• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.905-907
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• 1996

Current design standard of substation grounding systems is primarily concerned with conventional outdoor substations. But in case of 154kV substations in the nation, almost all are indoor-type GIS substations. So there became to be something not proper for application of present design standard to indoor-type substations. In this paper, as a preliminary stage of drawing-up of the grounding system design standard which concerned with in-door-type substions, issues of current design standard are mentioned and directions of improvement are also presented.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.529-530
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• 2008

The proposed CMOS Quadrature VCO for WLAN application was designed in TSMC $0.18\;{\mu}m$ RF CMOS technology. The QVCO based on NMOS back-gate as a coupling transistor and switched capacitors array without tail transistors is designed to generate quadrature output signals. The simulated results show that the QVCO core consumed 3.67 mA and 6.6 mW from a 1.8 V supply. The QVCO is tunable between $4.76\;GHz\;{\sim}\;6.35\;GHz$ and has a phase noise lower than -116.8 ㏈c/Hz at 1 MHz offset over the entire tuning range

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.2
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• pp.93-100
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• 2009

This paper presents a step up four channel DC-DC converter using charge pump voltage doubler structure. Our goal is to design and implement DC-DC converter for capacitive SP4T RF MEMS switch in front end module in wireless transceiver system. Charge pump structure is small and consume low power 3.3V input voltage is boosted by DC-DC Converter to $11.3{\pm}0.1V$, $12.4{\pm}0.1V$, $14.1{\pm}0.2V$ output voltage With 10MHz switching frequency. By using voltage level shifter structure, output of DC-DC converter is selected by 3.3V four channel selection signals and transferred to capacitive MEMS devices. External passive devices are not used for driving DC-DC converter. The total chip area is $2.8{\times}2.1mm^2$ including pads and the power consumption is 7.52mW, 7.82mW, 8.61mW.

• Food Science and Preservation
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• v.7 no.4
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• pp.395-402
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• 2000

To enlarge application field of electrolyzed acid-water(EAW) on food industry, the changes of EAW properties by storage conditions and heating were investigatet. It was showed that storing EAW in closed container is mon effective to keep up the oxidation-reduction potentials(ORP), hyperchloride content and pH than stored in opened ones. ORP of EAW stored in closed container could be kept mon than 1 month as 1,150 mV levels. Ruing heating from 2$0^{\circ}C$ to 95$^{\circ}C$, ORP was increased to 1,150 mV levels at 95$^{\circ}C$ after gradual decrease to 5$0^{\circ}C$. Tyrosinase activity was decreased approximately to 26%~35% in EAW having a 950 mV~1,140 mV ORP. Also it was confirmed that EAW has anti-browning effect as sliced apple and potato, and their juices treated with EAW had conspicous difference in their $\Delta$E value. 12 kinds of pesticides such as aldrine, capful diazinon, diedrin, $\alpha$-endosulfan $\beta$-endosulfan, endosulfan sulfate, endrin, $\alpha$-BHC, o,p'-DDT, procymidone, PCNB added in EAW were recovered from ND~73.6% comparing to ones added in distilled water. The recovered amounts of pesticides, procymidone and diazinon in lettuce after soaking in EAW were 1.12 ppm and ND, compared with those of amounts soaked in distilled water were 3.67 ppm and 3.05 ppm respectively. So, it seems that EAW has potentials to promote the degradation of pesticides.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.21-24
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• 2008

Properties of carbon nano fiber (CNF) as field emitters were described. Carbon nano fiber (CNF) of herringbone was prepared by thermal chemical vapor deposition(CVD). Field emitters mixed with organic binders, conductive materials and were prepared by screen-printing process. In order to increase field emissions, the surface treatment of rubbing & peel-off was applied to the printed CNF emitters on cathode electrode. The measurements of field emission properties were carried out by using a diode structure inline vacuum chamber. CNF of herringbone type showed good emission properties that a turn on field was as low as 2.1 $V/{\mu}m$ and current density was as large as 0.15 $mA/cm^2$ of 4.2 $V/{\mu}m$ with electric field. Through the results. we propose that CNFs are suitable for application of electron emitters in Field Emission Devices.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.444-446
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• 1995

This paper deals with semisphere-type sensor fo measuring the electric field waveforms by lightning discharges. The theoretical principle and design rule of the device are introduced, and also the calibration and application investigations are carried out. From the calibration experiments, the frequency bandwidth of the semisphere-type electric field measuring device ranges from 200 [Hz] to 1.56 [MHz], and the sensitivity of sensor is 0.96 [mV/V/m]. The electric field waveforms produced by lightning discharges were observed for June and August 1995. It is shown that the electric field waveforms produced at the distance of more than 50 [km] include only radiation component.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.6
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• pp.647-651
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• 2004

We fabricated the 1-inch diode type flat lamp using CNTs, which were grown directly on soda-lime glass substrate at 600 ∼ 650 $^{\circ}C$ by thermal chemical vapor deposition(CVD) of acetylene gas. Turn- on field was about 2.8 V/${\mu}{\textrm}{m}$. We observed that uniform and high brightness had been obtained. The brightness of CNT flat lamp was measured up to about 14 kcd/$m^2$ at 2000V in spacing of 500 ${\mu}{\textrm}{m}$. The results showed that the CNTs were very good emission source and suitable for application in the lamp.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.144-150
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• 2008

In this paper, the safety for passengers of composite car-body against lightning strikes was analyzed by the application of an impulse generator which can produce impulse current up to 50 [kA] with 8/20 [us] waveform. Potential difference on inside surface of the car-body was measured as a safety parameter for the passengers against lightning strikes. The potential difference between 20 [cm] distant was 175 [V] at 37.67 [kA], and it corresponded to 875 [V] between 1 [m] distant. The amount of charge flowing a passenger at 100 [kA] impulse current can be estimated to 0.31 [mA s]. This is much less than the limit amount of charge for human body, 30 [mA s] which is presented by Koeppen and Osypka.

• Journal of Electrical Engineering and information Science
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• v.2 no.4
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• pp.14-18
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• 1997

A design methodology of the analog current-mode and width programmable integrator for a low voltage (3V) and low power application is developed and the integrator designed by this method is successfully fabricated by the 0.8$\mu\textrm{m}$ CMOS n-well single poly/double metal standard digital process. The integrator occupies the active chip area of 0.3$\textrm{mm}^2$. The experimental result illustrates a low power dissipation (1.0mW∼3.55 mW), 65dB of the dynamic range, and digitally and width programmability (10MHz∼30MHz) with an external digital 4 bit.

• ETRI Journal
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• v.32 no.4
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• pp.520-529
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• 2010

In this paper, we present a low-voltage low-dropout voltage regulator (LDO) for a system-on-chip (SoC) application which, exploiting the multiplication of the Miller effect through the use of a current amplifier, is frequency compensated up to 1-nF capacitive load. The topology and the strategy adopted to design the LDO and the related compensation frequency network are described in detail. The LDO works with a supply voltage as low as 1.2 V and provides a maximum load current of 50 mA with a drop-out voltage of 200 mV: the total integrated compensation capacitance is about 40 pF. Measurement results as well as comparison with other SoC LDOs demonstrate the advantage of the proposed topology.