• Wind and Structures
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• 제24권2호
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• pp.185-204
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• 2017

High-resolution wind measurements at 2.25 m in height were used to investigate the mean and turbulence properties of an extreme thunderstorm wind event in West Texas. These data were combined with single Doppler scans from the Texas Tech University Ka-band mobile Doppler radars systems (TTUKa) to provide meteorological context over the surface measurement stations for portions of the outflow. Several features characteristic of a severe wind event were noted in the radar data, including a bowing portion of the thunderstorm complex and a small circulation on the leading edge. These features were reflected in the surface wind time histories and provided natural separation between various regions of the outflow. These features also contributed to the peak 1-s gust at all measurement stations. The turbulence characteristics of each outflow region were also investigated and compared. Reduced values of running turbulence intensity and elevated values of longitudinal integral scales were noted during the period of peak wind speed. Larger scales of turbulence within the outflow were also suggested via spectral analysis.

• 대한의용생체공학회:의공학회지
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• 제36권4호
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• pp.135-142
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• 2015

Outflow cannulation site of left ventricular assist device(LVAD) chosen by considering anatomical structure of thoracic cavity and vascular system. Though outflow cannulation site influences blood perfusion at each branch, there is no standard rule or quantitative data. In this study, we computed the amount of blood perfusion at each arterial branch numerically according to outflow cannulation sites(ascending aorta, aortic arch, descending aorta). We generated computational meshes to the three-dimensionally reconstructed arterial system. Clinically measured arterial pressure were used for inlet boundary condition, porous media were applied to mimic blood flow resistance. Blood perfusion through left common carotid artery was 2.5 times higher than other cases, and that through right common carotid artery was 1.1 times higher than other branches. Although this is simulation study, will be useful reference data for the clinical study of LVAD which considers blood perfusion efficiency.

• Journal of Chest Surgery
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• 제22권2호
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• pp.348-356
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• 1989

Seventeen patients of pulmonary atresia with intact ventricular septum were underwent operation during 4.8years period from Jan. 1983 to Aug. 1988 at Seoul National university Hospital. The patients were composed of 8 males and 9 females, aging 1day to 2.5 years [mean 88 days]. We classified pulmonary atresia according to right ventricular morphology; those with tripartite ventricles in 12, those with no trabecular portion to the cavity in 0, and those with inlet portion only in 5. The tripartite approach to right ventricular morphology is helpful in selecting the type of initial palliative procedures. Palliative procedures were as follows; pulmonary valvotomy in 5 with 3 early survivors, mod B-T shunt in 4 with 3 early survivors, and palliative right ventricular outflow tract reconstruction in 4 with 1 early survivor. Effective preliminary palliation of pulmonary atresia are pulmonary valvotomy or palliative right ventricular outflow tract reconstruction in those with tripartite right ventricle, and modified Blalock-Taussig shunt in those with no infundibular portion. The approach to definitive repair is based primarily on the actual size of the tricuspid annulus and the right ventricular cavity. Definitive repair was as follows: definitive right ventricular outflow tract reconstruction in 4 with all survivors and mod. Fontan operation in 2 with one survivors. Right ventricular outflow tract reconstruction can be done as complete repair for patients who had adequate tricuspid annulus and right ventricular cavitary size and mod. Fontan operation for patients who severely hypoplastic tricuspid valve annulus or small right ventricular cavity.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2003년도 가을 학술논문집
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• pp.300-305
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• 2003

방사성폐기물 처분장의 건설에 가장 중요한 부분 중의 하나는 처분안전성의 확보이다. 처분시스템의 기본적인 기능은 처분된 폐기물을 인간 환경으로부터 완벽하게 고립시켜 처분장 내에 영구적으로 격리시키는 것이다. 토양에서 수리전도도는 핵종의 이동과 밀접한 관련이 있다. 그러나 아직까지 국내에서 불포화 토양에 대한 수리 특성 연구는 많이 부족한 상황이다. 이에 본 연구에서는 빠르고 간단하게 불포화 수리 인자값을 산출하는 방법을 제시한다. 토양수분특성곡선과 수리전도도의 산출은 One-Step Outflow Method를 이용하였다.

• 천문학논총
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• 제30권2호
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• pp.99-101
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• 2015

Massive stars are some of the most influential objects in the Universe, shaping the evolution of galaxies, creating chemical elements and hence shaping the evolution of the Universe. However, the processes by which they form and how they shape their environment during their birth processes are not well understood. We use $NH_3$ data from "The $H_2O$ Southern Galactic Plane Survey" (HOPS) survey to define the positions of dense cores/clumps of gas in the southern Galactic plane that are likely to form stars. Then, using data from "The Millimetre Astronomy Legacy Team 90 GHz" (MALT90) survey, we search for the presence of infall and outflow associated with these cores. We subsequently use the "3D Molecular Line Radiative Transfer Code" (MOLLIE) to constrain properties of the infall and outflow, such as velocity and mass flow. The aim of the project is to determine how common infall and outflow are in star forming cores, and therefore to provide valuable constraints on the timescales and physical process involved in massive star formation. Preliminary results are presented here.

• International Journal of Advanced Culture Technology
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• 제9권3호
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• pp.243-252
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• 2021

The Gwangju Daein Art Market, once declared as a declined market, was regarded as a success after an inflow of artists. However, the number of resident artists decreased from 100 at the end of 2015 to 39, to 9 in 2018, and to 6 in 2021. The project site showed signs of decline toward the completion of the project, leading to a Longitudinal study on the project's sustainability. The purpose of this study is to investigate the causes of outflow of artists and the network characteristics of the remaining artists from a sustainability perspective and thereby draw policy implications. As an analysis method, in-depth interviews and surveys were conducted. After that, we checked the remaining artists in 2018 and 2021 and identified the network characteristics. Based on the interview results, the causes of outflow were classified into programmatic, physical, and other factors. The results of a comparison showed that the levels of understanding, satisfaction, and frequency of exchange decreased. The study also provides policy implications. First, a sustainable, long-term program for the artists must involve the improvement of physical space. Second, participation in the market should be encouraged by working with artists on program composition or business progress. Third, programs for supporting exchange among artists should be further strengthened.

• 한국물환경학회지
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• 제35권4호
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• pp.352-361
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• 2019

The purpose of this study is to analyze the characteristics and correlations of the Yeongcheon Lake in order to reduce the occurrence of harmful cyanobacteria. In this study, we investigated the water quality and phytoplankton of the lake from May to November in 2017. Correlation and data mining analyses were performed to analyze the relationship between the two factors. The water temperature was lowest at the point where the Yeongcheon Lake inflow occurs at Imha Lake. It was highest at the point where the outflow occurs to Angye Lake. The pH was also highest at the outflow point, but in the case of DO, it was highest at the midpoint between the inflow and outflow. The main cyanobacteria that emerged during the study period were Oscillatorialimosa, Microcysti saeruginosa and Aphanizomenon flos-aquae. As a result of correlation analysis, the water temperature, inflow, COD loading, TOC loading at the inflow point of the Yeongcheon Lake were the items that were related to the harmful cyanobacteria. The data mining analysis indicated that the TP loading and harmful cyanobacteria in the inflow point of the Yeongcheon Lake were influential on the detrimental cyanobacteria in the Yeongcheon Lake outflow point. When the TP loading was less than 39.0 kg/day at the inflow site, it was expected that the amount of harmful cyanobacteria could be maintained below 10,000 cells/mL.

• 천문학회보
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• 제44권2호
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• pp.48.1-48.1
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• 2019

We found a diffuse Hα feature with a large size of ~2' around a Herbig star, MWC 1080. It shows a strong correlation with the elongated outflow cavity centered on the star. To investigate the diffuse Hα source and the molecular cavity in detail, we carried out the high-resolution NIR spectroscopy using IGRINS. We detected six hydrogen Brackett line series, seven H2 lines, and an [Fe II] forbidden line. With the obtained spatial, kinematic, and line ratio results, we discuss the characteristics of the central MWC 1080A, the NE outflow cavity, and the SE molecular cloud regions separately. Most of the bright Brγ sources around MWC 1080A were found to be reflection nebulae, but a point-like Brγ source close to another young star, MWC 1080E, was identified as a distinct source due to MWC 1080E itself. The narrow components of the H2 lines observed around MWC 1080A were found to trace PDRs located on the wall of the main outflow cavity. Based on the shock-excited H2 and [Fe II] lines detected just inside a bow-shock shape Hα feature, we suggest that it represents the actual shock at the head of the NE outflow from MWC 1080A. Also, we newly detected the shock-excited H2 and [Fe II] lines with highly blueshifted velocities in the SE molecular cloud region. They could be related to unrevealed outflows from other young stars existing around MWC 1080A.

• 천문학회보
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• 제40권1호
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• pp.68.2-69
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• 2015

We present [Fe II] $1.644{\mu}m$ features around ultracompact H II regions (UCHIIs) found on a quest for the "footprint" outflow features of UCHIIs -the features produced by outflowing materials ejected during an earlier, active accretion phase of massive young stellar objects (MYSOs). We surveyed 237 UCHIIs in the first Galactic quadrant, employing the CORNISH UCHII catalog and UWIFE data, which is an imaging survey in [Fe II] $1.644{\mu}m$ performed with UKIRT-WFCAM under ~0.''8 seeing conditions. The [Fe II] features were found around five UCHIIs. We interpret the [Fe II] features to be shock-excited by outflows from YSOs and estimate the outflow mass-loss rates from the [Fe II] flux which are ${\sim}1{\times}10^{-6}-4{\times}10^{-5}M{\odot}yr^{-1}$. We propose that the [Fe II] features might be the "footprint" outflow features, but more studies are required to clarify whether or not this is the case. This is based on the morphological relation between the [Fe II] and 5 GHz radio features, the outflow mass-loss rate, the travel time of the [Fe II] features, and the existence of several YSO candidates near the UCHIIs.

• 한국방재학회 논문집
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• 제10권2호
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• pp.111-122
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• 2010

한강의 잠수교와 둔치는 장마철에 큰 홍수가 발생하면 침수가 되기 때문에 시민들의 안전과 편의를 위해 홍수로 인한 침수 발생시간을 예측하는 것은 대단히 중요하다. 본 연구에서는 FLDWAV모형을 이용하여 한강하류부의 팔당댐 방류량과 황해(서해) 조석이 한강하류부 수위에 미치는 영향을 분석하였다. 연구 대상구간은 팔당댐 하류부에서 전류지점까지이며, 조석영향을 고려하기위해 하류경계조건인 전류수위는 팔당댐방류량과 인천조위를 이용한 다중선형회귀분석을 통해 산정된 예측 전류수위를 사용하였다. 본 연구에서는 잠수교와 주요 둔치에서 수위상승도달시간을 산정하였고, 팔당댐 방류유형과 황해조석에 따른 수위상승도달시간을 팔당댐 방류량의 함수인 2차다항식으로 나타냈다.