• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.3
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• pp.224-229
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• 2009

Partial safety factors(PSFs) for Level I reliability based design of caisson type quay walls were calculated. First order reliability method(FORM) based PSFs are the functions of sensitivities of limit state function with respect to design random variables, target reliability index, characteristic values and first moment of random variables. Modified PSFs for water level and resilient water level are newly defined to keep consistency with the current design code. In the numerical example, PSFs were calculated by using a target reliability index. Seismic coefficient is defined to show extreme distribution. It was found that PSFs for seismic coefficient becomes smaller as the return period for design seismic coefficient grows longer.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.4
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• pp.62-70
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• 2017

Following the September $12^{th}$, 2016 earthquake in Gyeongju-city, the observation can be made that South Korea is not a non-earthquake country. Because of its particular characteristics, urban green spaces are good sites for protection during an earthquake but studies regarding the suitability of park green spaces as a form of earthquake shelter are few, making it difficult to highlight the function of park green spaces as emergency shelters. The purpose of this study is to identify indicators for suitability impact factors of comprehensive parks as emergency earthquake shelter zones. Using the Delphi method, three rounds of survey were implemented. According to the analysis results of Average value, CVR, Consultation and Convergence, ten candidate indicators were removed in the candidate group. Twenty-seven suitability impact factors of comprehensive parks were retained, including 8 indicators in the field of safety, 6 indicators in the field of accessibility, and 13 indicators in the field of service effectiveness.

• Journal of the Society of Disaster Information
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• v.16 no.4
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• pp.806-812
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• 2020

Purpose: This is aimed to evaluate the seismic fragility of curved bridge structure with I-shape girder subjected to 12 high frequency ground motions based on Gyeongju earthquake. Method: The linear elastic finite element model of curved bridge with I-Shape cross section was constructed and them linear elastic time history analyses were performed using the 12 artificial ground motions. Result: It was found that displacement response(LS1, LS2) was failed after PGA 0.1g and the stress response also showed failure after PGA 0.2g. Conclusion: The curved bridge with I-shape girder was sensitive to high frequency earthquakes.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.1
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• pp.32-40
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• 2005

Recent earthquakes over magnitude 5 in the eastern coast of Korea have aroused interests in the earthquake analyses and seismic design of breakwater structures. Most of earthquake analysis methods such as equivalent static analysis, response spectrum analysis, nonlinear analysis, and capacity analysis methods are deterministic and have been used for seismic design and performance evaluation of breakwater structures. However, deterministic methods are difficult to reflect one of the most important characteristics of earthquakes, i.e. the uncertainty of earthquakes. This paper presents results of probabilistic seismic risk assessment(PSRA) of an actual caisson type breakwater structure 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 seismic hazard map, and then seismic risk of the structure is assessed.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.5
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• pp.419-425
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• 2009

Although earthquake damage was negligible in Korea during the last a few decades, its historic records suggest that the peninsula have experienced severe earthquake damages throughout the history. The potential for disastrous earthquakes, therefore, should always be considered. Harbors handle 99.6% of imported and exported cargo in Korea. Thus, it is necessary to secure the safety of harbors against seismic events and to establish a support system of emergency measures. Although instrumental seismic data are favored for seismic hazard estimation, their history in the peninsula is limited only to the past 30 years, which does not represent the long-term seismic characteristics of the peninsula. We use historic earthquakes with magnitude greater than 5 to observe long-term regional seismic hazards. Results of historic earthquake records indicate relatively high seismic hazard at harbors in Pohang, Ulsan and Incheon. Analysis of instrumental earthquake records reveal relatively high seismic hazard for harbors located along the East coast including Okgye, Mukho, Donghae, Samcheok, Pohang, and Ulsan.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.720-725
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• 2017

This paper evaluated the safety and serviceability of a building structure considering the multi-hazard and proposed TMD-based adaptive smart control system to improve the structural performance. To make multi-hazard loads, an artificial earthquake and artificial wind loads were generated based on representative regions of strong seismicity and strong wind in U.S.A. The safety and serviceability of a 20-story example building structure were investigated using the generated artificial loads. A smart TMD was employed to improve the safety and serviceability of the example structure and its capacity of structural performance improvement was evaluated. The smart TMD was comprised of a MR (magnetorheological) damper. Numerical analysis showed that the example building structure could not satisfy the design limit of safety and serviceability with respect to multi-hazard. The smart TMD effectively reduced the seismic responses associated with the safety and wind-induce responses associated with serviceability.

• Journal of the Earthquake Engineering Society of Korea
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• v.4 no.3
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• pp.99-105
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• 2000

한반도 동남부 지역에서 발생하고 관찰된 약진 또는 중진의 자료를 이영하여 이 지역의 Q값과 지진원의 특성인 모서리 주파수 (fc), 응력강하량(Δ$\delta$) 및 모멘크규모 (Mw)를 산정하였다. 가속도 스펙트럼의 경사와 관련된 x의 통계학적 분포로부터 추정한 Q의 95% 신뢰범위는 1656~2454 이다. 1998년 1월 18일 울산 앞바다 지진과 1997년 6월 26일 경주지진의 지진원 요소를 구한 결과 fc 는 각각 4.22Hz , 2.94Hz, Δ$\delta$는 각각 106.8 bar, 106.2 bar, Mw는 각각 3.9, 4.0으로 추정되었다. 제한된 자료수로 인하여 이들의 통계학적 성질을 충분히 규명하지는 못하였지만 다른 연구자들의 기존결과와 유사한 값을 보인다. 본 연구의 결과는 강진동 모사에 직접 이용이 가능하며, 이 지역에 위치한 원자력 발전소 내진 안전성 검토에도 이용될 수 있다.

• Journal of Korea Society of Industrial Information Systems
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• v.26 no.4
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• pp.33-46
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• 2021

In Korea 2016, the largest earthquake occurred in Gyeongju since the beginning of monitoring earthquakes. Consecutively the second-largest earthquake occurred in Pohang. At that time, immediately after the earthquake, citizens were not notified adequate information for evacuation. In consequence the response process was very confusing and citizens were not able to properly evacuate to shelter. For resolving these problems, it is needed of a service to inform quickly information which citizens want to know immediately after the earthquake. So, we have developed the customized information service model, the earthquake safety service which help citizens to escape safely using an earthquake shaking alert device. In this paper, we will introduce this model and present the future direction of R&D and strategic plans for technology dissemination and improvement of practicality through user demand survey.

• Computational Structural Engineering
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• v.3 no.3
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• pp.5-9
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• 1990

지진예측 분야는 규준에 의한 방법이 일반 구조물에 적용하기에 무난하며, 가장 보편적으로 사용되는 방법은 확정론적 방법과 시간독립 확률론적 방법이라 하겠다. 물론 시간종속 확률론적 방법과 베이지만 방법이 연구되고 있지만, 아직은 실무에서는 사용되고 있지 않는 실정이다. 지진예측 분야에서는 아직도 많은 불확실성이 내재하며, 그 불확실성은 전문가의 판단에 의하여 서로 다른 안전폭을 결정함으로써 또는 안전율을 중복되게 적용함으로써 필연적으로 서로 다른 결과를 구하게 된다. 심지어 미국 동부의 경우 전문가에 따라 지반가속도가 2배 이상 차이가 나기도 하며, 그 전문가들이 모두 그 분야에서 능력을 인정받고 있는 실정이다. 우리나라의 경우도 기록기에 의한 자료 및 지질학적 연구가 미흡하고 역사기록도 한정되어 있는 실정이나, 원자력발전소의 위험성과 파급효과를 고려할 때 우리나라 특성에 맞는 지진예측 방법이 좀 더 연구되어야 할 것이다.

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.1
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• pp.33-41
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• 2002

Recently, the seismic safety evaluation of concrete gravity dams is raised due to the damage or the failure of dams occurred by the 1995 Kobe earthquake, the 1999 Taiwan earthquake, etc. Failre of dam may incur loss of life and properties around the dam as well as damage to dam structure itself. Recently, there has been growing much concerns about 'earthquake-resistance' or 'seismic safety'of existing concrete gravity dams designed before current seismic design provisions were implemented. This research develops three evaluation levels for seismic safety of concrete gravity dams on the basis of the evaluation method of seismic safety of concrete gravity dams in U.S.A., Japan, Canada, and etc. level 1 is a preliminary evaluation which is for purpose f screening. Level 2 is a pseudo-static evaluation on the basis of the seismic intensity method. Finally, level 3 is a detail evaluation by the dynamic analysis. Evaluation results on existing concrete gravity dam on operation showed good seismic performance under the designed artificial earthquake.