• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1265-1270
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• 2008

Electromigration is a one of a critical failure mechanism in microelectronic devices. Minimizing the thin film interconnections in microelectronic devices make high current densities at electrrical line. Under high current densities, an electromigration becomes critical problems in a microelectronic device. This phenomena under DC conditions was investigated with high temperature. The current density of 1.5MA/cm2 was stressed in interconnections under DC condition, and temperature condition $150^{\circ}C,\;175^{\circ}C,\;200^{\circ}C$. By increasing of thin film interconections, microelectronic devices durability is decreased and it gets more restriction by temperature. Electromigration makes electronic open by void induced, and hillock induced makes electronic short state.

• 대한의용생체공학회:의공학회지
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• 제30권4호
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• pp.318-326
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• 2009

A simple method for measuring magnetic flux and induced current in magnetic nerve stimulation for urinary incontinence treatment is proposed. Unlike electric nerve stimulation, direct measurement of the induced current in magnetic nerve stimulation is impossible. Since induced currents stimulate nerves or muscles in magnetic nerve stimulation, measuring induced current is very important in validating stimulation efficacy and securing safety. The magnetic flux measuring system is composed of 6 layers with pick-up coils of 7 by 7 in each layer, and the induced current measuring system is composed of 6 layers with 7 concentric circular coils in each layer. The proposed method can be used in the design or performance test of a magnetic nerve stimulator for many clinical applications such as urinary incontinence treatment, activation of peripheral nerves, and transcranial magnetic stimulation.

• 한국표면공학회지
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• 제30권1호
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• pp.44-56
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• 1997

Influence of electrochemical etching conditions on capacitance gain of aluminium electrolytic on capacitor foil has been investigated by etching cubic textured high purity aluminum foil in dilute hydrochloric acid. Uniformly distributed etch pit tunnels on aluminum surface have been obtained by pretreatment aluminium foil in 10% NaOH solution for 5 minutes followed by electrochemical etching. Electrostatic capacitance of etched aluminium foil anodized to high voltage increased with the increase of current density, total charge, temperature and concentration of electrolyte up to maximum CV-value and then deceased. Election optical observation of the etched foil revealed that the density of etch of etch pits increased with the increase of current density and concentration of electrolyte. this increase of etch pit density enlarged of the increase of capacitance. However, abnormal high current density and high electrolyte concentration induced the local dissolution of the foil surface which resulted the decrease of foil capacitance.

• 한국환경과학회지
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• 제6권4호
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• pp.313-322
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• 1997

한국수영만에서 잔차류장의 운동 위치에너지의 계절변화를 연구하기 위하여 우리는 에너지의 수지를 계산하고 조석에너지와 비교했다. 위치에너지는 겨울과 봄철에 크며, 밀도성층이 형성된 여름과 초가을에 작게 나타났다. 잔차류의 운동에너지는 계절적인 변화를 보이고 있으며, 단위면 적당 잔차류의 평균 운동에너지는 6.4$\times$$10^{-4}ergs s^{-1}cm^{-}2$이다. 수영 만에서 잔차류장의 계절변동은 조석잔차류의 운동에너지가 밀도류나 취송류의 운동에너지보다 큰 11월을 제외하고는 밀도류가 지배하고 있다. 잔차류의 주성분인 조석잔차류, 취송류 및 밀도류의 운동에너지의 평균백분율은 잔차류의 운동에너지에 대하여 각각 29.1%, 3.4%, 67.5% 이다. 단위면적당 잔차류의 운동에너지, 위치에너지 및 조석에너지의 비는 각각 1.0 : 6.7$\times$$10^3$ : 8.2$\times$$10^4$ 이다.

• 한국환경과학회지
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• 제11권1호
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• pp.41-56
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• 2002

In order to estimate the quantitative roles of the tide induced residual currents, density currents and wind driven currents on the residual currents in Kwangynag Bay Korea, numerical experiments with a diagnostic multi-level model were carried out. Density currents were calculated from the temperature and salinity data observed in January, May, August and November 1998. Anti-clockwise circulations are formed at the western inner part of the bay, the location from the east of Myodo Is. to the south of POSCO Co. and the place between Yeosu peninsula and Namhae Is. from the calculation results of the tide induced residual currents. Velocities of the density currents are less than 3cm/s at the western inner part of the bay and about 5cm/s at the southern entrance of the bay. Density currents get strong in summer and weak in autumn. Wind driven currents at the surface layer flow in the directions of the given winds which are the daily mean winds when the temperature and salinity observations are carried out. In the middle and lower layers, however the wind driven currents flow in the opposite direction to the surface currents as supplementary currents. The surface wind driven currents are greater than the tide induced residual currents or the density currents. The calculated residual currents including the tide induced residual currents, density currents and wind driven currents agree with the results of the current observations approximately. In the Bay, the wind driven currents affect on the residual currents greatestly and tide induced residual currents and density currents do in the second place and the third place.

• 전기학회논문지
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• 제59권10호
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• pp.1856-1861
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• 2010

To reduce a high fault current, neutral ground reactors (NGR) were installed in the Korean substation. Current with several harmonic components flows in a NGR due to load unbalance in normal steady state and magnetic fields with several harmonic components are also generated around a NGR. As results of study, we found magnetic fields around a NGR in Korean substation included two harmonics, 180Hz and 540Hz. Magnetic fields of 180 Hz increased 3 times more current density inside a worker near a NGR than same magnitude magnetic fields of 60 Hz. We know a worker near a NGR may not meet ICNIRP guideline of 10(mA/$m^2$) due to several harmonic components.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.458-458
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• 2003

In this study the induced-current density distributions in spherical human model by the magnetic field from electric power lines were analysed with visualization and also the effects of phase difference between components of magneto field were investigated.

• 한국표면공학회지
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• 제49권5호
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• pp.423-430
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• 2016

In this study, we investigated the corrosion damage characteristics of steel for offshore wind turbine tower substructure using an accelerated electrochemical test. The galvanostatic corrosion test method was employed with a conventional 3 electrode cell in natural sea water, and the steel specimen was served as a working electrode to induce corrosion in an accelerated manner. Surface and cross-sectional image of the damaged area were obtained by optical microscope and scanning electron microscope. The weight of the specimens was measured to determine the gravimetric change before and after corrosion test. The result revealed that the steel tended to suffer uniform corrosion rather than localized corrosion due to active dissolution reaction under the constant current regime. With increasing galvanostatic current density, the damage depth and surface roughness of surface was increased, showing approximately 25 times difference in damage depth between the lowest current density ($1mA/cm^2$) and the highest current density ($200mA/cm^2$). The gravimetric observation showed that the weight loss was proportionally increased with increment of current density that has 75 times different according by experimental conditions. Consequently, uniform corrosion of the steel specimen was conveniently induced by the electrochemically accelerated corrosion technique, and it was possible to control the extent of the corrosion damage by varying the current density.

• 한국전자파학회지:전자파기술
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• 제6권1호
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• pp.10-16
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• 1995

완전도체 스트립 회절격자에 의한 E-분극 산문제를 모멘트법을 이용하여 해석하였다. E분극의 경우는 청도 되는 표면전류밀도가 모서리 양 끝에서 매우 높을 것으로 추측된다. 이때 스트립에 청도되는 표면전류밀도는 차수가 0인 Ultraspherical 다항식의 급수와 적절한 모서리 경계조건을 만족하는 함수의 곱의 급수로 전개하였다. 전류밀도와 반사계수에 대한수직결과를 기존의 다른 수틀과 비교하였다. 본 논문의 수치결과가 기존의 다른 수를 사용했을 때 보다 기하학적 반사계수의 경도가 매우 빠르게 향상됨을 보였다. 기하학적 반사계수에서의 급변점 위치는 입사각, 스트립 폭 및 스트립 주기를 변화시킴으로써 이동시킬 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1410-1411
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• 2007

This paper analyses current densities induced inside a worker using AC arc welder. Applying the boundary element method, we calculate current densities induced in organs inside a worker in case he was located at 1[cm], 3[cm], 5[cm], 10[cm], 15[cm], 20[cm] far from a power cable of AC arc welder. As results of study, we find a maximum current density induces at a heart surface and may be higher than 10[$mA/m^2$] of ICNIRP guideline if he works within 15[cm] from a power cable.