• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.287-287
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• 2023

Surface water-groundwater interaction (SWGI) is an important hydrological process that influences both the quantity and quality of water resources. However, regional scale SWGI model calibration and uncertainty analysis have been a challenge because integrated models inherently carry a vast number of parameters, modeling assumptions, and inputs, potentially leaving little time and budget to explore questions related to model performance and forecasting. In this study, we have proposed the application of iterative ensemble smoother (IES) for uncertainty analysis and calibration of the widely used integrated surface-subsurface model, SWAT-MODFLOW. SWAT-MODFLOW integrates Soil and Water Assessment Tool (SWAT) and a three-dimensional finite difference model (MODFLOW). The model was calibrated using a parameter estimation tool (PEST). The major advantage of the employed IES is that the number of model runs required for the calibration of an ensemble is independent of the number of adjustable parameters. The pilot point approach was followed to calibrate the aquifer parameters, namely hydraulic conductivity, specific storage, and specific yield. The parameter estimation process for the SWAT model focused primarily on surface-related parameters. The uncertainties both in the streamflow and groundwater level were assessed. The work presented provides valuable insights for future endeavors in coupled surface-subsurface modeling, data collection, model development, and informed decision-making.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.295.1-295.1
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• 2003

A suitable model for the estimation of the drug release from nanoparticles has been varied and problematic, especially for the release from lipid nanoparticles containing water-insoluble drugs, due to the difficult particle collection from the release medium. Dialysis membrane has been widely used for the release test from colloidal carrier systems. The amount of drug from the carriers in normal dialysis diffusion technique was very low typically. (omitted)

• 농약과학회지
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• 제9권3호
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• pp.214-220
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• 2005

초기위해성평가는 신물질 개발시 급성자료와 물리화학적 특성자료를 이용하여 위해성평가를 수행하고 정책결정자들에게 위해성에 관한 정보를 제공하여 의사결정 수단으로 활용되고 있다. 본 연구에서는 초기위해성평가 체계의 틀을 구축하고 구축된 위해성평가 체계를 검증하기 위하여 captan, glyphosate, paraquat dichloride의 세 가지 농약을 대상물질로 하여 인체 및 생태의 초기위해성을 평가하였다. 이때 두 종류의 수계 예측 모형인 GENEEC (GENeric Estimated Environmental Concentration)과 FOCUS (FOrum for the Co-ordination of pesticide models and their USe)가 농약의 노출평가를 위하여 사용되었으며 glyphosate와 paraquat dichloride는 인체 및 생태에 위해성이 낮은 것으로 나타났으나 captan의 어류 위해성은 급성독성이 높은 것으로 나타났다. 이 결과는 U.S. EPA RED (Reregistration Eligibility Decision) 결과와 유사한 경향성을 보여 본 연구체계의 신뢰성을 검증할 수 있었다.

• 분석과학
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• 제8권4호
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• pp.759-770
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• 1995

By extensive studies with the quantitative status of the mineral constituents of thousands of water samples, it was found that almost in all natural waters irrespective of the surface or sub-surface sources, minimum 99.5% of the total amount of the cationic constituents are generally the contributions of 3 commonly present parameters viz. Ca, Mg and Na and that of the anionic species are same and contributed by $HCO_3$, Cl and $SO_4$ only. In the field of water works, all these major mineral substances are conventionally measured as their individual ions. But till now, no reliable and generalised methods or rules have been developed for the determination of the exact kinds of the individual salt components and their amounts from these ionic constituents normally present in water. As salt content, only the TDS (Total Dissolved Solids) parameter is frequently measured by evaporation of the water sample. But TDS can tell nothing about the kinds and amounts of the individual salts present in it. Considering the analytical importance of the estimation of the mineral substances as their individual salts, some generalised mathematical models have been developed by this research which are based on the 'hypothetical order of chemical combinations' as may occur among the ionic constituents. With the help of these models, one can easily assume the most probable salts with approximate quantities derived from the ionic constituents. In addition, approximate amount of Na content can also be estimated mathematically with simultaneous verification of the correctness of the water analysis results. The models are stated in this paper with practical illustrations and descriptions of the method of applications.

• 한국자동차공학회논문집
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• 제9권5호
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• pp.131-139
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• 2001

Highly accurate control of the air-fuel ratio is important to reduce exhaust gas emissions of the gaseous-fuel engines. In order to achieve this purpose, inlet air mass flow must be measured exactly, and precise engine models are necessary to design engine control systems. In this paper, the effects of water vapor and gaseous fuel that change the air mass flow are studied. The effective air mass ratio is defined as the air mass flow divided by the mixture mass flow, and also it is applied to the estimation of the inlet air mass flow. The presence of the gaseous fuel and the water vapor in the mixture reduces the air partial pressure and the effective air mass ratio of the gaseous-fuel engines. The Experimental results for an LPG engine show that the estimation of the inlet ai mass flow based upon the effective air mass ratio is more accurate than that of the normal air mass flow.

• 한국제4기학회지
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• 제13권1호
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• pp.53-65
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• 1999

기후변화와 이에 따르는 식생변화, 인위적인 토지이용 변화 등 '지역환경생태시스템의 변화'에 대한 '지역 물수지변화' 추정은 오직 필자가 개발한 BROO $K_{TOP}$과 같은 '물리기반 물수지 모델(Physical based Water Balance Model)'류에 의해서만 가능하다. 본 연구에서는 독일 중북부 농업지대와 산림지대에 대해서 $BROOK_{TOP}$ 소프트웨어를 이용하여 정립된 물리기반 지역물수지모델에 독일 포츠담 기후변화연구소(PIK) 시나리오와 체코 프라하대학에서 개발한 중부유럽 대상 GCM 기후변화 시나리오를 적용하여 물수지변화를 추정하였다. 이와 같은 기후와 지표.지하조건을 고려 한 지구온난화에 따른 수자원변화 예측시스템 개발은 하천수$\cdot$지하수 개발 및 수질 관리, 농업경작관리, 환경생태계 관리, 자연 재해 관리, 토지이용계획 및 지역개발계획 등을 위한 시스템개발의 기반이 된다

• 환경위생공학
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• 제15권2호
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• pp.65-74
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• 2000

The purpose of this study is to develop the stochastic stream water quality model for the intake station of Chung-Ju city waterworks in the Han river system. This model was based on the theory of Box-Jenkins Multiplicative ARIMA(SARIMA) and the state space model to simulate changes of water qualities. Variable of water qualities included in the model are temperature and dissolved oxygen(DO). The models development were based on the data obtained from Jan. 1990 to Dec. 1997 and followed the typical procedures of the Box-Jenkins method including identification and estimation. The seasonality of DO and temperature data to formulate for the SARIMA model are conspicuous and the period of revolution was twelve months. Both models had seasonality of twelve months and were formulates as SARIMA {TEX}$(2,1,1)(1,1,1)_{12}${/TEX} for DO and temperature. The models were validated by testing normality and independency of the residuals. The prediction ability of SARIMA model and state space model were tested using the data collected from Jan. 1998 to Oct. 1999. There were good agreements between the model predictions and the field measurements. The performance of the SARIMA model and state space model were examined through comparisons between the historical and generated monthly dissolved oxygen series. The result reveal that the state space model lead to the improved accuracy.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.216-219
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• 2006

Water retention curve (WRC), one of soil hydraulic properties, is often approximated by property-transfer models (PTMs). Using the PTMs, we can estimate the WRCs from other physical properties such as particle-size distribution (PSD). The objective of this work was to investigate the performance of two PTMs with different origins for numerical simulations on transport of Benzo[a]pyrene in a soil. To do this, we chose both PTMs with different origins, i.e., (1) the lognormal distribution model (L anti NL models), and (2) the modified $Kov\'{a}cs$ model (MK model). The MK model showed tile worse performance in estimation of the WRCs. When transport of B[a]P was simulated, the MK model predicted to move farther than the L and NL models did, indicating that transport of B[a]P in a soil can be greatly influenced by the choice of PTMs.

• 물과 미래
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• 제18권1호
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• pp.75-83
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• 1985

초기연구단계에 있는 ARMA(1, 1) 다계절모형에 의해 계절유량을 발생시키기 위한 모형의 변수결정방법과 유량발생 및 발생유량계열의 통계학적분석을 실시하였으며 타모형과의 비교를 위해 Thomas-Fiering 모형, Matalas AR(1) 다계절모형도 사용하였다. 다계절모형에 의해 발생시킨 계절유량을 연도별로 합산하여 얻은 연유량계열의 통계학적 특성치를 년모의발생모형에 의해 발생시킨 년유량계열의 통계특성치와 비교함으로써 ARMA(1, 1) 다계절모형에 의해 계절 및 년유량자료계열을 한꺼번에 모의발생시킬 수 있는 가능성을 평가하였다.

• 설비공학논문집
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• 제17권8호
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• pp.695-703
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• 2005

The objective of this study is to determine the effective thermal conductivity and thermal resistance values in test boreholes with three different fill materials. To evaluate these heat transfer properties, in-situ tests on four vertical boreholes were conducted by adding a monitored amount of heat to water over various test lengths. Two parameter estimation models, line-source and numerical one-dimensional models, for evaluation of thermal response test data were compared when applied on the same four data sets. Results show that the average thermal conductivity deviation between measured data and these two models is in the range of $3.03\%$ to $4.45\%$. The effect of increasing grout thermal conductivity from 1.34 to 1.82 $W/m^{\circ}C$ resulted in overall increases in effective formation thermal conductivity by $11.1\%$ to $51.9\%$ and reductions in borehole thermal resistance by $11.6\%$ to $26.1\%$.