• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.89-92
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• 2001

Silent gas discharge method has been widely applied for ozone production, ultraviolet light and UV laser generation. Since ozone and ultraviolet applications have tendency to spread widely in industry, the development of efficient and low-cost power supply for such systems is a task of great impotency. This paper introduces high-frequency inverter type mode power supply designed for ozone generation tube and ultraviolet generation excimer lamp and considerations on this inverter and pulse density modulation control strategy applied in it.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.12
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• pp.55-61
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• 1998

Recently, the needs of machining technologies of very small parts have been increasing with advent of micro-revolution. These technologies have mostly used the method applied to semi-conductor production process such as LIGA, etc. But they have serious difficulties to settle down in terms of workpiece materials, machining thickness, 3-dimensional structure. Therefore. mciro-machining technology using EDM(Electrical Discharge Machining) was proposed. It is very difficult to machine the micro-parts (microshaft, microhole) using conventional machining. Micro-machining using BDM can machine the micro-parts easily because it requires little machining force. This MEDM(Micro-EDM) need the capabilities to move a electrode and control a discharge energy precisely, and the gap control strategy to maintain the optimal discharge condition is necessary. Therefore, in this study, the new EDM machine with high precision motion stage and high-performance EDM device was developed. Using this MEDM machine, we have machined microshaft and microhole with various shapes and sizes.

• Journal of Power Electronics
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• v.2 no.3
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• pp.206-211
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• 2002

Silent gas discharge method has been widely applied fur ozone production, ultraviolet light and UV laser generation. Since ozone and ultraviolet applications have tendency to spread widely in industry, the development of efficient and low - cost power supply for such systems is an important task at present. This paper introduces high-frequency inverter type mode power supply designed fur ozone generation tube and ultraviolet generation excimer lamp and considerations on the design of the inverter and pulse density modulation control strategy applied in it.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.3
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• pp.101-105
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• 2004

The efficient power MOSFET inverter applied for a simple and low cost power supply is proposed for driving the dielectric barrier discharge (DBD) lamp load. For decades, the DBD phenomenon has been used for ozone gas production in industry. In this research, the ultraviolet and visible light sources utilizing the DBD lamp is considered as the load for solid-state high frequency power supply. It is found that the simple voltage-source single-ended quasi-resonant ZVS inverter with only one active power switch could effectively drive this load with the output power up to 700 W. The pulse density modulation based control scheme for the single-ended quasi-resonant ZVS inverter using a low voltage and high current power MOSFET switching device is proposed to provide a linear power regulation characteristic in the wide range 0-100％ of the full power as compared with the conventional control based Royer type parallel resonant inverter type power supplies.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.6
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• pp.703-712
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• 2019

In this study, capability of an air slot in a siphon spillway for controlling outflow discharge is investigated through hydraulic experiments. Arc and rectangular shapes of air slot are considered and the open area of air slot can be varied. Complex air-regulated flow occurs inside of the siphon spillway when the air slot is installed on it. The same discharge is measured at the same water level inside the reservoir when the water level rises or falls. Nondimensional discharge through the siphon spillway decreases as nondimensional open area of the air slot increases when head differences and water levels of reservoir are constant. The hydraulic experiments show that the control of outflow discharge of siphon spillway is possible by controlling the open area of the air slot.

• Korean Journal of Health Education and Promotion
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• v.20 no.3
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• pp.269-280
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• 2003

This study was conducted to identify the effects of telephone consulting follow- up on self care behaviors and self efficacy in diabetic patients after discharge. The subjects for this study were consisted of 39 patients and twenty subjects assigned to the experimental group received the telephone consulting follow-up after discharge once a week during 4 weeks with diabetic education before discharge and nineteen subjects assigned to the control group received diabetic education before discharge without telephone consulting follow-up. The results of this study are as follows： 1. The experimental group which received the telephone consulting had higher self care behaviors scores than the control group (t＝4.92, p＝.00). 2. The experimental group which received the telephone consulting had higher self efficacy scores than the control group (t＝4.71, p＝.00). 3. The relationship between self efficacy and self care behaviors showed a significant correlation in the subjects. In conclusion, the telephone consulting follow-up improved self care behaviors and self efficacy, therefore this intervention can be effective in promoting the care of diabetic patients

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.239-246
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• 2014

Incineration is conceptually sound as a waste treatment technology. There is, however, concern over its emissions when it is improperly designed and operated. An electrostatic precipitator is one of the most commonly used devices to control particulate emissions from boilers, incinerators and some other industrial processes. In this work, a modular electrostatic precipitator with sizing of $1m{\times}1m{\times}1m$ was developed for removal of particulate matter from the exhaust gases of a small waste incinerator. Its design was based on a simple wire-and-plate concept. The corona discharge wires were connected to a positive high-voltage pulse generator, while the collection plates were grounded. The high-voltage pulse generator was used to produce the corona discharge field between the individual discharge wire and the collection plate. The particulate-laden exhaust gas flow was directed across the corona discharge field. The charged particles were deflected outward and collected on the plate. The collection efficiency was evaluated as a mass loading ratio between the difference at the inlet and the outlet to the particulate loading at the inlet of the precipitator. The collection efficiency of this modular electrostatic precipitator design was approximately 80 %.

• Journal of Korean Society for Atmospheric Environment
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• v.11 no.2
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• pp.185-190
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• 1995

Recently, because of the worse of the air pollution, the excessive airtught of building and the inferiority of air conditioning system, the development of high efficiency air purification technology was enlarged to the environmental improvement of an indoor or a harmful working condition. The air purification technology has used chemical filters or charcoal filters or charcoal to remove hazardouse gaseous pollutants (SO$_{x}$, NO$_{x}$, NH$_{3}$, etc.) by air pollutant control technology, but they have many problems of high pressure loss, short life, wide space possession, and treatment of secondary wastes. For these reason, the object of reasearch shall be hazardous gaseous pollutants removal by the surface discharge induced plasma chemical process that is A.C. discharge of multistreams applied A.C. voltage and frequency between plane induced eletrode and line discharge eletrode of tungsten, platinum or titanium with a high purified alumina sheet having a film-like plane. As a result, the control performance for hazardous gaseous pollutants showed very high efficiency in the normal temperature and pressure. Also, after comtact oxidation decomposition of harmful gaseous pollutants, the remainded ozone concentration was found much lower than that of ACGIH or air pollution criteria in Korea.rea.

• Journal of East-West Nursing Research
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• v.16 no.1
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• pp.1-10
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• 2010

Purpose: This study tested the effects of Nei-Guan acupressure on nausea, vomiting, and anorexia of lung cancer patients on chemotherapy. Methods: A nonequivalent control group pre-post test design was used to identify the effect of Nei-Guan acupressure on nausea, vomiting, and anorexia of lung cancer patients on chemotherapy. The participants were 60 patients who were admitted to a hospital for chemotherapy from February 1 to October 28, 2009. The patients were randomly assigned to the control group (n=30) or experimental group (n=30). The data were analyzed using Mann-Whitney test. Results: Nausea, vomiting, and anorexia were significantly decreased in the experiment group compared to the control group on the day of discharge from the hospital. However, the levels of nausea, vomiting, and anorexia between two groups were not statistically significant seven days after the discharge. Conclusions: Nei-Guan acupressure is effective in decreasing nausea, vomiting and anorexia of the patients with lung cancer on chemotherapy on the on the day of the discharge while the effectiveness is not certain 7 days after the discharge. Further study is needed to confirm these findings.

• Journal of Digital Convergence
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• v.16 no.12
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• pp.309-315
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• 2018

In this paper, propose an efficient arc detection and control method to achieve fast machining speed, improved precision and surface roughness in discharge machining, especially for carbide and hard material processing and metal processing using discharge phenomenon as energy. A single discharge waveform is divided into three sections of Td (Time-Delay), Ton (Time-on) and Toff (Time-off) and the gate control timing is simulated using the HDL language. In this paper, we analyze the effect of the gap between the electrode and the workpiece on the machining results by determining the operation of the servo mechanism by sampling the Td section through the comparator circuit. As a result of the analysis, the Td section of the formed waveform was more precisely sampled at a high speed and the results were improved when applied to the gap control between the electrode and the workpiece.