• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.349-350
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• 2003

ISCST 등의 대기확산모델은 모두 EPA에서 개발된 것으로 모델 운영에 사용되는 모든 데이터가 미국의 실정에 맞게 프로그램 되어 있다. 특히 ISC모델을 운영하기 위하여 필요로 하는 기상자료를 생성하는 MIXHTS와 PCRAMMET등은 미국 기상청이나 기타 기상관련 기관에서 발표하는 자료를 사용하도록 되어있다. 따라서 ISC를 운영하는데 있어 국내 기상자료를 해당하는 형태로 전환해야 하는 번거로움이 있으며 우리나라 기상청에서 발표하는 기상자료의 형태와 MIXHTS PCRAMMET에서 요구하는 기상자료형태를 모두 알고 있어야만 ISC를 운영하기 위한 올바른 기상자료를 만들 수 있었다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.363-364
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• 2000

2000년 7월 환경부에서 발표한 대기오염물질 배출사업장의 수는 32,437개소이고, 그 중에서 대형굴뚝이 있는 1종 ∼ 3종 사업장이 3,117 개소에 이르고 있다. 이들 사업장의 대부분은 굴뚝을 통하여 오염물질을 배출하고 있다. 국내외적으로 21세기 대기환경관리 정책방향은 사업장의 대기오염물질 배출원 관리를 강화하고 있고, 대기오염물질 배출규제방식도 기존의 배출농도 규제중심에서 배출원이 주변지역에 미치는 기여농도를 중심으로 이동하는 추세이다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.397-398
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• 2001

대형 석탄화력 발전소에서는 발전소 가동으로 인해 발생되는 주변 오염농도를 평가하기 위하여 주기적으로 현장조사를 실시하고 있다. 본 연구에서는 미국 환경보호청(EPA) 권장 모델중 하나인 ISCST-3를 이용하여 하동화력본부 주변의 확산 모델링을 수행하여 최고 농도 발생 지점을 조사하였고 환경 기준치와의 비교결과를 나타내었다. 또한 현장에서의 실제 조사결과와 비교하여 국내 지형 및 농촌지역에의 ISC-3의 적용성을 조사하였다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.397-398
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• 2002

대기분야에서는 악취관련 민원이 거의 대부분을 차지하고 있고, 최근 환경부에서도 이에 적극적으로 대처하기 위해서 악취방지법을 제정한 바가 있다. 현재 국내에서 많은 연구자들이 노력한 결과로 악취물질 측정 분석 방법이 정립되었고, 대규모 공단지역에서 악취배출원 및 배출량에 대한 자료가 축적된 상황이다. 그러나 아직까지도 국내에서는 배출된 악취물질이 주변에 미치는 영향을 정량적으로 해석하기 위한 모델링 기법에 대해서는 심도 있게 연구된 바가 없는 실정이다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.393-394
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• 2002

현대 산업 사회의 급속한 발전으로 인해 대기 중에는 다양한 오염원을 통해서 많은 오염물질이 배출됨에 따라 이를 평가하고 방지할 대책이 필요하게 되었다. 이러한 대책 중의 하나로 배출원에서 배출되는 오염물질의 경로 및 발생량을 예측하는 방법이 있는데, 대기 상에 배출되는 오염물질의 농도를 예측할 경우 보통 대기 확산 모델링을 통하여 배출원 주변의 오염물질 확산 및 농도값을 산정한다. 현재 국내에서는 주로 가우시안 확산 모델인 ISC, CALPUFF 모델 등을 사용하여 모델링을 계산하게 된다. (중략)

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.1
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• pp.30-40
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• 2011

Numerical simulations were carried out to investigate the impact of SST spatial distribution on the result of air quality modeling. Eulerian photochemical dispersion model CAMx (Comprehensive Air quality Model with eXtensions, version 4.50) was applied in this study and meteorological fields were prepared by RAMS (Regional Atmospheric Modeling System). Three different meteorological fields, due to different SST spatial distributions were used for air quality modeling to assess the sensitivity of CAMx modeling to the different meteorological input data. The horizontal distributions of surface ozone concentrations were analyzed and compared. In each case, the simulated ozone concentrations were different due to the discrepancies of horizontal SST distributions. The discrepancies of land-sea breeze velocity caused the difference of daytime and nighttime ozone concentrations. The result of statistic analysis also showed differences for each case. Case NG, which used meteorological fields with high resolution SST data was most successfully estimated correlation coefficient, root mean squared error and index of agreement value for ground level ozone concentration. The prediction accuracy was also improved clearly for case NG. In conclusion, the results suggest that SST spatial distribution plays an important role in the results of air quality modeling on high ozone episode at coastal region.

• Journal of Korean Society on Water Environment
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• v.26 no.2
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• pp.332-342
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• 2010

A model has been developed to investigate in-river sediment and phosphorus dynamics. This advective-dispersive model is coupled with hydrodynamics and sediment transport submodels to simulate suspended sediment, total dissolved phosphorus, total phosphorus, and particulate phosphorus concentrations under unsteady flow conditions. It emphasizes sediment and phosphorus dynamics in unsteady flow conditions, in which the study differs from many previous solute transport studies, conducted in relatively steady flow conditions. The diffusion wave approaximation was employed for unsteady flow simulations. The first-order adsorption and linear adsorption isotherm model was used on the basis of the three-layered riverbed submodel with riverbed sediment exchange and erosion/deposition processes. Various numerical methods were tested to select a method that had minimal numerical dispersion under unsteady flow conditions. The responses of the model to the change of model parameter values were tested as well.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.5
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• pp.30-37
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• 2001

Most gasoline engines employ a port injection system to achieve the better fuel-air mixing. A part of injected fuels adheres to the wall or intake valve and forms a film of liquid fuel. The other is secondarily atomized by the spray-wall interaction. A better understanding of this interaction will help in designing injection systems and controlling the strategies to improve engine performance and exhaust emissions. In the present research, the spray-wall interaction was investigated by a laser sheet visualization method. The shape of sprays was pictured at various impinging velocities and angles. The fuel dispersion was estimated by fluorescence light, and the atomization was evaluated by the enlarged images of droplets. The experimental results were compared with model predictions which are based on OPT method. The model has been modified to have the better agreement with the experimental result, and was implemented in the KIVA-II code.

• Journal of Environmental Health Sciences
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• v.31 no.6
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• pp.489-497
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• 2005

A numerical method for the mathematical water modeling in 2-dimensional flow has been developed. The model based on a split operator technique, in which, the advection term is calculated using the upwind scheme. The diffusion term is one- dimensionalized and calculated using Crank-Nicholson's implicit finite difference scheme to reduce the numerical errors from large time steps and variable spacings. It also provides a relatively simple and economic method for more accurate simulation of pollutant dispersion. Water depths and flow velocities in the Boreyong reservoir during the normal water periods were predicted by numerical experiments with a 2-dimensional flow model so as to provide current field data for the study of advection and diffusion of pollutants. Developed 2-dimensional water quality model is applied to Boreyong reservoir to simulate a spatial and periodical changes of water quality.

• Journal of Korean Society for Atmospheric Environment
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• v.11 no.2
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• pp.145-152
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• 1995

Predictability of a Gaussian model, ISCST2 was assessed by scaling up wind tunnel experiments with a 1/3,000 terrain model to the real scale. Concentration profiles obtained from the flat-terrain experiment in the neutral condition were estimated to be in agreement with the calculated ones from ISCST2 in the stability class A, but the difference between the two was still large. Concentration profiles from the mountainous-terrain experiments were better fitted to the calculated ones primarily because in the experiment, concentration behind the source was raised due to the effect of a hill in the upstream side. Model prediction was improved with including the downwash effect of buildings and the hill, but overall concentration profiles were not much different from a typical Gaussian profile. While concentration profiles in the experiments were changed with local flows by varying the wind direction and the topography, those from the Gaussian modeling were mot freely changed together with these variations.