• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.57-61
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• 2010

국내 지진해일에 관한 연구는 범람 여부의 예측과 이에 대한 대비에 관하여 중점적으로 이루어지고 있다. 하지만 구조물에 직접적으로 피해를 주는 파력에 관한 연구는 거의 전무한 실정이다. 특히, 지진해일 1차 대피소는 지진해일 내습에 의한 파력에 대하여 안정하게 설계되어야 한다. 이를 연구하기 위한 방법으로 수리모형실험과 3D 모형을 이용한 수치모형실험의 두 가지 방법이 있으나 시간과 비용이 많이 소요되고 실제 지형에 적용하기에 곤란하다는 단점이 있다. 따라서 본 연구에서는 장파에 의한 파력식과 기존의 2D 수치모형을 이용하여 실용적으로 파력을 계산할 수 있는 방법을 제시하고, 이를 국내 무역항 중 하나인 동해항에 적용하였다.

• Journal of Korea Water Resources Association
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• v.34 no.2
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• pp.169-176
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• 2001

The propagation and associated run-up process of tsunami are numerically investigated in this study. A transoceanic propagation model is first used to simulate the distant propagation of tsunamis. An inundation model is then employed to simulate the subsequent run-up process near coastline. A case study is done for the 1960 Chilean tsunami. A detailed maximum inundation map at Hilo Bay is obtained and compared with field observation and other numerical model predictions. A very reasonable agreement is observed.

• International Journal of Advanced Culture Technology
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• v.11 no.1
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• pp.290-295
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• 2023

The global warming by greenhouse gases causes climate change and disasters such as earthquakes and tsunamis frequently, leading to great damage. It is important to build efficient and scalable disaster response services to minimize the damage. Existing disaster warning service by the mobile text is limited by the scalability and the data size to be delivered. In this paper, we propose a framework for disaster response services that is efficient and flexible by allowing to adopt various indexing schemes and scalable by supporting any number of clients in disaster situations anytime and anywhere. Also, the framework by wireless data broadcast can be free from the limitation of the size of data to be delivered. We design and implement the proposed framework and evaluate the framework. For the evaluation, we simulate the implemented framework by adopting various indexing schemes like HCI, DSI and TTSI, and by comparing the access times of the clients. Through the evaluation, we show that the proposed framework can provide efficient and scalable and flexible disaster response services.

• Journal of Information Processing Systems
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• v.18 no.6
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• pp.770-783
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• 2022

Early evacuations reduce the damage caused by catastrophic events such as terrorism, tsunamis, heavy rains, landslides, and river floods. However, even when warnings are issued, people do not easily evacuate during these events. To shorten the evacuation time, initiative-evacuation and its executors, initiative evacuees, are crucial in inducing other evacuations. The initiative evacuees take the initiative in evacuating and call out to their surroundings. This paper proposes a fast method to induce initiative-evacuation based on social graphs. The candidates are determined in descending order of the number of links for each person. The proposed method was evaluated through simulations. The simulation results showed a significant reduction in evacuation time.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.1072-1073
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• 2023

본 논문은 지진해일로 인한 인명피해를 감소시키고 항만 미관을 증진시킬 수 있는 "항만 지진해일 인명피해 감소 위한 디지털 사이니지 라이프가드"를 제안한다. 본 논문이 제안하는 특징은 다음과 같다. 첫째, 지진 해일 발생 시 라이프가드 내부 공간을 개방해 해일로부터 사람들을 보호한다. 둘째, 라이프가드 외부 디스플레이에 항만 홍보, 작업 정보, 지진해일 대피안내, 광고 영상을 재생한다. 셋째, 안전 통합관제센터 SW와 근로자/일반인용 모바일 앱을 통해 라이프가드의 동작 제어, 현황 조회를 수행한다. IoT기술과 연동된 디지털 사이니지 시스템을 통해 일상 안전 정보 제공 및 비상시 인명 보호를 통한 높은 안전 수준을 유지할 것으로 기대된다.

• 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.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.2
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• pp.62-72
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• 2019

Due to the difficulties in forecasting the intensity and the source location of tsunami the countermeasures prepared based on the deterministic approach fail to work properly. Thus, there is an increasing demand of the tsunami hazard analyses that consider the uncertainties of tsunami behavior in probabilistic approach. In this paper a fundamental study is conducted to perform the probabilistic tsunami hazard analysis (PTHA) for the tsunamis that caused the disaster to the east coast of Korea. A logic tree approach is employed to consider the uncertainties of the initial free surface displacement and the tsunami height distribution along the coast. The branches of the logic tree are constructed by reflecting characteristics of tsunamis that have attacked the east coast of Korea. The computational time is nonlinearly increasing if the number of branches increases in the process of extracting the fractile curves. Thus, an improved method valid even for the case of a huge number of branches is proposed to save the computational time. The performance of the discrete weight distribution method proposed first in this study is compared with those of the conventional sorting method and the Monte Carlo method. The present method is comparable to the conventional methods in its accuracy, and is efficient in the sense of computational time when compared with the conventional sorting method. The Monte Carlo method, however, is more efficient than the other two methods if the number of branches and the number of fault segments increase significantly.

• Journal of Navigation and Port Research
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• v.47 no.1
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• pp.18-24
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• 2023

After the Great East Japan Earthquake, many reports and books that compiled testimonies of adult victims were published. Thus, refugee situations are well known, but information on the refugee situations of Japanese students is not. This is because what actions the students took and how they sought refuge from an earthquake or tsunami have not been fully recognized. The purpose of this study was to examine and analyze students' refuge behavior in the Great East Japan Earthquake and to predict the refuge behavior of students affected by future disasters. The results of the study showed that students passively acquired information about earthquakes and tsunamis and that their refuge behavior was highly dependent on adults. Immediately after an earthquake, people tended to protect themselves and stay in place until the shaking stopped. However, they tended to move to another place after the shaking occurred frequently. Students living on ria coastlines were likely to move to high places to escape the threat of earthquakes and tsunamis, whereas students living in plain regions were likely to move vertically to tall buildings, such as schools. As for the mode of movement to refugee shelters, the students arrived at the final refugee shelters in one move, and it is assumed that the refugee shelters should be decided in advance and the students should move there.

• Journal of Navigation and Port Research
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• v.35 no.9
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• pp.755-763
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• 2011

Recently, extreme tsunami waves generated by submarine earthquake have caused tremendous damages to the coastal cities and ports. Strong seiche oscillations and runups are observed in specific sea areas around the world. Although no frequent impacts to the coast of Korean peninsula, there exist some important events in the east of Korea in the past. This study focuses on two historical events and recalculate with different fault and rupture mechanism for prediction considering the recent trend of submarine earthquake. The present study of the 1983 Akita tsunamis demonstrates the multi-scale resonance along continental coasts. Together with the Nankai tsunami for inland sea, we have confirmed the inland sea resonance surrounded by islands in defining the impact along the coast. Coherence and wavelet analyses for deducing a predominant period and time frequency are useful in reasoning the inundation. The resonance modes, which are largely independent of the tsunami source, allow identification of at-risk communities and infrastructure for mitigation of tsunami hazards. Furthermore, understanding of the resonance and the predicted runups for the site of power plant and industrial complex in the east coast of Korea would allow better preparation for the future disasters.

• Journal of Korea Water Resources Association
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• v.36 no.3 s.134
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• pp.437-445
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• 2003

Since many islands are located in the South Sea, unexpected damage by tsunamis could be caused by mutual interferences between adjacent islands. In this study, the variation of run-up heights is investigated by using different crest lengths of incident waves and different distances between two adjacent islands. The run-up height sharply increases when the crest length of Incident waves is greater than the distance bewteen outer boundaries of two islands. The run-up height also increases as the distance between two adjacent islands decreases.