• Tunnel and Underground Space
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• v.18 no.1
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• pp.44-57
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• 2008

In this study, a 2D finite-element analysis, using the SEEP/W program, was carried out to estimate the amount of groundwater flawing into a tunnel, as well as the groundwater tables around wetland areas during and after a tunnel excavation through rock mass. Four sites along the Wonhyo-tunnel in Cheonseong Mountain (Gyeongnam, Korea) were analysed, where the model damain of the tunnel included both wetland and fault zone. The anisotropy of the hydraulic conductivities of the rock mass was calculated using the DFN model, and then used as an input parameter for the cantinuum model. Parametric study on the influencing factors was perofrmed to minimize uncertainties in the hydraulic properties. Moreover, the volumetric water content and hydraulic conductivity functions were applied ta the model to reflect the ability of a medium ta store and transport water under both saturated and unsaturated conditions. The conductivity of fault zone was assumed ta be $10^{-5}m/sec\;or\;10^{-6}m/sec$ and the conductivity of grouting zone was assumed as 1/10, 1/50 or 1/100 of the conductivity of rock mass. Totally $6{\sim}8$ cases of transient flow simulation were peformed at each site. The hydraulic conductivities of fault zone showed a significant influence on groundwater inflow when the fault zone crossed the tunnel. Also, groundwater table around wetland maintained in case that the hydraulic conductivity of grouting zone was reduced ta be less than 1/50 of the hydraulic conductivity of rock mass.

• Journal of the Korean Society of Groundwater Environment
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• v.5 no.1
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• pp.37-43
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• 1998

Batch experiments were conducted to study the dissolution behavior of gasoline components. First, the dissolution kinetics of gasoline components and the applicability of Raoult's law in predicting their solubilities were investigated. In addition, the effects of compositional change of gasoline due to evaporization on the solubilities of individual components and TPH were determined. The kinetics of gasoline-water man transfer was found to be very similar for most components except for MTBE, which is a major additive for commercial gasoline. At equilibrium, the gasoline-water partitioning coefficients of individual components showed a log-linear relationship with their pure solubilities, though the slope was a little less than that predicted by Raoult's law. The concentrations of the individual components in the gasolines concentrated by volatilization could be characterized by the initial increase followed by substantial decrease. Almost the same behavior was observed for their solubilities. The total solubility (TPH) of gasoline decreased rapidly with the initial volume reduction and gradually decreased afterwards. The solubilities of BTEX, the major regulatory compounds, decreased even faster than the TPH solubilities. It was concluded that the compositional change of gasoline by volatilization may greatly affect their leaching potential and the toxicity of the contacting groundwater. The toxicity reduction efficiency by evaporating gasoline could be much more than the mass removal efficiency.

• Journal of Korean Society of Transportation
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• v.19 no.5
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• pp.21-33
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• 2001

Intelligent Transport Systems (ITS) was first introduced in Korea early 1990's, and Korean government has put a lot of efforts for flourishing it in the entire nation. Regardless of these efforts, private participation is not active enough to accelerate ITS implementation in Korea. Expert group made every endeavor to analyze the current situation, and found out some phenomena. It may be summarized as two folds. Firstly, private sector has a lack of confidence on the future ITS market. Budget in the strategic plan is the only publication and guide that private sector can refer to, and it merely indicates deployment costs. Secondly, direction and procedure of R&D are not well defined. It implies that private sector takes too much risk when they invest for R&D. This research, therefore, focuses on the first issues. Concretely, the goal of the project was to establish and analyze the model for estimation the future ITS market side. Author reviewed both quantitative and qualitative models, and concluded that diffusion model in qualitative model was suitable for ITS market estimation. According to model calibration. it is estimated that 14 trillion Won was the market size in 2020 under normal condition. Impact of this result may seduce Information Technology(IT) related private companies into ITS market. Although this research couldn't cover various topics, it nay dedicate in boosting ITS in Korea. Also, it will be a good starting point for further study for the advancement of ITS.

• 한국가시화정보학회:학술대회논문집
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• 2005.04a
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• pp.87-112
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• 2005

분무를 정량적으로 측정하는 것은 노즐의 설계와 개발을 위해서 뿐만 아니라 연소 시스템 전반의 효율 및 불안정성의 제거, 공해 저감 등의 요구 조건을 만족하기 위해서 중요하다. 이를 위해 이전에는 분무장 내에 수집관을 삽입하는 기계적 패터네이터(Mechanical Patternator)와 같은 삽입식 측정 방식을 이용하여 왔으나, 최근에는 고속카메라, Malvern particle analyzer, PDPA, 광학 패터네이터(Optical Patternator)와 같은 분무장을 교란시키지 않으면서도 빠른 측정이 가능한 가시화 기술들이 적용되고 있다. 특히 광학 패터네이터는 레이저 평면광을 이용하여 분무를 측정하는 비삽입식 기술로 단시간 내에 분무장 내 액체 연료의 질량 및 액적 크기의 단면 분포를 동시에 얻어낼 수 있는 장점을 갖고 있다. 그러나 분무 액적들의 수밀도가 증가하는 경우에는 이들 액적에 의한 입사광 및 신호 감쇠, 다중산란 등에 의한 오차가 심하게 발생하여, 기존의 PDPA, PLIF 등의 광학 기법으로는 충분히 신뢰할 만한 결과를 얻기가 어렵게 된다. 이러한 분무를 정량적으로 측정하기 위해서는 입사광의 감쇠뿐만 아니라 분무장 내 액적들에 의한 신호의 감쇠 과정에 대한 고려가 필요하다. 주면 액적들의 영향을 최소한으로 줄이기 위해서는 레이저 평면광을 사용하는 광학 패터네이터와 달리 레이저 광선을 분무장에 조사하여 고압에서 나타날 수 있는 다중 산란에 의한 오차를 최소화할 수 있다. 이러한 이미지 처리 기법을 이용하는 광학 선형 패터네이터(Optical Line Patternator)를 이용하여 기존 레이저 계측기법으로 측정이 곤란하였던 고압 환경 하에서의 스월 동축형 인젝터의 분무 특성을 해석할 수가 있다. 2015(년도) 6,388, 2025(년도) 13,367, 2035(년도) 18,756, 2045(년도) 22,595, 시장점유율 증가로 인한 수출액 증가분 누적(억원) : 2015(년도) 3,411, 2025(년도) 8,847, 2035(년도) 14,433, 2045(년도) 18,005 또한 시나리오 비교평가를 실시하여 본 결과, 본 연구에서 정의한 순편익 누적(Cumulative Net Profit) 변수를 적용하면 현재 연구비 추세 대비 $30\%$ 까지 연구비를 증가 시키는 것이 효율적임을 알 수 있었다.성, 생산 용이성, 제품 디자인의 우수한 정도가 a=0.01 수준 하에서 유의적으로 추정되었다. 이들 변수들 중에서 품질경쟁력에 가장 큰 영향을 미치는 측정변수는 제품의 기본 성능, 수명(내구성), 신뢰성, 제품 디자인의 순서로 추정되었다. 이것은 한국 제조업이 아직 산업 디자인이 품질경쟁력에 크게 영향을 미치는 성숙단계에 이르지 못하였음을 의미한다. (2) 제품 디자인에게 영향을 끼치는 유의적인 변수는 연구개발력, 연구개발투자 수준, 혁신활동 수준(5S, TPM, 6Sigma 운동, QC 등)이며, 제품 디자인은 우선 품질경쟁력을 높여 간접적으로 고객만족과 고객 충성을 유발하는 것으로 추정되었다. 상기의 분석결과로부터, 본 연구는 다음과 같은 정책적 함의를 도출하였다. 첫째, 신상품 개발과 혁신을 위한 포괄적인 연구개발 프로젝트를 품질 경쟁력의 주요 결정요인(제품의 기본성능, 신뢰성, 수명(내구성) 및 제품 디자인)과 연계하여 추진해야 할 것이다. 둘째, 기업은 디자인 경영 마인드 제고와 디자인 전문인력 양성을, 대학은 디자인 현장 업무를 통하여 창의력 증진과 기획 및 마케팅 능력 교육을, 정부는 디자

• Economic and Environmental Geology
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• v.47 no.3
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• pp.275-289
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• 2014

Recent scaled-up onshore and offshore field production tests revealed that the expectancy to produce gas from the gas hydrate deposits is gradually increasing, recognizing its potentials as one of the future energy resources. The total produced gas was approximately $480m^3$ by the hot water circulation method for 6 days' operation in Mallik 2002 project in Canada. In Mallik 2006-2008 project, the gas was successfully produced stably by the depressurization method for 6 days, up to $13,000m^3$ cumulatively. The depressurization method applied in the Mallik test was revealed as an effective way to produce gas from gas hydrates. The Alaska North Slope field trial in 2012 to inject mixed gas of $CO_2$ and $N_2$ to exchange $CH_4$ was successfully completed for the first time to produce maximum $1,270m^3$ per day. The remarkable achievement is that Japan has completed first offshore production test in the Eastern Nankai Trough, and produced approximately $120,000m^3$ of methane by the depressurization method for 6 days in March 2013. The technical challenges and uncertainties obtained from Nankai Trough production test give Korea more considerations in the aspects of well completion, reservoir formation and seafloor stability, sand control, flow assurance, and etc., due to the different geological environments and geomechnical properties in Ulleung Basin in Korea.

• Environmental and Resource Economics Review
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• v.23 no.4
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• pp.583-615
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• 2014

Including the rolling black out in 2011, Korea has suffered from rapid increase of electricity consumption and demand forecasting failure for last five years. In addition, because of the Fukushima disaster, high fuel prices, and introduction of new generation sources such as renewables, the uncertainty on a power supply strategy increases. Consequently, a stable power supply becomes the new agenda and a revisino of strategy for new power generation sources is needed. In the light of this, we appraises the sixth basic plan for long term electricity demand and supply considering the changes of foreign and domestic conditions. We also simulate a strategy for the new power generation sources using a portfolio analysis method. As results, a diversity of power generation sources will increase and the share of renewable power generation will be surged on the assumptions of a cost reduction of renewable power sources and an increase of fuel costs. Particularly, on the range of a risk level(standard deviation) from 0.06 and 0.09, the efficient frontier has the most various power sources. Besides, the existing power plan is not efficient so that an improvement is needed. Lastly, the development of an electricity storage system and energy management system is necessary to make a stable and efficient power supply condition.

• The Journal of Engineering Geology
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• v.20 no.2
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• pp.169-181
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• 2010

This study aimed at simulating several responses to stresses caused by the ground water level variations around the K-1 oil stockpile. For this simulation, we considered the characteristic hydrogeological condition including the special occurrence of long and thick acidic dyke, which is regarded as the main geological structure dominating the ground water flow system at this study area. We activated twenty-four imaginary wells which are located in northern and southern area around central K-1 site. Each neighboring distance is altogether 300 m and whole distance between K-1 site and remote wells is 1,200 m. Through the modeling, we operated the long-term and continuous pumping tests and finally categorized five zones based on maximum pumping rates for the imaginary wells; zone I within 300 meter distance from K-1 site with a pumping rate of 50 $m^3/day$; zone II between 300 to 600 meter distance from K-1 site with a pumping rate of 75 $m^3/day$; zone III between 600 to 900 meter distance from K-1 site with 150 $m^3/day$; zone IV between 900 to 1,200 meter distance from K-1 site with 300 $m^3/day$; and zone V of acidic dyke area. At zone V, especially because of their possibility of high transmissivity for groundwater flow, it is necessary to control and restrict groundwater discharge.

• Environmental and Resource Economics Review
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• v.16 no.1
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• pp.129-169
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• 2007

The purpose of this study is to experiment and simulate the newly-updated Second Generation Model for Korea (SGM-Korea). With the updated model, we tried to simulate effect of carbon tax on $CO_2$ emissions and other macroeconomic variables for Korea. The baseline data are compared with projected profiles by various scenarios to evaluate its performance. Our contribution in this study is to having up-graded the model from its earlier version by building new hybrid input-output table based on 2000 input-output and energy balanced tables. According to our estimation, total $CO_2$ emission in Korea has already increased in 2000 to about 1.86 times the 1990 figure. The level of carbon tax required for the current level of $CO_2$ emission to be reduced to the 1995 or 2000 level seems to be too high for Korean economy to bear. It is possible to find a reasonable level of carbon tax, however, if it can combine it with improvement of energy efficiency at the rate of 0.5% to 1% per year. For Korea to meet its obligation to reduce $CO_2$ emissions, therefore, it is imperative for her to improve energy efficiency as well as to develop alternative energy source reducing its dependence on fossil fuel.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.6
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• pp.3983-3989
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• 2014

As the storm water runoff characteristics in urban areas have changed owing to urbanization, centralized facilities to reduce the urban flood runoff had been implemented. On the other hand, because they have their limitations, LID (Low Impact Development) of the distributed facilities for storm water runoff reduction is being actively planned and applied. The purpose of this study was to analyze the runoff characteristics for the spatial distribution of typical LID element techniques. This study set a study basin consisting of the five subbasins with the same basin and drainage systems, and analyzed the flood runoff characteristics from the two scenarios, one is for the locations and the other is for the number of green roofs (GR) and permeable pavement (PP), respectively, selected as typical LID element techniques. The SWMM implementation results showed that GR reduces 11.07% of the total and 3.42% of the peak amounts of storm water runoff, and PP leads to 18.09% of the total and 17.94% of the peak discharge reduction for a subbasin. Such a reduction rate is constant regardless of the LID locations, and increases linearly with the number of LID applications. The different runoff reduction rates between the GR and PP applications appear to be due to the effects of the different hydraulic conductivities in the control parameters for each LID.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.5
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• pp.358-363
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• 2009

The HSPF (Hydrological Simulation Program-Fortran) model was applied to the Kyoungan stream watershed to analyze effects of watershed management plans on receiving water qualities. Utilizing BASINS 3.1 GIS program, the Kyoungan stream watershed was divided into 57 sub-basins and model input parameters were obtained, from DEM (Digital Elevation Model), land use type, stream map, and wastewater treatment facilities, etc.. The hydrologic module of the model was validated based on the measured meteorological data and stream flow data. Then the model was calibrated and verified against the field measurements of water qualities, including temperature, DO, BOD, $NO_3-N$, $NH_3-N$, Org-N, TN and TP. In most cases, there were reasonable agreements between measurements and predictions. The validated model was used to analyze the water quality improvements in the main stream of Kyoungan stream according to the watershed management plans in sub-basins, which are three different scenarios: water quality improvement in tributaries through watershed management activities, expansion and up-grade of wastewater treatment plants, and application of first and second scenarios together. It was concluded that expansion and upgrade of wastewater treatment plants would be more effective than watershed management activities. In order to improve water qualities to the satisfactory level, both watershed management and point source control must be required in the Kyoungan stream.