• 대한환경공학회지
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• 제36권10호
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• pp.719-723
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• 2014

수질오염총량관리제의 효율적인 시행을 위해 본 연구에서는 비점오염원의 분류, 비점부하량(발생, 배출) 산정, 비점 오염원 관리지역의 선정, 비점오염물질 관리 등을 포함한 비점오염원 관리방안을 제시하고자 하였다. 무엇보다도 먼저 점오염원과 비점오염원의 정의는 학술적 법률적 관점에 기초하여 명확히 구분 관리하여야 한다. 특히, 사업활동과 사람의 활동에 의해서도 환경피해가 발생하지 않는 임야, 초지, 하천 등은 별도로 자연배경오염원으로 구분하여야 한다. 비점오염원 발생 및 배출부하량의 원단위는 유역의 실제여건에 맞도록 우선적으로 변경하여야 하며, 비점오염원 발생 및 배출부하량의 산정방법은 유역의 강수량 및 강수 지속시간을 고려하도록 수정하여야 한다. 한편, 수질오염총량관리제를 시행함에 있어 비점 오염원 관리지역은 강우시 하천의 오염물질 농도가 중권역 목표(관리목표)를 초과하거나 초과할 우려가 있는 유역을 대상으로 하며, 전체 유역 가운데 초지, 임야를 제외한 도시지역, 농경지, 그리고 대지 가운데 비점오염물질의 배출밀도가 높은 지역을 비점오염원 관리지역으로 최소화하여 선정하여야 한다. 비점오염물질저감시설은 단위면적당 비점오염물질 배출량, 오염물질 초과농도 지속시간, 처리의 실현가능성, 점오염원 대비 처리비용 효과 등을 고려하여 단위면적당 비점오염원 발생부 하량이 많은 지역과 강우시 수질농도가 중권역 목표를 초과하는 유역에 설치하여야 한다.

• Water Engineering Research
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• 제7권1호
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• pp.1-8
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• 2006

Recently, the population growth and agricultural development are rapidly undergoing in the South-West Texas. The junction of three river basins such as Lavaca river basin, Colorado-Lavaca Coastal basin and Lavaca-Guadalupe Coastal basin, are interesting for non-point and point source pollutant modeling: Especially, the 2 basins are an intensively agricultural region (Colorado-Lavaca Coastal/Lavaca-Guadalupe Coastal basins) and several cities are rapidly extended. In case of the Lavaca river basin, there are many range land. Several habitat types wide-spread over three relatively larger basins and five wastewater discharge regions are located in there. There are different hazardous substances which have been released. Total nutrient loads are composed of land surface load and river load as Non-point source and discharge from wastewater facilities as point source. In 3 basins region, where point and non-point sources of poll Jtion may be a big concern, because increasing fertilizers and pesticides use and population cause. This project objective seeks to how to assess and control the accumulation of non-point and point source and discuss the main impacts of agriculture and environmental concern as non-point source with water quality related to pesticides, fertilizer, and nutrients and as point source with wasterwater discharge from cities. The GIS technique has been developed to aid in the point and non-point source analysis of impacts to natural resource within watershed. This project shows the losses in $kg/km^2/year$ of BOD (Biological Oxygen Demand), TN (Total Nitrogen) and TP (Total Phosphorus) in the runoff from the surface of 3 basins. In the next paper, sediment contamination will show how to evaluate in Estuarine habitats of these downstream.

• 한국관개배수논문집
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• 제18권2호
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• pp.54-65
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• 2011

This study was performed to analyze the influence of pollutant loads characteristics on the point and non-point sources in Saemangeum watershed area using Hydrological Simulation Program, Fortran (HSPF). The simulation items were flow, BOD, T-N, and T-P(2007~2010). The pollutant loads trend reflects the precipitation. Specifically, the point source loads were almost constant, but the non-point source loads were influenced in the precipitation. It was found that the effect of non-point source is larger than point source. The water quality had a clear trend by the season. However, pollutant loads did not show distinct seasonal changes. The reason is that the pollutant concentration is diluted by the increased flow at summer season. Therefore, it is important to control the non-point source in order to manage water quality in the region. For the management of Saemangeum lake, it is need to control of supplied pollutant loads from Saemangeum watershed.

• 한국지진공학회논문집
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• 제24권1호
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• pp.9-17
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• 2020

The stochastic point-source model has been widely used in generating artificial ground motions, which can be used to develop a ground motion prediction equation and to evaluate the seismic risk of structures. This model mainly consists of three different functions representing source, path, and site effects. The path effect is used to emulate decay in ground motion in accordance with distance from the source. In the stochastic point-source model, the path attenuation effect is taken into account by using the geometrical attenuation effect and the inelastic attenuation effect. The aim of this study is to develop accurate equations of ground motion attenuation in the Korean peninsula. In this study, attenuation was estimated and validated by using a stochastic point source model and observed ground motion recordings for the Korean peninsula.

• Membrane and Water Treatment
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• 제11권5호
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• pp.345-351
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• 2020

Eutrophication of surface waters is commonly caused by excessive inputs of nutrients such as nitrogen and phosphorus. Nakdong River basin was chosen as the study area to investigate the effect of point and non-point source pollution of nitrogen on eutrophication in water body. Non-point source inputs of nitrogen accounted for approximately 84% in the total nitrogen input of the upper Nakdong river watershed, which mainly consists of agricultural land and forests. However, point source inputs of nitrogen accounted for 58~85% in the total nitrogen input of the middle and lower watersheds, including urban area. Therefore, for watershed near urban area, control of point source inputs of nitrogen may be an optimal method to control eutrophication. In this respect, the enforcing reduction of nitrogen in the final effluent of wastewater treatment facilities is needed. On the other hand, to enact more stringent nitrogen regulations, the LOT (limit of technology) and environmental impact should be considered. In this study nitrogen data were analyzed to propose new nitrogen regulations.

• 환경영향평가
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• 제20권1호
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• pp.25-36
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• 2011

In this study, the accurate water quality analysis in rivers, including the non-point source is performed. First of all, watershed model, SWAT(Soil and Water Assessment Tool) was applied to analyze the impact of the non-point source in study area. And then, water quality analysis integrating the point source and the non-point source is implemented using QUALKO model. For more exact simulation, it should be the calibration and verification of variables and parameters which are needed for simulation. In addition, the importance of considering the non-point source was confirmed in river water quality simulation. BOD, TN, TP were analysed, and the results shows that BOD, TN and TP concentration was increased to 16.8%, 8.2% and 25.8% respectively. The more accurate estimate will be carried if use of reliable measurements and watershed simulation be done in models linking process. The suggested technique will improve the accuracy of the water quality analysis. The methodologies presented in this study will contribute to basin-wide water quantity and quality management.

• 상하수도학회지
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• 제33권6호
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• pp.457-467
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• 2019

Because non-point source pollution is very closely related to hydrological characteristics, its importance is highly emphasized nowadays along with accelerating climate change. Especially for Korea, the non-point source pollution and its control are entirely depending on runoff, precipitation, drainage, land use or development, based on geographical and topographical reasons of Korea. Many studies reported the physical (e.g., apparatus- and natural-type facilities, etc.) and chemical methods (e.g., organic and inorganic coagulants, etc.) of controling non-point pollutant source pollution, however, those are needed to be reconsidered along with climate change causing the unexpected patterns and amounts of precipitation and strengthen complexity of social community. The objectives of this study are to assess recent situations of non-point source pollution in Korea and its control means and to introduce possible effective ways of non-point source pollution against climate change in near future.

• 한국물환경학회지
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• 제24권4호
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• pp.465-472
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• 2008

Soil and Water Assessment Tool (SWAT) model was selected as a tool for assessing the effect of pollutant sources on the total loads from the Chungju Dam upstream watershed. The model was constructed through calibration of parameters related to nitrogen (N) and phosphorus (P), which was based on the runoff and sediment modeling performed in the previous research. Using this, the spatial and temporal pollutant loadings by source type were investigated. Results of this study indicated that in most forested upstream sub-watersheds, pollutant loadings from point sources were very low, and total loadings by point and non-point sources were also insignificant. On the other hand, in #14 sub-watershed including Jecheon city, the loadings by point source were relatively considerable. For the whole watershed, non-point sources accounted for 99% of sediment, 97% of N, and 93% of P loads. And monthly non-point source loadings were concentrated on rainy summer season, while point source loadings of N and P kept nearly constant throughout the year and were high on dry winter season relative to non-point source.

• 한국대기환경학회지
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• 제9권2호
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• pp.168-173
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• 1993

Air quality impacts of point and area sources were analyzed by using ISCST2 with wind speed and stability class combinations of SCREEN. Stack height was important in determining the impact of point sources. With the stack height reduced to 21m from 75m, the concentration in the vicinity increased several times in spite of decreasing the emission rate by half. When the emission rates were same, concentrations from an area source of 10m release height were slightly lower than those from a point source of 21m stack height at the plume centerline. Bur the area source resulted in larger area of high concentration. Concentration from the point source was high in neutral to slightly unstable conditions with strong winds in a short distance, and in stable conditions with weak winds in a long distance. Concentration from the area source decreased with distance from the source, and was high in stable conditions with weak winds.

• Journal of Electrical Engineering and Technology
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• 제12권3호
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• pp.1203-1210
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• 2017

Switched-inductor (SL) Z-source three-level inverter is a novel high power topology. The SL based impedance network can boost the input dc voltage to a higher value than the single LC impedance network. However, as all the neutral-point-clamped (NPC) inverters, the SL Z-source three-level inverter has to balance the neutral-point (NP) potential too. The principle of the inverter is introduced and then the effects of NP potential unbalance are analyzed. A NP balancing method is proposed. Other than the methods for conventional NPC inverter without Z-source impedance network, the upper and lower shoot-through durations are corrected by the feedforward compensation factors. With the proposed method, the NP potential is balanced and the voltage boosting ability of the Z-source network is not affected obviously. Simulations are conducted to verify the proposed method.