• Fire Science and Engineering
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• v.29 no.5
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• pp.57-66
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• 2015

This thesis is based on a research to investigate the electrical fire risk due to the single and composite cause in a terminal block. This paper analyzed the thermal characteristics depending on the screw torque change and contact resistance change to measure the fire risk due to the poor contact from single cause first. To measure the fire risk due to the composite cause, the acceleration tracking depending on the contact resistance change was experimented to check the correlation of poor contact and tracking to fire. The experiment result showed that the thermal characteristics were clearer as the screw torque in poor contact status and magnitude of contact resistance increased and that the thermal characteristics of terminal block depending on the contact resistance change was more reliable than the thermal characteristics depending on the screw torque change. Moreover, the terminal block poor contact and tracking were correlated in the case of the composite cause, and when two composite causes were interacted, the electrical fire risk was higher than the single cause.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.370-370
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• 2008

ITO 박막은 현재 차세대 디스플레이인 LCD, PDP, ELD 등의 평판 디스플레이의 화소전극 및 공통전극으로 가장 많이 적용되고 있는 소재이며, 최근에는 태양전지의 투명전극으로 그 용도가 더욱 증가되고 있다. 이러한 소자들의 투명 전도막으로 사용되기 위해서는 가시광선 영역에서 80% 이상의 높은 투과도와 낮은 면 저항을 가져야 한다. 광 투과도와 면 저항은 ITO 박막의 증착조건에 따라 변하게 되는데 본 연구에서는 DC 마그네트론 스퍼터링법을 이용하여 Indium-Tin Oxide (ITO) 박막을 제작하고, 제작된 ITO 박막의 전기적 특성과 광학적 특성을 측정하여 공정조건에 따른 박막의 특성 변화를 평가하였다. 증착 조건은 주로 기판 온도와 증착 시간을 변화시켰다. 본 실험에서는 $In_2O_3$ : $SnO_2$의 조성비가 9:1 비율의 순도 99.99% ITO 타겟을 사용하였으며, coming 1737 glass를 30$\times$30 mm 크기로 가공하여 기판온도와 증착시간을 변화시키면서 ITO 박막을 제조하였다. 예비실험을 통해 인가전력 50W, 초기 진공 $2\times10^{-6}$ Torr, 작업 진공 $3.5\times10^{-2}$ Torr, 기판과 타겟 사이의 거리를 10 cm로 고정하였다. 기판 온도는 히터를 가열하지 않은 상온 ($25^{\circ}C$)에서 $400^{\circ}C$까지의 범위에서 변화시켰고, 증착시간은 5분에서 30분까지의 범위에서 변화시켰다. 증착된 박막의 면 저항 촉정을 위해 4 point probe를 사용하였고, 홀 (hall) 계수 측정기 (HMS-300)를 이용하여 홀 계수를 측정하였으며, 또한 박막의 두께는 $\alpha$-step을 사용하여 측정하였다. ITO 박막의 상분석을 위해 XRD를 사용 하였고, SEM을 이용하여 미세구조를 관찰하였다. 실험 결과로는 기판온도 $400^{\circ}C$, 증착시간 15분 이상에서는 면 저항이 모두 $8\Omega$/$\Box$이하로 낮게 나왔으며, 투과율 또한 모두 80% 이상의 높은 투과도를 보였다. 또한 ITO박막의 전기 전도도는 캐리어 농도와 이동도의 측정을 통해 두 가지 인자들에 의해 비례되는 것을 확인하였다.

• Journal of the Korea Society of Computer and Information
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• v.18 no.10
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• pp.183-192
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• 2013

This paper examines the impact of the strategic leadership of CEOs after M&A on resistance to change and on perceived performance. Most M&A research has focused on the strategic, financial and economic aspects, while studies on leadership and employee behavior have been limited. CEO leadership is critical to a successful M&A. Recently, strategic leadership has been attracting more attention. Strategic leadership can be defined as a person's ability to anticipate, envision, maintain flexibility, think strategically and to work with others to initiate changes that will create a viable future for an organization. It can also reduce resistance and improve perceived performance. So this paper used empirical studies from the IT industry after M&A.

• Journal of the Korean Magnetics Society
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• v.11 no.3
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• pp.97-103
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• 2001

Polycrystalline thin films of La$_{2}$3/Sr$_{1}$3/MnO$_3$(LSMO) were prepared by water-based sol-gel processing on thermally oxidized Si(100) substrate. The thickness dependence of the low-field tunnel-type magnetoresistance properties at room temperature was studied. Tunnel-type magnetoresistance at low-field is found to be strongly dependent on film thickness. Maximum value of tunnel-type magnetoresistance of LSMO thin films was appeared at the film thickness of ~1500 $\AA$. This behavior can be explained in terms of dead layer between LSMO thin film and Si(100) substrate and thermal lattice strain effect in the LSMO thin films.

• Journal of Aerospace System Engineering
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• v.13 no.2
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• pp.43-50
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• 2019

Satellite and aircraft components are greatly affected by the possibility for missions and safety due to temperature effects. In the field of fuel cells, research is actively carried out for UAV. For the efficiency and stability of the fuel cells, the temperature for operations must be confirmed. In this paper, a smart paint was fabricated with $BaTiO_3$ and $SrTiO_3$ ceramics in order to take advantage of the rapid characteristics of the PTC thermistor, which is the resistance changes abruptly above the Curie point. A coating agent was prepared to prevent the paint from peeling off the samples and the coated models were checked for resistance changes. Moreover, the resistance change of the $BaTiO_3$ and $SrTiO_3$ with temperature conditions was measured before and after coating.

• Journal of IKEEE
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• v.27 no.1
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• pp.85-92
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• 2023

Recently, as the era of the 4th Industrial Revolution approaches, IoT devices that emphasize portability are increasing. At the same time, battery usage is also increasing rapidly. With the rapid increase in battery usage, issues related to battery safety have become inevitable problems and many studies have been conducted. This paper deals with explosion issues caused by swelling among various battery issues, and includes research and development of a system that detects battery swelling by identifying resistance changes. The core technology of this study is to develop a system that frequently detects changes in the resistance of wires drawn on the battery through changes in volume that occur when the battery swelling, and uses the resistance changes to prevent battery explosion. In addition, through pattern analysis, it was analyzed how the wire should be constructed to cause a lot of resistance changes.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 1999.10a
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• pp.171-172
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• 1999

• Geophysics and Geophysical Exploration
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• v.12 no.4
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• pp.328-337
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• 2009

To investigate the relation between pore fluid conductivity and bulk resistivity of a rock sample it is assumed that electrolyte solution perfectly substitute the pore fluid that occupied the pore space within the sample in general. In this study, it is investigated that how much can the electrolyte solution substitute the pore fluid by repeating the same saturation process. Four kinds of NaCl solutions of 8, 160, 3200, 64000 ${\mu}S$/cm are used. The saturation process has repeated four times for each electrolyte in increasing conductivity order first then four times each in decreasing order. The more the saturation process repeated with the same electrolyte, the more electrolyte solution substitute the pore fluid. Geometric mean of bulk resistivity in increasing and decreasing orders with the same electrolyte solution is assumed to be mostly close to the bulk resistivity with perfect substitution. Bulk resistivity measurements for both increasing and decreasing order differs within 10% to the geometric mean when repeating the saturation process 4 times while maximum 40% difference is observed when single saturation process for each electrolyte solution with increasing order. The modified parallel resistant model can generally represent the relations between pore fluid resistivity and bulk resistivity in the experiment, but more experimental data with various rock samples with different porosity is needed to generalize the model.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.586-591
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• 2009

권 등(2008)은 수면보다 높은 정방형 다열기둥의 수리실험을 수행하여 바닥마찰과 구조물에 의한 흐름저항을 포함하고 항력상호작용계수가 적용된 Manning계수 형태의 상당저항계수 이론식을 제안하였으나 저항체의 횡방향 간격에 대해서는 충분한 연구가 수행되지 못하였다. 따라서 본 연구에서는 오리피스의 에너지 손실계수를 적용하여 횡방향 간격에 따른 항력상호작용계수식을 제안하였다. 또한 정방형 다열기둥의 다양한 횡방향 간격에 따른 흐름양상을 FLOW-3D를 이용한 수치실험을 수행하여 상당저항계수 n을 측정하였으며 수치실험 결과를 본 연구에서 제안한 횡방향 항력상호작용계수식이 적용된 이론식과 비교하였다. 이론식과 수치실험 결과는 잘 일치하였으며 이 결과로부터 본 논문에서 제안한 횡방향 항력상호작용계수식이 유효함을 확인하였다.

• Journal of the Korean Ceramic Society
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• v.38 no.3
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• pp.256-260
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• 2001

본 연구에서는 Sbrk 치환된 BaTiO$_3$에 그라파이트를 첨가하고 고상반응법을 이용하여 PTC 소자를 제조한 후, 저항-온도 특성을 조사하였으며 미세구조 분석을 통하여 그라파이트 첨가로 인한 PTC 특성 변화를 고찰하였다. 시편의 저항-온도 특성은 자체 제작한 저항-온도 특성 자동 측정 시스템을 사용하였으며 미세구조 고찰은 주사 전자 현미경을 사용하였다. 상온 저항값은 그라파이트를 1.5 mol% 첨가한 시편이 8.8Ω.cm로 가장 낮은 저항값을 나타내었고 저항-온도 계수는 그라파이트를 3.0 mol% 첨가한 시편이 22.4%/$^{\circ}C$로 가장 좋은 PTC 효과를 보였다. 미세구조 고찰 결과 그라파이트를 1.5 mol% 첨가한 경우 90$^{\circ}$ 및 180$^{\circ}$전계구조가 상당히 발달되었음을 볼수 있었다.