• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.1
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• pp.50-56
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• 2005

The electrical properties, clamping voltage characteristics, and stability of dysprosia-doped ZnO-P $r_{6}$ $O_{11}$-based varistors were investigated with different dysprosia contents from 0 to 2.0 mol%. The incorporation of dysprosia in varistor ceramics greatly increased the varistor voltage from 50 to 481.0 V/mm. It was found that the dysprosia is good additive improving a nonlinearity, in which the nonlinear exponent is above or near 50, and the leakage current is below 1.0 $\mu$A. The dysprosia-doped varistors exhibited superior clamping voltage characetristics, in which clamping voltage ratio is above or neat 2 at surge current of 50 A. The 0.5 mol% dysprosia-doped varistors only exhibited high stability, with the rate of varistor voltage of -0.9%, under DC acceleraetd aging stress, 0.95 $V_{lmA}$/15$0^{\circ}C$/24 h.h.h.h.

• Journal of Welding and Joining
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• v.31 no.5
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• pp.77-81
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• 2013

We have investigated thermal stability of the mechanical and thermal conductive properties of Cu/STS/Cu 3 layered clad metal lead frame material for a LED device package at different temperatures ranging from RT to $200^{\circ}C$. The fabricated Cu/STS/Cu clad metal has a good thermal stability for the mechanical tensile strength and thermal conductivity of the over 50 $Kg/mm^2$ to the $150^{\circ}C$ and 270 $W/m{\cdot}K$ to the $200^{\circ}C$, respectively. This clad metal lead frame material at a high temperature of $150^{\circ}C$ shows a reinforced mechanical tensile strength by 1.5 times to conventional pure copper lead frame materials and also a comparable thermal conductivity to typical copper alloy lead frame materials.

• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.3
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• pp.41-53
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• 2011

For manufacturing the tape for repairing archival documents, we tested ten carrier candidates for selecting best material. The tensile strength, transmissivity, stability of deterioration, and processability were determined. Physical-chemical characteristics and stability of deterioration was best to the Hanji. Tensile strength and transmissivity was best in tracing paper, but was low in oil paper, white sketch paper, lyon coat paper. Synthetic carrier to tensile strength showed higher than paper carrier and to the transmissivity showed 2-8 times higher than paper carriers. The tracing paper to the transmissivity was 10 times higher than others. To determine characteristic of conservation to the selected carriers, stability of deterioration was examined at conditions of $90^{\circ}C$ for 15 days. Oil paper and white sketch paper turned strongly yellowish. Cellulopane, Felt, and Cpp film showed stable stability of deterioration, but deformation like wrinkles. PET film and Syntheletic film showed excellent conservation characteristics without any change of exterior. Test of adhesive uniform between carriers and adhesive processability was performed. PET film > Syntheletic film > Tracing Paper in order were determined. Ununiformal adhesive characteristics appeared to Hangi. Accordingly, we thought that Hanji as carrier material might be unsuitable because of low adhesive processability.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.330-333
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• 2002

The stability against DC accelerated aging stress of $Dy_{2}O_{3}-doped$ $ZnO-Pr_{6}O_{11}-based$ varistor ceramics was investigated. The calculated nonlinear exponent$(\alpha)$ in varistor ceramics without $Dy_{2}O_{3}$ was only 4.9, whereas the $\alpha$ value of the varistors with $Dy_{2}O_{3}$ was abruptly increased in the range of 48.8 to 58.6. The varistor ceramics with $Dy_{2}O_{3}$ content of 1.0 mol% exhibited maximum ${\alpha}$, reaching 58.6, whereas they exhibited very poor stability. While, The varistor ceramics doped with 0.5 mol% $Dy_{2}O_{3}$ exhibited not only the high nonlinearity, which the ${\alpha}$ is 55.3 and the leakage current is $0.1{\mu}A$， but also the highest stability, which the variation rates of varistor voltage and nonlinear exponent are -0.8% and -14.3%, respectively, under DC accelerated aging stress, $0.95 V_{1mA}/150^{\circ}C/24h$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.4
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• pp.204-209
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• 2017

Thermal and structural stability in the glass transition region of chalcogenide glasses has been investigated in terms of thermodynamics for application to various optoelectronic devices. In this study, the compositions of $Ge_xSb_{20}Se_{80-x}$ (x = 10, 15, 20, 25, and 30) were selected to investigate the glass stability according to germanium ratios. The chalcogenide bulks were fabricated by using a traditional melt-quenching method. Thin films were deposited by a thermal evaporation system, maintaining the deposition ratio of $3{\sim}5{\AA}$ in order to have uniformity. The thermal and structural properties were measured by a differential scanning calorimeter (DSC) and X-ray diffraction (XRD). The DSC analysis provided thermal parameters and theoretical glass region stabilities. The XRD analysis supported the theoretical stabilities because of where the crystallization peak data occurred.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.7
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• pp.510-514
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• 2018

This study discusses and demonstrates the structural stability of highly ordered Pt patterns formed on a transparent and flexible substrate through the process of nanotransfer printing (nTP). Bending tests comprising approximately 1,000 cycles were conducted for observing Pt line patterns with a width of $1{\mu}m$ formed along the direction of the horizontal (x-axis) and vertical (y-axis) axes ($15mm{\times}15mm$); and adhesion tests were performed with an ultrasonicator for a period greater than ten minutes, to analyze the Pt crossbar patterns. The durability of both types of patterns was systematically analyzed by employing various microscopes. The results show that the Pt line and Pt crossbar patterns obtained through nTP are structurally stable and do not exhibit any cracks, breaks, or damages. These results corroborate that nTP is a promising nanotechnology that can be applied to flexible electronic devices. Furthermore, the multiple patterns obtained through nTP can improve the working performance of flexible devices by providing excellent structural stability.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.3-6
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• 2001

In common globular proteins, the native form is in its most stable state. However, the native form of inhibitory serpins (serine protease inhibitors) and some viral membrane fusion proteins is in a metastable state. Metastability in these Proteins is critical to their biological functions. Our previous studies revealed that unusual interactions, such as side-chain overpacking, buried polar groups, surface hydrophobic pockets, and internal cavities are the structural basis of the native metastability. To understand the mechanism by which these structural defects regulate protein functions, cavity-filling mutations of ${\alpha}$1-antitrypsin, a prototype serpin, were characterized. Increasing conformational stability is correlated with decreasing inhibitory activity. Moreover, the activity loss appears to correlate with the decrease in the rate of the conformational switch during complex formation with a target protease. We also increased the stability of ${\alpha}$1-antitrypsin greatly via combining various stabilizing single amino acid substitutions that were distributed throughout the molecule. The results showed that a substantial increase of stability, over 13 kcal/mol, affected the inhibitory activity with a correlation of 11% activity loss per kcal/mol. The results strongly suggest that the native metastability of proteins is indeed a structural design that regulates protein functions and that the native strain of e 1-antitrypsin distributed throughout the molecule regulates the inhibitory function in a concerted manner.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.3-6
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• 2003

This paper describes the interface stability of Ta-Mo alloy metal on $SiO_2$ Alloy was formed by co-sputtering method, and the alloy composition was varied by controlling Ta and Mo sputtering power. When the atomic composition of Ta was about 91%, the measured work function was 4.2eV that is suitable for NMOS gate. To identify interface stability between Ta-Mo alloy metal and $SiO_2$, C-V, FE-SEM(Field Emission-SEM), and XRD(X-ray diffraction) were performed on the samples annealed with rapid thermal processor between $600^{\circ}C$ and $900^{\circ}C$. Even after $900^{\circ}C$ rapid thermal annealing, excellent interface stability and electrical properties were observed. Also, thermodynamic analysis was studied to compare with experimental results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.16-17
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• 2006

In this paper, Ni-V alloy was studied with different structures and thickness. In case of Ni-V and Ni-V/Co/TiN, low resistive Ni silicide was formed after one step RTP (Rapid Thermal Process) with temperature range from $400^{\circ}C$ to $600^{\circ}C$ for 30sec in vacuum. After furnace annealing with temperatures range from $550^{\circ}C$ to $650^{\circ}C$ for 30min in nitrogen ambient, Ni-V single structure shows the best thermal stability compare with the other ones. To enhance the thermal stability up to 650oC and find the optimal thickness of Ni silicide, different thickness of Ni-V was studied in this work. Stable sheet resistance was obtained through Ni-V single structure with optimal Ni-V thickness.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.2
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• pp.107-113
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• 2009

In order to improve air stability, we proposed a new active layer of an organic TFT by synthesizing P3HT/POSS conjugated polymer. P3HT/POSS OTFTs with the various P3HT/POSS volume ratios were fabricated and characterized. With the P3HT/POSS volume ratio of 1:1, we achieved the field-effect mobilities of ${\sim}1.19{\times}10^{-3}\;cm^2/v{\cdot}sec$ in the saturation region and the current on/off ratio of ${\sim}2.51{\times}10^2$. The resulting current on-off ratio was much higher than that of the P3HT-based OTFTs and resulted from the dramatic decrease of the off-current. Since the off-current can be reduced by preventing oxygen in atmosphere from doping the P3HT/POSS active layers, this new active layer shows its ability to avoid oxygen doping in atmosphere. Therefore, the improvement of the air stability can be achieved by employing the P3HT/POSS active layers.