• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.414-419
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• 2002

The dielectric breakdown of epoxy composites used for transformers was experimented and then its data were simulated by Weibull distribution probability. First of all, speaking of dielectric breakdown properties, the more hardener increased the stronger breakdown strength at low temperature because of cross-linked density by the virtue of ester radical. The breakdown strength of specimens with filler was lower than it of non-filler specimens because it is believed that the adding filler forms interface and charge is accumulated in it, therefore the molecular motility is raised and the electric field is concentrated. In the case of (idled specimens with treating silane, the breakdown strength become much higher Finally, from the analysis of weibull distribution, it was confirmed that as the allowed breakdown probability was given by 0.1[%], the applied field value needed to be under 21.5 MV/cm.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.1200-1203
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• 2003

The dielectric breakdown of epoxy composites used for transformers was experimented and then its data were applied to Weibull distribution probability. First of all, speaking of dielectric breakdown properties, the more hardener increased, the stronger breakdown strength became at low temperature because of cross-linked density by the virtue of ester radical. The breakdown strength of specimens with filler was lower than it of non-filler specimens because it is believed that the adding filler forms interface and charge is accumulated in it, therefore the molecular motility is raised and the electric field is concentrated. In the case of filled specimens with treating silane, the breakdown strength become much higher. Finally, according to Weibull distribution analysis, reducing breakdown probability of equipment insulation lower than 0.1% level requires the allowable field allowable field intensity values to be kept under 21.5 MV/cm.

• International Journal of Concrete Structures and Materials
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• 제3권2호
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• pp.97-101
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• 2009

It has been known that acid-resistant concretes on the liquid glass basis have high porosity (up to 18${\sim}$20%), low strength and insufficient water resistance. Therefore they can not be used as materials for load-bearing structural elements. Significant increasing of silicate matrix strength and density was carried out by incorporation of special liquid organic alkali-soluble silicate additives, which block of superficial pores and reduces concrete shrinkage deformation. It was demonstrated that introduction of tetrafurfuryloxisilane additive sharply increases strength, durability and shock resistance of silicate polymer concrete in aggressive media. This effect is attributable to hardening of contacts between silicate binder gel globes and modification of alkaline component owing to "inoculation" of the furan radical. The optimal concrete composition with the increased strength, chemical resistance in the aggressive environments, density and crack resistance was obtained.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
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• pp.212-217
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• 2002

The dielectric breakdown of epoxy composites used for transformers was experimented and then its data were simulated by Weibull distribution probability. First of all, speaking of dielectric breakdown properties, the more hardener increased the stronger breakdown strength at low temperature because of cross-linked density by the virtue of ester radical. The breakdown strength of specimens with filler was lower than it of non-filler specimens because it is believed that the adding filler forms interface and charge is accumulated in it, therefore the molecular motility is raised and the electric field is concentrated. In the case of filled specimens with treating silane, the breakdown strength become much higher Finally, from the analysis of weibull distribution, it was confirmed that as the allowed breakdown probability was given by 0.1[%], the applied field value needed to be under 21.5 MV/cm.

• 한국전기전자재료학회논문지
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• 제14권8호
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• pp.647-651
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• 2001

The dielectric breakdown of epoxy composites used for transformers was experimented and then its data were applied to Weibull distribution probability. First of all, speaking of dielectric breakdown properties, the more hardener increased, the stronger breakdown strength became at low temperature because of cross-linked density by the virtue of ester radical. The breakdown strength of specimens with filler was lower than it of non-filler specimens because it is believed that the adding filler forms interface and charge is accumulated in it, therefore the molecular motility is raised and the electric filed is concentrated. In the case of filled specimens with treating silane, the breakdown strength become much higher. Finally, from the analysis of weibull distribution, it was confirmed that to low allowed breakdown probability under 0,.1%, the applied field value needed to be under 21.5MV/cm.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 기술교육전문연구회
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• pp.159-163
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• 2003

In this study, the DC dielectric breakdown of epoxy composites used for PCB material was experimented and then its data were simulated by Weibull distribution equation. The more hardener increased the stronger breakdown strength at low temperature because of cross-linked density by the virtue of ester radical, and the breakdown strength of specimens with filler was lower than it of non-filler specimens because it is believed that the adding filler forms interface and charge is accumulated in it, therefore the molecular motility is raised, the electric field is concentrated, and the acceleration of electron and the growth of electron avalanche are early accomplished. From the analysis of Weibull distribution, it was confirmed that as the allowed breakdown probability was given by 0.1[%], the applied field value needed to be under 21.5[kV/mm].

• Biomolecules & Therapeutics
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• 제14권4호
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• pp.207-215
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• 2006

Sachungwhan reduced hepatotoxicity induced by carbon tetrachloride($CCl_4$). Improved liver function was observed by measuring the activities of aspartate aminotransferase(AST), alanine aminotransferase(ALT), alkaline phosphatase(ALP), blood urea nitrogen(BUN), creatinine(CRE), total cholesterol(TCHO), triglyceride(TG), low density lipoprotein cholesterol(LDL-CHO), high density lipoprotein cholesterol(HDL-CHO), total protein(TP), albumin(ALB) and total bilirubin(BIL) in serum. Hepatic parameters monitored were levels of cholesterol(CHO), triglyceride(TG), malondialdehyde(MDA), content of cytochrome P450(CYP), level of glutathione(GSH), and activities of NADPH-CYP reductase, superoxide dismutase(SOD), catalase(CAT), glutathione S-transferase(GST), glutathione reductase(GR), glutathione peroxidase(GPx). The histopathological examination showed that the treatment of Sachungwhan relieved the ballooning degeneration of hepatocytes which had been generated by $CCl_4$. The results suggested that hepatoprotective effects of Sachungwhan possibly are due to their promising antioxidative activity.

• Current Applied Physics
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• 제18권11호
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• pp.1375-1380
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• 2018

Atmospheric-pressure plasma has a great potential in many applications due to its simplicity rather than low pressure plasmas. In material processing, biomedical applications, and many other applications, the input power, gas flow rate, and the geometry of electrode have been mainly considered and studied as important external parameters of atmospheric-pressure plasma control. Besides, since the atmospheric-pressure plasmas are typically generated in an open air, the relative humidity is difficult to control and can change day by day. Therefore, the relative humidity cannot be ignored for plasmas. Thus, in this work, the atmospheric-pressure plasma jet was characterized by changing relative humidity, and it was found that the increase in electron density and OH radicals are due to Penning ionization between helium metastable and water vapors at higher humidity condition.

• 디지털융복합연구
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• 제16권4호
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• pp.95-105
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• 2018

본 연구는 구미 클러스터내 기술지식 교류 네트워크에서 기술적 급진성에 대한 네트워크 폐쇄와 구조적 공백의 역할을 실증적으로 검증한 연구이다. 분석을 위해 협회*기업(2-mode)네트워크 자료를 기업*기업(1-mode) 네트워크 자료로 변환하여 2,550개 기업 네트워크를 구축하였다. 또한 기업의 특성을 조사하기 위해 구미국가산업단지에 있는 기업을 대상으로 랜덤추출을 통해 101개 기업에게 설문을 실시하였으며 최종적으로는 86개 기업을 수집하였다. 분석을 위해, 네트워크 폐쇄와 구조적 공백의 사회네트워크 분석 지표인 네트워크 밀도와 효율성이 높은 수준의 다중공선성을 갖고 있어 능형회귀분석을 이용하였다. 분석결과 구조적 공백은 기업의 급진적 혁신에 긍정적인 영향을 미치는 것으로 나타났으며, 네트워크 밀도는 급진적 혁신에 부정적인 영향을 미치는 것으로 나타났다. 본 연구는 과거의 개념적인 논의와 문헌연구에 기반 했던 네트워크 패쇄와 구조적 공백의 논쟁에 실증적 증거 제시하는데 공헌하고 나아가 급진적 혁신을 달성하기 위한 사회적 자본의 구축 전략 수립에 도움을 준다. 향후 연구에서는 다양한 네트워크의 구조적 특성을 찾아내려는 노력이 필요할 것이며, 기술 지식의 특성, 혁신 유형, 네트워크 폐쇄와 구조적 공백의 상호작용 등에 관심을 두어야 할 것이다.

• 현장농수산연구지
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• 제21권2호
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• pp.35-47
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• 2019

간버섯 균주의 균사 생장은 PDA와 YMA에서 균사의 밀도와 생장량이 양호하였으나, MEA에서는 균사 생장량과 속도가 저조하였다. 배양 기간 중 광(光)조사는 균사체의 색소 형성과 균사체 밀도에 영향을 주었다. 간버섯은 병 재배와 봉지 재배 모두에서 자실체를 발생시킬 수 있었고 종균 배양과 재배를 위한 가장 적합한 배지 원료는 참나무톱밥으로 밝혀졌다. 톱밥배지를 사용한 인공재배에서 자실체의 발생은 15일째부터 육안으로 확인할 수 있는 정도로 자실체 원기가 생장하였으며 상대습도가 낮은 처리구에서 5일 정도 빠르게 형성되었다. 버섯 발생 40~45일째에는 성숙한자실체를 수확할 수 있었고, 생육실의 상대습도가 낮은 편이 버섯 발생과 생육에 유리하였다. 인공재배에서 수확한 자실체의 항산화 활성을 조사한 결과, 간버섯의 ABTS radical 소거 활성은 병 재배 자실체 추출물과 야생 간버섯 자실체 methanol 추출물이 각각 505㎍/㎖, 515㎍/㎖의 농도로 낮은 활성을 나타내었으나 봉지 재배에서 수확한 자실체는 910㎍/㎖로 높게 나타났다. DPPH radical 소거 활성 결과 모든 추출물이 활성 2,000㎍/㎖ 농도 이상의 IC₅₀값으로 활성을 나타내지 않았다. 간버섯의 ethyl acetate 추출물의 경우 간버섯 병 재배 자실체 추출물이 IC₅₀값 154.5㎍/㎖으로 가장 높은 활성을 보이는 것으로 나타났으며, 간버섯 methanol 추출물은 동일 농도(10mg/㎖)에서 ABTS radical 소거 활성은 야생 간버섯 자실체 추출물이 가장 높은 활성을 보였다.