• Korea Trade Review
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• v.43 no.5
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• pp.47-66
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• 2018

This study analyzes the potential economic effects of a trade war between the U.S. and China. The CGE model is used to estimate the macroeconomic variables of each country and the change in imports/exports by industry by considering three different scenarios: (i) the US imposes a 25% of tariff on China; (ii) the US and China impose a 25% tariff bilaterally; (iii) the United States expands protection in vehicles and metals to Korea, Japan, and the EU. According to the results of the study, when the US and China initiate a trade war, GDP and welfare of both countries decline. China's decline in GDP and welfare are larger than those of the United States, which implies a trade war is more favorable to the U.S. than to China. In the long run, China's GDP and welfare decline widens further. While the trade volumes of the US and China are greatly reduced, the trade volumes of other countries does not significantly fluctuate. Finally, if the US extends protection policy to Korea, Japan and the EU, it creates undesirable effects on the US. In particular, damage to the US jeopardizes its advantageous position in a trade war with China. In order to emphasize the unfairness of protectionist policy and the damage to Korean industry, Korea needs to establish a strategy to counter US protectionist policy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.1
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• pp.43-54
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• 2023

Due to climate change, drought and flood occurrences have been increasing. Accurate projections of watershed discharges are imperative to effectively manage natural disasters caused by climate change. However, climate change and hydrological model uncertainty can lead to imprecise analysis. To address this issues, we used two lumped models, IHACRES and GR4J, to compare and analyze the changes in discharges under climate stress scenarios. The Hapcheon and Seomjingang dam basins were the study site, and the Nash-Sutcliffe efficiency (NSE) and the Kling-Gupta efficiency (KGE) were used for parameter optimizations. Twenty years of discharge, precipitation, and temperature (1995-2014) data were used and divided into training and testing data sets with a 70/30 split. The accuracies of the modeled results were relatively high during the training and testing periods (NSE>0.74, KGE>0.75), indicating that both models could reproduce the previously observed discharges. To explore the impacts of climate change on modeled discharges, we developed climate stress scenarios by changing precipitation from -50 % to +50 % by 1 % and temperature from 0 ℃ to 8 ℃ by 0.1 ℃ based on two decades of weather data, which resulted in 8,181 climate stress scenarios. We analyzed the yearly maximum, abundant, and ordinary discharges projected by the two lumped models. We found that the trends of the maximum and abundant discharges modeled by IHACRES and GR4J became pronounced as changes in precipitation and temperature increased. The opposite was true for the case of ordinary water levels. Our study demonstrated that the quantitative evaluations of the model uncertainty were important to reduce the impacts of climate change on water resources.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.3
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• pp.149-155
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• 2008

To evaluate the formulae for the stability of riprap, the formulae of Isbash, California division of highway, Netherlands, ASCE, Pilarczk, and Maynord are comparatively analysed with the experimental results. The critical velocity which initiates the motion of riprap is increased with the weight and the size in diameter and the riprap size with water depth, Froude number, shear velocity with mean velocity, Shields parameter have great correlation with them. The results by 6 formulae are overestimated in riprap size in diameter and the result by Maynord formula proposed by U.S. Army Corps of Engineers estimates rather correct. The results by Isbash, Netherlands, and Pilarczk are overestimated in riprap weight but the result by California division of highway formula coincides with experimental result. In the experimental results of model riprap artificially made by gypsum with light weight density, the critical velocity is increased with shape factors. The critical velocity appears greater in regular arrangement of model riprap than in random arrangement of it. Therefore the shape factor and the degree of interlocking are an important parameters in riprap stability.

• International Commerce and Information Review
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• v.16 no.3
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• pp.97-119
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• 2014

This study measures the efficiency of intellectual capital of Korea's banks, financial investment companies, and insurance companies using the Value Added Intellectual Coefficient (VAICTM) model, which was developed by A. Pulic and investigates into the relationship of each of VAIC's elements - efficiency of human, structural, and material capital -with business performance of the institution. we found, first, average VAIC and human capital efficiency(HCE) of Korean financial institutions during 2001 - 2012 were highest among banks, followed by insurance companies and securities firm. Secondly, in general, banks in advanced countries tend to have higher HCE and VAIC compared with the banks of developing countries. Thirdly, Korean financial institutions' HCE and VAIC are lower than those of Australia and even Taiwan and Thailand and have been on the decrease in recent years. This suggests that Korean financial institutions should enhance VAIC and HCE to build-up the international competitiveness.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.256-256
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• 2017

최근 기후변화가 가속화되면서 집중호우가 급증하고 계획홍수량을 초과하는 홍수재해가 빈번하게 발생하고 있다. 이에 주요 선진국들은 홍수대응을 위한 새로운 패러다임을 도입하고 있다. 구조적 측면에서는 기존 제방 위주의 홍수방어에서 벗어나 유역에서 홍수 방어구획 설정, 대심도 터널 등 다원적 홍수방어체계로 전환하고 있다. 또한 ICT를 활용하여 다양한 수문정보를 실시간으로 관측하고 홍수상황을 신속하게 전파 대응할 수 있는 비구조적 대책도 적극적으로 개발하고 있다. 미국의 경우, 홍수량과 발생 확률을 예측한 정보를 시민들에게 조기에 제공함으로써 선제적으로 대응할 수 있도록 지원하고 있다. 그러나 우리나라의 홍수대응은 여전히 구조적 대책과 사후복구에 집중되어 있는 안타까운 상황이다. 세계 최고수준인 우리나라의 ICT 인프라를 이용하여 실시간 수문자료를 공유하고 이를 홍수대응에 활용하면 재난을 미연에 방지하는데 크게 기여할 수 있을 것으로 판단된다. 그러나 홍수관련 유관기관 자료를 연계한 실시간 수문상황 모니터링 시스템을 구축하는 것만으로는 지자체 홍수피해 저감에 한계가 있을 수 있다. 이를 보완하기 위해 수집된 실시간 수문정보를 활용한 홍수분석 및 하천수위별 대응기준 수립을 통한 예방적 재난대응 체계를 마련해야 한다. 이에 본 연구에서는 A지자체를 대상으로 홍수분석 모형을 구축하고, 구축된 모형의 계산결과를 활용하여 예상강우별 도달시간, 수위상승 등을 예측하고, 하천수위별 대응기준을 수립하는 연구를 진행하였다. 수위별 대응기준은 현장에서 계측되는 수위값을 기준으로 홍수예보기준, 하천기본계획의 제방고 및 주변 제약 사항을 고려하여 직접알람 기준으로 활용하였다. 또한 대상 수위국에 대하여는 2~3년간의 관측자료 확보 및 유량측정을 통해 대응기준의 보완을 진행할 예정이다. 재난관련 골든타임을 확보하고 홍수피해 최소화를 위한 홍수재해 통합관리 체계 구축은 이제 선택이 아닌 필수라 할 수 있다. 특히 본 연구로 산정된 홍수대응기준과 함께 물관리 유관기관의 실시간 수문자료 공유체계 구축, 홍수통제기관 또는 기술력을 보유한 재해대책 책임기관과의 유기적인 기술교류 등을 통해 지자체 홍수피해 저감을 위한 능동적인 홍수대응 체계 구축이 수행되어야 할 것이다.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.425-425
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• 2017

최근 기후변화의 영향으로 태풍과 국지성 집중호우가 빈번하게 발생하면서 인명 및 재산피해가 증가하고 있다. 이러한 자연재해를 줄이기 위하여 국가적 차원에서 피해예측 및 피해규모를 정확하게 산정하는 시스템 구축이 필요한 시점이다. 해외 주요국에서는 풍수해 재해통계 DB를 구축하고, 이를 피해예측시스템에 적용하여 피해규모를 산정함으로써 풍수해 재난관리에 활용하고 있다. 그러나 국내의 경우, 재해정보 피해통계가 공공시설에 한정되어 있거나 단순 복구비의 직접관리 수준에 그치고 있는 등 피해예측기술 및 시스템 개발 수준은 초기단계에 머물고 있다. 따라서 재해정보 기본통계를 정비하고 재난대응 단계별 의사결정 지원에 활용할 수 있는 풍수해 피해예측 및 피해액 산정 시스템을 구축할 필요가 있다. 본 연구에서는 풍수해피해예측시스템 구축을 위한 핵심 기술요소 도출하고자 한다. 이를 위하여 사전단계인 재해정보 기본통계 DB구축 방안을 검토하여 재해연보 개선안을 제시하였다. 먼저, 피해예측시스템 구축에 필요한 필수 DB를 파악하고 기존 재해연보의 활용성을 검토하였다. 검토 결과를 바탕으로 재해연보의 문제점을 파악하고 피해예측시스템에 적용이 가능한 기초 DB를 구축하기 위하여 재해연보의 개선방안을 도출하였다. 다음으로 미국에서 개발한 HAZUS-MH 시스템의 피해예측 관련 기술정보를 분류하고, 국내에서 개발 중인 피해예측시스템과 비교분석하여 핵심 기술요소를 도출하였다. 본 연구의 결과는 다음과 같다. 첫째, 풍수해 피해예측시스템의 핵심요소로서 세분화된 재해통계 DB의 구축이 필수적이다. 재해연보를 기초 DB로서 활용하기 위하여 재해항목 구체화 및 자료형태 다양화 등 재해연보의 개선이 시급하다. 둘째, 피해예측시스템 개발을 위한 핵심기술 요소는 (1)함수(모형)의 개발, (2)지리정보시스템(GIS)과의 연계, (3)피해예측시스템 구축 및 모형분석을 위한 컴퓨팅기술, (4)실시간 관측기술 및 강우량 사전예측 등으로 도출이 되었다. 이와 같이 도출한 핵심 기술요소를 바탕으로 국가 R&D 및 재난안전분야의 기술개발을 추진하여야 한다.

• International Area Studies Review
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• v.13 no.3
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• pp.759-780
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• 2009

The purpose of this paper is to analyse the effect of Korean FDI(1990-2008) in China by industries on exports and imports between two countries. We use time series regression, Vector Error Correction Model and Impulse Response Function as methodologies. Our findings through empirical tests are as follows. First Korean FDI in China increases Korean exports with China but shows a tendency to decrease due to the local content of China. Second Korean FDI in China increases Korean imports in SITC 8 with China. Finally Korean trade surplus caused by Korean FDI in China shrinks due to the decreasing of exports and increasing of imports in Korea. Korean FDI in China should be oriented host country's market oriented rather than production efficiency oriented because of unfriendly foreign investment environments in China.

• Journal of Korean Academy of Nursing
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• v.51 no.3
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• pp.280-293
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• 2021

Purpose: This study aimed to identify the risk factors for diabetic foot ulceration (DFU) to develop and evaluate the performance of a DFU prediction model and nomogram among people with diabetes mellitus (DM). Methods: This unmatched case-control study was conducted with 379 adult patients (118 patients with DM and 261 controls) from four general hospitals in South Korea. Data were collected through a structured questionnaire, foot examination, and review of patients' electronic health records. Multiple logistic regression analysis was performed to build the DFU prediction model and nomogram. Further, their performance was analyzed using the Lemeshow-Hosmer test, concordance statistic (C-statistic), and sensitivity/specificity analyses in training and test samples. Results: The prediction model was based on risk factors including previous foot ulcer or amputation, peripheral vascular disease, peripheral neuropathy, current smoking, and chronic kidney disease. The calibration of the DFU nomogram was appropriate (χ² = 5.85, p = .321). The C-statistic of the DFU nomogram was .95 (95% confidence interval .93~.97) for both the training and test samples. For clinical usefulness, the sensitivity and specificity obtained were 88.5% and 85.7%, respectively at 110 points in the training sample. The performance of the nomogram was better in male patients or those having DM for more than 10 years. Conclusion: The nomogram of the DFU prediction model shows good performance, and is thereby recommended for monitoring the risk of DFU and preventing the occurrence of DFU in people with DM.

• Korean Journal of Remote Sensing
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• v.33 no.5_2
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• pp.741-750
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• 2017

The objective of this study was to estimate corn and soybean yield in Illinois and Iowa in USA using satellite and meteorological data. MODIS products for NDVI were downloaded from a NASA website. Each layer was processed to convert projection and extract layers for NDVI. Relations of NDVI from 2002 to 2012 with corn and soybean yield were investigated to find informative days for rice yield estimation. Weather data for the county of study state duration from 2002 to 2012 to correlate crop yield. Multiple regression models based on MODIS NDVI and rainfall were made to estimate corn and soybean yields in study site. Corn yields estimated for 2013 were $10.17ton\;ha^{-1}$ in Illinois, $10.21ton\;ha^{-1}$ in Iowa and soybean yields estimated were $3.11ton\;ha^{-1}$ in Illinois, $2.58ton\;ha^{-1}$ in Iowa, respectively. Corn and Soybean yield distributions in 2013 were mapped to show spatial variability of crop yields of the Illinois and Iowa state.

• Journal of Korea Water Resources Association
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• v.45 no.1
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• pp.15-27
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• 2012

SWMM (Storm Water Management Model) has been widely used in the world as a typical model for flood runoff analysis of urban areas. However, the calibration of the model is difficult, which is an obstacle to easy application. The purpose of the study is to develop an automatic calibration module of the SWMM linked with SCE-UA (Shuffled Complex Evolution-University of Arizona) algorithm. Generally, various objective functions may produce different optimization results for an optimization problem. Thus, five single objective functions were applied and the most appropriate one was selected. In addition to the objective function, another objective function was used to reduce peak flow error in flood simulation. They form a multiple objective function, and the optimization problem was solved by determination of Pareto optima. The automatic calibration module was applied to the flood simulation on the catchment of the Guro 1 detention reservoir and pump station. The automatic calibration results by the multiple objective function were more excellent than the results by the single objective function for model assessment criteria including error of peak flow and ratio of volume between observed and calculated flow. Also, the verification results of the model calibrated by the multiple objective function were reliable. The program could be used in various flood runoff analysis in urban areas.