• Title/Summary/Keyword: outflows

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Estimation of Geostrophic Current Calculated from Sea Surface Topography in East Sea (동해의 해면지형 계산에 의한 지형류의 흐름 추정)

  • Yun Hong-Sic;Lee Dong-Ha
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.24 no.2
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    • pp.159-165
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    • 2006
  • This paper deals with the estimation of geostrophic current using the sea surface topography calculated from the geoidal height from EGM96 geopotential model and the mean sea surface height from CLS_SHOM mean sea surface model. The CLS_SHOM model was developed using the altimetry data set. The estimation of geostrophic current is available in the characteristic research of ocean in many country, while for East Sea a few studies were done. The goal of this study is basically to provide the characteristics of geostrophic current in East Sea. The results show that the mean sea surface topography (SST) in East Sea is about 0.37 m and the mean geostrophic velocity is -0.028 m/sec. The Pacific water enters into the East Sea through the Korea Strait and after passing the strait, this inflow splits into two branches: one flows northward along the Korean coast and another outflows into Pacific ocean through Tsugaru and Soya strait passing the east-northeastward along the Japanese outer shelf, and outflows into Okhotsk ocean.

Evaluation of Drain Pump System by Inundation Analysis in Urban Underground Passage (도시 지하차도 침수 분석을 통한 강제배제시설 평가)

  • Lee, Jung-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.5
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    • pp.1192-1200
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    • 2007
  • A general rainfall outflow in urban drainage has early time of concentration because urban drainage areas are most paved area. In general, rainfall outflow is flowed in drainage pump station and is discharged to rivers in urban areas. However it is excluded through drainage pumps about a heavy rainfall which exceed the design rainfall and the rainfall outflows increase the urban inundation risk. A current pump operation is control according to water level of collecting well or reservoir in drain pump station. But recently, the localized downpours are happened frequently in urban drainage and the current pump stations are frequently incapable of the heavy rainfall outflows. In this study, a real urban inundation was simulated and the drain capacity of drain pump station was evaluated by analysis about flood-factor in urban underground passage. Then the analysis about the inundation was done by the simulation about the real rainfall which cause the inundation. Also, in the simulation the inundation risk and the evaluation of flood-factor were analyzed according to change of the pump operation rule.

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The Implications of Simultaneous Capital Stop and Retrenchment during Financial Crises

  • Suh, Jae-Hyun
    • Journal of Korea Trade
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    • v.24 no.7
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    • pp.38-53
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    • 2020
  • Purpose - A financial crash triggers asset fire sales by foreign investors and, as a consequence, the price of domestic assets severely decreases. Domestic investors take advantage of these low prices by replacing foreign assets with domestic assets, which helps to alleviate the liquidity shock caused by foreigners. However, is the amount of capital retrenchment by domestic investors sufficient to protect the Korean economy from capital stop by foreign investors during financial crisis? This paper answers this question and suggests the implications of this phenomenon for the Korean economy. Design/methodology - We estimate the associations between capital stop and retrenchment and various financial crises such as banking, currency, debt, and inflation crises using the complementary log-log model. Specifically, we use data of gross capital flows to differentiate between the role of foreign and domestic investors in financial markets. Capital stop and retrenchment designate a sharp decrease in gross capital inflows and outflows, respectively. Findings - Capital stop is significantly associated with financial crises, especially currency and debt crises. This implies that increased risk aversion during times of financial turmoil encourages foreign investors to retrench their investments, worsening liquidity shocks. Conversely, capital retrenchment is not significantly associated with such crises. The results show that, although financial crises reduce gross capital outflows, the reduction is not as large as that with capital inflows. Originality/value - The contribution of this paper is threefold. First, this study investigates how domestic investors behave during times of financial distress by studying gross capital flows-not net capital flows. Second, we concentrate on sharp changes in capital flows during crises. Third, we examine the associations between capital stop and retrenchment and financial crises in general, not specific events.

A Comparative Study of Numerical and Theoretical Predictions of Oil Outflows from Damaged Ships (손상 선박 기름 유출량 추정을 위한 수치해석과 이론식의 비교 연구)

  • Yo-Seop, Moon;Je-In, Kim;Il-Ryong, Park;Seong-Bu, Suh;Seung-Guk, Lee;Hyuek-Jin, Choi;Sa-Young, Hong
    • Journal of the Society of Naval Architects of Korea
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    • v.59 no.6
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    • pp.400-412
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    • 2022
  • This paper provides the results of numerical and theoretical predictions of oil outflows from damaged single-hull and double-hull ships.Theoretical equations derived from the unsteady Bernoulli equation and a CFD method for multi-phase flow analysis were used to estimate the oil outflow rate from cargo tank. The predicted oil outflow rate from a single-hull cargo tank damaged due to grounding and collision accidents showed a good agreement with the available experimental results in both numerical and theoretical analyses. However, in the case of the double-hull conditions, the time variation of the amount of water and oil mixture inside the ballast tank predicted by the theoretical equation showed some different behavior from the numerical results. The reason was that the interaction of the oil flow with the water inflow in the ballast tank was not reflected in the theoretical equations. In the problems of the initial pressure condition in the cargo and ballast tanks, the oil outflow and water inflow were delayed at the pressure condition that the tanks were sealed. When the flow interaction between the oil and water in the ballast tank was less complicated, the theoretical and the numerical results showed a good agreement with each other.

Gas and Stellar Kinematics of 9 Pseudo Bulge Galaxies

  • Jo, Kooksup;Woo, Jong-Hak;Matsuoka, Kenta;Cho, Hojin
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.78.4-79
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    • 2015
  • We present the spatially resolved kinematics of ionized gas and stars along the major axis of 9 pseudo bulge galaxies. Using the high quality long-slit spectra obtained with the FOCAS at the Subaru telescope, we measured the flux, velocity, and velocity dispersion of the [OIII] and $H{\beta}$ lines to determine the size of the narrow-line region, rotation curve, and the radial profile of velocity dispersions. We compare ionized gas kinematics and stellar kinematics to investigate whether ionized gas shows any signs of outflows and whether stars and ionized gas show the same sigma-dip feature (i.e., decrease of velocity dispersion) at the very center.

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Large-scale quasi-steady modelling of a downburst outflow using a slot jet

  • Lin, W.E.;Savory, E.
    • Wind and Structures
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    • v.9 no.6
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    • pp.419-440
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    • 2006
  • This article synthesizes the literature on the meteorology, experimental simulation, and wind engineering ramifications of intense downburst outflows. A novel design of a large-scale test facility and experimental evidence of its validity are presented. A two-dimensional slot jet is used to simulate only the outflow region of a downburst. Profiles of mean velocity and turbulence quantities are acquired using hot-wire anemometry. Comparison with the literature provides empirical evidence that supports the current approach. A geometric analysis considers the validity of applying a two-dimensional approximation for downburst wind loading of structures. This analysis is applicable to power transmission lines in particular. The slot jet concept can be implemented in a large boundary layer wind tunnel to enable large-scale laboratory experiments of thunderstorm wind loads on structures.

Proposed large-scale modelling of the transient features of a downburst outflow

  • Lin, W.E.;Orf, L.G.;Savory, E.;Novacco, C.
    • Wind and Structures
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    • v.10 no.4
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    • pp.315-346
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    • 2007
  • A preceding companion article introduced the slot jet approach for large-scale quasi-steady modelling of a downburst outflow. This article extends the approach to model the time-dependent features of the outflow. A two-dimensional slot jet with an actuated gate produces a gust with a dominant roll vortex. Two designs for the gate mechanism are investigated. Hot-wire anemometry velocity histories and profiles are presented. As well, a three-dimensional, subcloud numerical model is used to approximate the downdraft microphysics, and to compute stationary and translating outflows at high resolution. The evolution of the horizontal and vertical velocity components is examined. Comparison of the present experimental and numerical results with field observations is encouraging.

MAPPING STUDY OF MASSIVE CLOUD CORES

  • WEI Y;WU Y;WANG Y;Xu D;Ju B
    • Journal of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.291-293
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    • 2005
  • Using 13.7 m telescope of Qinghai station of NAO, PMO at Delin Ha, 43 IRAS sources were mapped with $^{13}CO\;J=1-0\;C^{18}O\;J=1-0$ and CO J=1-0. Each source has one or more cores. The distances of these cores range from 1 pc to several pc, and the masses from $10^2\;M_{\bigodot}$ to $10^5\;M_{\bigodot}$. High velocity outflows were detected. The mass, momentum and energy of these massive cores are larger than those of the low mass ones. With radio, IRAS, MSX data, stellar source distribution were investigated, and sourceless cores that deviate from infrared sources were identified. They are potential high mass star formation sites.

A research on the features of suspended sediments origination in natural world (자연계에 있어 부유사 발생원의 특성에 관한 연구)

  • 이성기
    • Journal of Environmental Science International
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    • v.11 no.6
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    • pp.483-488
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    • 2002
  • Suspended sediment outflows mainly by natural situation and artificial action and affects in down-stream. This research studied suspended sediments origination in forests size and mountain stream for natural situation, density for artificial action, and measured the size and possible quantity of suspended sediments origination and studied obstruction method of the generation by artificial action. As the result, I found that the size of generation is about 2~3% of forest size and the forest size which is affecting bare area of valley is about 1∼2ha. In addition, possible outflow segments quantity by artificial facilities is assumed to be maximum 200ton/ha and abstract of mountain incline for mountain development needs minimize bare area valley by make right angle with minimum size.

Development of Flow Forecasting System in Large Drainage Basin (대유역의 유량예측 시스템 개발에 관한 연구)

  • 배덕효
    • Water for future
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    • v.28 no.3
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    • pp.123-132
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    • 1995
  • The subject research attempts to develop a hydrologic-hydraulic forecasting system suitable for use in large river basins. A conceptual hydrologic rainfall-runoff model is used to produce streamflow from meteorological and hydrologic input data over each subbasin, while a hydraulic model is used to route the catchment outflows in the stream network. For operational flow prediction, an efficient state estimator has been designed for the real-time updating of model states from newly recorded data. The real-time application of the forecasting system indicates that this model produces reliable short-term predicted results.

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