• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2617-2624
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• 2012

Interferential currents (IFC) and transcutaneous electrical nerve stimulation (TENS) are used for pain management. This study compared the analgesic effects of IFC and TENS on experimentally induced ischemic pain in otherwise pain-free subjects using a modified version of the submaximal-effort tourniquet technique. The subjects were 14 volunteers (7 male, 7 female) without known pathology that could cause pain. Their mean age was $26.7{\pm}2.0$ years. A single-blind, sham controlled, parallel-group method was used. The primary outcome measure was the change in the self-report of pain intensity during 1 of 3 possible interventions: (1) IFC, (2) TENS, or (3) sham electrotherapy. The IFC and TENS were administered on the forearm, and the sham electrotherapy group received no current output via a dummy stimulator. The results show that a 2-way repeated-measures analysis of variance revealed that there was no change in pain intensity during treatment when all 3 groups were considered together. The mean to pain intensity with the IFC intervention was no different than with TENS. Thus, Statistical analysis showed that both interventions decreased the pain intensity ratings significantly and the difference between interventions was not simply insignificant. IFC has been shown to be more comfortable than TENS in present studies and is likely to be better accepted and tolerated by patients, clinical investigation is warranted.

• Korean journal of applied entomology
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• v.24 no.2 s.63
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• pp.51-60
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• 1985

This paper was performed to study the nature of varietal resistance of some Korean-new rice cultivars to the brown planthopper (BPH), Nilaparvata lugens ($ST{\AA}L$). The rice cultivars tested were Cheongcheong, Gaya, Hangangchal, Samgang, Nampoong and Yeongpoong which have been reported as having resistant genes for the BPH. The check varieties were Jinheung, Sangpoong and Chucheong for susceptible and IR-36 for resistant. The factors studied were referred to the seedling responses, preference in feeding and oviposition of BPH, antibiosis (nymphal development, adult emergence and sex ratio, adult body weight, population build-up, feeding amount and amylase activity), and chemical composition (inorganic components, chlorophyll contents, cell wall components, amino acids and esterase isozymes) of leaf- sheath and/or roots of rice plants. In conclusion, the natures of varietal resistance of rice cultivars to the BPH were not only correlated with the resistant reaction of rice plant, but also they were related with the non preference in feeding and oviposition and those resistant cultivars had the antibiotic effects to the insects. Their antibiotic effects of rice cultivars to the BPH would be related with some of the chemical components of rice plants, such as the contents of magnesium oxide (MgO), and chlorophyll and the different esterase isozymes.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.4
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• pp.595-599
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• 2018

Interruption system with the transformer type superconducting fault current limiter(TSFCL) is proposed in this paper. The interruption system with a TSFCL is a technology that it maximizes the interruption function of a mechanical DC circuit breaker using a transformer and a superconducting fault current limiter. By a TSFCL, the system limits the fault current till the breakable current range in the fault state. Therefore, the fault current could be cut off by a mechanical DC circuit breaker. The Interruption system with a TSFCL were designed using PSCAD/EMTDC. In addition, the Interruption system with a TSFCL was applied to the DC test circuit to analyze characteristics of a current-limiting and a interruption operation. The simulation results showed that the Interruption system with a TSFCL interrupted the fault current in a stable when a fault occurred. Also, The current-limiting rate of the Interruption system with a TSFCL was approximately 69.55%, and the interruption time was less than 8 ms.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04a
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• pp.197-200
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• 2000

All-optical NOR logic device was realized by use of two pump signals with a single wavelength and a semiconductor optical amplifier(SOA). Specially, Mach-Zehnder(MZ) modulator was used for an external modulation of the pump signals. To obtain the sufficient gain saturation of the SOA, pump signals are amplified by an Er-doped fiber amplifier(EDFA) at the input of the SOA. Pump and probe signals are obtained from a DFB laser diode(${\lambda}_p$=1554 nm) and a tunable laser diode(${\lambda}_s$=1535 nm), respectively. The operation characteristics of the NOR logic device are successfully measured and demonstrated at the modulation frequency of 4.83 MHz.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.7
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• pp.438-442
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• 2014

Channel length dependence of NBTI (negative bias temperature instablilty) and CHC (channel hot carrier) characteristics in PMOSFET is studied. It has been considered that HC lifetime of PMOSFET is larger than NBTI lifetime. However, it is shown that CHC degradation is greater than NBTI degradation for PMOSFET with short channel length. 1/f noise and charge pumping measurement are used for analysis of these degradations.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.338_339
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• 2009

송전전압을 배전전압으로 변성하여 고객에게 배분하는 154kV 주변압기의 경우 과거 옥외철구형 변전소에서는 주로 동을 이용한 모선을 이용하였다. 최근 부지확보의 어려움 및 빈번한 민원 발생으로 지하 또는 옥내변전소로 바뀌어 가는 추세이고 과거 동모선 방식에서 케이블을 이용한 방식이 선호되고 있다. 모선방식의 경우는 구리나 알루미늄 바의 부식문제, 습기문제, 그리고 좁은 공간에서 사용시 절연 문제 등과 관련하여 지속적인 관리가 요구되고 있으나 케이블을 사용할 경우 이러한 문제들로부터 벗어날 수 있는 이점을 가지고 있다. 그러나 케이블을 사용하여 대전류를 송전할 경우 단일 케이블의 허용전류 용량에 따른 제한으로 복수의 케이블을 병렬 연결하여 사용하여야 한다. 그러나 케이블 동상 병렬사용시 케이블 포설 방식에 따라 동상간의 불평형전류 차가 심하게 발생한다. 본 논문에서는 이러한 송 배전 선로의 불평형전류 현황을 알아보고, 송전선로에 있어서 상배열 변경 및 배전선의 동상 케이블 배열방법을 변경함으로써 불평형전류를 최소화 하여 최적의 계통상태 유지를 위한 방안을 찾고자 한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.912-916
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• 2002

In this paper, the $CF_4$ decomposition rate and by-product were investigated for a simulated two plasma reactors which are metal particle reactor and spiral wire reactor as function of mixed gases. The $CF_4$ decomposition rate by plasma reactor with metal particle electrode had a gain of 20~25[%] over that by plasma reactor with spiral wire electrode. The $CF_4$ decomposition efficiency increases with increasing applied voltage up to the critical voltage for spark formation. The $CF_4$ decomposition efficiency of metal particle reactor was about 80[%] at AC 24[kV]. The $CF_4$ decomposition rate used $Ar-N_2$ as base gas was the highest among three base gases of $N_2$, $Ar-N_2$, air. The by-products of the $N_2$, $Ar-N_2$ base as were similar, but in case of air base they were different.

• Journal of Hydrogen and New Energy
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• v.26 no.2
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• pp.148-155
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• 2015

Electrospun $LaCoO_3$ perovskite nanofibers were produced for the air electrode in Zn-air rechargeable batteries using electrospinning technique with sequential calcination. The final calcination temperature was varied from 500 to $800^{\circ}C$ in order to determine its effect on the physical and electrochemical properties of the prepared $LaCoO_3$ perovskite nanofibers. The surface area of the electrospun $LaCoO_3$ perovskite nanofibers were observed to decrease with increasing final calcination temperature. Electrospun $LaCoO_3$ perovskite nanofibers calcined with final calcination temperature of $700^{\circ}C$ had the best electrocatalytic activity among the prepared perovskite nanofibers.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.4
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• pp.311-316
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• 2010

$Zr_{0.7}Sn_{0.3}TiO_4$ (ZST) thin films were fabricated by metal-organic decomposition, and their dielectric properties were investigated in order to evaluate their potential use in passive capacitors for rf and analog/mixed signal integrated circuits. The ZST thin film annealed at the temperature of $800^{\circ}C$ showed a dielectric constant of 27.3 and a dielectric loss of 0.011. The capacitor using the ZST film had quadratic and linear voltage coefficient of capacitance (VCC) of -65 ppm/$V^2$ and -35 ppm/V at 100 kHz, respectively. It also exhibited a good temperature coefficient of capacitance (TCC) value of -32 ppm/$^{\circ}C$ at 100 kHz.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1023-1024
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• 2008

The road surface scripture season must be interpreted with hitherto whole aspect line scripture season different. TRAM (street cars) it respects an operation it stands and back must be operated the bus which runs place and riding grade different public transportation means and to be mixed. With the numerous crossroads zebra crossing and the coat platform must operate back. The role of the operation article most is important. It undergoes the influence of traffic signal specially directly. It considers each facility etc. of the road and must construct a proper equipment in him with connection method of the signal system which it follows in the middle urethra. Must secure the fixed time characteristic of the operation which road surface scripture season is efficient and expression speed and operation. In order the [le] according to interface plan with traffic signal it does to consider a traffic signal first of all. This the research of operation provision is necessary.