• 천문학회보
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• 제41권2호
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• pp.47.1-47.1
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• 2016

We present a preliminary result of search for CO molecular outflows toward a sample of 68 candidate Very Low Luminosity Objects (VeLLOs; Lint ${\leq}0.1L_{\odot}$) to help to understand their physical properties. The sources have been identified using the data at IR to radio wavelengths by M. Kim et al. 2016 toward nearby star-forming regions in the Gould belt. These sources were observed in rotational transitions 2-1 and 3-2 of $^{12}CO$, $^{13}CO$, and $C^{18}O$ molecules with SRAO, CSO, JCMT, and ASTE telescopes. In the beginning of our survey we made a single pointing observation in $^{12}CO$ 2-1 or 3-2 lines for our sample, identifying 53 sources as potential outflow candidates from their line wing features. We made full or partial mapping observations for these candidates with the same lines, finding 33 sources with bipolar or one-sided outflow features. Out of these 33 sources, 6 VeLLOs are previously known sources to have their outflows and 27 VeLLOs are found to be new outflow sources identified from this study. We estimated outflow properties with corrections for excitation temperature, optical depth, and inclination. Their outflow forces range from $8.7{\times}10^{-10}$ to $6.0{\times}10^{-5}M_{\odot}\;km\;s^{-1}yr^{-1}$ with a median value of $3.6{\times}10^{-7}M_{\odot}\;km\;s^{-1}yr^{-1}$, indicating that most of the VeLLOs are less powerful than those for protostars. Their accretion luminosities vary from $9.7{\times}10^{-9}$ to $166L_{\odot}$ with a median value of $0.004L_{\odot}$, implying that most VeLLOs have larger ratios of the accretion luminosity to the internal luminosity but a significant number of VeLLOs have smaller ratios. This result suggests that many of the VeLLOs can be explained with episodic accretion but a significant number of VeLLOs cannot.

• 천문학회보
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• 제37권1호
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• pp.33.2-33.2
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• 2012

Low-ionization nuclear emission-line region (LINER) galaxies constitute a major fraction of low-luminosity AGN population in the local Universe. In contrast to Seyfert galaxies, it is theoretically expected that LINERs would not have an outflow due to their low Eddington ratio. Using Keck/LRIS spectroscopy on a nearby LINER galaxy SDSS J091628.05+420818.7, we find a significant radial velocity offset for [OIII]${\lambda}$5007 emission line as - 50 km $s^{-1}$ blueshifted compared to systemic velocity of the galaxy, while other emission lines exhibit no or little offset. The observed [OIII] velocity offset possibly indicates an outflow of gas in the LINER galaxy, and it is probable that we only detected the [OIII] velocity offset because [OIII] ionization region is closer to the accretion disk, hence, more affected by an outflow. We further investigate the [OIII] velocity offset of -4000 SDSS AGN-host galaxies to compare the strength of AGN outflow. We find that a number of both LINER and Seyfert galaxies show [OIII] velocity offset, but the fraction of LINER galaxies with velocity offset is smaller than that of Seyfert galaxies. The preliminary results imply the presence of gas outflow in LINER galaxies, although outflow strength is probably weaker compared to Seyfert galaxies.

• 대한지리학회지
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• 제42권3호
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• pp.421-433
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• 2007

대도시권은 인구나 경제활동이 주변지역으로 재배치됨에 따라 주변지역에서 새로운 중심지가 형성되는 패턴으로 변화하고 있다. 중심도시와 주변지역의 중심성 변화는 대도시권에서 발생하는 공간상호작용의 패턴을 변화시킨다. 본고에서는 서울대도시권의 통근통학통행을 통하여 공간상호작용의 변화 패턴을 고찰하였다. 서울과 접한 지역에서는 역외통행의 비중이 감소하고 있는 반면, 서울로부터 거리가 먼 지역에서는 역외통행의 비중이 증가하고 있다. 그리고 시간이 흐름에 따라 역외로 유출되는 최대통행의 목적지 분포가 점차 다원화하고 있으며, 서울 주변지역에서 서울을 목적지로 하는 역외통행률 또한 감소추세를 나타내었다. 서울대 도시권의 상호작용 변화는 대체로 인접한 지역들간에 강하게 이루어졌으며, 중심도시인 서울에서 유출되는 역외통행의 변화가 현저하였다. 통행량의 증감에 따른 상호작용변화의 유사성 분석에서는 용인 서울 수원 화성 등지가 상호작용변화의 속성을 뚜렷하게 보여주었다.

• 천문학회보
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• 제41권1호
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• pp.40.2-41
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• 2016

To understand the observed kinematics in the narrow-line region (NLR) of type 2 AGNs, we construct a model of 3-D biconical outflow combined with a thin dust plane. The model consists of two identical cones whose apex is located at the nucleus, and the cones are axisymmetric with respect to the bicone axis. After we define the properties of the bicone and the dust plane, we calculate a spatially integrated velocity and velocity dispersion along the line-of-sight using various physical parameters. As we test the effect of model parameters, we find three key parameters determining the integrated kinematics: intrinsic outflow velocity, bicone inclination, and the amount of dust extinction. The velocity dispersion increases as the intrinsic outflow velocity or the bicone inclination increases, while the velocity shift increases as the amount of dust extinction increases. We confirm that the integrated velocity dispersion can be a good indicator of the intrinsic outflow velocity unless dust extinction is not very strong (>~80%), while the effect of dust extinction can be alleviated by combining the integrated velocity and the velocity dispersion. Based on the simulated velocity distributions using the 3-D models, the variety of the observed [O $_{III}$] line profiles of type 2 AGNs can be well reproduced. In addition, we perform Monte Carlo simulations based on the different sets of model parameters. By comparing the model results with the observed [O $_{III}$] kinematics of ~39,000 SDSS type 2 AGNs (Woo et al. 2016), we find that the observed [O $_{III}$] velocity-velocity dispersion distribution is well reproduced by the biconical outflow model, enabling us to constrain the intrinsic physical parameters of outflows.

• 디지털융복합연구
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• 제11권11호
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• pp.305-312
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• 2013

이 연구의 목적은 신정보화환경에서의 중소기업의 기술유출에 대한 보안인식 및 보안관리 실태를 측정하고, 대기업과 중소기업간의 수준비교분석을 통해 기술유출 방지대책을 위한 정책의 기초자료를 제시하고자 한다. 분석결과 보안인식 및 보안관리실태 모두 중소기업은 대기업에 비해 열악한 것으로 나타났으며, 정보화환경의 급격한 발달에 따른 부문별 관리가 필요한 상황인 것으로 보인다. 현재 중소기업의 신정보화환경 구축은 도입기에 있으므로, 구축과 동시에 보안시스템을 함께 갖출 수 있는 지원이 필요하며, 동시에 중소기업 자체적 대응이 가능하도록 신정보화환경에 맞는 보안시스템이 필요하다. 중소기업의 경우 급변하는 정보화환경의 변화에 따른 기술보호 역량을 갖추기에는 한계가 있음으로 정부의 체계적인 보안관리 지원이 요구된다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회 논문집
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• pp.1403-1407
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• 2005

In order to analyze the water storage of the Daecheong dam after constructing the Yongdam dam situated in upstream, a daily cascaded simulation model for analyzing water storages in the Yongdam-Daecheong dams was developed. Operation scenarios of the Yongdam dam were selected to 8 cases with the combinations of downstream outflows and water supplies to the Jeonju region. Daily water storages in the Daecheong dam was analyzed daily by simulating from 1983 to 2004. The results are summarized as follows. Firstly, water supplies from the Daecheong dam were analyzed to amount $1,964.2Mm^3$ on a yearly average in case without the Yongdam dam. In case with the Yongdam dam, water supplies from the Daecheong dam were analyzed to amount $1,858.7\~1,927.3Mm^3$ in case with downstream outflow of $5\;m^3$ is, and were analyzed to amount $1,994.9\~2,017.8Mm^3$ in case with downstream outflow of $10\;m^3/s $. These values are compared to $1,649Mm^3$ applied in design. Secondly, reservoir use rate which was defined rate of water supply to effective water storage reached $241.3\% in case without the Yongdam dam. In case with the Yongdam dam, reservoir use rate reached $228.3\~236.8\% In case with downstream outflow of $5\;m^3/s$, and reached $245.1\~247.9\% in case with downstream outflow of $10\;m^3/s$. Thirdly, runoff rate which is defined rate of dam inflow to areal rainfall reached $57.3\% in case without the Yongdam dam. In case with the Yongdam dam, reservoir use rate reached $62.0\~68.4\% in case with downstream outflow of $5\;m^3/s$, and reached $64.1\~68.5\% in case with downstream outflow of $10\;m^3/s$. Fourth, in case with downstream outflow of $10\;m^3/s$ is from the Yongdam dam, appropriate water supply amounts to the Jeonju region were analyzed to only $0.50Mm^3/day$ from the daily simulation of water storages in the Yongdam dam. Comprehensively, water supply capacity of the Daecheong dam was analyzed to affect in small amounts in spite of the construction of the Yonsdam dam. It is effected to achieve the effective water management of the Yongdam dam and the Daecheong dam by using the developed cascaded model.

• 한국조경학회지
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• 제34권4호
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• pp.116-128
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• 2006

This study focuses on hydrological changes caused by developments in the 13th, 14th (Motjarigol) district in Eun Pyoung New Town, Seoul on the basis of the Land Use Planning of development plan. Through analyses from the hydrological experiments about rainfall outflow using universal equation and amounts of infiltration through soils, the changes in amounts of overflows were estimated and the results were discussed from a urban ecological point of view. As a result, it has been predicted that the amount of rainfall outflow at post-development was dramatically increased, compared to pre-development. Installing of Derbris Dams and infiltration facilities were suggested as alternative plan to meditigate these changes. If we apply these alternatives, the rainfall outflow would be reduced up to 30% compared to the development plan without BMPs (Best Management Practice). In conclusion, it is proposed that once the ecological principles were considered during development planning process, we can minimize the adverse effects of developments to our environments.

• 상하수도학회지
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• 제19권5호
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• pp.619-624
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• 2005

This work is for examining a simplified equation based on the rational formula, which can easily decide storm-water detention volume in small urban catchments. The storm-water detention volume is determined by the inflow hydrograph flowing to detention basin and the outflow hydrograph discharged from the detention basin. The ratio of average outflow over the period of rainfall duration against allowable discharge was 0.5 in former simplified equation. But this research has found that the average outflow ratio depends on the storage methodology. In the case of the on-line storage method, the average outflow ratio is a function of the time of concentration of the catchments and rainfall duration, which ranged from 0.5~1.0. In the case of the off-line storage method, the average ratio is a function of peak discharge and allowable discharge except above time of concentration and rainfall duration, where its function value ranged from 1.0~2.0. When applying this equation to small catchment in Mokpo city, South Korea, we could easily calculate the relation curve between the storm-water detention volume and allowable discharge.

• Journal of Chest Surgery
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• 제39권8호
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• pp.637-639
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• 2006

심장 내 점액종은 심장에 발생하는 원발성 종양 중 가장 흔하지만, 우심실 유출로 협착을 유발하는 점액종은 비교적 드물다. 15세 여자 환자가 운동 시 호흡 곤란 및 간헐적인 의식 소실을 주소로 내원하였고, 심초음파상 우심실 유출로를 거의 폐쇄하는 $3.6{\times}3.0\;cm$ 크기의 종괴가 발견되어 응급수술이 시행되었다. 우심실 종괴가 폐동맥 직하 부위의 우심실 전벽으로부터 기시하고 있음을 확인하고, 종괴 기시 부위 주위의 우심실 전벽을 광범위하게 절제하면서 종괴를 제거하였고 우심실 전벽의 결손은 Gore-Tex 포편 봉합하였다. 병리학적 검사상 우심실에 발생한 점액종으로 진단되었으며, 환자는 특별한 문제없이 술 후 7일째 퇴원하였다.

• Journal of Chest Surgery
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• 제28권5호
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• pp.491-494
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• 1995

A fibroma arising in the right ventricle outflow tract of a 14 month-old infant was successfully removed. The patient was first seen because of shortness of breath and tachycardia. Pertinent clinical and laboratory findings included a grade II/VI systolic murmur, blood pressure of 120/60 mmHg, slight cardiomegaly on chest X-ray, a mass obstructing the outflow tract of the right ventricle on echocardiography and magnetic resonance imaging. On october 30,1992, under cardiopulmonary bypass, a 4cm x 3cm x 3cm tumor was resected from the right ventricular outflow tract, together with a portion of the ventricular wall. Histologically, it was diagnosis as a fibroma. The patient was sent home on the 6th postoperative day following an uneventful recovery form the operation. Although cardiac fibroma is the second most common cardiac tumor in infancy and childhood, it is usually found in the left ventricle and one arising in the right ventricle is considered rare. Although it is a benign tumor, it could produce a severe cardiac dysfunction and even sudden death, depending on its size and location. With the advance in diagnostic techniques and operative management, there is a renewed interest in the early detection and operative removal of these tumors. The case herein presented is the first such case successfully managed and reported in the Korean literature.