• 제목/요약/키워드: Inflows

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Simulation of Gate Operations on Samangeum Reservoir to Maintain Target Water Level (새만금호 관리수위 유지를 위한 수문 운영방안모의)

  • Suh, Seung-Won;Cho, Wan-Hei;Lee, Hwa-Young
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.11 no.4
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    • pp.133-144
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    • 2006
  • It is investigated using ADCIRC model to find an optimal gate operation in order to maintain target water level of the inner Saemangeum Reservoir. Various developing procedures and river inflows conditions are considered in modeling. For the gate operations, consecutive openings to inflow and outflow, such as once a day, twice a day and once per two days are considered. However water level increases gradually due to river inflows regardless of gate operations. In order to maintain target level 0.0 m, it is recommended to shut down of gate in order to prevent inflows of outer sea water at least once per 6 days for normal riverine inflows and once per 3 days for flood inflows during consecutive operations. Then it is balanced within maximum of ${\pm}0.4m$ of deviations from target level of 0.0 meter.

Asymmetric Effects of Global Liquidity Expansion on Foreign Portfolio Inflows, Exchange Rates, and Stock Prices

  • Rhee, Dong-Eun;Yang, Da Young
    • East Asian Economic Review
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    • v.18 no.2
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    • pp.143-161
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    • 2014
  • This paper examines the effects of global liquidity expansion on advanced and emerging economies by using panel VAR methodology. The results show that global liquidity expansion tends to boost economy by increasing GDP growth and stock prices. However, we find that the effects are asymmetric. The effects of global liquidity on GDP and stock prices are greater and more persistent in emerging economies than in liquidity recipient advanced economies. Moreover, global liquidity appreciates emerging economies' exchange rates more persistently than those of advanced economies. Lastly, while global liquidity expansion increases foreign portfolio investment inflows to Asian countries and liquidity recipient advanced economies, there is no evidence for Latin American countries.

Forecasting of Daily Inflows Based on Regressive Neural Networks

  • Shin, Hyun-Suk;Kim, Tae-Woong;Kim, Joong-Hoon
    • Proceedings of the Korea Water Resources Association Conference
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    • 2001.05a
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    • pp.45-51
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    • 2001
  • The daily inflow is apparently one of nonlinear and complicated phenomena. The nonlinear and complexity make it difficult to model the prediction of daily flow, but attractive to try the neural networks approach which contains inherently nonlinear schemes. The study focuses on developing the forecasting models of daily inflows to a large dam site using neural networks. In order to reduce the error caused by high or low outliers, the back propagation algorithm which is one of neural network structures is modified by combining a regression algorithm. The study indicates that continuous forecasting of a reservoir inflow in real time is possible through the use of modified neural network models. The positive effect of the modification using tole regression scheme in BP algorithm is showed in the low and high ends of inflows.

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Debt Investment Outflows and Inflows in Korea and Covered Interest Parity Deviation (채권시장 자본유출입과 무위험 금리평형 이탈)

  • Gab-Je Jo
    • Korea Trade Review
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    • v.47 no.1
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    • pp.181-198
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    • 2022
  • This paper investigates the arbitrage effect by the covered interest parity (CIP) deviation, as well as other push or pull factor effect on capital inflows and ouflows in the Korean bond market, by utilizing OLS, TSLS, IRF and VDC in EC model. The sample period covers February 2002 to December 2020. It is found that, the swap basis reflecting the CIP deviations have the significant effects on both debt investment inflows and debt investment outflows. Also, it is found that, the Korean risk factors have decreasing effects on foreigner's investment in the Korean bonds, while the global risk factors have decreasing effects on Korean resident's investment in the foreign bonds.

An Evaluation of the Emptiness Passage Time of the Kuemgang Estuary Reservoir by Two-Step Transition Model (2단계 추이모형에 의한 금강하구호의 공수도달시간의 평가)

  • Lee, Jae-Hyoung;Chung, Mahn
    • Water for future
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    • v.26 no.3
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    • pp.113-124
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    • 1993
  • This study aims at the evaluation of the stationary distribution and the emptiness passage time for the effectiveness of water utility in the Keumgang estuary reservoir by two-step transition model. It was taken discrete Markovian correlated inflows for the joint probability of inflows and storage, and was used binomial distribution for inflows distribution. As the results, it was decreased from 0.952 to 0.904 the emptiness probability of the reservoir stationary distribution during 1952-1980, and from 0.900 to 0.829 during 1981-1989, and the average emptiness passage time was increased from 23 days to 37 days during 1952-1980, and from 29 days to 61 days during 1981-1989 at low state of storage. From this, it is found that the emptiness passage time is varied with the increase of the inflows auto-correlation coefficient in the Keumgang estuary reservoir. Therefore, it is understood that auto-correlation coefficient must be taken into consideration for the evaluation of water utility in a small reservoir at drought time.

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An Empirical Analysis on the Effects of FDI to the Economic Growth - Based on the Service Industry in China (FDI유입의 경제성장효과 실증분석 -중국 서비스산업을 중심으로-)

  • Lee, Sung-Joon;Ning, Cui-Ying
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.8
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    • pp.5282-5286
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    • 2015
  • This study is to analyze the effects of the FDI inflows service industry on China's economic growth using panel data from China's service industry for the period 1990-2012. The results of this study show that the FDI inflows into service industry in China is behind a key driving force to develop its economic growth, and that other factors like investment in the fixed assets and investment in human capital and labor make contribution to promoting its economic development. The results suggest that in order to enhance its growth, the government should expend a great deal of effort trying to make a good environment for investment to increase the FDI inflows into China's service industry.

Securing Inflows to Reservoir with Low Ratio of Watershed to Paddy Field Areas by Operating Outside Diversion Weir (유역외 보의 연계운영에 의한 유역배율이 작은 저수지의 유입량 확보 가능성)

  • Noh, Jae-Kyoung
    • Journal of The Korean Society of Agricultural Engineers
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    • v.53 no.1
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    • pp.17-28
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    • 2011
  • This study was performed to ascertain the possibility of securing inflows to reservoir with low ratio of watershed to paddy field areas by outside diversion weir. The case of Maengdong reservoir and Samryong diversion weir was selected. Most of inflows to Maengdong reservoir with watershed area of $7.06\;km^2$ and total storage capacity of $1,269{\times}10^4\;m^3$ are filled with intake water from outside Samryong diversion weir. Only using water storage data in Maengdong reservoir from 1991 to 2009, the range of water intake in Samryong diversion weir to Maengdong reservoir was optimized to 0.135~30 mm/d, from which water intake to Maengdong reservoir was $1,672.9{\times}10^4\;m^3$ (70.1 %) and downstream outflow to Weonnam reservoir was $714.4{\times}10^4\;m^3$ (29.9 %). The parameters of DAWAST model for reservoir inflow were determined to UMAX of 313.8 mm, LMAX 20.3 mm, FC 136.8 mm, CP 0.018, and CE 0.007. Inflows to Maengdong reservoir were $427.1{\times}10^4\;m^3$ (20.3 %) from inside watershed, and $1,672.9{\times}10^4\;m^3$ (79.7 %) from outside. Paddy irrigation water requirements were estimated to $1,549{\times}10^4\;m^3$ on annual average. Operation rule curve was drawn by using daily inflow and irrigation requirement data. By securing the amount of inflow to Maengdong reservoir to about 80 % from outside Samryong diversion weir, water supply capacity for irrigation of $1,549{\times}10^4\;m^3/yr$ was analyzed to be enough. Additional water supplies for instream flow were analyzed to $1,412\;m^3/d$ in normal reservoir operation, $36,000\;m^3/d$ in withdrawal limit operation by operation rule curve from October to March of non irrigation period.

Determinants of Foreign Direct Investment: Evidence from Vietnam

  • NGO, Minh Ngoc;CAO, Huy Hoang;NGUYEN, Long Ngoc;NGUYEN, Thuc Ngoc
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.6
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    • pp.173-183
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    • 2020
  • The paper investigates the determinants of foreign direct investment (FDI) in Vietnam in 2000-2019 period. This study uses difference Generalized Methods of Moments (GMM) and Pooled Mean Group (PMG) to analyse panel data officially provided by General Statistical Office of Vietnam. The results show that market size impacts positively significant on FDI attraction: 1% -1.45% (PMG) and 1% -1.25% (GMM). Besides, some other factors have positive influences as labor force, macroeconomic policy, macroeconomic stability and skilled labor. Meantime, the trade openness negatively affects FDI inflows in the short-term, while not being statistically significant in the long-term. Moreover, economic shocks often have a negative impact on FDI inflows. The findings of this study lead to the following recommendations. First, authorities should pay special attention to encourage economic growth rate in Vietnam to expand market size because this is the first priority of foreign investors. Second, authorities need to continue increasing the rate of skilled labor, especially highly qualified management force, engineers and well-skilled workers. Third, the authorities should adjust trade openness to boost the role of its determinant in attracting FDI inflows. Fourth, macroeconomic stability needs to be governed by international standards in order to secure the belief of foreign investors in the long-term.

Star Formation in Nuclear Rings of Barred-Spiral Galaxies?

  • Seo, Woo-Young;Kim, Woong-Tae
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.39.2-39.2
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    • 2013
  • We use grid-based hydrodynamic simulations to study star formation history in nuclear rings of barred-spiral galaxies. In our previous study, we concentrated on bar-only galaxies without spirals, finding that the star formation rate (SFR) in a nuclear ring exhibits a strong primary burst at early time before decreasing to below 1 $M_{\odot}/yr$ at late time. The rapid decline is caused by the paucity of the gas in the bar region, due to early massive gas inflows to the nuclear ring. Since star formation in nuclear rings is observed to be sustained for about 1-2 Gyr, this requires mechanisms to supply the gas to the bar regions. In this work, we study the effect of spiral arms on the radial gas inflows and related star formation in the nuclear rings. We show that spiral arms are efficient to remove angular momentum of the gas to cause significant gas inflows to the bar region, provided the patten speed of the arms is much smaller than that of the bar. The inflowing gas is added to a nuclear ring, making the ring SFR episodic over a long period of time. The time interval of multiple bursts of star formation is a few tens to hundred million years, with the mean peak SFR of ${\sim}5M_{\odot}/yr$, consistent with observations of M100.

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Does Asymmetric Relation Exist between Exchange Rate and Foreign Direct Investment in Bangladesh? Evidence from Nonlinear ARDL Analysis

  • QAMRUZZAMAN, Md.;KARIM, Salma;WEI, Jianguo
    • The Journal of Asian Finance, Economics and Business
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    • v.6 no.4
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    • pp.115-128
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    • 2019
  • The study aims to investigate the pattern of relationships such as symmetric or asymmetric, between exchange rate and foreign direct investment in Bangladesh by applying Autoregressive Distributed Lagged (ARDL) and nonlinear ARDL. In this study, we employed quarterly data for the period of 1974Q1 to 2016Q4. Data were collected and aggregated from various sources namely, Bangladesh Economic Review published by Ministry of Finance and statistical yearbook published by Bangladesh Bureau of Statistics and an annual report published by Bangladesh Bank. The relationship between exchange rate and FDI inflows attract immense interest in the recent periods, especially for developing countries' perspective. The results of the study ascertain the long run relationship between FDI, exchange rate, monetary policy, and fiscal policy. Considering the asymmetric assumption, the findings from NARDL confirm the existence of a long-run asymmetric relationship in the empirical equation. In the long run, it is observed that positive change that is the appreciation of exchange rate against USD decrease FDI inflows and negative shocks results in grater inflows of FDI, however, the positive shocks produce higher intensity that negative shocks in Exchange rate. For directional causality, the coefficients of error correction term confirm long-run causality, in particular, bidirectional causality unveiled between FDI and exchange rate.