• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1737-1739
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• 1998

The paper presents experimental results of Partial Discharge(PD) in Gas Insulated Switchgear(GIS), obtained using a computer-aided PD measurement system. Different discharge sources are simulated and identified. These included internal, interface, surface and protrusion. For internal discharge, it showed symmetrical discharge type between positive and negative cycle. Interface discharge showed smaller number and higher peak than internal discharge but symmetrical discharge as well. For surface discharge, it showed small number and high peak in positive half cycle but large number and low peak in negative half cycle. For protrusion discharge, small number and high peak of discharge were shown only in negative half cycle.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.7
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• pp.533-541
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• 1999

Multi-discharge type ozonizer(MDO) using superposed silent discharge has been designed and manufactured. It consists of three electrodes( central electrode, internal electrode, and external electrode ) and double gaps( gap between central electrode and internal electrode, gap between internal electrode and external electrode ). Therefore, ozone is generated by superposing silent discharges generated between the gaps respectively. And the MDO consists of three types of superposed discharge ozonizers according to voltage appling method for each electrode ; A.C. high voltages are applied two of three electrodes with phase difference of 180[˚], the other electrode is a ground. This paper describes that discharge and ozone generation characteristics of MDO which comprising central electrode and internal electrode applied A.C. high voltages with phase difference of 180[˚] respectively, and the grounded external electrode. As a result, the maximum ozone concentration, generation, and yield can be obtained 10208[ppm], 6.4[g/h], and 280[g/kwh] respectively.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.5
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• pp.60-67
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• 2005

The superposed discharge type ozonizer of high ozone concentration using vacuum discharge tube has been designed and manufactured. It consists of three electrodes(central electrode, internal electrode, and external electrode) and one discharge gap(discharge gap between internal electrode and external electrode), is a superposed silent discharge type ozonizer for which the AC high voltages applied to the central electrode within discharge tube and the internal electrode has a $180{[^\circ]}$ phase difference and for which the external electrode is a ground. Ozone is generated by overlapping silent discharge between central electrode and external electrode, and silent discharge between internal electrode and external electrode. At the moment, discharge characteristics and ozone generation characteristics were investigated in accordance with vacuum of discharge tube, discharge power of ozonizer, and quantity of supplied oxygen gas. In consequence, high ozone concentration can be obtained 8840[ppm].

• The Journal of Internal Korean Medicine
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• v.27 no.3
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• pp.572-578
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• 2006

Objectives : This study investigated whether taking herbal medicine over the long-term had any side effects of liver damage. Methods : We checked LFT levels of the 58 admitted patients. Results : When we compared admission LFT levels with discharge LFT levels, we found the levels of AST, ALT and LDH had decreased. This test showed statistically significant decrease. When we compared admission LFT levels with discharge LFT levels, we found the increases of discharge LFT levels fell within the standard deviation. When we compared admission LFT levels with discharge LFT levels, we found the levels of LFT did not increase as much as two standard deviations. Conclusions : According to the above results, taking herbal medicine over a long-term did not have any side effects of drug-induced liver damage.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2259-2261
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• 1999

In this paper, an ozonizer, which can generate individual and superposed silent discharge, using three-phase voltage has been designed and manufactured. The ozonizer consists of 3 electrodes(Central Electrode, Internal Electrode and External Electrode) and 2 gaps(gap between Central Electrode and Internal Electrode, gap between Internal Electrode and External Electrode). Ozone is generated according to voltage supplying method to each electrode by individual silent discharge and three-phase superposed discharge. The characteristics of ozone generation were investigated with variation of discharge power and the quantity of supplied gas($O_2$). In case of individual silent discharge, the maximum values of ozone concentration, ozone generation and ozone yield were obtained between internal electrode and external electrode, and its values were 2300[ppm], 570[mg/h] and 745[g/kWh] respectively. Each maximum values was 5039[ppm], 1773[mg/h] and 851[g/kWh] respectively, when three-phase superposed silent discharge was employed. Therefore, characteristics of ozone generation with three-phase voltage are improved compared with single-phase voltage because silent discharge is generated continuously.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.381-385
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• 2003

In this paper, a co-axial type ozonizer varied with discharge gap was designed and manufactured for investigating $\circled1$ discharge characteristics with variation of output voltage power supply, flow rate and gap $\circled2$ ozone generation characteristics with variation of flow rate, gap and discharge power. pure oxygen was used as process gas of the co-axial type ozonizer. In this paper, a double cylindrical type superposed silent discharge type ozonizer which internal electrode can be produced a vacuum has been designed and manufactured. Discharge and ozone generation characteristics have been investigated in accordance with output voltage of power supply, flow-rate, discharge power and vacuum of internal electrode.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.387-391
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• 2003

In this paper, a double cylindrical type superposed silent discharge type ozonizer which internal electrode can be produced a vacuum has been designed and manufactured Discharge and ozone generation characteristics have been investigated in accordance with output voltage of power supply, flow-rate, discharge power and vacuum of internal electrode.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.2
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• pp.59-67
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• 2000

In this paper, an ozonizer, which can supply individual and superposed silent discharge using three-phase voltage has been designed and manufactured. The ozonizer consists of 3 electrodes(Central Electrode, Internal Electrode and External Electrode and External electrode) and 2 gaps (gap between Central Electrode and Internal Electrode, gap between Internal Electrode and External Electrode). Ozone is generated according to voltage supplying method to each electrode by individual silent discharge and three-phase superposed discharge. The characteristics of ozone generation were investigated with variation of discharge power and the flow rate of supplied gas (O2). In case of individual silent discharge, the maximum values of ozone concentration, ozone generation and ozone yield were obtained between internal electrode and external electrode, and its values were 2300[ppm], 570[mg/h] and 745[g/kWh] respectively. Each maximum value was 5039[ppm], 1773[mg/h] and 851[g/kWh] respectively, when three-phase superposed silent discharge was employed. Therefore, characteristics of ozone generation with three-phase voltage are improved compared with single-phase voltage because silent discharge is generated continuously.

• International Journal of Heart Failure
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• v.6 no.3
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• pp.119-126
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• 2024

Background and Objectives: Beta-blockers (BBs) improve prognosis in heart failure (HF), which is mediated by lowering heart rate (HR). However, HR has no prognostic implication in atrial fibrillation (AF) and also BBs have not been shown to improve prognosis in heart failure with preserved ejection fraction (HFpEF) with AF. This study assessed the prognostic implication of BB in HFpEF with AF according to discharge HR. Methods: From the Korean Acute Heart Failure Registry, 687 patients with HFpEF and AF were selected. Study subjects were divided into 4 groups based on 75 beats per minute (bpm) of HR at discharge and whether or not they were treated with BB at discharge. Results: Of the 687 patients with HFpEF and AF, 128 (36.1%) were in low HR group and 121 (36.4%) were in high HR group among those treated with BB at discharge. In high HR group, HR at discharge was significantly faster in BB non-users (85.5±9.1 bpm vs. 89.2±12.5 bpm, p=0.005). In the Cox model, BB did not improve 60-day rehospitalization (hazard ratio, 0.93;95% confidence interval [95% CI], 0.35-2.47) or mortality (hazard ratio, 0.77; 95% CI, 0.22-2.74) in low HR group. However, in high HR group, BB treatment at discharge was associated with 82% reduced 60-day HF rehospitalization (hazard ratio, 0.18; 95% CI, 0.04-0.81), but not with mortality (hazard ratio, 0.77; 95% CI, 0.20-2.98). Conclusions: In HFpEF with AF, in patients with HR over 75 bpm at discharge, BB treatment at discharge was associated with a reduced 60-day rehospitalization rate.

• Journal of Electrical Engineering and Technology
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• v.6 no.1
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• pp.111-118
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• 2011

In recent years, various types of partial discharge (PD) methods such as capacitive, inductive, electromagnetic, and acoustic coupling techniques have been developed for diagnosing rotating machines. An electromagnetic (EM) probe, which is an inductively coupled type of sensor, is required for detecting corona and internal discharges during off-line tests. In this study, a new technique for enhancing the measurement sensitivities for corona and internal discharge based on an EM inductive position sensor is proposed. An EM probe that winds wires around horseshoe-shaped and cylindershaped ferrites as helices is designed and optimized for the implementation of off-line PD monitoring of the stator winding of a rotating machine. The measurement system based on this design is implemented, and it is verified from the results of the experiment performed in this study that the probe provides similar performance as existing commercial products.