• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.9
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• pp.421-426
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• 2005

A wire-plate discharge system with a slit barrier has been proposed and investigated experimentally by focusing on the discharges on the slit barrier and ozone generation characteristics. This wire-plate discharge system with a slit barrier can generate an intensive corona discharges, and produce corona discharge twice, once from the corona wire electrode and second time from the surface and the slits of the slit dielectric barrier. As a result this propose wire-plate discharge system with the slit barrier can produce greatly increased ozone than without the slit barrier. This type of wire-plate discharge system with the slit barrier could be used for effective ozone generation as a means with retard to the removal of pollutant gas

• Journal of the Korean Vacuum Society
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• v.16 no.5
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• pp.383-387
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• 2007

In this paper the design of the discharge cleaning system for KSTAR vacuum vessel is described. We first discuss about the parameters which are related the efficiency of discharge cleaning. The RG(RF-assisted Glow) discharge which has the ignition and sustain pressure lower than those in the case of DC discharge, thus has the higher efficiency of discharge cleaning. So we adopt the RG discharge, in practical design, for KSTAR discharge cleaning system. For uniformity of the cleaning effect, we plan to install two discharge cleaning systems in A- and I-port of the KSTAR vacuum vessel. The designed system will be adapted for the study of the fuel recycling and of the boronization as well as the discharge cleaning of the KSTAR vacuum vessel.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.488-493
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• 2006

Accurate river discharge is the most important factor in managing river basins and for successfully maintaining total maximum daily loads in Korea. It is not easy to measure the discharge directly in large rivers owing to physical and environmental constraints, even after investing much time and money. Recently, to overcome these historical drawbacks in river discharge measurement, we have developed the Automatic Discharge Acquisition & Management System (ADAMS) that scans the river cross-section and measures each cell $(1m{\times}1m)$ velocity using HADCP. The hardware system is composed of an HADCP sensor and winch, as well as a PC and software system for the discharge calculation module and hardware control module. It is controlled remotely via the internet and uses the velocity-depth integration method and the velocity-contour method for calculating river discharges. The characteristics of ADAMS are a ubiquitously accessible system, featuring real time automatic discharge measurement, remote control via the internet. The results using ADAMS at the Jindong stage site show less than 5% uncertainty and are 4 times more efficient than the ADCP & Q-boat system. This system can be used to measure any large river, river mouth or tributary river affected by backwater, all of which have a very difficult measuring real time discharge. The next generation of ADAMS will feature an upgrade to increase portability and GPS integration.

• Journal of Korean Society on Water Environment
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• v.24 no.4
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• pp.452-457
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• 2008

Nonpoint source (NPS) pollution is caused by rainfall moving over and through the ground. As the runoff moves, it picks up and carries away various pollutants from NPS. The discharge pattern of NPS pollutant loads is affected by the distribution of the rainfall during the year. This study analysed relationship between the rainfall event and the stream flow rate, and estimated the rainfall discharge ratio on the specific design flow which can be used as nonpoint discharge coefficient for the estimation of NPS pollution load. It is considered that nonpoint discharge coefficient can be effectively used for the calculation of NPS pollution load at the time of water quality modelling for the management of Total maximum daily load (TMDL).

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.261-262
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• 2011

본 연구는 HMDS/$O_2$/He/Ar의 gas mixture를 이용하여 remote-type의 DBD source를 통한 APPECVD를 통한 SiOx 양질의 무기막 증착 공정을 개발하였다. 이때 기판에 바이어스를 인가 하거나 혹은 접지를 하여 대기압 플라즈마의 환경 내에서도 바이어스 효과를 확인할 수 있도록 double discharge system을 구축하였다. 그리고 이 double discharge system의 다양한 특성과 기존의 전형적인 DBD와 비교 하였을 때 어떠한 차이점을 가지는지에 대해서도 관찰하였다. 그리하여 전형적인 DBD system과 double discharge를 통해 증착된 SiOx 무기막의 특성을 역시 비교 관찰하였다. Gas mixture 중 HMDS의 유량이 증가함에 따라, 그리고 $O_2$ gas의 유량이 감소함에 따라 SiOx 무기막의 증착률은 감소하였다. 그러나, SiOx 무기막 내의 불순물들, 예를 들어, carbon 혹은 hydrogen 계열의 chemical bond에 대한 정성적인 양은 HMDS 의 유량이 증가하거나 혹은 $O_2$ gas의 양이 감소함에 따라 오히려 증가함을 관찰할 수 있었다. 그리고 기판에 바이어스를 인가하는 double discharge system을 사용하였을 경우, 같은 HMDS, $O_2$ gas 유량을 사용한 전형적인 DBD type의 증착 공정 보다 더 높은 공정 효율을 나타냄과 동시에 더 낮은 불순물 함량을 가짐을 알 수 있었다. 이러한 double discharge system을 통해 증착된 양질의 SiOx 무기막이 증착 되었음을 FT-IR을 통한 막질 분석을 통해 확인 할 수 있었다. 이러한 double discharge system의 증착 공정에 대한 긍정적인 효과들은 atmospheric discharge의 효율 향상에 따른 gas dissociation efficiency 증가와 이를 통한 HMDS 분해 및 산소와의 recombination 효율의 증가에 따른 결과로 사료된다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.4
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• pp.783-787
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• 2009

A point-to-mesh type discharge system, utilizing a water-pen point as a corona discharge electrode and a mesh as an ion induction electrode, has been proposed, and the effect of the water-pen point electrode of the discharge system to the ionic wind velocity and generation yield was investigated. It was observed that the proposed discharge system with the water-pen point electrode can generate a higher ionic wind velocity as compared with that of the metal point electrode. As a result, the peak ionic wind velocities of 2.61 and 4.05 m/s for the positive and negative corona discharges of the proposed discharge system can be obtained, which are 1.39 and 1.15 times higher than those of the metal point electrode with same design. The ionic wind generation yield of 4.72 m/s/W of the discharge system with the water-pen point electrode was obtained for the positive corona, which was 3.66 times higher than that of the metal point electrode. This enhancement may be due to the effect of the water-pen point electrode.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.151-155
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• 2007

A compact discharge plasma system with a photocatalyst has been proposed and investigated experimentally for application to air conditioners. It was found that there was intense ultra violet radiation with high energy of 3.2 eV from the corona discharge due to the DC-biased pulse voltage applied on a wire. An electrophotochemical reaction took place apparently on the surfaces of the photocatalyst of $TiO_2$ irradiated ultra violet front the discharge plasma in the proposed plasma system. The proposed discharge plasma system with the photocatalyst of $TiO_2$ showed very high removal efficiency of VOCs by tile additional electrophotochemical reactions on the photocatalyst. The proposed discharge plasma system also showed very high removal efficiency of particles such as smokes, suspended bacteria, and pollen and mite allergens by the electrostatic precipitation part. This type of corona discharge plasma system with a photocatalyst can be used as an effective means of removing both indoor pollutant gases and particles including suspended allergens.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.5
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• pp.482-489
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• 2002

This paper studies the stand-alone photovoltaic system for the solar lighting lamp. The solar lighting lamp has PV modules, batteries, and charge & discharge system. The charge efficiency is improved for the control of each battery which is divided the charge from the discharge to change the structure of existing solar lighting lamp charge & discharge system. so, the charge and discharge times are reduced of 50% and the depth of discharge control can be controlled in the discharge cut off voltage. It can be effective of the battery use. If a battery is out of order, this system can be executed for a regular period. So we saved the repair cost and developed of system's stabilization. It Is possible to make economical effects to apply for solar lighting lamp used photovoltaic system.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.6
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• pp.323-327
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• 2006

In this paper a new wire-wire discharge system with a slit dielectric harrier has been proposed, and, its corona discharge and ozone generation characteristics have been investigated experimentally. When the slit mica barrier is installed between corona wires, instead of the grounded plate electrode, a significant increase in the generation of ozone, about 2.2 times higher than that of the conventional ones without the slit harrier, could be obtained. Photographs show that this type of discharge system with a slit barrier was found to produce a corona discharge twice, once from the upper and bottom corona wires, and. again from both sides of surfaces and slits of the slit barrier. As a result, the proposed discharge system has the potential to increase significantly ozone production and it may be useful as an effective means for removing pollutant gases.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.11
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• pp.1512-1516
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• 2018

The power system and control system constantly reveals surge voltage such as switching surge of lighting devices and power conversion devices, operating and stops surge of rotating devices, charge & discharge surge, opening & closing surge of circuit breakers and the like. Such a surge voltages can cause damage or malfunction of the element such as CPU, Memory, semiconductor etc. In the industry, in order to protect the system from the surge voltage, a surge protector with low discharge starting voltage, fast response time, and low capacitance is required, and technical development research for that is ongoing. In this paper, in order to solve the problem of the existing GDT discharge tube not discharging from the transient voltage which is higher than the commercial voltage and lower than the discharge voltage of the discharge element, we have developed a discharge element having the control electrode & control circuit. The discharge element having the control electrode and the control circuit can control the discharge voltage according to the needs of the consumer and can satisfy the requirement of the discharge element and the technology of the surge protector downsizing technology and the surge protection technology. It is judged to be effective for development.