• 한국가스학회지
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• 제8권3호
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• pp.37-42
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• 2004

본 연구는 계절별 기후상태를 고려한 정성적 및 정량적 위험성 평가에 의해 최악의 시나리오와 가능성이 높은 시나리오를 설정하고, 비용-편익분석에 의해 시나리오별 안전관리비의 효율을 평가하였다. 그 결과, 최악의 시나리오는 비정상조업에서 유지보수 오류이었고, 가능성이 높은 시나리오는 HAZOP 구간 $\sharp$4에서 발생되는 가스 누출사고이었다. 또한 각 시나리오에서 전체 안전관리비에 대한 편익/비용과 효과적인 안전관리 항목을 평가할 수 있었다.

• 천문학회보
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• 제41권1호
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• pp.49.1-49.1
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• 2016

Solar System has evolved with numerous collisions among asteroids. Ancient catastrophic collisions of large parent bodies led the formation of asteroid families and relevant dustband structures up to the present day, and it would be interesting to address a question - "what happens if an asteroid collides with another asteroid?" Recent discoveries of "active asteroids" in the main-belt have attracted interest for their potential to witness a catastrophic collision in the current Solar System. So far, however, there is no direct evidence for catastrophic collision on active asteroids while several objects have been confirmed for other mechanisms (e.g., 596 Scheila for impact cratering, P/2013 R3 and P/2013 P5 for rotational breakup). The most potential candidate for catastrophic collision could be a sub-km active asteroid P/2010 A2, which is still controversial on its driving mechanism, but if confirmed, would have made P/2010 A2 the unique example of catastrophic collision on the current main asteroid belt. In this presentation, we revisit all of archival data of P/2010 A2 in a combination with our own observation using Subaru/Suprime-Cam on 2011 June, where we have a great benefit of a large orbital coverage. We found a grain size dependence of dust ejection velocity from P/2010 A2 (a power-law size distribution with an index of k~ -1/10), which is favorable to a catastrophic disruption scenario in agreement with laboratory impact experiments. At this conference, we plan to provide our understanding of the morphology of P/2010 A2 through a perspective of catastrophic collision.

• 한국군사과학기술학회지
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• 제15권3호
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• pp.266-271
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• 2012

The rescue methods for the marine casualties are limited due to the characteristics of operation environment of the vessel. Especially the most of marine accidents have been occurred at the bow structure of ship. Moreover the failure of bow structure may lead to catastrophic mishaps. In this paper, the extents of damage of a bow structure fracture subject to collision accident was investigated by using numerical method. The computer simulation approach by using Finite Element Method was employed to accomplish this goal. A finite element model, a 3D model of ship, has been utilized to evaluate damage of bow structure according to collision scenario. In conclusion, we have demonstrated that the plastic deformation occurred at the bow structure. Also it was shown that the collision angle clearly plays a role in determining amount of damage of ship structures.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.423-430
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• 2005

Fire accidents in underground space may bring much loss of lives as well as properties and result in catastrophic disasters. This study aimed to manufacture the high-temperature furnace capable of simulating fire scenarios (RABT and RWS) and carry out the preliminary fire tests to evaluate fire-induced damage in underground structures. Specimens used in the fire tests were the concrete segments generally used in shield TBM tunnels. The simulated fire scenario was set to the RABT curve that is the most representative fire scenario in underground space. From the fire tests, the spalling was estimated to reach approximately 20cm from the surface exposed to fire. In addition, from the observation of core specimens obtained after fire tests, the deteriorated zone of unspalled specimens amounted to approximately 10cm from the surface of spalling.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2016년도 학술발표회
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• pp.199-199
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• 2016

In recent decades, climate change phenomenon has developed towards critical tendency and increased in both frequency, intensity and time which causes catastrophic damage in both people and property, especially in the field of agriculture and water resources. At the current, some researches in the world and Viet Nam studies on climate change impacts on the water resources sectors. Results of scientists'studies showed that climate change will seriously impact productivity, livelihoods and the environment on a global scale; especially large flood phenomena increasingly developing in intensity, drought more violently occurring in a long time. In recent years, the shortage of water supply for economic activity has started to happen with quite serious degree at the Viet Nam, especially in the northern mountainous provinces of Viet Nam.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2017년도 학술발표회
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• pp.190-190
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• 2017

In recent decades, climate change phenomenon has developed towards critical tendency and increased in both frequency, intensity and time which causes catastrophic damage in both people and property, especially in the field of agriculture and water resources. At the current, some researches in the world and Viet Nam studies on climate change impacts on the water resources sectors. Results of scientists' studies showed that climate change will seriously impact productivity, livelihoods and the environment on a global scale; especially large flood phenomena increasingly developing in intensity, drought more violently occurring in a long time. In recent years, the shortage of water supply for economic activity has started to happen with quite serious degree at the Viet Nam, especially in the northern provinces of Viet Nam.

• Structural Engineering and Mechanics
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• 제36권3호
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• pp.321-341
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• 2010

The seismic-induced failure of a dam could have catastrophic consequences associated with the sudden release of the impounded reservoir. Depending on the severity of the seismic hazard, the characteristics and size of the dam-reservoir system, preventing such a failure scenario could be a problem of critical importance. In many cases, the release of water is controlled through a reinforced-concrete intake tower. This paper describes the application of a static nonlinear procedure known as the Capacity Spectrum Method (CSM) to evaluate the structural integrity of intake towers subject to seismic ground motion. Three variants of the CSM are considered: a multimodal pushover scheme, which uses the idea proposed by Chopra and Goel (2002); an adaptive pushover variant, in which the change in the stiffness of the structure is considered; and a combination of both approaches. The effects caused by the water surrounding the intake tower, as well as any water contained inside the hollow structure, are accounted for by added hydrodynamic masses. A typical structure is used as a case study, and the accuracy of the CSM analyses is assessed with time history analyses performed using commercial and structural analysis programs developed in Matlab.

• Earthquakes and Structures
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• 제13권4호
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• pp.421-427
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• 2017

Seismic safety evaluation of weir structure is significant considering the catastrophic economical consequence of operational disruption. In recent years, the seismic probabilistic risk assessment (SPRA) has been issued as a key area of research for the hydraulic system to mitigate and manage the risk. The aim of this paper is to assess the seismic probabilistic risk of weir structures employing the seismic hazard and the structural fragility in Korea. At the first stage, probabilistic seismic hazard analysis (PSHA) approach is performed to extract the hazard curve at the weir site using the seismic and geological data. Thereafter, the seismic fragility that defines the probability of structural collapse is evaluated by using the incremental dynamic analysis (IDA) method in accordance with the four different design limit states as failure identification criteria. Consequently, by combining the seismic hazard and fragility results, the seismic risk curves are developed that contain helpful information for risk management of hydraulic structures. The tensile stress of the mass concrete is found to be more vulnerable than other design criteria. The hazard deaggregation illustrates that moderate size and far source earthquakes are the most likely scenario for the site. In addition, the annual loss curves for two different hazard source models corresponding to design limit states are extracted.

• 전기전자학회논문지
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• 제26권1호
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• pp.19-26
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• 2022

본 논문에서는 LwF에서 도메인 차이에 따른 성능 하락 현상을 해결하기 위해, 각 손실값에 각각 다른 가변람다를 적용하는 알고리즘을 제안하여, 향상된 과거 지식유지가 이루어 지게 한다. 이 지식 전달 기반의 방법을 LwF와 접목하여, 과거 학습 태스크의 지식 유지 성능을 강화하였다. 가변 람다 방법을 추가적으로 적용하여, 현재 학습할 태스크를 잘 학습할 수 있도록 람다 값을 가변적으로 조절할 수 있었다. 본 논문의 제안 방법을 적용하여 학습한 결과 시나리오에 상관없이 평균 5% 정도 데이터의 정확도가 향상하였고, 특히 본 논문의 목표인 과거 지식을 유지하는 성능이 최대 70% 가까이 개선되었고, 과거 학습 데이터의 정확도가 기존 LwF 대비 평균 22% 상승하였다.

• 한국항해항만학회지
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• 제29권10호
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• pp.865-870
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• 2005

선박 침수 사고의 경우, 선박의 운용 책임자가 취할 수 있는 대응방안이 한정되어 있어 정확한고 신속한 의사결정을 위해서는 기존의 안전관련 시스템을 활용한 효율적인 의사결정 지원 시스템이 필요하다. 수밀 및 준수밀 문, 격벽 밸브, 배수 펌프 등과 같이 침수 사고 시작동하는 대부분의 시스템들은 침수가 선박 전체로 전파되는 것을 막도록 충분한 구획분할 정도를 확보하는데 목적이 있다. 침수 시나리오가 파국적이지 않다고 가정하더라도 발라스트 탱크의 사용은 침수 전파 방지와 선박 안정성을 향상하기 위한 매우 효과적인 방안이 될 수 있다. 본 논문에서는 침수 손상 시 최적의 대응방안을 위해 채워져야 하는 발라스트 탱크들을 선정하고, 각 발라스트 탱크의 수위를 결정하는 최적화 알고리즘을 기술한다.