• 대한방사선기술학회지:방사선기술과학
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• 제40권3호
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• pp.501-508
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• 2017

본 연구는 연구용원자로(하나로)와 국가방사선연구시설을 이용한 전문교육과정을 개발 운영함으로써 방사선학 전공 대학생들에게 전문화된 교육 기회를 제공하고 현장적응 능력을 증진시킬 목적으로 수행되었다. 이를 위해 하나로와 국가방사선연구시설을 이용한 전문 교육과정을 개발하고 운영함으로써 대학생들에게 하나로 활용 기회를 제공하였고, 대학생을 대상으로 하는 방사선학과 실험 실습을 운영함으로써 차세대 전문가를 양성하였다. 방사선학과 대학생들에게 현장실험실습 기회를 제공함으로써 향후 방사선학 연구 분야의 잠재 이용자를 육성하여 방사선학 인력의 저변 확대를 하고자 하였다. 본 실험실습 과정을 위해 서술형 교재와 강의용 교재, 설문지를 개발하고 활용하였다. 2006년부터 2017년까지 방사선학과 대학생을 대상으로 운영된 실험실습교육과정에 714명이 수료하였다. 방사선학과 대학생들을 대상으로 개발 운영되는 교육과정은 하나로와 국가방사선연구시설의 이용을 더욱 활성화하여 궁극적으로 방사선 산업인력의 저변을 확대하고 올바른 정책 결정 및 기술기반을 확립하는 주요 자원이 될 것이며 방사선 분야의 활성화에도 기여하게 될 것이다.

• The Korean Journal of Physiology and Pharmacology
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• 제18권4호
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• pp.289-296
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• 2014

Human adipose-tissue-derived stromal cells (hADSCs) are abundant in adipose tissue and can differentiate into multi-lineage cell types, including adipocytes, osteoblasts, and chondrocytes. In order to define the optimal harvest site of adipose tissue harvest site, we solated hADSCs from different subcutaneous sites (upper abdomen, lower abdomen, and thigh) and compared their proliferation and potential to differentiate into adipocytes and osteoblasts. In addition, this study examined the effect of phorbol 12-myristate 13-acetate (PMA), a protein kinase C (PKC) activator, on proliferation and differentiation of hADSCs to adipocytes or osteoblasts. hADSCs isolated from different subcutaneous depots have a similar growth rate. Fluorescence-activated cell sorting (FACS) analysis showed that the expression levels of CD73 and CD90 were similar between hADSCs from abdomen and thigh regions. However, the expression of CD105 was lower in hADSCs from the thigh than in those from the abdomen. Although the adipogenic differentiation potential of hADSCs from both tissue regions was similar, the osteogenic differentiation potential of hADSCs from the thigh was greater than that of hADSCs from the abdomen. Phorbol 12-myristate 13-acetate (PMA) treatment increased osteogenic differentiation and suppressed adipogenic differentiation of all hADSCs without affecting their growth rate and the treatment of Go6983, a general inhibitor of protein kinase C (PKC) blocked the PMA effect. These findings indicate that the thigh region might be a suitable source of hADSCs for bone regeneration and that the PKC signaling pathway may be involved in the adipogenic and osteogenic differentiation of hADSCs.

• 한국지진공학회논문집
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• 제20권7_spc호
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• pp.527-536
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• 2016

This paper investigates seismic damage potential of recent September 12 M5.8 Gyeongju earthquake from diverse earthquake engineering perspectives using the accelerograms recorded at three stations near the epicenter. In time domain, strong motion durations are evaluated based on the accelerograms and compared with statistical averages of the ground motions with similar magnitude, epicentral distance and soil conditions, while Fourier analysis using FFT is performed to identify damaging frequency contents contained in the earthquake. Effective peak ground accelerations are evaluated from the calculated response spectra and compared with apparent peak ground accelerations and the design spectrum in KBC 2016. All these results are used to consistently explain the reason why most of seismic damage in the earthquake was concentrated on low-rise stiff buildings but not quite significant. In order to comparatively appraise the damage potential, the constant ductility spectrum constructed from the Gyeongju earthquake is compared with that of the well-known 1940 El Centro earthquake. Deconvolution analysis by using one accelerogram speculated to be recorded at a stiff soil site is also performed to estimate the soil profile conforming to the response spectrum characteristics. Finally, response history analysis for 39- and 61-story tall buildings is performed as a case study to explain significant building vibration felt on the upper floors of some tall buildings in Busan area during the Gyeongju earthquake. Seismic design and retrofit implications of M5.8 Gyeongju earthquake are summarized for further research efforts and improvements of relevant practice.

• 한국기후변화학회지
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• 제7권3호
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• pp.351-356
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• 2016

The carbon capture and storage (CCS), which collects and stores carbon dioxide in a geological site, is a promising option to mitigate climate change. However, there is the possibility of carbon dioxide leakage from the soil in the steps of collecting, transporting, and storing. To ensure the feasibility of this technology, it is important to monitor the leakage of carbon dioxide and to assess the potential impacts. As plants are sensitive to the changes in carbon dioxide in the soil environment, we can utilize plant parameter to detect the carbon dioxide leakage. Currently, chlorophyll a content is a conventional index indicating the changes in plants, however, this method is labor intensive and it only utilizes a small portion of leaves. To overcome its limitations, a simple spectroscopic parameter, DGCI (dark green color index), was suggested as an easy and quick indicator. In this study, we compared the values of chlorophyll a contents with DGCI from the experiment investigating the impacts of high underground $CO_2$ on grape plants. Results suggest that DGCI had high correlation with chlorophyll a contents and it has high potential to be utilized as an easy indicator to monitor plants' responses to $CO_2$ treatment.

• The Korean Journal of Physiology and Pharmacology
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• 제23권3호
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• pp.191-201
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• 2019

The transient receptor potential canonical (TRPC) 5 channel, known as a nonselective cation channel, has a crucial role in calcium influx. TRPC5 has been reported to be activated by muscarinic receptor activation and extracellular pH change and inhibited by the protein kinase C pathway. Recent studies have also suggested that TRPC5 is extracellularly activated by englerin A (EA), but the mechanism remains unclear. The purpose of this study is to identify the EA-interaction sites in TRPC5 and thereby clarify the mechanism of TRPC5 activation. TRPC5 channels are over-expressed in human embryonic kidney (HEK293) cells. TRPC5 mutants were generated by site-directed mutagenesis. The whole-cell patch-clamp configuration was used to record TRPC5 currents. Western analysis was also performed to observe the expression of TRPC5 mutants. To identify the EA-interaction site in TRPC5, we first generated pore mutants. When screening the mutants with EA, we observed the EA-induced current increases of TRPC5 abolished in K554N, H594N, and E598Q mutants. The current increases of other mutants were reduced in different levels. We also examined the functional intactness of the mutants that had no effect by EA with TRPC5 agonists, such as carbachol or $GTP{\gamma}S$. Our results suggest that the three residues, Lys-554, His-594, and Glu-598, in TRPC5 might be responsible for direct interaction with EA, inducing the channel activation. We also suggest that although other pore residues are not critical, they could partly contribute to the EA-induced channel activation.

• 대한토목학회논문집
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• 제30권6B호
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• pp.617-625
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• 2010

풍속의 세제곱에 비례하는 풍력발전기의 전기발전량을 효과적으로 증대시키기 위해서는, 풍속이 강한 부지 선정이 중요하다. 일반적으로 내륙지역보다 풍속이 강한 연안지역에 풍력발전기를 설치하는 것이 바람직하다. 또, 해상풍력개발은 풍력발전기의 중요한 단점 중 하나인 소음 문제를 해결할 수 있는 방법으로 기대된다. 풍력개발 사업을 실행하는 과정에서, 어떤 지역의 풍력발전 가능성을 미리 파악하는 것은 풍력발전의 최적지를 선정하는데 있어서 중요한 요소들 중 하나이다. 본 연구는 기상청이 10년간 관측한 제주도 14개 지역의 풍향 및 풍속데이터를 가지고 제주 연안지역의 풍력발전 가능성에 대해 검토하였다. 풍력발전기의 설치높이를 80 m로 가정하고 풍속데이터를 보정하였으며, 이 값을 가지고 풍력에너지 밀도와 연간 풍력에너지량을 산출하였다. 그리고 모든 관측지점의 연간 전기발전량과 에너지취득률은 3,000 KW 풍력발전기에 관한 정보를 이용하여 산출되었다.

• 한국수자원학회논문집
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• 제51권10호
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• pp.929-939
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• 2018

북한은 수력발전이 전체 발전량의 약 63%를 차지할 만큼 비중이 높고, 지리적으로 수력발전 개발에 많은 이점을 가지고 있다. 본 연구에서는 33개의 북한 댐개발 가능지점에 대해 DEM자료를 이용하여 유역분석 및 저수량을 산정하고, MWSWAT 모델을 이용한 30년간의 장기유출 분석 결과를 적용하여 연간가능발생전력량을 추정하였다. 33개 지점의 연간가능발생전력량은 현재 북한 수력발전량의 약 28% 수준으로 평가되었다. 또한 도별 공업지구 규모를 추정하고, 장래 인구 변동을 전망하여 도별 댐개발 우선순위를 선정하고, 저수량과 연간가능발생전력량을 기초로 도내 댐개발 우선선위를 선정하였다. 도별 우선순위는 평안남도, 함경남도, 함경북도, 황해북도, 평안북도, 자강도, 량강도, 황해남도, 강원도 순으로 나타났다. 본 연구의 결과는 북한지역의 수력발전댐 개발사업의 진출을 위한 초기 검토 자료로 활용이 가능할 것으로 판단된다.

• 조명전기설비학회논문지
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• 제15권2호
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• pp.97-104
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• 2001

본 논문에서는 전위강하법에 의한 접지저항 측정시 전위보조전극 위치의 영향에 대하여 기술하였다. 전위강하법에서 접지저항은 이론적으로 전위보조전극을 피측정 접지전극과 전류보조전극이 이루는 일직선상에 위치시킬때 61.8[%]법칙을 적용하여 측정한다. 하지만 측정현장의 사정상 전위보조전극의 위치를 피측정 접지전극과 전류 보조전극이 이루는 일직선과 어느 정도의 각도를 가지도록 시설하여 접지저항을 측정하게 될 경우에 측정오차가 발생하게 되고 보정이 필요하다. 본 연구에서의 측정대상 전극은 길이 2.4 [m]의 봉형 접지전극으로 하였으며, 피측정 접지전극, 전위보조전극, 전류보조전극이 일직선상에 놓이지 않은 상태에서 접지저항을 측정하면 측정값은 항상 (-)의 오차를 나타내었고, 이들 전극이 이루는 각도가 증가함에 따라 측정 오차도 증가하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.245-252
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• 2004

When some enormous earthquake hazards broke out in the neighboring Japan and Taiwan, many Korean earthquake engineers thought that seismic guidelines must be adjusted safely and economically to consider the moderate earthquake characteristics. In the present aseismic guideline for liquefaction potential assessment, a simplified method using SPT-N value and a detail method based on the dynamic lab-tests were introduced. However, it is said that these methods based on the equivalent stress concept to simplify an irregular earthquake are not reliable to simulate the kaleidoscopical characteristics of earthquake loading correctly. Especially, even though various data from the dynamic lab-test can be obtained, only two data, a maximum cyclic load and a number of cycle at an initial liquefaction are used to determine the soil resistance strength in the detailed method. In this study, a new assessment of liquefaction potential is proposed and verified. In the proposed assessment, various data from dynamic lab-tests are used to determine the unique soil resistance characteristic and a site specific analysis is introduced to analyze the irregular earthquake time history itself. Also, it is found that the proposed assessment is reasonable because it is devised to reflect the changeable soil behavior under dynamic loadings resulted from the generation and development of excess pore water pressure.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 봄 학술발표회 논문집
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• pp.517-524
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• 2001

In this study, the effect of relative density and fine contents(Finer then # 0.08mm sieve) on liquefaction phenomenon in reclaimed land by hydraulic hammer compaction is analyzed. For more site-specific studies, reclaimed land in Inchon International Airport is selected and the cyclic triaxial tests are performed on disturbed samples. In cyclic triaxial tests, the characteristics of reclaimed land in Inchon International Airport are considered sufficiently. The liquefaction resistance stress ratio ($\tau$$\ell$/$\sigma$v') can be defined by relative density 40, 50, 60, and 70% and also by fine contents : 0, 10, 20, 30, and 40% under relative density (D$\_$r/) 50% used disturbed samples. From tile result of comparing tile cyclic triaxial tests, it is shown that the liquefaction strength of soil increases with increases of relative density and fine contents. Fspecially fine contents is the main factor affecting the liquefaction potential. In addition, the liquefaction resistance stress ratio is reduced by the increase of fine content and tile ratio of change is steep until fine contents 20% and that is flexible during the range of fine contents 20% to 40%. Through this study, it is proved that the soil characteristics (fine contents 5∼20%) of the reclaimed land in Inchon International Airport flays an important role in the reduction of liquefaction potential.