• 한국대기환경학회지
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• 제18권5호
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• pp.393-400
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• 2002

Separation distance between industrial source and residential areas to avoid odor annoyance was investigated using AUSPLUME model. A Gaussian plume model (AUSPLUME) for the dispersion was used to calculate odor emission from ground level area source. Using the dispersion model to calculate ambient odor concentrations, the separation distance between industrial source and residental areas was defined by %HA (percentage of highly annoyed person) and odor percentile concentration (C98). The result was compared with the separation distance of various nation guidelines for livestock buildings. The calculated separation distance for industrial source showed similar pattern comparing with various guidelines for livestock buildings.

• Nuclear Engineering and Technology
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• 제55권6호
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• pp.2305-2314
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• 2023

The governing equations of atmospheric dispersion most often taking the form of a second-order partial differential equation (PDE). Currently, typical computational codes for predicting atmospheric dispersion use the Gaussian plume model that is an analytic solution. A Gaussian model is simple and enables rapid simulations, but it can be difficult to apply to situations with complex model parameters. Recently, a method of solving PDEs using artificial neural networks called physics-informed neural network (PINN) has been proposed. The PINN assumes the latent (hidden) solution of a PDE as an arbitrary neural network model and approximates the solution by optimizing the model. Unlike a Gaussian model, the PINN is intuitive in that it does not require special assumptions and uses the original equation without modifications. In this paper, we describe an approach to atmospheric dispersion modeling using the PINN and show its applicability through simple case studies. The results are compared with analytic and fundamental numerical methods to assess the accuracy and other features. The proposed PINN approximates the solution with reasonable accuracy. Considering that its procedure is divided into training and prediction steps, the PINN also offers the advantage of rapid simulations once the training is over.

• 한국가스학회지
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• 제19권1호
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• pp.51-56
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• 2015

To assess downward positions of water spray for the small-scale release of chlorine gas, dispersion coefficients for the Gaussian dispersion model were validated at the small-scale release experiment. And the downwind distances of water spray were assessed with the simulated results. As results, the Gaussian plume model using the Briggs' dispersion coefficient well estimated the dispersed characteristics for small-scale release of chlorine gas. The best adequate downwind position of water spray is the position of the maximum concentration of chlorine at the ground level. And the adequate vertical and horizontal dimensions of water spray consider the maximum width and height of cloud.

• Journal of Radiation Protection and Research
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• 제29권3호
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• pp.157-163
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• 2004

원자력시설에서 만일의 방사성 물질의 누출이나 화학시설에서 독성물질의 누출시 오염물질의 환경 중 거동을 파악하기 위해서 대기확산 모형이 많이 이용된다. 대기확산 모형을 통한 환경 중 유해물질의 농도 예측에 대한 정확도를 높이기 위해서는 무엇보다 모형으로 입력되는 선원항에 대한 정확한 정보를 필요로 한다. 본 연구는 이러한 선원항 추정을 위하여 최소자승법을 적용하였다. 영광원자력 시설에서 실시된 추적자 확산실험 자료를 이용하여 가우시안 모형으로 계산한 값과 비교를 시도하였으며, 가우시안 모형으로 계산한 값들과 추적자 확산실험 결과 값들의 오차의 제곱이 최소가 되도록 선원항을 추정하였다. 추정한 선원항은 확산실험시 실제추적자 방출량의 1.24정도로 비교적 정확한 예측력을 나타내었다.

• 한국대기환경학회지
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• 제12권5호
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• pp.529-540
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• 1996

Dispersion experiment using SF$_{6}$ tracer was performed in the flat field of Chunchon Basin during four nights from August 29 to September 2, 1991. The purpose of this study is to analyze toe horizontal distribution of tracer concentration under the strong stable conditions and to evaluate the results calculated by INPUFF model. Incase of high wind speed, plume spread of SF$_{6}$ concentration appeared in narrow area of the downwind and the standard deviation of the horizontal wind angle (.sigma.$_{a}$) was amall. However, the SF$_{6}$ was spread widely in cases of low wind speed because of the large .sigma.$_{a}$. The result of the INPUFF model was similar to the observed distribution of the SF$_{6}$ concentration. It is proved that the Gaussian puff model is useful when wind direction varies significantly.tly.tly.tly.

• 환경영향평가
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• 제22권1호
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• pp.89-97
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• 2013

RADCONS Ver. 1.0 (RADiological CONSequence Assessment Program) was developed for radiological risk assessment in this study. A Gaussian plume model was used to analyze the fate and transport of radionuclides released into the air in case of accidents. Both single meterological data and time series meterological data can be used in RADCONS. To assess the radiological risk of the early phase after an accident, ED (Effective Dose) estimated by both deterministic and probabilistic approaches are presented. These EDs by deterministic and probabilistic will be helpful to efficient decision making for decision makers. External doses from deposited materials by time are presented for quantifying the effects of mid and late phases of an accident. A radiological risk assessment was conducted using RADCONS for an accident scenario of 1 Ci of Cs-137. The maximum of ED for radii of 1,000 meters from the accident point was 8.51E-4 mSv. After Monte-Carlo simulation, considering the uncertainty of the breathing rate and dispersion parameters, the average ED was 8.49E-4, and the 95 percentile was 1.10E-3. A data base of the dose coefficients and a sampling module of the meteorological data will be modified to improve the user's convenience in the next version.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제4권4호
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• pp.263-271
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• 2000

To investigate the distribution of air pollutants dispersion in the horizontal wind fields, a chaff release experiment was carried out by an airplane. The temporal and spatial variations of a chaff plume from an elevated point source using the WSR-88D(NEXRAD) radar. The observed profiles of radar reflectivity were compared with the Gaussian diffusion model at slightly unstable atmospheric condition. The present study shows that the distributions of radar reflectivity from chaffs and their concentration by the model are in general agreement with time variation. The dispersion coefficients in downwind($\sigma$(sub)x) and crosswind($\sigma$(sub)y) spread data exceeded what has generally been found at Pasquill and Brigg\`s estimates. As a result, it was clearly shown that horizontal and vertical diffusion coefficients are more accurately determined as compared with theoretical coefficients. At longer diffusion distances(than 10km), a radar observation provided the determination of maximum range and diffusion height more qualitatively, too.

• 한국가스학회지
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• 제22권4호
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• pp.32-38
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• 2018

본 연구는 불화 수소 탱크 컨테이너 하역장에서 불화수소 누출 시 누출량 및 확산 정도를 정량적으로 평가하여 동종사고의 재발을 방지하고 안전성 향상방안을 제시하는데 목적이 있다. 2012년 H사에서는 최대 저장량이 18 Ton인 탱크컨테이너에서 누출사고가 발생하여 인근 지역으로 8 Ton이 누출되었고, 그로인해 사회적 이슈가 되었다. 가우시안 플럼(Gaussian plume) 모델을 이용하여 계산한 결과 누출지점으로부터 반경 1,321m까지의 농도가 20ppm 이상으로 예측되었다. 2014년 R사에서 발생한 불화수소 누출사고에서는 누출량이 11.02kg으로 추정되었고, 그 중 2.9kg이 세정기로 회수되었다. 가우시안 플럼 모델을 사용하여 계산 한 결과, 누출 원으로 부터 20ppm 이상의 농도를 갖는 피해 범위가 반경 69m로 예상되었다. 위의 두 가지 사고를 비교 한 결과, 누출량은 약 987배 차이가 발생했고, 피해 지역은 19 배 이상 차이가 나는 것으로 나타났다. 따라서 보호구의 착용, 하역 장소의 밀폐 및 세정기 설치, 그리고 비상훈련을 실시하여 하역장에서 불화수소가 대량으로 누출되는 사고가 발생하지 않도록 관리해야 한다는 결론을 얻었다.

• Nuclear Engineering and Technology
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• 제19권2호
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• pp.99-106
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• 1987

가상적인 1,000MWe의 석탄화력발전과 원자력 발전소로부터 배출되는 방사성물질에 의한 피폭 영향을 상호 비교 연구하였다. 본 논문에서는 정상가동중에 배출되는 기체상 방사성물질에 국한하였으며 석탄화력발전소에 대한 방사선원은 국내자료가 부족하여 외국자료에 근거했고, 원자력발전소에 대해서는 표준발전소에 대해 계산된 방사선원을 사용하였다. 고리 기상탑의 1년 기상자료를 이용하여 Gaussian모델에 의해 방사성물질의 대기확산을 평가했으며, 개인 피폭선량은 대기확산인자가 최대인 지점의 성인에 대해 계산하였다. 방사선피폭선량은 석탄화력발전소보다 원자력발전소의 경우가 약간 컸으며 석탄화력의 경우는 원자력발전소와 달리 피폭선량의 73.5%가 오염된 엽채류의 섭취에 따른 것이었다.

• 한국환경과학회지
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• 제14권9호
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• pp.851-860
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• 2005

In order to how well predict ISCST3(lndustrial Source Complex Short Term version 3) model dispersion of air pollutant at point source, sensitivity was analysed necessary parameters change. ISCST3 model is Gaussian plume model. Model calculation was performed with change of the wind speed, atmospheric stability and mixing height while the wind direction and ambient temperature are fixed. Fixed factors are wind direction as the south wind(l80") and temperature as 298 K(25 "C). Model's sensitivity is analyzed as wind speed, atmospheric stability and mixing height change. Data of stack are input by inner diameter of 2m, stack height of 30m, emission temperature of 40 "C, outlet velocity of 10m/s. On the whole, main factor which affects in atmospheric dispersion is wind speed and atmospheric stability at ISCST3 model. However it is effect of atmospheric stability rather than effect of distance downwind. Factor that exert big influence in determining point of maximum concentration is wind speed. Meanwhile, influence of mixing height is a little or almost not.