• 자원환경지질
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• 제52권6호
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• pp.541-554
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• 2019

옥천대 태백산지역은 한반도의 지각 진화 과정 동안 중첩된 다변형 조산운동의 증거를 보존하고 있는 주요 습곡-단층대 가운데 하나로, 북서부의 평창-정선지역을 중심으로 서쪽의 주천지역 및 남쪽의 영월지역이 각각 단층 경계로 구분되며, 층서 및 지질구조에 있어서 차이를 보인다. 본 논문에서는 북서부 태백산지역에 분포하는 고생대 지층들의 이러한 지역적 차이와 지구조 운동과의 연관성을 이해하기 위해 구조기하학적 형태 해석 연구를 수행하였다. 이를 위해 우선, 기 발간된 평창지역 지질도들에서 지질연대가 상이하게 제안된 시대미상 퇴적암체에 대한 연대분석을 실시하였고, 그 결과 해당 암체가 후기 고생대 평안누층군에 대비되는 지층임을 확인하였다. 이러한 연대 결과와 야외조사를 통해 획득한 구조요소 자료를 종합하여 북서부 태백산지역에 보존되어 있는 지질구조들의 기하학적 형태를 해석하였다. 이 지역의 가장 주된 지질구조는 북동-남서 방향의 힌지를 가지는 광역 규모의 정선대향사로, 지동리배사, 남병산향사 및 임하리배사 등과 같은 이차습곡구조들을 수반한다. 하반구 투영 및 하향 투영 단면 해석 결과, 정선대향사는 힌지가 남부에서는 남쪽으로, 북부에서는 북쪽으로 완만하게 침강하는 향사형 극융 형태의 이중 침강 구조를 가진다. 그러므로 지질도 상에서 연구지역 남부와 북부의 지질구조의 특성이 상이하게 나타나 복잡하게 보이는 것은 침강하는 힌지로 인해 지질도 상에 노출되는 이차습곡들의 구조적 높이가 달랐기 때문으로 해석된다. 평창지역과 정선지역 고생대 지층의 분포를 규제하는 지질구조가 광역 규모의 정선대향사이고, 동익부인 정선지역에서만 보고된 행매층 및 회동리층이 서익부인 평창지역에서도 확인됨을 고려할 때, 향후 평창지역의 행매층 및 회동리층에 대한 상세 연구를 통해 습곡 등과 같은 구조 운동에 의한 이들의 대칭 반복 가능성에 대해 추가 연구가 이루어지길 제언한다.

• 미술이론과 현장
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• 제1호
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• pp.109-144
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• 2003

Orientalness is a concept that expresses the collective identity of the Orient in relation to the West. The concept itself is mutable and defined by the relationship between the two regions at different points in time. Changes in the concept depend on a number of factors, such as cultural influence, the political balance of power between the two regions, and on the interpretative scheme that defines the relationship. In addition, the geographical notion of the concept evolves culturally, socially and politically. During this process, Oriental-ness becomes Oriental-ism at times. I will attempt to survey and measure the progression of Orientalness from its emergence in early 17th century to its subsequent transformation in modern Korea as reflected in art theory and art works. The recognition of the comparative characteristics of Oriental art began when the Orient was exposed to the art of the West in the late Ming dynasty during the early 17th century. The changes in the artistic climate in China affected the late Chosun. I will start with a brief introduction of this time and the birth of Orientalness. The concept gradually changed during the period of Enlightenment(開化期) towards the end of the 19th century, and during the colonial period( 1910-1945) it took on a new form. Establishment of the concept of "Orient"as a single, unifying concept spanning across cultures and national boundaries has been attributed to late Meiji period Japan, whose intention at that time is believed to have been to build a pan-Asia(亞細亞) empire with Japan at its commanding center. It has been stressed that the real motive behind the formation of one single cultural unit, where the shared common written language was Chinese and Confucianism and Taoism were the common metaphysical traditions, was to build one political unit. When the notion of a geographical unit of Asia was replaced by the concept of Asia as a cultural and political unit, a massive growth of interest and discourse were provoked around the concept of Orientalism. When Orientalism was being formulated, Korea automatically became member of "one Asia" when the country became colonized. For Koreans, the identity of the Orient had to be defined in cultural terms, as the political notion of a nation was non-existent at that time. The definition of identity was pursued at two levels, pan-Asian and local. If Orientalism was an elite discourse centered in pan-Asian philosophical and religious tradition, localized Orientalism was a popular discourse emphasizing locality as the byproduct of natural geographic condition. After the liberation in 1945 from colonial rule, a thrust of movement arose towards political nationalism. Two types of discourses on Orientalism, elite and popular, continued as central themes in art. Despite the effort to redefine the national identity by eradicating the cultural language of the colonial past, the past was enduring well into the present time. As discussed above, even when the painting themes were selected from Korean history, the tradition of using history painting as a manifestation of political policy to glorify the local identity had its founding during the Meiji period. The elevation of folk art to the level of high art also goes back to the colonial promotion of local color and local sentiment. Again, the succession of the past (colonial) ideal was defended as the tradition assumed a distinct modern shape that was abstract in style. The concept of the "Orient" is of relative and changing nature. It was formulated in relation to Western culture or civilization. Whatever the real motive of the adoption of them had been, the superiority of the Orient was emphasized at all times. The essence of the Orient was always perceived as the metaphysical tradition as a way to downgrade Western culture as materialistic. This view still prevails and the principle of Orient was always sought in Confucianism, Taoism, and Buddhism. Even when Orientalism was employed by imperialist Japan in an effort to establish her position as the center of the Orient, the spiritual source was still in Chinese philosophy and religion. In art also, the Chinese literati tradition became the major platform for elite discourse. Orientalism was also defined locally, and the so-called local color was pursued in terms of theme and style. Thus trend continued despite the effort to eradicate the remnants of colonial culture long after liberation. These efforts are now being supported politically and also institutionalized to become the aesthetic ideal of the modern Korean art.

• KEPCO Journal on Electric Power and Energy
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• 제6권3호
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• pp.305-313
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• 2020

전력송전을 위한 터널식 전력구는 점차 시공실적이 증가하고 있는 추세이며, 해저 및 대심도 등 시공환경이 어려운 구간의 건설도 증가하고 있다. 이에 소단면 쉴드TBM의 효율적 운영을 위해 굴진율 및 설계모델이 필요하다. 그러나, 제한된 지반조사 회수 및 굴착면 맵핑으로 인하여 암반특성과 굴진데이터를 정확히 매칭시켜 상호간 상관관계 및 굴진율 모델을 도출하는데 어려움이 있다. 이에 소단면 쉴드TBM에 적합한 굴진율 및 설계모델을 제시하기 위하여 커터헤드의 직경이 3.56 m인 실험용 EPB 쉴드TBM을 제작하고, 총 부피 87.5 ㎥인 인공암반 내에서 총 19번의 실대형 굴진실험을 수행하였다. 본 실험은 70MPa의 균질한 암반강도에서 수행되었기 때문에 운전변수인 추력과 커터헤드의 RPM에 따른 굴진율과 기계데이터간 상관관계를 효율적으로 분석할 수 있으며, 실제 굴착메커니즘과 동일하기 때문에 도출된 압입깊이와 토크값은 활용성이 높다. 본 연구를 통해 디스크커터 당 연직력과 압입깊이의 상관관계 및 연직력과 회전력의 상관관계를 도출하였다. 이러한 상관관계들을 이용하여 70 MPa급 암반에 대해 굴진율 예측과 TBM 설계가 가능할 것으로 판단한다. 또한, 인공암반의 RQD가 100%로 현장적용에 대한 한계점에 대해 FPI의 개념을 도입하여 굴진율 모델의 활용성을 증대시키고자 하였다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제36회 춘계학술대회논문집
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• pp.1-2
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• 2011

Hybrid rockets have lately attracted attention as a strong candidate of small, low cost, safe and reliable launch vehicles. A significant topic is that the first commercially sponsored space ship, SpaceShipOne vehicle chose a hybrid rocket. The main factors for the choice were safety of operation, system cost, quick turnaround, and thrust termination. In Japan, five universities including Hokkaido University and three private companies organized "Hybrid Rocket Research Group" from 1998 to 2002. Their main purpose was to downsize the cost and scale of rocket experiments. In 2002, UNISEC (University Space Engineering Consortium) and HASTIC (Hokkaido Aerospace Science and Technology Incubation Center) took over the educational and R&D rocket activities respectively and the research group dissolved. In 2008, JAXA/ISAS and eleven universities formed "Hybrid Rocket Research Working Group" as a subcommittee of the Steering Committee for Space Engineering in ISAS. Their goal is to demonstrate technical feasibility of lowcost and high frequency launches of nano/micro satellites into sun-synchronous orbits. Hybrid rockets use a combination of solid and liquid propellants. Usually the fuel is in a solid phase. A serious problem of hybrid rockets is the low regression rate of the solid fuel. In single port hybrids the low regression rate below 1 mm/s causes large L/D exceeding a hundred and small fuel loading ratio falling below 0.3. Multi-port hybrids are a typical solution to solve this problem. However, this solution is not the mainstream in Japan. Another approach is to use high regression rate fuels. For example, a fuel regression rate of 4 mm/s decreases L/D to around 10 and increases the loading ratio to around 0.75. Liquefying fuels such as paraffins are strong candidates for high regression fuels and subject of active research in Japan too. Nakagawa et al. in Tokai University employed EVA (Ethylene Vinyl Acetate) to modify viscosity of paraffin based fuels and investigated the effect of viscosity on regression rates. Wada et al. in Akita University employed LTP (Low melting ThermoPlastic) as another candidate of liquefying fuels and demonstrated high regression rates comparable to paraffin fuels. Hori et al. in JAXA/ISAS employed glycidylazide-poly(ethylene glycol) (GAP-PEG) copolymers as high regression rate fuels and modified the combustion characteristics by changing the PEG mixing ratio. Regression rate improvement by changing internal ballistics is another stream of research. The author proposed a new fuel configuration named "CAMUI" in 1998. CAMUI comes from an abbreviation of "cascaded multistage impinging-jet" meaning the distinctive flow field. A CAMUI type fuel grain consists of several cylindrical fuel blocks with two ports in axial direction. The port alignment shifts 90 degrees with each other to make jets out of ports impinge on the upstream end face of the downstream fuel block, resulting in intense heat transfer to the fuel. Yuasa et al. in Tokyo Metropolitan University employed swirling injection method and improved regression rates more than three times higher. However, regression rate distribution along the axis is not uniform due to the decay of the swirl strength. Aso et al. in Kyushu University employed multi-swirl injection to solve this problem. Combinations of swirling injection and paraffin based fuel have been tried and some results show very high regression rates exceeding ten times of conventional one. High fuel regression rates by new fuel, new internal ballistics, or combination of them require faster fuel-oxidizer mixing to maintain combustion efficiency. Nakagawa et al. succeeded to improve combustion efficiency of a paraffin-based fuel from 77% to 96% by a baffle plate. Another effective approach some researchers are trying is to use an aft-chamber to increase residence time. Better understanding of the new flow fields is necessary to reveal basic mechanisms of regression enhancement. Yuasa et al. visualized the combustion field in a swirling injection type motor. Nakagawa et al. observed boundary layer combustion of wax-based fuels. To understand detailed flow structures in swirling flow type hybrids, Sawada et al. (Tohoku Univ.), Teramoto et al. (Univ. of Tokyo), Shimada et al. (ISAS), and Tsuboi et al. (Kyushu Inst. Tech.) are trying to simulate the flow field numerically. Main challenges are turbulent reaction, stiffness due to low Mach number flow, fuel regression model, and other non-steady phenomena. Oshima et al. in Hokkaido University simulated CAMUI type flow fields and discussed correspondence relation between regression distribution of a burning surface and the vortex structure over the surface.

• 암석학회지
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• 제25권3호
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• pp.169-193
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• 2016

한반도 일원의 신기 지각변형과 현생 응력장의 특징을 규명하고 지구조적 형성 배경을 이해하기 위해, 제4기 단층과 발진기구해에 관한 기존 자료와 더불어 최근의 지각천부 시추공 응력자료를 종합하여 재분석하였으며, 마이오세 이후 동아시아 일원의 지구조 환경 변화와 지각변형 특징을 정리하였다. 한반도 남동부의 제4기 단층은 대부분 기존 단층대를 따라 발견된다. 또한 대부분 남-북으로 배열된 상반 서향의 충상단층의 기하와 운동특성을 보이며, 동-서 방향의 순수 압축응력 하에서 적절히 배향된 기존 약대가 재활된 특징을 보인다. 한반도와 인근 해역의 발진기구해 분석 결과, 내륙에서는 주향이동단층 또는 역이동성 운동감각을 포함하는 주향이동단층이 우세한 반면, 동해와 서해 연안의 경우에는 역단층이 우세한 특징을 보인다. 압축 축은 동북동과 서남서를 향해 수평 내지 아수평한 자세로 군집되며, 인장 축은 북북서-남남동 주향을 가지는수직의 대원 상에 배열된다. 시추공 내 응력측정 자료를 취합한 결과, 한반도 지각천부의 평균 최대수평응력은 동북동-서남서 방향으로 나타났다. 따라서 한반도 일원은 현재 광역적인 동북동-서남서 내지 동-서 방향의 압축력에 의한 압축구조가 발달중인 것으로 판단된다. 동아시아 일원의 광역적인 현생 응력장 분포와 비교한 결과, 이러한 동북동-서남서 내지 동-서 방향의 압축응력환경은 태평양판의 서향 저각 섭입과 인도-유라시아 충돌로부터 전파된 응력장이 중첩된 결과로 판단되며, 대부분 고각 섭입의 양상을 보이는 필리핀해판은 배호지역 내에서 인장 환경의 특징을 보여주고 있어 한반도에서의 영향은 미미한 것으로 판단된다. 이상과 같은 동아시아 일원의 신기 지구조환경과 지각변형은 약 5~3.2 Ma 경 태평양판의 이동방향과 섭입각도의 변화와 함께 시작된 것으로 해석된다.