• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.6 no.3
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• pp.237-246
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• 1994

Experimental data are reported for charging and collection of NaCl aerosols in the 0.03- to $0.2{\mu}m$-geometric-mean-diameter range in 2-stage parallel-plate electrostatic precipitators. The NaCl aerosols are generated with geometric standard deviation of about 1.74 and particle generation rate of about 10^9 particles/see by the constant output atomizer and injected into the air flow in the clean wind-tunnel. The 2-stage parallel-plate electrostatic precipitator installed in the test section of the wind-tunnel is operated with a positive corona discharge. The NaCl aerosols in the channel flow are sampled and transported to the aerosol particle number concentration measurement system by using the isoaxial sampling and transport system constructed based on the Okazaki and Willeke design. The aerosol particle number concentration measurement system measures the size distribution of submicrometer aerosols by an electrical mobility detection technique. It is confirmed from comparing the measured collection efficiencies in this study and the predicted ones by our previous theoretical analysis that the predicted collection efficiencies agree well with the experimental ones. It is also found from the comparison that below about $0.02{\mu}m$ all particles are not charged and the uncharged particles are not collected, and consequently 2-stage parallel-plate electrostatic precipitators are not suitable for that particle size range.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.80-83
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• 2008

As SOC (Social Overhead Capital) has been expanded, the highway road construction has been accelerated and city road system has been more complicated. So, long road tunnels have been increased and traffic flow rate also has been raised. Accordingly, the exhausting gas of vehicle cars seriously deteriorates the tunnel inside air quality and driving view. In order to improve tunnel inside air quality, we may need to introduce a compulsory ventilation system as well as natural ventilation mechanism. The natural ventilation mechanism is enough for short tunnels, meanwhile longer tunnels require a specific compulsory ventilation facility. Many foreign countries already have been devoting on development of effective tunnel ventilation system and especially, some European nations and Japan have already applied their developed tunnel ventilation system for longer road tunnels. More recently, as the quality of life improved, our concerns about safety of driving and better driving environment have been increased. In order to obtain clearer and longer driving view, we are more interested in EP tunnel ventilation system in order to remove floating contaminants and automobile exhaust gas. Evan though it's been a long time since many European countries and Japan applied more economical and environment-friendly tunnel ventilation system with their self-developed Electrostatic Precipitator, we are still dependant on imported system from foreign nations. Therefore, we need to develop our unique technical know-how for optimum design tools through validity investigation and continuous possibility examination, eventually in order to localize the tunnel ventilation system technology. In this project, we will manufacture test-run products to examine the performance of system in order to develop main parts of tunnel ventilation system such as electrostatic precipitator, high voltage power generator, water treatment system, etc.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1238-1243
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• 2009

As Social Overhead Capital(SOC) has been expanded, the highway road construction has been accelerated and city road system has been more complicated. So, long road tunnels have been increased and traffic flow rate also has been raised. Accordingly, the exhausting gas of vehicle cars seriously deteriorates the tunnel inside air quality and driving view. In order to improve tunnel inside air quality, it is needed to introduce a compulsory ventilation system as well as natural ventilation mechanism. The former, that is, a special compulsory ventilation facility is very useful and helpful to prevent a tunnel of being contaminated by traffic in most case. In the case of obtaining clearer and longer driving view, the ventilation systems have to be considered in order to remove floating contaminants or exhaust gas from engines. In this paper, discharge electrode design technology will be discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.288-288
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• 2009

Most of Static electricity forms part of our daily experience broadly. Most people have noticed from time to time electric shocks when closing of their car or after walking across a carpet, operating shredder in winter and touching a metal handle. This electrostatic discharge nuisance is normally a minor inconvenience, but in some cases static electricity can cause more serious problems. Static electricity can also be harnessed to good effect in Position Control System.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1997.05a
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• pp.77-82
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• 1997

현대 사회는 첨단 산업의 발전으로 공장내에서 발생되는 정전기를 적절히 제어하지 않으므로 여러 형태의 산업재해와 생산성 저하등의 장ㆍ재해로 인한 많은 피해가 발생되고 있다. 특히 정전기 방전 (Electrostatic Discharge)(1) 중에서 인체의 대전으로 인한 방전 현상은 다른 물체의 대전으로 인한 정전기 방전 문제보다 더 심각하게 취급하여 이에 대한 정량적 해석 및 그 위험성을 올바르게 인식하는 것이 필요하다. 본 논문에서는 대전 인체와 근접 물체간의 방전 현상을 규명하기 위하여 인체와 근접물체의 정전 용량을 측정하여 이와 동일한 정전 용량을 가지는 구로 모델링한 two-body 문제로 정전기 현상을 해석하고자 한다. (중략)

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.93-94
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• 2008

In order to suppress the current crowding in light emitting diodes (LEDs) grown on sapphire substrate, the effect of nonuniform contact resistivity between TME layer and p-GaN layer on the LED surface was theoretically investigated. The analysis results showed that current crowding occurring around p-electrode could be considerably improved, which in turn would be helpful to improve the electrostatic discharge (ESD) characteristic.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1370-1371
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• 2006

An electrostatic discharge (ESD) protection device, so called, N-type extended drain silicon controlled rectifier (NEDSCR) device, was analyzed for high voltage I/O applications. A conventional NEDSCR device shows typical SCR-like characteristics with extremely low snapback holding voltage. This may cause latchup problem during normal operation. However, a modified NEDSCR device with proper junction / channel engineering demonstrates itself with both the excellent ESD protection performance and the high latchup immunity.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1372-1373
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• 2006

An electrostatic discharge (ESD) protection device, so called, N-type SCR with P-type MOSFET pass structure (NSCR_PPS), was analyzed for high voltage I/O applications. A conventional NSCR_PPS device shows typical SCR-like characteristics with extremely low snapback holding voltage, which may cause latchup problem during normal operation. However, a modified NSCR_PPS device with proper junction/channel engineering demonstrates highly latchup immune current- voltage characteristics.

• Journal of Environmental Science International
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• v.26 no.2
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• pp.231-238
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• 2017

Rapid industrial development has led to a serious problem of pollution in the industrial sector. With the increasing social need for environmental protection, research on air pollution prevention equipment for reducing pollutants in industrial processes is actively being undertaken. The deterioration of existent, installed facilities, their increased emission rates, and the strengthening of the effluent quality standards make complying with permissible emission standards difficult. In fact, installing new electric precipitators or complementing existent facilities is inevitable. The expansion and complementation of the installed electrical precipitators have led to improvements in dust collection efficiency, shorter working times, and lower costs. Because of its easy installation and simple manufacturing process, the production method with the discharge electrode of an electric precipitator is widely used. The following conclusions were reached by classifying discharge electrodes into four types based on the production method and mutually comparing them by their dust collection efficiency. None of the four types used in this study were damaged by impact. However, we were able to confirm some strain from the compression sites of both type A and type B. Both type B and type C are expected to have greater dust collection efficiencies than the other models due to their large vibration transmissibility. Moreover, the high vibrational energy is expected to cause rapping damage during its operation. Particularly, in the case of type B, some of the strain was found at the end of the compression site. The coupling schemes of both type C and type D are out of vibration transmissibility. On the other hand, the ability to maintain straightness and solidity of the side is regarded as outstanding and stable. Type D has outstanding on-site workability, considering the presence of locking, structural stability, and work conditions. From these experiments, we determined that type C is the most ideal connection method of discharge electrode, considering its construction period of renovation. Type C is inferior to type D with regard to on-site workability. However, type C has outstanding dedusting transmission with regard to the straightness, solidity maintenance, and vibration of shearing stress.

• Journal of Industrial Technology
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• v.18
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• pp.249-258
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• 1998

In this paper, we investigated the post-combustion removal of nitrogen oxide($NO_x$) and sulfur oxide($SO_x$) which is based on the gas to particle conversion process by the pulsed corona discharge. Under normal pressure, the pulsed corona discharge produces the energetic free electrons which dissociate gas molecules to form the active radicals. These radicals cause the chemical reactions that convert $SO_x$ and $NO_x$ into acid mists and these mists react with $NH_3$ to form solid particles. Those particles can be removed from the gas stream by conventional devices such as electrostatic precipitator or bag filter. The reactor geometry was coaxial with an inner wire discharge electrode and an outer ground electrode wrapped on a glass tube. The simulated flue gas with $SO_x$ and $NO_x$ was used in the experiment. The corona discharge reactor was more efficient in removing $SO_x$ and $NO_x$ by adding $NH_3$ and $H_2O$ in the gas stream. We also measured the removal efficiency of $SO_x$ and $NO_x$ in a cylinder type corona discharge reactor and obtained more than 90 % of removal efficiency in these experimental conditions. The effects of process variables such as the inlet concentrations of $SO_x$, $NH_3$ and $H_2O$, residence time, pulse frequencies and applied voltages were investigated.