• Journal of Ocean Engineering and Technology
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• v.31 no.2
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• pp.121-129
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• 2017

The present study numerically investigated the influence of the waveform distribution on the tsunami-vegetation interaction using a non-reflected wave generation system for various tsunami waveforms in a two-dimensional numerical wave tank. First, it was possible to determine the wave attenuation mechanism due to the tsunami-vegetation interaction from the spatial waveform, flow field, vorticity field, and wave height distribution. The combination of fluid resistance in the vegetation and a large gap and creates a vortex according to the flow velocity difference in and out of the vegetation zone. Thus, the energy of a tsunami was increasingly reduced, resulting in a gradual reduction in wave height. Compared to existing approximation theories, the double volumetric ratio of the waveform increased the reflection coefficient of the tsunami-vegetation interaction by 34%, while decreasing the transfer coefficient and energy attenuation coefficient by 25% and 13%, respectively. Therefore, the hydraulic characteristics of a tsunami is highly likely to be underestimated if the solitary wave of the approximation theory is applied for the tsunami.

• Journal of Korea Water Resources Association
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• v.56 no.5
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• pp.363-371
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• 2023

In this study, the validity of the Korean expression for tsunami will be examined and a method to use it correctly will be proposed. First, we will review the scientific definition of the tsunami and the origin of the tsunami expressed in various languages. Based on this review, after reviewing whether the Korean expression 'Jijinhaeil', which is currently used representatively in Korea, a reasonable method that can be used appropriately will be proposed. In conclusion, it is suggested that the Korean pronunciation of tsunami should be used in a uniform manner as in the case of English and other languages.

• Proceedings of the KSRS Conference
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• v.1
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• pp.43-46
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• 2006

The main tsunami wave triggered by the December 2004 Sumatra tsunami was detected in the ocean south of India by satellite altimeters on Jason, Topex/Poseidon and Envisat. All three altimeters also detected shorter-wavelength (10 to 100 km), slower-propagating surface waves, spreading from the site of the earthquake. The shorter waves give additional information about the tsunami event, and can be used to better define the generating region in this, and future tsunamis. The properties of the area of shorter tsunami-generated waves may also be important in designing a future satellite-based detection system.

• Journal of the Korean Professional Engineers Association
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• v.38 no.1
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• pp.59-63
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• 2005

A Tsunami was generated by the magnitude 9.0 earthquake which occurred near Indonesia. An energetic Tsunami will display vertical water displacement of the order of ten meters and lateral scales of the order of tens of kilometers. The Tsunami destroyed many coastal villages in Asia. So, there are many victims in southeastern part Asia by Tsunami. Therefore, the construction of Tsunami prediction and warning system is needed for minimize the damage by seismic sea waves.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.221-223
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• 2008

It is the best way that to make an inundation map and distribute it to inhabitants for the purpose of decreasing damage of tsunami. To make an inundation map, tsunami which broughthuge damage to Korea should be properly investigated and maximum inundation zonewas selected by simulating tsunami phenomenan. An inundation map must involve the location of shelters and evacuation routes. New evacuation simulation program connected evacuation simulation procedure and tsunami inundation procedure to get inhabitants' evacuation states in real-time.

• Journal of Korea Water Resources Association
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• v.51 no.8
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• pp.643-654
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• 2018

In order to generate the stable tsunami in a numerical wave tank, a two-dimensional numerical model, LES-WASS-2D has been introduced the non-reflected wave generation system for various tsunami waveforms. And then, comparing to existing experimental results it is revealed that computed results of the LES-WASS-2D are in good agreement with the experimental results on spatial and temporal tsunami waveforms in the vicinity of a seawall. It is shown that the applied model in this study is applicable to the numerical simulations on tsunami overtopping and inundation. Using the numerical results, the characteristics of overtopping and inundation on a seawall are also discussed with volume ratio of tsunami and relative tsunami height. The wider the tsunami waveform, tsunami overtopping quantity and inundation distances are linearly increased. Therefore, the hydraulic characteristics is highly likely to be underestimated against the real tsunami if the solitary wave of approximation theory is applied for the overtopping/inundation simulations due to a tsunami.

• Journal of the Earthquake Engineering Society of Korea
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• v.18 no.3
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• pp.151-160
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• 2014

Probabilistic tsunami hazard analysis (PTHA) is based on the approach of probabilistic seismic hazard analysis (PSHA) which is performed using various seismotectonic models and ground-motion prediction equations. The major difference between PTHA and PSHA is that PTHA requires the wave parameters of tsunami. The wave parameters can be estimated from tsunami propagation analysis. Therefore, a tsunami simulation analysis was conducted for the purpose of evaluating the wave parameters required for the PTHA of Uljin nuclear power plant (NPP) site. The tsunamigenic fault sources in the western part of Japan were chosen for the analysis. The wave heights for 80 rupture scenarios were numerically simulated. The synthetic tsunami waveforms were obtained around the Uljin NPP site. The results show that the wave heights are closely related with the location of the fault sources and the associated potential earthquake magnitudes. These wave parameters can be used as input data for the future PTHA study of the Uljin NPP site.

• Ocean and Polar Research
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• v.36 no.3
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• pp.225-234
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• 2014

The 2011 Tohoku earthquake triggered extremely destructive tsunami waves which propagated over the Pacific Ocean, Atlantic Ocean through Drake Passage and Indian Ocean respectively. A total of 10 tide-gauge records collected from the UNESCO/IOC site were analyzed through a band-pass digital filtering device to examine the observed tsunami characteristics. The ray tracing method and finite-difference model with GEBCO 30 arc second bathymetry were also applied to compare the travel times of the Tohoku-originated tsunami, particularly at Rodrigues in the Indian Ocean and King Edward Point in the Atlantic Ocean with observation-based estimates. At both locations the finite-difference model produced the shortest arrival times, while the ray method produced the longest arrival times. Values of the travel time difference however appear to be within tolerable ranges, considering the propagation distance of the tsunami waves. The observed tsunami at Rodrigues, Mauritius in the west of the Madagascar was found to take a clockwise travel path around Australia and New Zealand, while the observed tsunami at King Edward Point in the southern Atlantic Ocean was found to traverse the Pacific Ocean and then passed into the Atlantic Ocean through the Drake Strait. The formation of icebergs captured by satellite images in Sulzberger in the Antarctica also supports the long-range propagation of the Tohoku-originated tsunami.

• Proceedings of the KSRS Conference
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• v.2
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• pp.827-830
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• 2006

The tsunami from the megathrust earthquake magnitude 9.3 on 26 December 2004 is the largest tsunami the world has known in over forty years. This tsunami destructively attacked 13 countries around Indian Ocean with at least 230,000 fatalities, displaced people 2,089,883 and 1.5 million people who lost their livelihoods. The ratio of women and children killed to men is 3 to 1. The total damage costs US$ 10.73 billion and rebuilding costs US$ 10.375 billion. The tsunami's death toll could have been drastically reduced, if the warning was disseminated quickly and effectively to the coastal dwellers along the Indian Ocean rim. With a warning system in Indian Ocean similar to that operating in the Pacific Ocean since 1965, it would have been possible to warn, evacuate and save countless lives. The best tribute we can pay to all who perished or suffered in this disaster is to heed its powerful lessons. UNESCO/IOC have put their tremendous effort on better disaster preparedness, functional early warning systems and realistic arrangements to cope with tsunami disaster. They organized ICG/IOTWS (Indian Ocean Tsunami Warning System) and the third of this meeting is held in Bali, Indonesia during $31^{st}$ July to $4^{th}$ August 2006. A US$ 53 million interim warning system using tidal gauges and undersea sensors is nearing completion in the Indian Ocean with the assistance from IOC. The tsunami warning depends strictly on an early detection of a tsunami (wave) perturbation in the ocean itself. It does not and cannot depend on seismological information alone. In the case of 26 December 2004 tsunami when the NOAA/PMEL DART (Deep-ocean Assessment and Reporting of Tsunami) system has not been deployed, the initialized input of sea surface perturbation for the MOST (Method Of Splitting Tsunami) model was from the tsunamigenic-earthquake source model. It is the first time that the satellite altimeters can detect the signal of tsunami wave in the Bay of Bengal and was used to validate the output from the MOST model in the deep ocean. In the case of Thailand, the inundation part of the MOST model was run from Sumatra 2004 for inundation mapping purposes. The medium and high resolution satellite data were used to assess the degree of the damage from Indian Ocean tsunami of 2004 with NDVI classification at 6 provinces on the Andaman seacoast of Thailand. With the tide-gauge station data, run-up surveys, bathymetry and coastal topography data and land-use classification from satellite imageries, we can use these information for coastal zone management on evacuation plan and construction code.

• The Korean Journal of Emergency Medical Services
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• v.15 no.3
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• pp.81-96
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• 2011

Purpose : The purpose of this study was to analyse early childhood teachers' perspectives and actual conditions of earthquakes and tsunami safety education. Methods : A total of 119 teachers were recruited from kindergarten and child-care center located in J city, all of whom gave consent to take part in these research. The data have been collected for 45 days from May to July in 2011. The data was analyzed by SPSS (version 17.0) and chi-square test. Results : The results of this study are summarized as follow. 1. 97.5% of the subjects considered earthquakes and tsunami safety education necessary, however, only 34.6% of them were given the education related to earthquakes and tsunami. 2. 63.9% of the early childhood teachers provided children in the kindergarten or childhood center with earthquakes and tsunami safety education, however, 30.3% of them were found to be without any experiences of earthquakes and tsunami safety education. 3. 68.5% of the teachers were informed earthquakes and tsunami safety knowledge. 4. 35.0% of respondents answered that the single session of earthquake and tsunami education was not efficient, thus expecting to receive continuing education. Conclusions : The study suggested that more teachers necessarily provide earthquake and tsunami safety education to reduce children's mortality rate in earthquakes and tsunami. The education program should be developed and systematized to improve teacher's knowledge. Moreover, the program should be continuously provided to teachers and children in the kindergarten or childhood center.