• International Area Studies Review
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• v.15 no.3
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• pp.95-126
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• 2011

The objective of this study is to quantify the potential economic effects of Non-Agricultural Market Access (NAMA) negotiations of the WTO on automotive industry of the world using a multi-region, multi-sector Computable General Equilibrium (CGE) model with 21 countries/regions and 22 sectors. According to the December 2008 NAMA modalities text, issued by the chair of the negotiation on NAMA, three different scenarios of tariff liberalization of NAMA are conducted on the basis of the Swiss formula with a coefficient of 8 for developed members and 20 for developing (scenario 1), with a coefficient of 8 for developed members and 22 for developing (scenario 2) and with a coefficient of 8 for developed members and 25 for developing (scenario 3). Simulation results show potential economic effects at the macroeconomic and microeconomic level of 21 countries concerned. In particular, Korea is to be one of the winners of tariff liberalization of NAMA in the WTO and Korean automotive industry is to benefit from it to a large extent in terms of its output, domestic sales, exports and trade balance, which implies that Korea needs to actively engage in NAMA negotiations of the WTO.

• Journal of agriculture & life science
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• v.43 no.5
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• pp.47-55
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• 2009

This study analyzes the correlation between noise and the size of urban forests. Under the assumption that the main cause of the noise m the city is the population density, the size of urban forests per capita and the ratio of urban forests with respect to the size of urban per 100 thousand persons are used for the calculation of correlations with noise. The results of the calculations of Pearson's and Spearman's correlation coefficients indicate that the increase in the size of urban forests has a significant effects in reducing the day-time as well as night-time noise for most regions in the cities. The size of urban forests within public parks has a significantly negative correlation with the noise. However, calculated correlation coefficients imply the increase in the size of total urban forests is more effective in reducing the noise than the increase in the urban forests in public parks.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1063-1067
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• 2009

강원도 홍천군에 위치한 기타광물질 지역의 유출과 수질농도의 특성을 파악하기 위하여 연구를 수행하였다. 연구기간동안 13회의 강우사상에 대하여 모니터링을 실시하였다. 13회의 강우모니터링 기간동안 발생한 강우량은 6.5 ${\sim}$ 149.0 mm의 범위를 나타냈고, 유출계수는 0.28${\sim}$0.98의 범위를 나타냈다. 유출률은 수리, 수문,지형 및 지질학적 특성 등 여러 가지 요인에 의하여 변화할 수 있다. 어느 한 지역의 강우사상에서 강우량과 강우강도 그리고 선행무강우일수 등의 수리, 수문학적 특성은 유출량과 유출율의 크기에 큰 영향을 준다. 강우량과 선행무강우일수 그리고 강우강도와 유출율의 상관관계에서 유출률은 강우량과 강우강도가 증가할수록 선행무강우일수가 감소할수록 증가하는 경향을 나타냈다. 또한 유출율과 강우량, 선행무강우일수, 평균강우강도 그리고 최대강우강도의 Pearson 상관계수는 0.75857, -0.36346, 0.68323 그리고 0.74594로 나타났으며, 강우량, 평균강우강도, 최대강우강도는 유의수준 0.05에서 통계적으로 유의하며 유출율과 강우량의 관계가 가장 큰 것으로 나타났다. 기타광물질 지역의 수질농도들 사이의 상관관계는 $COD_{Cr}$과 $COD_{Mn}$에서 0.81097로 가장 큰 상관계수가 나타났으며, 유기물질인 $COD_{Cr}$, $COD_{mn}$, BOD 그리고 TOC는 통계적으로 유의한 상관 계수를 갖는 것으로 나타났다. 하지만 유기물을 제외한 다른 수질항목은 큰 관계가 없는 것으로 나타났다. 기타광물질 지역의 유출수와 수질농도의 특성을 더 신뢰성있고 과학적으로 검증하기 위한 장기적인 연구와 노력이 더욱 필요할 것으로 사료된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.282-286
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• 2017

Rapid industrialization and urbanization have resulted in an increase in impervious areas and an increase in runoff, therefore, this causes more flooding and damage in urban areas. This study has analyzed the effects of improvements to the roughness coefficient in storm sewer pipes on flood runoff and outflow through rainfall-runoff simulations. The simulations are implemented by three scenarios to evaluate effects of improvements to the roughness coefficient for the improved length ratio to the total length, diameters and mainlines of sewer pipes. The size and length of the sewer mains are large and long to effectively increase the flow rate to the outlet, secure the passage discharge capacity of the pipe and reduce the overflow. It is effective for flood reduction that the improvement to roughness coefficient is first conducted in mainlines with longer lengths and larger diameters. The results from this study can provide a guideline for prioritizing of the sewer pipe replacement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.406-411
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• 2012

The undrained strength of soils is open determined from the results of the piezocone penetration. The reliability of the value of the undrained strength lies on the cone factor value, whose evaluation needs a lot of experimental data and investigation for each site. In this study, the cone factors were evaluated for the northeastern part of Shiwha area in Gyunggi province using the experimental data of the field vane, unconfined compression, and UU triaxial compression tests. The values of the conventional cone factors $N_{kt}$, $N_{ke}$, $N_{{\Delta}u}$, and the new factor $N_e$ were determined to be 12, 11, 3, and 13, respectively. It was observed that there is a remarkable relationship between $N_{{\Delta}u}$ and the pore pressure ratio Bq.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.65-69
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• 2005

SWAT 모형은 우리나라 논 지역에서의 수리관행을 이행할 수 있도록 관개용수의 공급과 담수지역에 대한 성분해석에 대한 기본적인 틀을 갖추고 있으며, 각종 물관리 체계의 조작이 가능한 우수한 모형이다. 그러나, 실제 우리나라 농업지역에 관개용수를 공급하고 담수상태의 논 지역을 충분히 모사하지 못하고 있다. 따라서, 이러한 결함을 제거하기 위해서는 SWAT 모형의 관개용수공급과 관련한 내부 모듈의 전면적인 수정$\cdot$보완과 교체작업이 필요하였다. 이러한 SWAT 모형의 문제점 해결을 위해 우리나라 는 농사의 특징인 담수를 고려하고, 관개량 및 관개일정을 제어하여 담수 논에 대한 수문성분이 전체 하천유출을 포함하는 수문순환 과정에 미치는 영향을 정량적으로 평가할 수 있는 SWAT-AGRIMAN(SWAT-AGRIculture MANagement) 모형을 개발하였다. 개발된 SWAT-AGRIMAN 모형을 보청천 기대교 상류유역에 적용하였고, 적용결과를 SWAT 모형에 의한 모의결과와 비교$\cdot$평가하였다. 관개용수의 수원의 제기능 여부 및 담수상태의 유지여부와 논의 침투량 및 증발산량, 유역 출구에서의 유출량의 변화특성을 살펴보았으며, 실제 관측유량과의 유출율, 평균제곱근오차(RMSE), 모형효율계수(ME), 상관계수(CORRL), 결정계수($R^2$)의 비교$\cdot$분석을 통해 모형을 평가하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.3
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• pp.395-406
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• 2018

The XP-SWMM model, widely used for inundation analysis of urban watersheds, underestimated the inundation area (range) because the manhole was regarded as a node and the influence of the local loss occurring in the surcharged manhole can not be considered. Therefore, it is necessary to analyze the applicability of the head loss coefficients considering the local loss in the surcharged manholes in inundation analysis using XP-SWMM. The Dorim 1 drainage section of the Dorim-river watershed, where frequent domestic flood damage occurred, was selected as the study watershed. The head loss coefficients of the surcharged manholes estimated from the previous experimental studies were applied to the inundation analysis, and the changes of the inundation area with and without the application of the head loss coefficients with manhole types were compared and analyzed. As a result of inundation simulation with the application of head loss coefficients, the matching rates were increased by 17% in comparison with the without application of them. In addition, the simulated inundation area applied only the head loss coefficients of straight path manholes and applied up to the head loss coefficients of combining manholes ($90^{\circ}$ bend, 3-way, and 4-way) were similar. Therefore, in order to accurately simulate the storm drain system in urban areas, it could be to carry out two-dimensional inundation analysis considering the head loss coefficients at the surcharged manholes. It was expected that the study results will be utilized as basic data for establishing the identification of the inundation risk area.

• Journal of Korea Water Resources Association
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• v.53 no.5
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• pp.337-345
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• 2020

In order to provide information for proper management of groundwater resources, an analysis of the effects of precipitation and groundwater withdrawal on groundwater levels is needed. In this study, we analyzed the correlation of precipitation-groundwater level and groundwater withdrawal-groundwater level using time series data converted by normalized standard deviation (Nor.St.Dev) and cross correlation coefficient (CCC) for nine groundwater monitoring wells in the middle mountainous area in the southeastern Jeju Island. First, the CCCs of precipitation-groundwater level were estimated using daily time series data, and the low CCCs of up to 0.3 were obtained. However, the result of using the Nor.St.Dev showed a clearer correlation by obtaining a CCC of up to 0.8. In addition, in most cases, precipitation variability and groundwater level variability had positive CCCs, whereas groundwater withdrawal variability and groundwater level variability had negative CCCs. Therefore, the groundwater level in this study area was largely influenced by precipitation with little effect of groundwater withdrawal. Lastly, as a result of analyzing the relative effects of Seongpanak and Gyorae rainfall station on the groundwater level, the rainfall at the relatively downstream Gyorae rainfall station has more influence. The analysis method used in this study can be easily used for analyzing the effects of precipitation and groundwater withdrawal on groundwater level variability in other regions in the future.

• The Journal of Engineering Geology
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• v.3 no.2
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• pp.115-124
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• 1993

Hydrogeological survey related to groundwater condifiors was performed at the study area in Gyukpo, BuanGun, ChunlabukDo to express the relationships between groundwater conditions and the geologic structures such as joints, faults and beddings in bedrock About 200 joints and sjgnfficant faults were measured in this area. Typically, The fracture analysis on cores of 7 boreholes was tried to quantify fracture numerically. Groundwater level was periodically measured for three months. The packer tests of about 175 were carried out in 7 boreholes. As the result, Fractures are locaHy developed as ground water bearing zone and an average hydraulic conductivity of bedrock is $1{\times}10^{-5}cm/sec$ in this area the hydraulic conductivity of this area is correlated with fracture frequency value of F15 and is also well correlated with fracture developed and depth. In accordance with depth, fracture frequency and hydraulic conductivity are decreased. Hydraulic conductivity of granite along depth shows an obiouse change in values but that of sedimentary rocks do not shows changeless. Groundwater movement in the bedrocks of the study area affected not by joints but faults developed in the different rock boundary. In the northern part of this area, The differences of hydraulic conductivity between granite and sedimentary rocks give rise abrsspt at difference in groundwater leveL In the southern part of the study area, there is no different in groundwater level of both same rock types.

• Journal of Korea Water Resources Association
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• v.48 no.2
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• pp.127-136
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• 2015

In general, XP-SWMM regards manholes as nodes, so it can not consider local head loss in surcharged manhole depending on shape and size of the manhole. That might be a reason why XP-SWMM underestimates inundated-area compared with reality. Therefore, it is necessary to study how we put the local head loss in surcharged manhole in order to simulate storm drain system with XP-SWMM. In this study, average head loss coefficients at circular and square manhole were estimated as 0.61 and 0.68 respectively through hydraulic experiments with various discharges. The estimated average head loss coefficients were put into XP-SWMM as inflow and outflow energy loss of nodes to simulate inundation area of Gunja basin. Simulated results show that not only overflow discharge amount but inundated-area increased considering the head loss coefficients. Also, inundation area with considering head loss coefficients was matched as much as 58% on real inundation area. That was more than simulated results without considering head loss coefficients as much as 18 %. Considering energy loss in surcharged manholes increases an accuracy of simulation. Therefore, the averaged head loss coefficients of this study could be used to simulate storm drain system. It was expected that the study results will be utilized as basic data for establishing the identification of the inundation risk area.