• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.271-274
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• 1999

In this paper, we studied the matrix type Powder AC Electroluminescence using ZnS:Cu,Cl Phosphor. Previously, Powder AC EL was used in Backlighting of LCD. Rescently, organic Thin Film EL was rapidly developed because of high Luminescence and low applied voltage. But Powder AC EL has Superior features that include sheet like flexibility thickness, low weight, self-emission, a wide viewing angle and a fast response time. We tried to change of phosphor thickness and binder mixture rate in order to obtain the good condition of powder AC EL and we obtained the very low breakdown voltage that was just 15V. Till now, we measured the current-voltage(V-I), luminance-voltage(V-L), Luminance-current (L-I), color coordinate (CIE), and phosphor Intensity of variable thickness. In experiment result, the devices has the luminance of 840 cd/$m^2$ and improved color coordinate, x=0.1557, y=0.2145, using a 10kHz drive frequency.

• Journal of Electrochemical Science and Technology
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• v.14 no.3
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• pp.222-230
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• 2023

Capacitive deionization of saline water is one of the most promising water purification technologies due to its high energy efficiency and cost-effectiveness. This study synthesizes porous carbon composites composed of reduced graphene oxide (rGO) and activated carbon (AC) with various rGO/AC ratios using a facile chemical method. Surface characterization of the rGO/AC composites shows a successful chemical reduction of GO to rGO and incorporation of AC into rGO. The optimized rGO/AC composite electrode exhibits a specific capacitance of ~243 F g^-1 in a 1 M NaCl solution. The galvanostatic charging-discharging test shows excellent reversible cycles, with a slight shortening in the cycle time from the ~260^th to the 530^th cycle. Various monovalent sodium salts (NaF, NaCl, NaBr, and NaI) and chloride salts (LiCl, NaCl, KCl, and CsCl) are deionized with the rGO/AC electrode pairs at a cell voltage of 1.3 V. Among them, NaI shows the highest specific adsorption capacity of ~22.2 mg g^-1. Detailed surface characterization and electrochemical analyses are conducted.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.406-407
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• 2018

본 논문에서는 SPMSM의 속도 및 전류제어기를 PI 혹은 I-P제어기를 조합한 네 가지 형태의 제어시스템으로 구성하여 서보시스템에 가장 적합한 형태의 제어시스템 구성과 설계기법을 도출하고, 시뮬레이션 해석을 통해 유효성을 검증한다.

• Korean Journal of Optics and Photonics
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• v.1 no.1
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• pp.1-6
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• 1990

We studied two-photon-resonant three-photon ionization processes via 4D[channel #1] and 5S(channel #2] intermediate state of Na atom in a quartz ionization cell. For each channel. the bandwidth of ionization spectrum increased linearly with laser intensity and the ionization signal followed J3 dependence at low intensity. Compared with channel # 1 . ionization signal of channel #2 was enhanced by a factor of 20 - 25. The measured AC Stark shift factor of 3S - 4I) transition was $174\pm60MHz/MW/textrm{cm}^2$..

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.4
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• pp.586-593
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• 2010

In this paper, I have proposed that the 1st and 2nd AC-DC transformation methods using multi-level pulsating currents and selection switches. Through making the rectified voltage of the proposed AC-DC translation which is similar to reference voltage by selecting from multi-level pulsating currents, the proposed translation has dramatically reduced the ripple voltage. I have compared the performance of the DC voltage, the ripple voltage and the peak to peak voltage of the proposed method with the conventional method. The simulation results show that the proposed 2nd method has the better performance than the 1st method in the point of average DC voltage drop and peak to peak voltage increase.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.1989-1992
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• 1997

A new soft switching single stage AC-DC full bridge boost converter with unit input power factor and isolated output is presented. Due to using of the non-dissipative snubber in the primary side, a single stage high-power factor isolated full bridge boost converter has a significant reduction of switching losses in main switching devices and output rectifiers of the primary and secondary side, respectively. The non-dissipative snubber adopted in this study is consisted of a snubber capacitor C. and a snubber inductor $L_r$, a fast recovery snubber diode $D_r$, a commutation diode $D_p$. This paper presents the complete operating principles, theoretical analysis and simulation results.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.291-294
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• 2007

This paper preserts the characteristics of leakage currents flowing through 18 kV zinc oxide (ZnO) surge arrester under the mixed DC and AC voltages. The I-V curves of ZnO surge arrester were measured as a function of the voltage ratio K The I-V curves under the mixed DC and AC voltages lay between the pure DC and AC characteristics, and the cross-over phenomenon in I-V curves was observed at the low current region As a result, the increase of DC component to mixed voltages causes the increase of resistive component of total leakage current th ZnO surge arrester.

• 한국초전도학회:학술대회논문집
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• v.14
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• pp.24-24
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• 2004

• BMB Reports
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• v.36 no.2
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• pp.149-153
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• 2003

The dibucaine number (DN) was determined for serum cholinesterase (EC 3.1.1.8, SChE) in plasma samples. The ones with a DN of 79-82 were used, because they had the "usual" SChE variant. The enzyme was assayed colorimetrically by the reaction of 5,5'-dithiobis-[2-nitrobenzoic acid] (DTNB) with the free sulfhydryl groups of thiocholine that were produced by the enzyme reaction with butrylthiocholine (BuTch) or acetylthiocholine (AcTch) substrates, and measured at 412 nm. Dibucaine, a quaternary ammonium compound, inhibited SChE to a minimum within 2 min in a reversible manner. The inhibition was very potent. It had an $IC_{50}$ of $5.3\;{\mu}M$ with BuTch or $3.8\;{\mu}M$ with AcTch. The inhibition was competitive with respect to BuTch with a $K_i$ of $1.3\;{\mu}M$ and a linear-mixed type (competitive/noncompetitive) with respect to AcTch with inhibition constants, $K_i$ and $K_I$ of 0.66 and $2.5\;{\mu}M$, respectively. Dibucaine possesses a butoxy side chain that is similar to the butryl group of BuTch and longer by an ethylene group from AcTch. This may account for the difference in inhibition behavior. It may also suggest the existence of an additional binding site, other than the anionic binding site, and of a hydrophobic nature.

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.280-285
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• 2014

In order to evaluate the insulation deterioration in the stator windings of five gas turbine generators(137 MVA, 13.8 kV) which has been operated for more than 13 years, diagnostic test and AC dielectric breakdown test were performed at phases A, B and C. These tests included measurements of AC current, dissipation factor, partial discharge (PD) magnitude and capacitance. ${\Delta}I$ and ${\Delta}tan{\delta}$ in all three phases (A, B and C) of No. 1 generator stator windings showed that they were in good condition but PD magnitude indicated marginally serviceable and bad level to the insulation condition. Overall analysis of the results suggested that the generator stator windings were indicated serious insulation deterioration and patterns of the PD in all three phases were analyzed to be internal, slot and spark discharges. After the diagnostic test, an AC overvoltage test was performed by gradually increasing the voltage applied to the generator stator windings until electrical insulation failure occurred, in order to determine the breakdown voltage. The breakdown voltage at phases A, B and C of No. 1 generator stator windings failed at 28.0 kV, 17.9 kV, and 21.3 kV, respectively. The breakdown voltage was lower than that expected for good-quality windings (28.6 kV) in a 13.8kV class generator. In the AC dielectric breakdown and diagnostic tests, there was a strong correlation between the breakdown voltage and the voltage at which charging current increases abruptly ($P_{i1}$, $P_{i2}$).