• 콘크리트학회지
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• 제17권2호
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• pp.60-64
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• 2005

• 드라이브 ㆍ 컨트롤
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• 제17권4호
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• pp.161-164
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• 2020

• 한국제4기학회지
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• 제15권1호
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• pp.13-20
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• 2001

한반도 남동부 산지대의 식생과 자연환경변천 과정을 밝히기 위하여 무제치늪(해발 52Om)의 퇴적물을 대상으로 화분분석과 $^{14}C$측정을 실시하였다. 그 결과 화분군은 냉온대 북부/고산지형 침엽.낙엽활엽혼합림 시대(MI), 냉온대 중부/산지형 낙엽활엽수림 시대(MIIa), 냉온대 남부/저산지형 침엽.낙엽활엽혼합림 시대(MIIb)로 변천하였음을 알 수 있었다. 그리고 현재 한반도 남동부 산지대에 분포하는 냉온대 낙엽활엽수림은 약 8,000yr B.P.부터 분포역을 확대하기 시작하였고. 약 6,700yr B.P.부터 지역적으로 분화 발달하였음을 알 수 있었다.

• 설비공학논문집
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• 제19권7호
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• pp.485-490
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• 2007

The LNG BOG re-liquefaction system for LNG carriers was designed based on the Claude refrigeration cycle and the thermodynamic analysis was carried out in order to find the design point of the three heat exchangers constituting the system. The thermodynamic analysis revealed that the system state could be defined by the three cold endpoint temperatures of the three-pass heat exchanger. Hence the iso-lines of the specific liquefaction work, taken as the performance indicator, were presented in terms of those three temperatures and discussed. The system was found most economical when those three temperatures approached a single temperature of $-140^{\circ}C$ and thus this system state could be taken as the design point for the heat exchangers.

• 복식
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• 제5권
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• pp.83-101
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• 1981

This study is to research and analyse the Musicians' Costumes in Yi dynasty. Each costume for the musicians was, at that time, different in its design and style in accordance with what class the musicians were belonging to and what ceremony they were playing for, and the form and substance of them were changed according to the ages. In the early of Yi dynasty, the musicians wore their costumes imitated from the Song dynasty's. Especially in the 13th year of King Sae-Jong(1431), they divided the costumes into A-ag-Seo Jeon-ag Gwan-bog(雅樂署 典樂冠服) and Jeon-ag-Seo Gwan-bog(典樂署冠服). Meanwhile the musicians had to put on their different kinds of costumes according to the sorts of ceremonies they were playing for since January of the 16th year of king Sae-Jong(1434). It is widely known that confucianism was made a national policy in Yi dynasty. Compared the musicians' costumes for sacrificial rituals, however, with those for every kind of ceremony, one was simpler and shabbier without any strictly established forms than the other. At the same time, the musicians' costumes for ceremonies were, instead, designed in more gorgeous forms; it means that the sacrificial ritual was very lightly dealt at that time. It is very difficult to define, by standard pictures the whole style and form of the musicians' costumes in Yi dynasty in this study. Since we haven't shown any examples of the costumes, this attempt will be keepful.

• 대한기계학회논문집B
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• 제28권11호
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• pp.1390-1397
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• 2004

This study is concerned with the thermal analysis during the cool-down period of 135,000㎥ class GT-96 membrane type LNG carrier under IMO and USCG design condition. During the cool-down period, the spraying rate for the NG cooling decreases as the temperature of NG falls down from -4$0^{\circ}C$ to -l3$0^{\circ}C$, and the spraying rate for the cooling of the insulation wall increases as the temperature gradient of the insulation wall is large. It was confirmed that there existed the largest temperature decrease at the first barrier and the first insulation, which are among the insulation wall, especially in the top side of the insulation wall under IMO and USCG design condition. Also, as the NG temperature distribution is fixed, the outer temperature condition under the design condition has influence on the temperature variation at the insulation. By the 3-D numerical calculation about the cargo tank and the cofferdam during the cool-down period, the temperature variation in hulls and insulations is precisely predicted under IMO and USCG design condition. From the comparison between two conditions; IMO design condition shows more severe temperature gradient than USCG design condition, therefore, it provides the conservative estimation of the BOG.

• 한국수소및신에너지학회논문집
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• 제33권6호
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• pp.827-837
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• 2022

If the hydrogen industry is activated, the introduction of C-type and pressurized liquefied hydrogen (LH2) tank suitable for small and medium-sized transp- ortation and storage will be given priority in the future. Therefore in this paper, the behavior for the LH2 property changes and boil-off gas (BOG) treatment of the C-type cargo tank through voyage of the LH2 carrier and pressurized tank of the LH2 receiving terminal were analyzed through computational simulations by making assumptions about the carrier operation and unloading conditions.

• 한국초전도ㆍ저온공학회논문지
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• 제25권4호
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• pp.65-69
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• 2023

Hydrogen is an eco-friendly energy source and is being actively researched in various fields around the world, including mobility and aerospace. In order to effectively utilize hydrogen energy, it should be used in a liquid state with high energy storage density, but when hydrogen is stored in a liquid state, BOG (boil-off gas) is generated due to the temperature difference with the atmosphere. This should be re-condensed when considering storage efficiency and economy. In particular, large-capacity liquid hydrogen storage tank is required a gaseous helium circulation cooling system that cools by circulating cryogenic refrigerant due to the increase in heat intrusion from external air as the heat transfer area increases and the wide distribution of the gas layer inside the tank. In order to effectively apply the system, thermo-hydraulic analysis through process analysis is required. In this study, the condenser design and system characteristics of a gaseous helium circulation cooling system for BOG recondensation of a liquefied hydrogen storage tank were compared.

• 대한기계학회논문집 C: 기술과 교육
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• 제1권1호
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• pp.99-105
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• 2013

LNG 극저온기계기술 시험인증센터에 구축되는 LNG 선박용 펌프 및 압축기 성능시험에서 발생하는 증발가스는 안전을 위하여 전량 회수가 요구된다. 본 논문에서는 36 MTD 용량의 천연가스 재액화 시스템에 대한 기본 설계 연구를 수행하였다. 대기압, $-60^{\circ}C$, 일반적인 도시가스 조성비, 1,500 kg/hr 유량의 공급 가스를 기본 설계 조건으로 하여 공정 설계가 이루어졌고, 입구 온도 조건 및 가스 조성비에 따른 LNG 생산량 또한 계산하여 다양한 입구 설계 조건에 따른 시스템의 성능 변화를 비교, 분석하였다. 공정 설계 외에도 재액화 시스템의 핵심 기기인 송풍기, 압축기, 극저온 열교환기, 컴팬더의 제작 사양이 도출되었으며, 전력 및 냉각수의 유틸리티 요구조건 또한 기본 설계를 통해 도출되었다.

• 농업과학연구
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• 제20권2호
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• pp.145-152
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• 1993

대암산(大岩山) 용늪 주변(周邊) 산림군집(森林群集)의 구조(構造) 및 종조성(種組成)과 입지(立地)와의 관계(關係)를 구명(究明)하기 위하여 TWINSPAN과 DCCA를 사용(使用)하여 분석(分析)한 결과(結果)는 다음과 같다. 중요치(重要値)가 높은 종(種)은 Quercus mongolica, Acer pseudo-sieboldianum, Betula costata, Acer mono 등(等)의 순(順)이다. 산림토양(森林土壤)의 pH는 용늪 주변(周邊)이 5.0-5.5이고 용늪 내에서 5.3-5.4로 차이가 없었다. 대암산(大岩山)의 산림군집(森林群集)은 Quercus mongolica-Acer mono, Quercus mongolica-Prunus sargentii, Quercus mongolica-Abies nephrolepis-Acer tschonoskii var. rubripes, Quercus mongolica-Abies nephrolepis-Betula costata의 4 group으로 나누어지며, 또한 주요(主要) 군집(群集)들과 환경(環境) 요인(要因)들과의 관계(關係)로 보면 신갈나무-산벚나무 군락이 전질소(全窒素), cation exchange capacity, $Mg^{+{+}}$, $Ca^{+{+}}$ 등(等)의 양료(養料)가 많은 곳에 주로 분포(分布)하고 있는 반면 신갈나무-분비나무-거제수나무 군락이 양료(養料)가 적은 곳에 분포(分布)하고 있다.