• 한국재료학회지
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• 제26권9호
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• pp.460-467
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• 2016

Activated carbons (ACs) have been used as EDLC (electric double-layer capacitor) electrode materials due to their high specific area, stability, and ecological advantages. In order to prepare ACs with high density and crystallinity, coal tar pitch (CTP) was activated by $K_2CO_3$ and the textural and electrochemical properties of the obtained ACs were investigated. Although the CTP ACs formed by $K_2CO_3$ activation had much smaller specific surface area and pore volume than did the CTP ACs formed by KOH activation, their volumetric specific capacitance (F/cc) levels as electrode materials for EDLC were comparable due to their higher density and micro-crystallinity. Structural characterization and EDLC-electrode performance were studied with different activation conditions of $CTP/K_2CO_3$ ratio, activation temperature, and activation period.

• 한국안전학회지
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• 제6권3호
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• pp.12-20
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• 1991

The dielectric properties that effect to electric safety for unsaturated Pelvester resin were studied over the temperature range of 30-40［$^{\circ}C$］ and the frequency range of 110~3$\times$10$^{6}$ ［Hz］. According to the results of the study, it has been observed that two kinds of dielectric losses in electric safety were existed by the molecular movement of C-H and OH group. When the ,adio of hardener was 1.5［%］, the characteristics of specimens were excellent in view of the electrical materical. In the range of measuring frequency the dielectric constants and the dielectric losses were 3.5~5.5 and 10$^2$~10$^3$ respectly. The activation energy of loss spectrum in aspect of electric safety and the entropy appeared at the 30［$^{\circ}C$］ were 33.4［Kacl/mole］ and 54.9［cal/mole.deg］ respectly.

• Journal of Korean Vacuum Science & Technology
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• 제3권1호
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• pp.95-97
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• 1999

A 3.12" FED panel was packaged successfully using the anode plate on which phosphors and black matrix were coated and cathode plate containing emitter arrays. The vacuum level of the panel was investigated during panel evacuation, tip-off and getter activation process. The packaged panel exhibited vacuum level below 2${\times}$10-6 Torr. Similar experiments were carried out for 10" panel made of bare plates. In addition, the vacuum level of two panels was compared continuously after tip off process; one with the getter and the other without it.

• Corrosion Science and Technology
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• 제2권1호
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• pp.41-46
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• 2003

Flow-Accelerated Corrosion behavior concerning both activation and mass transfer process of SA106 Gr.C steel was studied using rotating cylinder electrode in room temperature alkaline solution by DC and AC electrochemical techniques. Passive film was tanned from pH 9.8 by step oxidation of ferrous product into hydroxyl compound. Corrosion potential shifted slightly upward with rotating velocity through the diffusion of cathodic species. Corrosion current density increased with rotating velocity in pH 6.98, while it soon saturated from 1000 rpm at above pH 9.8. On the other hand the limiting current increased with rotating speed regardless of pH values. It seems that activation process, which represents formation of passive film on the bare metal surface, controls the entire corrosion kinetics

• 한국재료학회:학술대회논문집
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• 한국재료학회 2010년도 춘계학술발표대회
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• pp.56.1-56.1
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• 2010

A novel electrochemical potentiostatic method has been examined in order to enhance the hole concentration of p-type GaN thin films using KOH and HCl electrolyte. The hole concentration was increased more than 2 times by the electric voltge apply with the mobility of $10{\sim}12cm^2/V.s$. At optimum condition of 3V apply, hole concentration was enhanced more than reference sample from $1.7{\times}10^{-17}cm^{-3}$ to $4.1{\times}10^{-17}cm^{-3}$. Application of this activation method to blue-LED fabrication improved optical output from 18.4mW to 20.6mW, that is ~12% increase. SIMS analysis indicates that nearly 70% of hydrogen atoms could be removed by this method.

• 한국세라믹학회지
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• 제32권12호
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• pp.1331-1336
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• 1995

The glass-ceramics for ferro-electric were made from compositions of 70PbO.16TiO2.8SiO2.4B2O3.2AlPO4 (wt%) and 67.5PbO.20TiO2.8.5SiO2.2B2O3.2AlPO4 (wt%). The crystallization kinetics for PbTiO3 crystalline phase formation from glass was studied using non-isothermal DSC techniques. The values of activation energy, ΔE using variables of heating rate and temperature were calculated at various reaction fractions obtained from peak area over DSC. The results indicated that activation energy was lowest at 60% reaction fractions and the activation energy of glass containing 20.0 wt% TiO2 is higher than that of glass containing 16.0 wt% TiO2. The crystallization mechanism was three dimensional growth (n=4).

• 제어로봇시스템학회논문지
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• 제3권6호
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• pp.594-601
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• 1997

A new algorithm is proposed for training the multilayer perceptrion(MLP) in pattern classification problems to accelerate the learning speed. It is shown that the sigmoid activation function of the output node can have deterimental effect on the performance of learning. To overcome this detrimental effect and to use the information fully in supervised learning, an objective function for binary modes is proposed. This objective function is composed with two new output activation functions which are selectively used depending on desired values of training patterns. The effect of the objective function is analyzed and a training algorithm is proposed based on this. Its performance is tested in several examples. Simulation results show that the performance of the proposed method is better than that of the conventional error back propagation (EBP) method.

• 한국수소및신에너지학회논문집
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• 제26권6호
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• pp.547-553
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• 2015

For commercialization of fuel cell electric vehicles, one of the key objectives is to reduce cost of full stack assembly. Regarding Membrane Electrode Assembly, the major issue is to improve fuel cell activation process in the initial Hydrogen Oxidation Reaction and Oxygen Reduction Reaction. In this research, the VD (Vacuum Drying) process has been developed for improvement of activation process. The VD condition is developed by controlling the temperature and degree of vacuum to remove the remaining solvent of electrode. Consequently, the electrode applied to VD process showed the low characteristics such as 3.5% of remaining solvent content and the improved efficiency such as 15% of activation process speed.

• 한국가축번식학회지
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• 제17권4호
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• pp.287-294
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• 1994

This study was to investigate the effects of electrofusion, activation and developmental stage of donor embryos on in vitro development of nuclear transplant bovine embryos. A single blastomere nucleus from 8-cell to morula stage embryos produced by in vitro fertilization(IVF) was transferred into a recipient oocyte enucleated at 23∼25 h after in vitro maturation(IVM) or into a recipient oocyte enucleated and cultured for 14∼15 h. In one experiment the nuclear transplant embryos were subjected to additional activation treatments. Fusion rate of nuclear transplant eggs was high at direct current(D.C) voltages of 1.0 and 1.5 kV/cm 991.5 and 93.3%, respectively), but decreased at 2.0kV/cm (81.8%). Additional activation treatments by electric pulases or 7% ethanol did not affect the cleavage and development of nuclear transplant embryos. Development of nuclear transplant embryos slightly increased by delayed nuclear transfer and fusion (42∼43 h after IVM). With this system, blastocysts were obtained from transfer of 8-cell to morula stage donor nuclei (9.6%∼2.4%). The result of this study suggests that nucleo-cytoplasmic interactins, expecially activation of ooplast are very important for the development of nuclear transplant embryos, and donor cell stage does not affect the development of nuclear transplant embryos.

• Reproductive and Developmental Biology
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• 제30권1호
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• pp.1-5
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• 2006

핵이식 방법을 이용하여 성공적인 복제를 이루기 위해서 인위적인 활성화 처리는 필수적인 요소이다. 본 연구는 전기자극에 의해 활성화된 난자를 chemical agent를 이용하여 추가적인 활성화 처리를 하였을 때 돼지 단위발생란의 발달에 미치는 영향을 알아보고자 수행되었다. 체외에서 $40{\sim}44$시간 동안 배양된 난자를 전기자극(E)으로 활성화 처리한 후 Thimerasol + Dithiothreitol(Thi+DTT), 6-Dimethylaminopurine(6-DMAP) 및 Cycloheximide(CH)를 사용하여 추가 활성화 처리를 하였다. 활성화 방법(E, E+Thi+DTT, E+6-DMAP 및 E+CH)에 따른 단위발생란의 배반포까지의 발달율을 조사한 결과, chemical agent에 의해 추가 활성화된 단위발생란이 전기자극만으로 처리된 구의 단위발생란보다 유의적으로 높은 발달율을 보였다($21.5{\sim}28.1%$ vs. 18.0%, P<0.05). 특히, E+Thi+DTT를 이용하였을 때 발달율이 유의적으로 높게 나타났다(28.1%, P<0.05). 활성화 처리별 전핵 형성율을 조사한 결과, chemical agent에 의해 추가 활성화 처리된 구에서 하나의 극체(1PN) 형성률은 처리별로 차이를 보이지 않았으나$(59.9{\sim}64.7%)$, 2PN 형성율은 추가 활성화 처리구에서 전기자극만을 사용하였을 때보다 유의적으로 높게 나타났다($7.2{\sim}9.7%$ vs. 4.3%, P<0.05). 이상의 결과를 살펴볼 때, 전기자극 후 chemical agent를 이용한 추가 활성화는 단위발생란의 배반포까지의 발달능력을 증가시키는 것으로 생각된다.