• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1165-1166
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• 2015

현재 가장 널리 사용되고 있는 전력용 지중케이블의 고분자 절연재료인 가교 폴리에틸렌(XLPE)은 전기적, 기계적으로 특성이 우수하다는 장점을 가지고 있지만 열경화성으로 인해 재활용이 어렵다. 본 연구에서는 환경친화적인 전력용 케이블을 개발하기 위해 열경화성인 XLPE를 대체할 수 있는 열가소성의 고분자 절연재료를 개발하는 것이다. 이를 위해 후보군의 재료들에 대한 단기적인 특성인 교류절연파괴 시험을 시행하였다. 또한, 중장기 특성을 평가하기 위해 가속수명시험(accelerated life test: ALT)을 수행하였다. 신뢰성있는 실험결과를 위하여 교류절연파괴시험과 가속수명시험에는 McKeown 전극계를 제작, 사용하였다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.479-480
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• 2015

단기 전력수급계획 시 미리 전력수요를 예측하고, 또 그때의 공급능력을 산정하는 일은 계통운영 측면에서 매우 중요한 과업중 하나이다. 각 발전기들은 시험기준 온도에 맞는 정격용량 값을 갖고 있지만, 실제 기온의 변화에 따라 각기 다른 출력변화를 갖게 되므로 계통운영자는 공급능력 산정 시 이러한 온도의 영향을 고려할 필요가 있다. 본 논문에서는, 온도를 고려한 공급능력 산정방안을 과거 실적 데이터 분석을 통한 두 가지 방법으로 제시해 보았다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.968-971
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• 2017

In this study, manufacturing the Single Base propellant using a Nitroguanidine(NGD A%, NGD-B%, 2A=B). The Factors affecting the combustion rate are Moisture and Volatiles, Residual Solvents, Dimension. These Factors were analyzed and compared. Also, NGD-A% propellants and NGD-B% propellants were compared with firing test Test. As a result, NGD-A% was confirmed to have a higher speed at a similar pressure than NGD-B% propellants.

• Korean Journal of Plant Resources
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• v.9 no.2
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• pp.157-163
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• 1996

This study was carried out to control the decrease of yield and the deterioration of quality of Angelica gigas roots by bolting. This phenomenon resulted from lignificartion and dwarfishness of roots because of bolting formed for inflorescence and fruition. Seedlings were grown for 60,90 and 120 days in nursery of the green house, and transplanted in main field to compare with traditional seedling that grew for 1 year. Growth of the petiole length compare with length and leaf width of aerial parts in nursery showed a remarkably progress, and root characters as root length, root diameter and root weight grew more vigorously in the order of nursery periods. Bolting was not entirely formed in plots transplanted the seedlings which grown for short-time; 60, 90 and 120days, but showed the high bolting rate, 64.3%,in traditional seedling plots. Yield was higher in plots that transplanted short-time growing seedlings than that transplanted traditional seedlings, and among 3 kinds of nursery periods yields were high in the order of nursery periods. For the increase of yield and decrease of bolting rate, it was needed to transplant small seedlings of 3-4g/plant which grew in nursery for 90-120 days.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3260-3268
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• 2009

A test apparatus has been fabricated to simulate chemical effect on head loss through a strainer in a pressurized water reactor (PWR) containment water pool after a loss of coolant accident (LOCA). Tests were conducted under condition of same ratio of strainer surface area to water volume between the test appratus and the containment sump. A series of tests have been performed to investigate the effects of spray, existence of calcium-silicate with tri-sodium phosphate (TSP), and composition of materials. The results showed that head loss across the chemical bed with even a small amount of calcium-silicate insulation instantaneously increased as soon as TSP was added to the test solution. Also, the head loss across the test screen is strongly affected by spray duration and is increased rapidly at the early stage, because of high dissolution and precipitation of aluminum and zinc. After passivation of aluminum and zinc by corrosion, the head loss increase is much slowed down and is mainly induced by materials such as calcium, silicon, and magnesium leached from NUKONTM and concrete. Furthermore, it is newly found that the spay buffer agent, tri-sodium phosphate, to form protective coating on the aluminum surface and reduce aluminum leaching is not effective for a large amount of aluminum and a long spray.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.609-616
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• 2019

This paper proposes a design plan of short-term temporary housing for the victims by disaster. Also construction workability and residential environment evaluated by mock-up. In particular, in the event of a disaster, victims have lived the auditorium or gymnasium of the nearby school which is an emergency shelter. However, there was a problem of livability. Therefore, it is the purpose of study to provide temporary housing that resides within 30 days. For this purpose, a composite panel with light weight and insulation select to produce mock-up. The mock-up complete in about an hour. This is because it is made only of the composite panels. The composite panels confirm to be easy to load and construct. And mock-up evaluates insulation and waterproofing performance in the laboratory. As a result, Mock-up has insulation and waterproofing performance. This suggests an alternative to short -term temporary housing.

• International Journal of Highway Engineering
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• v.8 no.1 s.27
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• pp.25-32
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• 2006

Behavior of concrete pavement due to temperature gradient was investigated for 48 hours at test road using Falling Weight Deflectometer. The deflections at slab center changed similarly to those of ambient temperature and temperature gradients in the slab. And rapid variations in the deflections were observed between 8 to 12 in the morning. However, dynamic modulus of subgrade reaction and joint deflections showed reverse trends to the ambient temperature and temperature gradients. The dynamic modulus of subgrade reaction was significantly affected by temperature gradient when its value got higher. Backcalculated elastic moduli were obtained using AREA method and Method of Equivalent Thickness. The trends of the backcalculated elastic modulus were similar to those of dynamic modulus of subgrade reaction. Measured load transfer efficiencies showed maximum peak in the morning due to dowel locking. However, additional effort is necessary to verify the result.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.149-154
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• 2005

최근에 이르러 농촌 인구의 도시유입으로 도시의 주거공간이 절대적으로 부족해지고 있으며, 이는 대도시의 아파트 가격 상승을 유발하는 등 부수적인 사회/경제적 문제를 일으키고 있다. 정부나 지방자치단체에서는 이러한 문제를 해결하기 위하여 대규모의 신도시 개발계획을 추진하고 있으며, 이러한 신도시 개발은 도시화로 인하여 환경적, 수문학적으로 부정적인 영향을 미치는 것으로 조사되고 있다. 도시화는 수문학적으로 산림이나 농경지와 같은 투수지역을 건물, 도로 등의 불투수지역으로 변화시키는 것이며 (Im 등, 2003), 이로 인하여 홍수파의 도달시간이 줄어들고 첨두유량이 증가하는 등의 수문변화를 수반하게 된다. 도로나 건물 등이 대부분을 차지하고 있는 도시지역에서는 지표면이나 식생으로부터 대기중으로 방출되는 증발산량이 농촌이나 산림지역보다 상대적으로 적으며, 강우시 토양중의 침투량과 지표면의 저류량도 도시지역에서는 매우 적게 나타난다. 신도시 개발 전후의 수문순환을 평가하는 방법 중의 하나는 개발예정지에 대한 장$\cdot$단기의 수문/수질 관측을 통하여 개발 전과 개발 후의 유출특성과 수질부하를 정량적으로 비교하는 것이다. 본 연구에서는 도시화로 인하여 대규모의 토지이용 변화가 예상되는 신도시 개발예정지구를 시험유역으로 선정하여 장기적인 수문/수질 모니터링을 실시하고자 한다. 또한, 시험유역에서 계측된 자료와 유역수문모형을 활용하여 개발전후의 홍수 및 유출특성을 분석하고 도시화가 하천의 수문 및 수질에 미치는 영향을 정량적으로 비교분석 함으로써 효율적인 저감 대책의 수립에 활용할 계획이다. 본 연구에서는 국내$\cdot$외의 시험유역의 운영 실태를 조사하고, 신도시 개발 등으로 인하여 급격한 도시화가 진행되고 있는 지구를 시험유역으로 선정하여 유역의 물순환 체계를 조사하고자 한다. 이를 위하여 신도시 개발지구와 도시정비사업지구를 대상후보지로 선정하여 개발계획 및 유역의 특성 등을 조사하고, 시험유역의 선정기준을 수립하여 연구의 목적과 부합되는 지구를 시험유역으로 선정하였으며 선정된 시험유역에 대하여 수문$\cdot$수질 조사 계획을 수립하고, 계측시설을 설치하여 시험운영을 실시하고, 향후 시험유역의 수문계측 및 관리방안을 수립하고자 한다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.1172-1175
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• 2003

Mutagenicity of white layer cake including 20 kGy-gamma irradiated egg white manufactured as a research on the practical approaches of gamma irradiation for the reduction of egg allergy was evaluated by Salmonella typhimurium reversion assay (Ames test). The water-soluble and organic solvents mixture of methanol: chloroform (2 : 1)-soluble fractions of the white layer cake including 20 kGy-gamma irradiated egg white were examined in S. typhimurium TA98 and TA100. Both with and without metabolic activation, the number of revertant colonies were not increased in each extract compared with negative controls. No significant difference in the formation of the colonies was observed at the non-irradiated and 20 kGy-irradiated samples. The results indicate that there is no evidence of mutagenicity in white layer cake including 20 kGy-gamma irradiated egg white.

• Journal of the Society of Disaster Information
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• v.15 no.4
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• pp.590-596
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• 2019

Purpose: An experimental study was conducted on the sand samples for the size effect of the test specimens, one of the problems of the direct shear test. Method: Jumunjin standard sand, a representative sand of Korea, was used as sand sample. The large direct shear test was performed to analyze the shear strength at 50%, 60%, 70%, and 80% relative density, and then the comparative results were compared with the test results of the small direct shear test. Result: It was analyzed that the internal friction angle of the small shear tester tended to be relatively large in the dense region. It was analyzed that the results of the large shear tester tend to be relatively large in the region of medium relative density. Conclusion: The size effect on the samples in the direct shear test on sandy soil was analyzed to be relatively small.