• 한국항공운항학회지
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• 제20권2호
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• pp.32-38
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• 2012

The United Nations (UN) has tried to make international agreement to restrict artificial greenhouse gas emissions and the UN has concluded the UN Framework Convention Climate Change (UNFCCC) and the Kyoto protocol. Moreover, in 2012, the European Union announced that they will enforce the Directive 2008/101/EC. Therefore, after 2012, aircraft carriers that depart or arrive from EU will follow that regulation. For these reasons, Korea should prepare systematic and effective policy to reduce greenhouse gas emission from aviation activities. The purpose of this study is to find out effective measures to reduce greenhouse gas emission from aviation activities through research by countries all over the world. Here are the 4 measures to reduce greenhouse gas emission from Aviation activities that were found through research UK and Japan's policies. First, Korea should implement aggressive incentive policies. Providing proper incentive can attract voluntary participation of aircraft carriers to reduce greenhouse gas emission. Second, the government should adopt environmental tax on use of fossil fuels. Third, Korea should adopt the greenhouse gas Emissions Trading Scheme (ETS). Lastly, the Korea government should pull in with the international community to establish world-wide environmental policies.

• 국제초고층학회논문집
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• 제4권4호
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• pp.241-247
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• 2015

In this study, an approximate computer-based method was developed to analyze the behavior of raft and piled raft foundations. Special attention is given to the improved analytical method proposed by considering raft flexibility and soil nonlinearity. The overall objective of this study is to focus on the application of a simplified analysis method for predicting the behavior of sub-structures. Through the comparative studies, it is found that the computer programs (YS-MAT and YSPR), developed in this study, is in agreement with the general trends observed by field measurements. Therefore, YS-MAT (Yonsei-Mat) and YSPR (Yonsei Piled Raft) can be effectively used for the preliminary design of a raft or a piled raft foundation for high-rise buildings.

• 한국환경과학회지
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• 제29권1호
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• pp.25-32
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• 2020

The determination of soil parameters is important in predicting the simulated surface runoff using either a distributed or a lumped rainfall-runoff model. Soil characteristics can be collected using remote sensing techniques and represented as a digital map. There is no universal agreement with respect to the determination of a representative parameter from a gridded digital map. Two representative methods, i.e., arithmetic and predominant, are introduced and applied to both FLO-2D and HEC-HMS to improve the model's accuracy. Both methods are implemented in the Yongdam catchment, and the results show that the former seems to be more accurate than the latter in the test site. This is attributed to the high conductivity of the dominant soil class, which is A type.

• 한국환경과학회지
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• 제8권3호
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• pp.355-361
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• 1999

The aim of this study is to develop the water quality simulation model (BAYQUAL) that deal with the physical, chemical and biological aspects of fate/behavior of pollutants in the bay. BAYQUAL is a two dimensional, time-variable finite element water quality model based on the flow simulation model in bay(BAYFLOW). The algorithm is composed of a hydrodynamic module which solves the equations of motion and continuity, a pollutnat dispersion module which solves the dispersion-advection equation. The applicability and feasibility of the model are discussed by applications of the model to the Kwangyang bay of south coastal waters of Korea. Based on the field data, the BAYQUAL model was calibrated and verified. The results were in good agreement with measured value within relative error of 14% for COD, T-N, T-P. Numerical simulations of velocity components and tide amplitude(M2) were agreed closely with the actual data.

• 한국환경과학회지
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• 제8권3호
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• pp.309-318
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• 1999

In order to fast predict the wind-driven current in a small bay, a convolution method in which the wind-driven current can be generated only wih the local wind is developed and applied in the Sachon Bay. The root mean square(rms) ratio defined as the ratio of the rms error to the rms speed is 0.37. The rms ratio is generally less than 0.2, except for all the mouths of Junju Bay and Namhae-do and in the region between Saryang Island and Sachon. The spatial average of the recover rate of kinetic energy(rrke) is 87%. Thus, the predicted wind-driven current by the convolution model is in a good agreement with the computed one by the numerical model. The raio of the difference between observed residual current (Vr) and predicted wind-driven current (Vc) to a residual current, that is, (Vr-Vc)/Vr shows 56%, 62% at 2 moorings in the Sachon Bay.

• 한국환경과학회지
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• 제12권7호
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• pp.809-816
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• 2003

The short-term version of Industrial Source Complex Model(ISCST3) was evaluated for estimating short-term concentrations using criteria pollutant(SO$_2$, NO$_2$, CO, PM10) data from emission inventory of Young Tong area in Suwon for the year 2002. The contribution of pollutant concentration from point, line, area sources was found 21.8, 76.5 and 1.6%. Statistical parameters, such as correlation coefficient, index of agreement(IA), normalized mean square error(NMSE) and fractional bias(FB) were calculated for each pollutants. The model performance were found good for PM10(82%) and NO$_2$(69%), but poor for SO$_2$(34%) and CO(13%).

• 한국환경과학회지
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• 제4권2호
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• pp.245-251
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• 1995

Generally, It is Introduced to well-known other models without considering tidal current of the field. The paper presents field measurements and numerical model solving velocity field of Cheonsu Bay by two-dimensional tidal model. It was proved that this scheme is easy to handle complex topography. Computed results is represented characteristics of tidal current for Cheonsu Bay. The results of the study can be summarized as follows ; 1. Tide form number has 0.21 value. Tidal range estimated 630.3 cm on spring, 454.1 cm on mean and 277.9 cm on neap, respectively 2. Tidal current has semi-diurnal form. Distance of traveling observed 16.6 km on flood and 15.5 km on ebb. 3. Tidal velocity showed reversing current. It was found that tidal velocity above 100 cm/sec is about 20 %. 4. Computed results are in good agreement with the observed data. Applying the algorithm to Cheonsu Bay, velocity fields and dry bank phenomena are simulated well in spite of complex topography. 5. An advanced study on the effects of open boundary conditions should be continuously performed.

• 한국환경과학회지
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• 제4권2호
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• pp.169-180
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• 1995

This Daper presents effective simulation of the dispersion of thermal discharge which can be relesed at Boryong power plant. Applied numerical models are finite difference method for hydrodynamic analysis and Masch-model comprised of conditions for ambient current velocity. Application of these models is done in Cheonsu Bay Summing up the results of this study are as follows; 1. It is found that the result for measurements of temperature appears high at southwardly Songdo on flood. The reason is that tidal currents which flowed north direction were accompanied with southwardly dispersed thermal discharge. A minute Particle of thermal Plume has a tendency to dispels inward Deacheon Bay. 2. According to the results of numerical experiment, maximum distance for thermal discharge dispersion appeared 10.8 km at lower part and 8.6 km at upper part with power plant outlet as starting point. 3. Comparative the numerical simulation and Airbone Multispectral Scanner indicated that thermal discharge should be verified separative phenomena. The simulated results were compared with field data set showing good agreement. It is concluded that these model can be simulated well.

• 한국환경과학회지
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• 제7권4호
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• pp.433-440
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• 1998

This study was carried out to develop the stream water quality model for the intaking station of Kongju waterworks in the Keum River system. The monthly water quality(total nitrogen and total phosphorus) with periodicity and trend were forecasted by multiplicative ARIU models and then the applicability of the models was tested based on 7 years of the historical monthly water quality data at Kongju intaking strate. The parameter estimation was made with the monthly observed data. The last one year data was used to compare the forecasted water Quality by ARU model with the observed one. The models are ARIMA(2,0,0)$\times$(0,1,1)l2 for total nitrogen, ARIMA(0,1,1)x(0,1,1)l2 for total phosphorus. The forecasting results showed a good agreement with the observed data. It is implying the applicability of multiplicative ARIMA model for forecasting monthly water quality at the Kongju site.

• 한국환경과학회지
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• 제13권6호
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• pp.591-597
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• 2004

In this study, sixty chemicals including 47 pesticides were screened for estrogenic activity using E-screen assay. MCF-7 cell, used in E-screen assay, is known to be proliferated by addition of estrogenic chemicals. Eight of the measured pesticides showed estrogenic activity at the concentration range of 100-10,000nM. Their relative proliferative effect (RPE) and the relative proliferative potency (RPP) were 20-65% and 0.01-1.0%, respectively, when compared with 1.0nM of $\beta-Estradiol-17-acetate(E_{2}).$ DDVP and diazinone showed most strong estrogenic potency(RPP; 1.0%) and effect(RPE; 65%) of the eight pesticides. These results are in agreement with estrogenic activity of bisphenol A is known as a positive endocrine disrupter. Also, in this study, paraquat, DDVP, 4-chloro-3-methylphenol, 2,4,6-trichlorophenol and diazinon of the measured pesticides are estimated to estrogenic chemical.