• Title/Summary/Keyword: Inflow effect

검색결과 506건 처리시간 0.03초

외부자본 유치가 지역경제가 미치는 경제적 효과 (The Effect of Inviting External Capital on Regional Economy)

  • 김영용;손용엽
    • 지역연구
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    • 제13권2호
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    • pp.25-43
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    • 1997
  • This paper empirically estimates gains from capital inflow to a regional ecomomy. It will be a usefulc for indicator for a local government to build a policy for attracting capital. We estimate the respective Cobb-Douglas production function for 11 provinces of Korea, derive its marginal productivity of capital, and then calculate the amount of capital moved between two provinces and gains from the capital movement. With no barriers to capital movement, there would be a strong motive for capital inflow to Seoul, Pusan, and Kyungki, whereas capital outflow would be expected in Chonnam, Chungbuk, Chungnam, and Kyungbuk. The ratio of gains from capital movement to the regional domestic from capital movement to the regional domestic product(RDP) is high in Cheju, Kangwon, Chungbuk, and so on. It turns out that capital flows from an area with lower productivity of capital to one with hihger productivity. This implies that if the local government of an underdeveloped region wants to lure capital investment from outside, it needs to provide it with strong incentives of eax reduction and special loans.

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난류 유동장 내 두께를 가지는 단일 에어포일의 음향파워 예측 (Prediction of acoustic power radiated from an airfoil with thickness in turbulent flow)

  • 김대환;정철웅
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2013년도 춘계학술대회 논문집
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    • pp.353-358
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    • 2013
  • Present paper deals with turbulence-airfoil interaction noise and mainly investigates the effects of airfoil thickness on the broadband noise spectrum. The acoustic power radiation from an airfoil is predicted using high-order time-domain method, which is based on the computational aeroacoustic technique solving the linear Euler equations. The homogeneous and isotropic turbulence is generated by utilizing the synthetic turbulence modeling based on random particle method. The airfoils taken into consideration are a flat-plate and a NACA0012 airfoil aligned with uniform mean flow. The effects of airfoil thickness on the radiated inflow turbulence noise are investigated by comparing acoustic power spectrum predicted for each airfoil. The comparison of acoustic power spectrum reveals that the airfoil thickness significantly contributes the high frequency noise reduction.

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암석절리와 균열망내에서의 채널흐름에 관한 이론적 수치해석적 연구 (A Theoretical and Numerical Study on Channel Flow in Rock Joints and Fracture Networks)

  • 송명규;주광수
    • 터널과지하공간
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    • 제4권1호
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    • pp.1-16
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    • 1994
  • The study on the flow characteristics and analysis of groundwater in discontinuous rock mass is very important, since the water inflow into the underground opening during excavation induces serious stability and environmental problems. To investigate the flow through single rock joint, the effect of various aperture distribution on the groundwater flow has been analyzed. Observed through the analysis is the "channel flow", the phenomenon that the flow is dominant along the path of large aperture for given joint. The equivalent hydraulic conductivity is estimated and verified through the application of the joint network analysis for 100 joint maps generated statistically. Both the analytic aproach based on isotropic continuum premise and the joint network analysis are tested and compared analyzing the gorundwater inflow for underground openings of different sizes and varying joint density. The joint network analysis is considered better to reflect the geometric properties of joint distribution in analyzing the groundwater flow.ater flow.

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패시브환기외피의 열성능 수치시뮬레이션 (Numerical Simulation on Thermal Performence of Passive Ventilation Skin)

  • 이태철;손유남;윤성환
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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    • pp.144-149
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    • 2011
  • This study aims to evaluate performance of ventilation and thermal about breathing wall by flowing air to indoor on appropriate conditions that is effective aperture area in the Central region(20, 50, $80cm^2/m^2$). The result is as follows : 1) Sectional temperature distribution of inflow and outflow out under the constant ventilation was reviewed. In the case of inflow, outside temperature increase effect was confirmed. 2) The more differences of temperature between outdoor and indraft of air was high, the more heat recovery was high.

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Significance of nonlinear permeability in the coupled-numerical analysis of tunnelling

  • Kim, Kang-Hyun;Kim, Ho-Jong;Jeong, Jae-Ho;Shin, Jong-Ho
    • Geomechanics and Engineering
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    • 제21권2호
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    • pp.103-109
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    • 2020
  • The inflow rate is of interest in the design of underground structures such as tunnels and buried pipes below the groundwater table. Soil permeability governing the inflow rate significantly affects the hydro-geological behavior of soils but is difficult to estimate due to its wide range of distribution, nonlinearity and anisotropy. Volume changes induced by stress can cause nonlinear stress-strain behavior, resulting in corresponding permeability changes. In this paper, the nonlinearity and anisotropy of permeability are investigated by conducting Rowe cell tests, and a nonlinear permeability model considering anisotropy was proposed. Model modification and parameter evaluation for field application were also addressed. Significance of nonlinear permeability was illustrated by carrying out numerical analysis of a tunnel. It is highlighted that the effect of nonlinear permeability is significant in soils of which volume change is considerable, and particularly appears in the short-term flow behavior.

입구 유동 가진에 의한 사각 발열체 주위의 유동제어 및 열전달촉진 (II) 온도장 수치해석 (Flow Control and Heat Transfer Enhancement from a Heated Block by an Inflow Pulsation (II) Thermal Field Computation)

  • 리광훈;김서영;성형진
    • 설비공학논문집
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    • 제14권7호
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    • pp.599-606
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    • 2002
  • uniform temperature. The surfaces of the block are taken at a constant higher temperature. The channel walls are assumed to be adiabatic. Results on the time-dependent temperature field are obtained and averaged over a cycle of pulsation. The effect of the important governing parameters, such as the Strouhal number on the flow and the heat transfer is investigated in detail. The results indicate that the recirculating flow behind the block are substantially affected by the pulsation frequency. These, in turn, have a strong influence on the thermal transport from the heated element to the pulsating flow. The frequency at which the enhancement is maximum is determined.

Forecasting of Daily Inflows Based on Regressive Neural Networks

  • Shin, Hyun-Suk;Kim, Tae-Woong;Kim, Joong-Hoon
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2001년도 학술발표회 논문집(I)
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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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FDI가 어떻게 경제 성장을 촉진하는가?: 메콩강 주변국 연구 (How does FDI promote Economic Growth: Evidence from Mekong River Countries?)

  • ;최창환
    • 무역학회지
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    • 제44권6호
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    • pp.247-265
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    • 2019
  • This research focuses on the influences of FDI on the economic growth of four countries by Mekong river: Vietnam, Laos, Cambodia and Thailand. At the same time, the study also analyzes the contributing of economic growth to attract FDI inflow to these countries. The panel data during the period 1998-2017 were collected from World Bank. Empirical analysis figures out that GDP, mobile phone, labor force are the determinants affecting positive to FDI and vice versa exchange rate, wage are the negative factors. Secondly, FDI, export, exchange rate, government expenditure impact positively on economic growth but inflation and population have negative effect on the economic development. Thirdly, The FDI and economic growth have impact mutually in Vietnam, Laos, Cambodia and Thailand economy. FDI plays a very crucial role in contributing greatly to the economic development of the Mekong sub-region. The economic growth is higher, the FDI inflow is more attractive. From the results, some practical suggestions are offered to enhance the competitiveness in attracting FDI.

동태적 변이-할당분석을 이용한 대한(對韓) 외국인직접투자 유입요인 분석: 선진국과의 비교 (Dynamic Shift-Share Analysis of FDI Inflow into Korea: Comparison to Developed Countries)

  • 손정수;조정란;이상학
    • 국제지역연구
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    • 제18권3호
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    • pp.23-46
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    • 2014
  • 효율적인 외국인직접투자유치를 위해서는 투자의 증감요인을 적기에 파악하는 것이 중요하다. 본 논문은 선진국그룹을 모집단으로 한 동태적 변이-할당분석(dynamic shift-share analysis)을 실시하여 2003-2012년 기간 중 한국으로 유입된 외국인직접투자의 증감을 세계성장효과, 산업구성효과, 경쟁력효과 등의 3개 요인으로 분해한다. 또한 분석결과를 세계를 모집단으로 한 분석결과 및 일반적인 변이-할당분석 결과와 비교한다. 2003-2012년 기간 중 대한(對韓) 외국인직접투자의 증가세는 선진국그룹의 추세보다 낮은 수준이었으며, 그 결과 산업구성효과와 경쟁력효과는 전체적으로 부(-)의 효과를 기록한 것으로 나타났다. 산업별로는 섬유 직물 의류, 화공, 전기 전자, 운송용 기계, 음식 숙박, 비즈니스서비스 산업이 양(+)의 경쟁력효과를 나타냈다. 분석기간을 2003-2007년 및 2008-2012년의 2개 기간으로 구분하면 2003-2007년 기간에는 대부분의 업종이 부의 경쟁력효과를 나타냈으나 2008-2012년 기간에는 대부분의 제조업 세부업종들이 양의 경쟁력효과를 나타냈다. 이는 한국으로 유입되는 외국인직접투자가 금융위기의 영향을 비교적 적게 받은 것을 반영한 것으로 해석된다.

이유체 노즐 미립화 특성이 요소 열분해에 미치는 영향 (Effect of Atomization Characteristics of Twin Fluid Nozzle on Urea Pyrolysis)

  • 구건우;정경열;윤현진;석지권;홍정구
    • 한국분무공학회지
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    • 제20권3호
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    • pp.162-167
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    • 2015
  • Recently, there has been rising interest in applying urea-SCR systems to large marine diesel engines because the International Maritime Organization (IMO) has decided to enforce NOx reduction regulations. Generally, in the case of urea-SCR of the marine diesel engine, a type of twin fluid atomizer has been using for injection of the urea solution. This study conducted to investigate an effect of the atomization of external-mixing twin fluid nozzle on the conversion efficiency of reductant. The lab-scaled experiment device was installed to mimic the urea-SCR system of the marine diesel engine for this study. In a low temperature inflow gas condition which is similar with the exhaust temperature of large marine diesel engine, this study found that the conversion efficiency of reductant of when relative big size urea solution droplets are injected into exhaust gas stream can be larger than that of when small size urea solution droplets are injected. According to results of this study, the reason was associated with decrease of reaction rate constant caused from temperature drop of inflow gas by assist air of twin fluid atomizer.