• 한국대기환경학회지
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• 제22권1호
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• pp.35-41
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• 2006

The steel foundries with electric arc furnaces handling metal scraps have recently gained an attention as a potential source of dusts. The present study focuses on the analysis of dust emissions and removals during furnace charging and melting processes by commercial CFD software named FLUENT. A body fitted grid system consisting of 880,000 meshes was first generated by Gambit for the electric arc furnace with the capacity of 60 ton/cycle and then FLUENT was invoked to solve the corresponding NavierStokers equation for the momentum, temperature and dust concentration. The entire processes from metal charging to metal melting were simulated to investigate the unsteady behaviors of fluid flows and dust concentrations. The model simulation results showed that as the top of the electric arc furnace opened for metal charging, hot plumes bursted out from the furnace rose strongly by buoyance and escaped mostly through the main hood. Therefore, the capacity of main hoods determined the vent efficiency in the metal charging process. As the furnace was closed after the metal charging and the metal melting processes was followed, the hot flow stream stretching from the furnace to the main hood was dissipated fast and the flow from the inlet of the bottom of the left hand side to the main and monitoring hoods constituted the main stream. And there was only a slow flow in the right hand side of the furnace. Therefore, the dust concentrations were calculated higher in the left hand side of the furnace, which was consistent with observations.

• 한국조명전기설비학회지:조명전기설비
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• 제6권5호
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• pp.50-56
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• 1992

This paper presents the effect of moisture and dust on streaming electrification in transformer oil, in order to investigate the electrification tendency of oil adding moisture an dust. Authors designed series electrification device to analyse streaming electrification phenomena easily. Experimental results show that the streaming current is linearly increased with oil velocity and it has a peak value at about a 50 [%]. Adding of moisture and dust in oil decreased charging level and it was dominant in case of moisture.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1992년도 추계학술발표회논문집
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• pp.60-63
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• 1992

This paper presents the effect of moisture and dust on streaming electrification in transformer oil, in order to investigate the electrification tendency of oil adding moisture and dost. Authors designed series electrification device to analyse streaming electrification phenomena easily. Experimental results show that adding of moisture and dust in oil decreased charging level and it was dominant in case of moisture.

• 한국기계가공학회지
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• 제21권5호
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• pp.40-45
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• 2022

In recent years, indoor air pollution has become a crucial environmental problem. Hence, the purification of indoor air is an important issue. Typical physical filters show relatively high dust collection efficiency at a dust particle size of more than 5.0 ㎛ but extremely low efficiency at an ultrafine size of less than 2.5 ㎛. In this study, an electric field filter was proposed to capture ultrafine dust with a size of less than 5.0 ㎛. Simulation results showed that the electric field filter effectively removed ultrafine dust. In addition, sufficient dust collection efficiency was obtained even with a simple plate-shaped filter without bending the Chevron filter.

• Design & Manufacturing
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• 제16권2호
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• pp.13-19
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• 2022

Recently, electric vehicles are gaining popularity among many domestic and foreign users due to their eco-friendly advantages of reducing fine dust and environmental greenhouse gases. As the demand and supply of electric vehicles increase, the demand for electric vehicle charging infrastructure is also growing together. Many users are experiencing inconvenience due to poor charging infrastructure, which makes them hesitant to buy electric vehicles. Research on the user experience of chargers in apartment complexes, a common residential type in Korea, is being conducted somewhat, but research on the design of electric vehicle charging devices in public places is insufficient. The purpose of this research is to identify user requirements and complaints based on the product design of the electric vehicle charger in public places and propose a new electric vehicle product design concept that meets the requirements. The research method understood the charging base and status of electric vehicles in public places through literature research and examined and analyzed the characteristics and problems of product design cases that improved the charging problem of electric vehicles recently released in the market. It is intended to identify and analyze the problems of the charging device product design through user interviews, a qualitative research method, and based on this, it is intended to propose a user-centered product design concept that improves major complaints.

• Journal of Korean Society for Atmospheric Environment
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• 제17권E2호
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• pp.53-59
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• 2001

A hybrid dust-collector combining electrostatic charging with fabric filtration method was developed, and its performance characteristics were evaluated in this study. Charged particles build porous dendritic structure on the surfaces of filter by electrostatic attraction, increasing the collection efficiency of dust particles and reducing the pressure drop through the deposited dust layer and filter media. The cleaning performance of the dust layer is improved because the dendritic structured dust layer can be removed more easily by pulse jet cleaning flow. The results of the experiment showed a reduction of fine particle emission of 37% and the energy saving of 13% by precharging dust particles before filtration.

• 전기학회논문지
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• 제67권3호
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• pp.343-351
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• 2018

Renewable energy sources has drawn considerable attention as clean energy sources because of changing public attitudes regarding greenhouse gas and fine dust. Recently, in this respect, the government provides the drivers of electric vehicles with various benefits such as tax reduction, financial incentives and free parking from the public to the private sector. Plug-in electric vehicles are the most common in the private sector. Otherwise, different types of battery-based buses in the public sector are being developed, and there are three main types of charging: plug-in, battery swapping and wireless. Therefore, economic assessment of charging types in each bus route is required in order to facilitate the use of battery-based buses instead of the existing CNG buses. In this paper, net present value(NPV) and B/C ratio of charging types are evaluated in consideration of the bus schedule, the cost of charging station, and the life cycle of battery, etc. per each bus route. In case study, main bus routes in Daegu City are simulated with the proposed evaluation method to validate the eco-bus project.

• 한국환경과학회지
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• 제22권9호
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• pp.1187-1197
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• 2013

The result of a small electrostatic precipitator which is in order to decrease indoor air pollution for optimal efficiency was shown as follows. Although the closer distance between the discharge electrode and dust collecting electrode shows the better throughput efficiency by forming strong electrostatic Field, it does not have profound impact in case of optimal dust collecting area. G.P(gas passage) which is the distance from dust collecting electrode to dust collecting electrode is a crucial factor to decide dust collecting efficiency. The narrower distance of G.P shows the better throughput efficiency whereas it decreases when the distance is too narrow since sparks ensue by increasing the capacity of electrostatic charging system 5 mm regards as optimal efficiency in this experiment. Although the higher voltage shows the higher dust collecting efficiency overall, the experiment was not able to keep performing since the sparks which decrease dust collecting efficiency ensue over 40 kV. The efficient and safe voltage state is considered 3.6 kV in this experiment. The most crucial factor for dust collecting efficiency of an electrostatic precipitator which is in order to decrease indoor air pollution is applied voltage. In addition, optimal raw gas flow rate(2.4 m/sec) is more important factor than the excessive increase of dust collecting area.

• 한국정보통신학회논문지
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• 제21권8호
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• pp.1575-1580
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• 2017

전기자동차 사업은 수도권에 발생하는 미세먼지의 30%를 감소시킬 수 있는 중요한 사업이고, 인체 위해도가 높은 자동차 배출가스를 내연기관에서 친환경 전기자동차로 대체하여 대기오염 문제를 획기적으로 해결할 수 있다. 이러한 전기자동차 사업의 핵심인 충전인프라 구축과 관련하여 서울시 내의 전기자동차 충전소 최적의 위치를 선정하고자 한다. T-Map 네비게이션 사용자 데이터 (위도, 경도, 위치) 분포와 서울시 교통정책과의 교통량 통계를 이용하였고, 최적의 위치에 전기자동차 충전소를 배치하고, 효율을 높이는 것에 본 논문의 목적이 있다. 본 논문에서 제안한 알고리즘은 두 가지 충전소 위치 선정 방식을 포함한다. 첫 번째는 교통량 및 권역을 이용한 방식이고, 두 번째는 T-Map 데이터 분포를 이용한 방식이다. 실제 충전소 위치 선정 시 두 가지 방식을 모두 고려하여 선정하게 된다.

• 인터넷정보학회논문지
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• 제24권2호
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• pp.47-56
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• 2023

수소 에너지는 높은 에너지 효율로 열과 전기를 생산하면서도 온실가스와 미세먼지 등 유해물질 배출이 없는 친환경 에너지로서, 전 세계적으로 탄소중립으로의 전환을 위한 핵심으로 주목받고 있다. 특히 스마트 수소에너지는 경제적이고 지속 가능하며, 안전한 미래 스마트 수소에너지 서비스로써 수소 에너지의 기반 시설이 디지털로 통합되어 '데이터' 기반으로 안정적으로 운영되는 서비스를 의미한다. 본 논문에서는 데이터 기반 수소 충전소 수요예측 모델 구현을 위해 강원도 내 설치되어 있는 수소 충전소 3곳(춘천, 속초, 평창)을 선정, 수소 충전소의 수요공급 데이터를 확보하였고, 머신러닝 및 딥러닝 알고리즘 7개를 선정하여 총 27종 입력 데이터(기상데이터+수소 충전소 수요량)로 모델을 학습하였고, 평균 제곱근 오차(RMSE)로 모델을 평가하였다. 이를 통해 본 논문에서는 최적의 수소 에너지 수요공급을 위한 머신러닝 기반 수소 충전소 에너지 수요 예측 모델을 제안한다.