• 한국농공학회논문집
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• 제59권6호
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• pp.9-18
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• 2017

The objective of this study was to estimate the climate change impact on inflow to Namgang Dam using SWAT (Soil and Water Assessment Tool) model. The SWAT model was calibrated and validated using observed flow data from 2003 to 2014 for the study watershed. The $R^2$ (Determination Coefficient), RMSE (Root Mean Square Error), NSE (Nash-Sutcliffe efficiency coefficient), and RMAE (Relative Mean Absolute Error) were used to evaluate the model performance. Calibration results showed that the annual mean inflow were within ${\pm}5%$ error compared to the observed. $R^2$ were ranged 0.61~0.87, RMSE were 1.37~7.00 mm/day, NSE were 0.47~0.83, and RMAE were 0.25~0.73 mm/day for daily runoff, respectively. Climate change scenarios were obtained from the HadGEM3-RA. The quantile mapping method was adopted to correct bias that is inherent in the climate change scenarios. Based on the climate change scenarios, calibrated SWAT model simulates the future inflow and evapotranspiration for the study watershed. The expected future inflow to Namgang dam using RCP 4.5 is increasing by 4.8 % and RCP 8.5 is increasing by 19.0 %, respectively. The expected future evapotranspiration for Namgang dam watershed using RCP 4.5 is decreasing by 6.7 % and RCP 8.5 is decreasing by 0.7 %, respectively.

• 한국수자원학회논문집
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• 제32권6호
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• pp.637-647
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• 1999

본 연구는 토양내에서 투수량 계수가 연직방향으로 지수함수적으로 감소한다는 TOPMODEL의 기존 가정을 일반화시킨 투수량계수의 멱급수형 감소모형의 국내지형에 대한 적용성을 검토하였다. 유출모의는 위천 대표 시험 유역의 동곡 소유역(33.6km2)을 대상으로 50m 수치지형도(Digital Elevation Model : DEM)을 사용하였다. 임의의 매개변수 결정의 신뢰성을 확보하기위해 TOPMODEL 운영시 산정과정에 난수발생 알고리즘을 추가하여 변형된 모형의 효율성을 검토하였다. TOPMODEL 투수량계수 멱급수 감소모형의 멱급수 2와 3의 경우가 다름 멱급수들의 경우나 투수량계수 지수형 감소모형에 비해서 상대적으로 높은 모의 효율을 보였다. 이러한 결과는 유출수문곡선의 감쇠곡선 부분 추정에 있어 멱급수 2와 3인 감소모형의 모의능력이 다른 모형들에 비해서 대상유역의 토양특성을 잘 반영하는데 기인한다고 판단된다.

• 한국물환경학회지
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• 제23권2호
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• pp.228-235
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• 2007

For efficient turbid water withdrawal in the Imha reservoir, a selective withdrawal facility was recently installed and operated during summer season of year 2006. In this research, CE-QUAL-W2 model was utilized to assess the efficiency of the selective withdrawal facility, in comparison with the original surface withdrawal, on turbid water management. Model calibration was carried out using data observed at four automatic monitoring stations in the reservoir. It was found that the model appropriately simulated, with the RMSE less than 5.2 NTU, the observed vertical and horizontal distributions of water temperature and turbidity as well as the location of maximum turbid water at each monitoring station. The analysis results showed that selective withdrawal is more effective in removing high turbid water than surface withdrawal as selective withdrawal contributed to reducing $35Mm^3$ of high turbidity water (> 100 NTU) in the reservoir by increasing outflows of high turbid water. Therefore, effective management of turbid water in the reservoir can be achieved by changing locations of intake depending on turbid water distribution conditions. The results of this study will provide some basic information for establishing better operation strategies to cope with turbid water problems.

• Bulletin of the Korean Chemical Society
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• 제22권8호
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• pp.821-826
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• 2001

Solvent sublation has been studied for the separation and determination of trace Zn(Ⅱ) and Pb(Ⅱ) in water samples. A synergy producing method was utilized to improve the efficiency of extraction in the sublation using an ion-pair of metal-naphth oate {M-(Nph)3- } complexes and tetra-n-butylammonium (TBA+ ) ion. After the M-(Nph)3- complexes were formed by adding 1-naphthoic acid to the sample solution, tetra-n-butylammonium bromide was added in the solution to form the ion-pair. And sodium lauryl sulfate (SLS) was added to make the ion-pair hydrophobic. The ion-pairs of the metal complexes were floated and extracted into methylisobutyl ketone (MIBK) from the aqueous solution by bubbling with nitrogen gas in a flotation cell. Metal ions in MIBK solution were measured by graphite furnace-AAS. Experimental conditions were optimized as follow so. After the pH of a 1.0 L water sample was adjusted to 5.0, 6.0 mL of 0.1 M 1-HNph and 10 mL of 0.03 M TBA-bromide were added to the sample to form ion-pairs, and 2.0 mL of 0.2%(w/v) SLS was added to make the ion-pairs hydrophobic. The solution was bubbled with 30 mL/min N2 gas for 5 minutes in a flotation cell. Linear calibration curves were obtained for the determination of Zn(Ⅱ) and Pb(Ⅱ) in several water samples. Reproducible results of showing a relative standard deviation of < 10% and recoveries of 80-100% could be obtained.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.99-99
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• 2015

본 연구에서는 금강 유역을 대상으로 토양저류함수모형기반의 개념적 강우유출모형의 장기 유출모의를 평가하였다. 연구유역인 금강 22개 계측유역을 주요 유역특성인자(면적, 경사도, SCS-CN등)을 수문학적 거리 산정방법을 활용하여 3개의 유역그룹을 선정하였다. 적용모형인 개념적 강우유출모형은 3개의 토양저류함수모형[확률분포모형(PDM: Probability Distributed Moisture), 유역습윤지수모형(CWI: Catchment Wetness Index), 수정펜맨타입모형(MP: Modified Penman type model)]과 3개의 유역추적모형[병렬2선형 저류지 유출 모형(2PAR: 2-conceptual reservoirs in parallel), 빠른 지표하 흐름을 고려한 병렬 2선형 저류지 유출모형(2PMP: 2Macro-pre Approach parallel structure), 병렬 3선형 저류지 유출모형(3PAR: 3-conceptual reservoirs in parallel)]의 조합인 9개의 모형을 사용하였으며, 2006년부터 2012년의 일자료를 바탕으로 검정(Calibration), 2001년부터 2005년의 일자료를 검증(Validation)을 Monte carlo method(Uniform Random Sampling)로 수행 후, 모형의 성능은 NSE(Nash sutcliffe Efficiency)로 평가하였다. 분석결과 유역그룹에 대한 모형성능의 편차는 작아서 유역그룹에 대한 토양저류 함수모형의 뚜렷한 상관성을 확인할 수 없었다. 이는 금강 유역을 단일 유역 그룹으로 적용할 수 있음을 제시하고 있다. 검정 검증성능 및 검정매개변수의 개수를 바탕으로 적용성 평가를 실시한 결과에서 토양저류함수모형인 확률분포모형(PDM)과 유역추적모형의 병렬2선형 저류지 유출모형(2PAR)와 빠른 지표하 흐름을 고려한 병렬2선형 저류지 유출모형(2PMP)의 조합이 금강 22개 유역에서 적용성이 우수함을 확인하였다. 향후 이 모형을 바탕으로 금강유역의 대표적인 강우유출모형을 개발하고자 한다.

• 한국지반환경공학회 논문집
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• 제20권5호
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• pp.39-46
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• 2019

준설점토를 활용한 연약지반은 장비주행성 및 진입로의 확보를 위해 시멘트 계 고화재 및 무기질 고화재 등을 활용한 표층고화처리공법이 사용되고 있으나 환경에 유해한 물질의 용출로 인한 문제가 제기되고 있어 환경과 기능성을 모두 만족하는 표층고화처리 공법의 개발이 필요하다. 표층처리 공법으로는 조기강도와 장기적인 안정 등을 고려하여 시멘트계 고화재를 이용한 표층고화처리공법이 많이 활용되고 있으며, 지반개량 효과가 크고 경제적 효율성으로 인해 국 내외에서는 시멘트계 고화재를 이용한 표층개량에 대한 연구과 수행되어 지고 있다. 그러나 최근 환경과 기능성의 문제가 제기되어 시멘트에서 발생되는 6가크롬(Cr6+), 수은(Hg) 등의 유해물질로 인해 지반오염과 환경문제가 발생되어 다양한 친환경적인 공법의 개발이 요구되고 있는 실정이다. 따라서 이 연구에서는 자연함수비의 준설점토를 시멘트와 친토양고화재를 혼합한 혼합토를 대상으로 동일한 배합조건 및 양생조건에 따른 일축압축강도를 분석하고 이 결과를 기준으로 표층개량범위 적용 및 실내모형토조시험을 수행하여 초연약지반의 강도특성 및 지지력 특성을 검토하고자 한다.

• 한국방사선학회논문지
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• 제13권5호
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• pp.819-824
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• 2019

본 연구에서 서로 다른 양성자 에너지를 사용하여 핵반응에 의해 생성된 감마선의 차이를 통해 고에너지 양성자 Pb(p, nx) 핵반응에서 생성된 동위원소를 식별하는 방법을 제안했다. 한국원자력연구원의 100-M eV 양성자 선형 가속기에서 생성된 고 에너지 양성자를 이용하여 실험을 수행 하였다. 양성자 핵반응을 통해 생성된 다양한 핵종에 의해 생성된 감마선은 HPGe 검출기로 구성된 감마선 분광법 시스템을 사용하여 측정되었습니다. 감마선 표준선원은 감마선 검출기의 정확한 에너지교정 및 효율측정을 위해 사용되었습니다. 제안한 방법을 위하여 동일한 천연 납 시료에 서로 다른 100 및 60 MeV 양성자 에너지빔을 사용하였다. 이 방법은 동일한 시료에서 발생되는 감마선들을 서로 비교함으로써 생성된 핵종들을 확인하는데 매우 효과적임을 알 수 있었다. 이 연구의 결과는 향후 다른 양성자 핵반응 결과를 얻는데도 매우 효과적으로 적용될 것이라 생각된다.

• 한국지형학회지
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• 제23권1호
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• pp.87-101
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• 2016

This study was conducted to develop a hydrological model of catchment water balance which is able to estimate irrigation return flows, so BROOK90-K (Kongju National University) was developed as a result of the study. BROOK90-K consists of three main modules. The first module was designed to simulate water balance for reservoir and its catchment. The second and third module was designed to simulate hydrological processes in rice paddy fields located on lower watershed and lower watershed excluding rice paddy fields. The models consider behavior of floodgate manager for estimating the storage of reservoir, and modules for water balance in lower watershed reflects agricultural factors, such as irrigation period and, complex sources of water supply, as well as irrigation methods. In this study, the models were applied on Guryangcheon stream watershed. R2, Nash-Sutcliffe efficiency (NS), NS-log1p, and root mean square error between simulated and observed discharge were 0.79, 0.79, 0.69, and 4.27 mm/d respectively in the model calibration period (2001~2003). Furthermore, the model efficiencies were 0.91, 0.91, 0.73, and 2.38 mm/d respectively over the model validation period (2004~2006). In the future, the developed BROOK90-K is expected to be utilized for various modeling studies, such as the prediction of water demand, water quality environment analysis, and the development of algorithms for effective management of reservoir.

• Journal of Preventive Medicine and Public Health
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• 제55권1호
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• pp.28-36
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• 2022

The current multimorbidity correction method in the Global Burden of Disease studies assumes the independent occurrence of diseases. Those studies use Monte-Carlo simulations to adjust for the presence of multiple disease conditions for all diseases. The present study investigated whether the above-mentioned assumption is reasonable based on the prevalence confirmed from actual data. This study compared multimorbidity-adjusted years of lived with disability (YLD) obtained by Monte-Carlo simulations and multimorbidity-adjusted YLD using multimorbidity prevalence derived from National Health Insurance Service data. The 5 most common diseases by sex and age groups were selected as diseases of interest. No significant differences were found between YLD estimations made using actual data and Monte-Carlo simulations, even though assumptions about the independent occurrence of diseases should be carefully applied. The prevalence was not well reflected according to disease characteristics in those under the age of 30, among whom there was a difference in YLD between the 2 methods. Therefore, when calculating the burden of diseases for Koreans over the age of 30, it is possible to calculate the YLD with correction for multimorbidity through Monte-Carlo simulation, but care should be taken with under-30s. It is useful to apply the efficiency and suitability of calibration for multiplicative methods using Monte-Carlo simulations in research on the domestic disease burden, especially in adults in their 30s and older. Further research should be carried out on multimorbidity correction methodology according to the characteristics of multiple diseases by sex and age.

• Nuclear Engineering and Technology
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• 제53권4호
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• pp.1189-1198
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• 2021

When performing remote tasks using robots in nuclear power plants, a 3D shape measurement system is advantageous in improving the efficiency of remote operations by easily identifying the current state of the target object for example, size, shape, and distance information. Nuclear power plants have high-radiation and underwater environments therefore the electronic parts that comprise 3D shape measurement systems are prone to degradation and thus cannot be used for a long period of time. Also, given the refraction caused by a medium change in the underwater environment, optical design constraints and calibration methods for them are required. The present study proposed a method for developing an underwater 3D shape measurement system with improved radiation tolerance, which is composed of commercial electric parts and a stereo camera while being capable of easily and readily correcting underwater refraction. In an effort to improve its radiation tolerance, the number of parts that are exposed to a radiation environment was minimized to include only necessary components, such as a line beam laser, a motor to rotate the line beam laser, and a stereo camera. Given that a signal processing circuit and control circuit of the camera is susceptible to radiation, an image sensor and lens of the camera were separated from its main body to improve radiation tolerance. The prototype developed in the present study was made of commercial electric parts, and thus it was possible to improve the overall radiation tolerance at a relatively low cost. Also, it was easy to manufacture because there are few constraints for optical design.