• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1856-1858
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• 2002

As the statistical data, the most of electrical shock accidents have been caused by human errors including those of mistake, carelessness, and so on during normal condition. But, there are currently no international standards for the determination of withstand distance to ensure safety of personnel form 22.9 kV electrical power facilities during their normal operation. Therefore, this paper describes the characteristics of flash-over voltage by moisture variation to establish the distance clearances in terms of electrical safety.

• 전기학회논문지
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• 제60권3호
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• pp.486-491
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• 2011

Since Korea has high accident rate for the electrical shock than other advanced countries, it causes very serious problems. In this paper, a new classification method for analyzing electricity accidents is proposed, which is based on the microscopic view while existing methods have been based at the macroscopic view point. Electrical accidents cases can be mainly divided by three cases, which are from live works, incompleteness of the grounding system and imperfectness of the safety education and public relations. New data format of electrical shocks are proposed in the environment of smart grids.

• 한국전기전자재료학회논문지
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• 제24권12호
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• pp.949-954
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• 2011

In this study, the characteristics and error ranges of the mechanical bonding strength were analyzed according to before and after thermal shock test for various chips of automotive application component using Sn-3.0Ag-0.5Cu solder. In the after thermal shock test, the mechanical bonding strengths tend to decrease, meanwhile decreasing rates of mechanical strengths were less then 12% at specimen's bonding area below 3.5$mm^2$, and were from 17 to 21% at specimen's bonding area above 12 $mm^2$. On the other hand, Specimen's mean deviation rates were about 5% at specimen's bonding area more than 12 $mm^2$. Inversely, at specimen's bonding area is less then 3.5 $mm^2$, mean deviation rates were increased to about 8%. It means that the smaller device size is, the larger mean deviation rate. In addition, error ranges and deviation rates of the mechanical bonding strengths may differ slightly depending on their bonding area. Furthermore, process conditions as well as method of mechanical reliability evaluation should be established to reduce the error ranges of bonding strength.

• Transactions on Electrical and Electronic Materials
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• 제16권5호
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• pp.268-273
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• 2015

While analyzing the specimens before and after the thermal shock test, we found that the power drop rate of the bare cell was 5.08%, while the power drop rate of the ribboned cell was 16.49%. In comparative terms, the efficiency was lower at the ribboned cell than at the bare cell. While analyzing through EL (Electroluminescence) shots and cross sections, we tried to decipher the exact cause of the power drop. Although mere color change of the cell was observed at the surface of the bare cell, no abnormality could be found inside the cell. On the surface of the ribboned cell, the short circuit of gridfinger extended from the front part of the front electrode of the ribboned cells. Therefore, cracks occurred on the surface of the cell. Cracks also appeared inside the cell. While analyzing the I-V curve, we determined an increase in the leakage current and an increase of resistances in series in the bare cell. In the ribboned cell, the resistances in parallel reduced remarkably. An increase of resistances in series could also be verified. Conclusively, we deduced that the power drop rate in the bare cell is a life span of the cell itself; aging is the cause of power drop rate in cells. In case of ribboned cell, the power drop rate was directly influenced by internal cracks and an intermetallic compound layer joining the ribbon at the front electrode.

• 조명전기설비학회논문지
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• 제21권1호
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• pp.142-147
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• 2007

본 논문은 대지구조와 접지봉의 매설깊이에 따른 대지표면의 전위상승에 대해서 기술하였다. 대지표면의 전위상승에 따른 인체의 감전사고의 저감에 관한 기초적 자료를 제안하기 위해서 접지봉 부근에서의 대지표면전위를 계산하고 측정하였다. 접지봉 부근의 대지표면전위상승은 대지구조에 크게 의존하며, 매설깊이가 깊어질수록 낮아졌다. 대지표면전위상승은 접지봉의 직상부에서 최대이었으며, 측정결과는 접지해석프로그램으로 계산한 결과와 잘 일치하였다.

• 한국전기전자재료학회논문지
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• 제30권12호
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• pp.776-781
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• 2017

In this study, we investigated the effect of electrode pattern design on the thermal shock resistance and temperature uniformity of a ceramic heater. A cordierite substrate with a low thermal expansion coefficient was fabricated by tape casting, and a tungsten electrode was printed and used as a heating element. The temperature distribution of the ceramic heater was calculated by a finite-element method (FEM) by considering various electrode patterns, and the tensile stress distribution due to the thermal stress was calculated. In the electrode pattern with a single-line width, the central part of the ceramic heater was heated to the maximum temperature, and the position of the ceramic heater having a double-line width was changed to the maximum temperature, depending on the position of the minimum line width pattern. The highest tensile stress was found along the edges of the ceramic heater. The temperature gradient at the edge determined the tensile stress intensity. The smallest tensile stress was observed for electrode pattern D, which was expected to be advantageous in resisting thermal shock failures in ceramic heaters.

• 한국전기전자재료학회논문지
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• 제22권3호
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• pp.199-204
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• 2009

The effect of temperature on ACF thermocompression bonding for FPD assembly was investigated, It was found that Au bumps on driver IC's were not bonded to the glass substrate when the bonding temperature was below $140^{\circ}C$ so bonds were made at temperatures of $163^{\circ}C$, $178^{\circ}C$ and $199^{\circ}C$ for further testing. The bonding time and pressure were constant to 3 sec and 3.038 MPa. To test bond reliability, FPD assemblies were subjected to thermal shock storage tests ($-30^{\circ}C$, $1\;Hr\;{\leftrightarrow}80^{\circ}C$, 1 Hr, 10 Cycles) and func! tionality was verified by driver testing. It was found all of FPDs were functional after the thermal cycling. Additionally, Au bumps were bonded using ACF's with higher conductive particle densities at bonding temperatures above $163^{\circ}C$. From the experimental results, when the bonding temperature was increased from $163^{\circ}C$ to $199^{\circ}C$, the curing time could be reduced and more conductive particles were retained at the bonding interface between the Au bump and glass substrate.

• 화약ㆍ발파
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• 제40권1호
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• pp.17-28
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• 2022

고전압 방전에 의한 파분쇄기술 중 ED(Electrical pulse Disintegration)는 고체 내 절연파괴를 유도하여 고체 내 취약한 경계면을 분리하여 유가자원을 분리·회수하는 고효율 자원처리 기술로 알려져 있다. 본 연구에서는 고전압 방전에 의하여 고체 내 발생한 충격파가 황화광물 내 존재하는 아연광물의 단체분리특성을 분석하기 위하여, ED분쇄실험과 기계식 분쇄실험을 수행하고 분쇄산물에 대한 SEM-BSE 분석과 Microfocus X-Ray CT 분석을 수행하여 단체분리도를 비교하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.1276-1279
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• 1987

Cardiac arrhythmias are associated with electrical Instability and, hence, with abnormal mechanical activity of the heart in many cases, arrhythmias can be treated with drugs or electric shock to control and/or stop them. Hence fast arrhythmia detection is very important. In this paper RR interval, QRS width, and morphology are used for diagnosis and QRS complex is detected by hardware system. hence diagnosing time is shorten. Moreover doctors or nurses who have little knowledge of computer manipulation can get the Information of Patient's ECG by showing characteristics of abnormal waveform and by mapping graphs of RR interval .vs. QRS width and RR interval .vs. morphology on screen.

• Journal of Electrical Engineering and Technology
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• 제1권1호
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• pp.8-15
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• 2006

Since the power swing depends on the operating time of the relay, the swing's magnitude can be reduced by an autoreclosure relaying system with an optimal reclosing algorithm. This paper proposes a method for stability improvement using optimal reclosure relaying. An optimal reclosure algorithm is applied to identify both temporary and permanent faults, and to predict system stability by applying WAM and high speed communication technology. It provides optimal control by predicting and determining the degree of stability, considering the real time transient stability using EEEAC. For temporary faults, the algorithm determines the system's stability and either recloses optimally for stable systems, or inserts series capacitance before optimal reclosure for unstable systems. It also applies an optimal reclosure algorithm to minimize shock and damage to the power system when reclosure fails due to permanent faults.