• Title/Summary/Keyword: 원동

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Volcanisms and Volcanic Processes of the Wondong Caldera, Korea (원동 칼데라의 화산작용과 화산과정)

  • 황상구;이기동;김상욱;이재영;이윤종
    • The Journal of the Petrological Society of Korea
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    • v.6 no.2
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    • pp.96-110
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    • 1997

  • The Wondong Caldera, formed by the voluminous eruption of the rhyolitic ashflows of the Wondong Tuff which is about 1,550 m thick at the intracaldera and 550 m at the outflow, is a resurgent caldera which shows a dome structure on the central exposure of the caldera. The Wondong caldera volcanism eviscerated the magma chamber by a series of explosive eruptions during which rhyolitic magma was ejected, as small fallouts and voluminous ash-flows, to form the Wondong Tuff. The explosive eruptions began with ash-falls, progressed through pumice-falls and transmitted ash-flows. During the ash-flow phase the initial central vent eruption transmitted into late ring-fissure eruption which accompanied with caldera collapse. Contemporaneous collapse of the roop of the chamber resulted in the formation of the Wondong Caldera, a subcircular depression subsiding about 1,930 deep. Following the collapse, quartz porphyry was intruded as ring dykes along the ring fracture near the southwestern caldera rim. Subsequently the central part of the caldera floor began to be uplifted into a circular resurgent dome by the rising of residual magma. Concurrent with the resurgent doming, the volcaniclastic sediments of Hwajeri Formation were accumulated in the caldera moat and then rhyodacite lava erupted from the initial central resurgent dome and another ash-flow tuff from the northern ring fracture. After the sedimentation, the find-grained granodiorite was intruded as an arc along the eastern ring fracture of the caldera. Finally in the central part, the resurgent magma was emplaced as a hornblende biotite granite stock that formed the central dome.

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패스워드 기반 키분배 프로토콜 표준화 동향

  • 손기욱;서인석;원동호
    • Review of KIISC
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    • v.12 no.4
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    • pp.46-55
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    • 2002

  • 패스워드는 단순성, 편리성으로 인해 개인의 전자 거래 등에 있어 많이 사용되는 비밀 정보이다. 그러나 상대적으로 짧은 데이터의 사용이나 추축가능성 등의 보안상 취약한 부분도 내포하고 있다. 이에 대한 개선책으로 사전 공격이나 전수 조사 등의 공격 방법 등에 적용 가능한 프로토콜이 발표되었다. 본 논문에서는 패스워드 기반의 키 분배 프로토콜에 대한 기술에 대해 살펴보고자 한다.

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Magnetism in $d^0$ system

  • Hwang, Chan-Yong;Han, Sang-Uk;Lee, Do-Hyeon;Kim, Won-Dong;Lee, Han-Gil;Kim, Jae-Yeong;Hong, Ji-Sang
    • Proceedings of the Korean Vacuum Society Conference
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    • 2007.02a
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    • pp.77-77
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    • 2007

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