 태아 간 조혈모세포 이식의 실제적인 임상적용을 위해서는 체계적인 더 많은 연구가 필요할 것으로 생각된다.

• Asian Journal of Atmospheric Environment
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• 제7권3호
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• pp.169-175
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• 2013

Measurement of the phosphorus concentration in aerosols in Beijing, which was a representative East Asian mega-city, was carried out. The optimum procedure for analyzing phosphorus in aerosols was found in this study. Recovery of phosphorus in environmental samples through the improved method was almost 100%. The concentration of phosphorus in TSP was $145{\pm}47\;ng/m^3$, with a seasonal variation showing high concentrations in winter and low concentrations in summer. The concentrations of phosphorus in $PM_{2.5}$ accounted for $35{\pm}6%$ of those in TSP, with no seasonal variations. The major source of phosphorus in aerosols in Beijing was soil dust, and additional sources of phosphorus in fine particles could be coal combustion and biomass burning.