• Journal of Korean Society for Atmospheric Environment
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• v.22 no.1
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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.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.6 no.5
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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.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1992.11a
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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.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.5
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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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• v.16 no.2
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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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• v.17 no.E2
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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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.3
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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.

• Journal of Environmental Science International
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• v.22 no.9
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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.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.8
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• pp.1575-1580
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• 2017

The electric vehicle business is important because it can reduce 30% of the fine dust generated in the metropolitan area and it can solve the air pollution problem by replacing automobile exhaust gas from an internal combustion engine with eco-friendly electric cars. For the construction of the electric charging station infrastructure, which is the core part of the electric car business, we focus to select the optimal location of the electric car charging station in Seoul. The goal of this paper is to utilize and analyze the traffic statistics of T-Map navigation users data and Seoul Metropolitan Transportation Policy Department to deploy the electric cars charging station with optimal location to increase the efficiency. In this paper, the proposed algorithm is composed of two parts of electric charging station selection. First, we analyze real traffic statistics and area. Second, we utilize T-Map navigation data distribution. To select optimal electric charging station location, we apply these two algorithms.

• Journal of Internet Computing and Services
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• v.24 no.2
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• pp.47-56
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• 2023

Hydrogen energy is an eco-friendly energy that produces heat and electricity with high energy efficiency and does not emit harmful substances such as greenhouse gases and fine dust. In particular, smart hydrogen energy is an economical, sustainable, and safe future smart hydrogen energy service, which means a service that stably operates based on 'data' by digitally integrating hydrogen energy infrastructure. In this paper, in order to implement a data-based hydrogen charging station demand forecasting model, three hydrogen charging stations (Chuncheon, Sokcho, Pyeongchang) installed in Gangwon-do were selected, supply and demand data of hydrogen charging stations were secured, and 7 machine learning and deep learning algorithms were used. was selected to learn a model with a total of 27 types of input data (weather data + demand for hydrogen charging stations), and the model was evaluated with root mean square error (RMSE). Through this, this paper proposes a machine learning-based hydrogen charging station energy demand prediction model for optimal hydrogen energy supply and demand.