• 한국환경과학회지
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• 제24권12호
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• pp.1559-1567
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• 2015

This study investigated the association between $PM_{2.5}$ concentrations obtained with portable real-time monitors and those obtained with gravimetric methods in national urban air-quality monitoring sites in Seoul, South Korea. We used the SidePak AM510 Personal Aerosol Monitor (TSI Inc., 500 Cardigan Road Shoreview, MN) and DustTrak DRX 8533 (TSI Inc., 500 Cardigan Road Shoreview, MN) as portable real-time monitors for measuring $PM_{2.5}$ concentrations and compared these values with those measured with the PMS-103 or SEQ 47/50 models operated by Federal Reference Method (FRM) or the European Committee for Standardization(ECS), respectively, in national urban air-quality monitoring sites in Seoul. Measurements were conducted every other day in the winter and spring seasons of 2014. The estimated daily mean concentrations of $PM_{2.5}$ ranged between 13.4 and $161.9{\mu}g/m^3$ using AM 510 and between 22.0 and $156.0{\mu}g/m^3$ using DustTrak. The Spearman correlation coefficient for $PM_{2.5}$ concentrations between AM 510 and gravimetric results was 0.99, and the correlation between DustTrak and gravimetric results was 0.87. The correction factor suggested was 0.42 and 0.29 for AM 510 and DustTrak, respectively. We found that $PM_{2.5}$ concentrations measured with real-time monitors could overestimate true $PM_{2.5}$ concentrations and therefore the application of a correction factor (0.43) is strongly suggested for quantification when Real-time monitors were operated of $PM_{2.5}$ levels at urban atmospheric environment of South Korea.

• 대한방사선기술학회지:방사선기술과학
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• 제37권3호
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• pp.233-238
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• 2014

경기도 수원시에 있는 한 대학의 두 건물(오래된 건물과 새 건물)의 실내외(지하, 옥상)에서 2013년 4월 첫 주부터~ 2014년 3월 말 주 까지 1년간 1주일에 2회씩 환경방사선량을 측정한 결과 다음과 같은 결론을 얻었다. 1. 두 건물의 환경방사선량은 $0.169727{\mu}Sv/hr$이었고, 가장 작게 측정된 값은 $0.076{\mu}Sv/hr$이었고, 가장 높게 측정된 값은 $0.300{\mu}Sv/hr$이었다. 2. 오래된 건물의 환경방사선량이 $0.176374{\mu}Sv/hr$, 새 건물이 $0.163053{\mu}Sv/hr$로 오래된 건물에서 더 높게 측정되었다. 3. 1년 중 가장 낮게 환경방사선량이 측정된 달은 11월로 평균 $0.152844{\mu}Sv/hr$이고, 가장 높게 측정 된 달은 5월로 평균 $0.197222{\mu}Sv/hr$이다. 4. 측정 장소 비교에서 실내의 환경방사선량은 $0.164649{\mu}Sv/hr$, 실외는 $0.174779{\mu}Sv/hr$로 실외에서 높게 측정되었다. 5. 계절별로 가장 낮게 측정된 환경방사선량은 겨울로 $0.157788{\mu}Sv/hr$이고, 가장 높게 측정된 계절은 봄 $0.183846{\mu}Sv/hr$이며, 봄, 여름, 가을, 겨울 순으로 적게 측정되었다.

• 설비공학논문집
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• 제26권9호
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• pp.409-415
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• 2014

Ground-source heat pump (GSHP) systems have become an efficient alternative to conventional cooling and heating methods due to their higher energy efficiency. These systems use the ground as a heat source and the heat sink for cooling mode operation. The purpose of this simulation study is to evaluate the performance of a hypothetical GSHP system in an office building and to assess the energy saving effect against the existing HVAC systems (boiler and turbo chiller). We collected monthly energy consumption data from an actual office building ($32,488m^2$) in Seoul, and created a model to calculate the hourly building loads with EnergyPlus. In addition, we used GLD (Ground Loop Design) V8.0, a GSHP system design and simulation software tool, to evaluate hourly and monthly performance of the GSHP system. The energy consumption for the GSHP system based on the hourly simulation results were estimated to be 582.6 MWh/year for cooling and 593.2 MWh/year for heating, while those for the existing HVAC systems were found to be 674.5 MWh/year and 2,496.4 MWh/year, respectively. The seasonal performance factor (SPF) of the GSHP system was also calculated to be in the range of 3.37~4.28.

• Genomics & Informatics
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• 제7권4호
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• pp.195-202
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• 2009

BIRC5 (Survivin) belongs to the inhibitor of apoptosis gene family. The BIRC5 protein inhibits caspases and consequently blocks apoptosis. Thus, BIRC5 contributes to the progression of cancer allowing for continued cell proliferation and survival. In this study, we identified eight sequence variants of BIRC5 through direct DNA sequencing. Among the eight single nucleotide polymorphisms (SNPs), six common variants with frequencies higher than 0.05 were selected for larger-scale genotyping (n=1,066). Results of the study did not show any association between the promoter region polymorphisms and the clearance of hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC) occurrence. This is in line with a previous study in which polymorphisms in the promoter region does not influence the function of BIRC5. Initially, we were able to detect a signal with the ＋9194A>G, which disappeared after multiple corrections but led to a change in amino acid. Similarly, we were also able to detect an association signal between two haplotypes (haplotype-2 and haplotype-5) on the onset age of HCC and/or HCC occurrence, but the signals also disappeared after multiple corrections. As a result, we concluded that there was no association between BIRC5 polymorphisms and the clearance HBV infection and/or HCC occurrence. However, our results might useful to future studies.

• Genomics & Informatics
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• 제7권4호
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• pp.187-194
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• 2009

Cytochrome P450 2E1 (CYP2E1) is a member of the cytochrome P450 superfamily, and it is a key enzyme responsible for the metabolic activation of many smallmolecular-weight compounds such as alcohol, which is classified as a human carcinogen. In this study, we identified 19 single nucleotide polymorphisms (SNPs) in CYP2E1 in Korean population. In these SNPs, we examined possible genetic association of CYP2E1 polymorphisms with HBV clearance and the risk of hepatocellular carcinoma (HCC). Five common polymorphic sites were selected, CYP2E1 polymorphisms at rs381-3867, rs3813870, rs2070673, rs2515641 and rs2480257, considering their allele frequencies, haplotype-tagging status and LDs for genotyping in larger-scale subjects (n=1,092). Statistical analysis demonstrated that CYP2E1 polymorphisms and haplotypes show no significant association with HBV clearance, HCC occurrence and onset age of HCC (p>0.05). Previous studies, however, have shown contradictory findings on associations of CYP2E1 polymorphisms with CYP2E1 activities and HCC risk. Comparing the contrasting results of previous researches suggest that CYP2E1 polymorphism is associated with CYP2E1 activity induced by ethanol, but is not directly associated with HCC risk. CYP2E1 variation/haploype information identified in this study will provide valuable information for future studies on CYP2E1.

• Anatomy and Cell Biology
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• 제49권2호
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• pp.143-150
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• 2016

Understanding of morphological structures such as the sphenoid spine and pterygoid processes is important during lateral transzygomatic infratemporal fossa approach. In addition, osseous variations such as pterygospinous and pterygoalar bridges are significant in clinical practice because they can produce various neurological disturbances or block the passage of a needle into the trigeminal ganglion through the foramen ovale. Two hundred and eighty-four sides of Korean adult dry skulls were observed to carry out morphometric analysis of the lateral plate of the pterygoid process, to investigate, for the first time among Koreans, the incidence of the pterygospinous and pterygoalar bony bridges, to compare the results with those available for other regional populations, and to discuss their clinical relevance as described on literatures. The mean of maximum widths of the left and right lateral plates of the pterygoid process were 15.99 mm and 16.27 mm, respectively. Also, the mean of maximum heights of the left and right lateral plates were 31.02 mm and 31.01 mm, respectively. The ossified pterygospinous ligament was observed in 51 sides of the skulls (28.0%). Ossification of the pterygospinous ligament was complete in four sides (1.4%). In 47 sides (16.6%), the pterygospinous bridge was incomplete. The ossified pterygoalar ligament was observed in 24 sides of the skulls (8.4%). Ossification was complete in eight sides (2.8%) and incomplete in 16 sides (5.6%). This detailed analysis of the lateral plate of the pterygoid process and related ossification of ligaments can improve the understanding of complex clinical neuralgias associated with this region.

• 대한건축학회논문집:구조계
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• 제34권6호
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• pp.63-69
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• 2018

The machine learning model can capture the dynamics of building systems with less inputs than the first principle based simulation model. The training data for developing a machine learning model are usually selected in a heuristic manner. In this study, the authors developed a machine learning model which can describe supply air temperature from an AHU in a real office building. For rational reduction of the training data, the progressive sampling method was used. It is found that even though the progressive sampling requires far less training data (n=60) than the offline regular sampling (n=1,799), the MBEs of both models are similar (2.6% vs. 5.4%). In addition, for the update of the machine learning model, the normalized mutual information (NMI) was applied. If the NMI between the simulation output and the measured data is less than 0.2, the model has to be updated. By the use of the NMI, the model can perform better prediction ($5.4%{\rightarrow}1.3%$).

• 한국분말재료학회지
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• 제29권4호
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• pp.320-324
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• 2022

Lightweight steel is a crucial material that is being actively studied because of increased carbon emissions, tightening regulations regarding fuel efficiency, and the emergence of UAM, all of which have been recently labeled as global issues. Hence, new strategies concerning the thickness and size reduction of steel are required. In this study, we manufacture lightweight steel of the Fe-Mn-Al-C system, which has been recently studied using the DED process. By using 2.8 wt.% low-Mn lightweight steel, we attempt to solve the challenge of joining steel parts with a large amount of Mn. Among the various process variables, the laser scan power is set at 600 and 800 W, and the laser scan speed is fixed at 16.67 mm/s before the experiments. Several pores and cracks are observed under both conditions, and negligibly small pores of approximately 0.5 ㎛ are observed.

• 한국식품영양학회지
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• 제28권5호
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• pp.829-834
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• 2015

현대인의 과도한 설탕 섭취, 채소 및 칼슘 섭취 부족 등과 같은 문제점들을 해결하기 위하여 칼슘을 첨가한 무설탕의 과일 채소잼을 제조하였으며, 제조한 제품에 대하여 이화학적 변화와 관능평가를 실시하였다. 당도는 사과의 농도를 줄이고, 케일의 함량을 증가시킨 결과, 낮은 당도를 보였으며, 제조한 잼의 pH에서는 당도와는 달리 사과와 케일의 양과는 상관없이 전반적으로 유의적인 차이를 보이지 않았지만, 사과의 함량이 적을수록 약간 높은 pH를 보이는 것으로 나타났다. 명도 및 황색도의 경우, 케일 함량이 증가할수록 점점 명도 및 황색도의 값이 증가하는 경향으로 나타났다. 그러나 적색도의 값은 -2.05~-1.37로 케일의 함량이 증가한다고 하여 증가 또는 감소의 경향을 보이지는 않는 것으로 나타났다. 조직감의 경우, 케일의 함량이 증가할수록 경도(hardness), 탄력성(springiness), 응집성(cohesiveness), 검성(gumminess) 및 씹힘성(Chewiness)은 유의적으로 감소하는 경향을 보였다. 그러나 부착성(adhesiveness)은 케일 함량이 증가할수록 증가하는 경향을 나타내었다. 관능검사의 경우, 10.0~12.0%의 케일 첨가군이 유의적인 차이 없이 가장 높은 기호도를 보였으며, 케일의 농도가 높을수록 맛을 비롯하여 향, 색, 발림성 및 종합적 기호도는 모두 감소하였다. 이와 같은 결과로 보아 설탕 대신 프락토올리고당으로 대신하고, 식이섬유의 함량이 높은 케일을 첨가하여 잼을 제조할 때 사과와 케일의 비율은 3:1 또는 4:1 정도가 적합할 것으로 판단되었다.

• Journal of Radiation Protection and Research
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• 제21권1호
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• pp.27-39
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• 1996

DUPIC핵연료주기로 인해 변화되는 경수로 사용 후 핵연료 물질의 핵종별 농도, 방사능, 붕괴열, 위해지수 및 방사선원항등을 시간의 함수로 그 변화특성을 분석하고, 각 인자별로 크게 영향을 미치는 주요핵종의 거동을 물질농도 측면에서 추적 분석평가하였다. 방사성물질 농도에 있어서 연소도 19,000 MWD/MTU의 사용 후 DUPIC핵연료에 존재하는 악티나이드 양은 연소도 35,000 MWD/MTU의 경수로 사용후 핵연료에 비해 약 2% 감소한 반면 핵분열생성물의 양은 약 20% 증가된 것으로 나타났다. 그리고 사용 후 DUPIC핵연료의 방사능 및 붕괴열은 일반적인 사용후핵연료 특성과는 달리, 방사성물질 농도 변화와 비례하지 않는 것으로 나타났다. 사용후 DUPIC핵연료가 갖는 감마 스펙트럼을 경수로핵연료의 경우와 비교해 볼 때, 전체적인 특징은 사용후 DUPIC핵연료의 경우가 $0.01{\sim}0.575MeV$의 낮은 에너지 범위에서는 경수로핵연료 보다 약 $40{\sim}50%$ 낮은 감마선 세기를 보여주고 있으나, 3.5 MeV이상의 높은 에너지 범위에서는 사용후 DUPIC핵연료의 감마선 세기가 휭씬 크게 나타났다. 중성자 선원항은 모두 악티나이드 물질의$({\alpha},\;n)$ 반응 및 자발핵분열에 의해 결정되고 있고, 특히 Cm-244의 자발 핵분열에 의한 중성자선원이 지배적인 것으로 나타났다. 이런 이유 때문에 Cm-244의 농도가 약 3.3배 큰 사용후 DUPIC핵연료의 중성자 선원이 경수로핵연료보다 4배 이상 크게 나타났다.