• Journal of Ocean Engineering and Technology
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• v.19 no.1 s.62
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• pp.26-32
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• 2005

Recent earthquakes, measuring over a magnitude of 5.0, on the eastern coast of Korea, have aroused interest in earthquake analyses and the seismic design of caisson-type breakwaters. Most earthquake analysis methods, such as equivalent static analysis, response spectrum analysis, nonlinear analysis, and capacity analysis, are deterministic and have been used for seismic design and performance evaluation of coastal structures. However, deterministic methods are difficult for reflecting on one of the most important characteristics of earthquakes, i.e. the uncertainty of earthquakes. This paper presents results of probabilistic seismic hazard assessment(PSHA) of an actual caisson-type breakwater, considering uncertainties of earthquake occurrences and soil properties. First, the seismic vulnerability of a structure and the seismic hazard of the site are evaluated, using earthquake sets and a seismic hazard map; then, the seismic risk of the structure is assessed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.6_1
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• pp.503-509
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• 2012

The cities keep growing due to industrialization and the risk of disaster gets higher as the society gets sophisticated. The center of current disaster plan has spent more efforts on post processing of disaster and it is the current status that the plan for shelter that minimizes the life and property damage has not been established effectively. Especially, the whole area of Noksan Industrial Complex at Noksan-dong, Gangseo-gu, Busan Metropolitan City was designated as danger area of tsunami, but the shelter has not been selected. Thus, this paper is willing to select the shelter using AHP analysis and GIS method that is multi criteria decision making analysis after grasping the buildings that can be selected as the shelter.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.4 s.50
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• pp.25-33
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• 2006

The purpose of this study is to develop the curve fitted equations for practicality and actual calculation during seismic performance evaluation of buried pipelines. Curve fitting for strain curve according to the wavelength of the seismic wave was produced using the non-linear least square method and the equations with the best results was suggested. In addition, a degree and coefficient of polynomial fitting equation needed to use curve fitted equation were identified. Interpreting process during the test of resistance of earthquake of buried pipelines with various end boundary conditions were provided through example questions. The results of this study were used to conduct a dynamic response analysis and a seismic performance evaluation of concrete, steel, and FRP pipes with various end boundary conditions.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.1
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• pp.21-34
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• 2006

The simulation of tsunami inundation using detailed bathymetry and topography is required to establish the countermeasure of disaster mitigation and the tsunami hazard map. In this study, a simulation of the 1983 tsunami event in the East Sea using parallel finite element model, which is possible to simulate with suitable accuracy by the Beowulf parallel computation method, is performed to produce detailed features of coastal inundation. Results of simulations are compared with measured data. The evolution of statistic distribution of tsunami heights is studied numerically and the distribution functions of tsunami heights show a tendency to the log-normal curve along coastal area.

• Journal of Ocean Engineering and Technology
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• v.24 no.5
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• pp.48-54
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• 2010

The analysis of the seismic risk of an offshore structure with a control device is presented. First, a probability density function was developed to represent seismic hazard, and seismic fragility under artificial earthquake conditions was determined. Fragility curves for an offshore structure with both passive and active control devices were determined. Displacement criteria were set to evaluate the performance of the structure. Based on numerical analysis, the seismic risk to the structure was considerably reduced when the structure had a seismic control device. The seismic risk to the actively controlled structure was decreased by 80% compared to the uncontrolled case. Reasonable performance evaluations of offshore structure with control devices can be conducted through risk analysis.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.6
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• pp.73-79
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• 2008

Economic growth, industrialization and urbanization have made society more vulnerable than ever to seismic hazard in Korea. Although Korea has not experienced severe damage due to earthquakes during the last few decades, there is little doubt of the potential for large earthquakes in Korea as documented in the historical literature. As we see no immediate promise of short-term earthquake prediction with current science and technology, earthquake early warning systems attract more and more attention as a practical measure to mitigate damage from earthquakes. Earthquake early warning systems provide a few seconds to tens of seconds of warning time before the onset of strong ground shaking. To achieve rapid earthquake location, we propose to take full advantage of information from existing seismic networks; by using P wave arrival times at two nearest stations from the earthquake hypocenter and also information that P waves have not yet arrived at other stations. Ten earthquakes in the Korean peninsula and its vicinity are selected for the feasibility study. We observed that location results are not reliable when earthquakes occur outside of the seismic network. Earthquakes inside the seismic network, however, can be located very rapidly for the purpose of earthquake early warning. Seoul metropolitan area may secure $10{\sim}50$ seconds of warning time before any strong shaking starts for certain events. Carefully orchestrated actions during the given warning time should be able to reduce hazard and mitigate damages due to potentially disastrous earthquakes.

• Computational Structural Engineering
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• v.3 no.3
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• pp.16-19
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• 1990

내진설계를 위한 연구는 세계각국에서 많이 수행되어 왔으며 현재도 이에 대한 연구는 활발히 진행되고 있다. 국제연합에서는 금년부터 앞으로 10년간을 자연재해 방지 기간으로 정하여 내진설계 분야의 연구를 더욱 활성화 시키는데 크게 기여할 것이다. 우리나라에서도 최근 몇년 사이에 내진설계 분야의 연구가 활발해지고 있으며 내진설계 기준이 제정되어 시행되기도 하는 등 이 분야에 대한 관심이 높아지고 있다. 이러한 점들은 우리나라의 지진 위험도에 비추어 볼 때 앞으로 발생할 가능성이 있는 지진에 의한 피해를 줄일 수 있는 좋은 계기가 될 수 있다고 생각된다.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.09a
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• pp.285-291
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• 2002

This paper proposes the concept and the general framework of the risk-based seismic design. Because earthquakes and the behaviors of structures are very unpredictable, probabilistic seismic design methods have been proposed after deterministic design methods. Considering these changes, we can find that the important point of seismic design is not the structural behavior itself, but the consequence of structural behavior under possible earthquakes. Risk-based seismic design can tell these consequences under any earthquakes. In this paper, structural confidences are considered by using fragility curve, and risk is modeled by failure probability and consequence-property damage cost, casualty cost.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.4
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• pp.269-282
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• 2006

We numerically studied tsunami propagation characteristics through Korean Straits based on nonlinear shallow water equation, a robust wave driver of the near field tsunamis. Tsunamis are presumed to be generated by the earthquake in Tsuhima-Koto fault line. The magnitude of earthquake is chosen to be 7.5 on Richter scale, which corresponds to most plausible one around Korean peninsula. It turns out that it takes only 60 minutes for leading waves to cross Korean straits, which supports recently raised concerns at warning system might be malfunctioned due to the lack of evacuation time. We also numerically obtained the probability of tsunami inundation of various levels, usually referred as tsunami hazard, along southern coastal area of Korean Peninsula based on simple seismological and Kajiura (1963)'s hydrodynamic model due to tsunami-generative earthquake in Tsuhima-Koto fault line. Using observed data at Akita and Fukaura during Okushiri tsunami in 1993, we verified probabilistic model of tsunami height proposed in this study. We believe this inundation probability of various levels to give valuable information for the amendment of current building code of coastal disaster prevention system to tame tsunami attack.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.04a
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• pp.48-52
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• 2010

최근 우리나라는 건축물화재가 지속적으로 증가하고 있으며 지진으로 인한 화재 위험성 또한 증가하고 있다. 이러한 건축물화재는 화재경계지구 등 화재에 취약한 도심지에서 발생 시 대규모 시가지 화재로 확대될 위험성이 있다. 하지만 현재 이에 대한 위험성 평가 및 대응책에 관한 연구는 미비한 실정이다. 본 연구에서는 일본의 도시화재 위험성 평가기법의 분석 및 적용성 검토를 통해 우리나라의 도시화재 위험성 평가기법구축을 위한 기초자료로 활용하고자 한다.