• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5534-5541
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• 2012

This paper classifies cities in the metropolitan area based on natural hazard vulnerability. The procedure of our empirical analysis is divided into three parts as follows: First, it summarizes variables related to natural hazard vulnerability to significant factors, carrying out principal component analysis. Second, it classifies cities in the metropolitan area, conducting cluster analysis using factor scores. Lastly, it proposes differential measures for natural hazard mitigation for classified cities in the metropolitan area, based on natural hazard vulnerability.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.5
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• pp.109-116
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• 2010

Infiltration and the rising level of groundwater caused by rainfall are a major cause of the landslide and sliding. In order to secure the safety factor of slope, the slope stabilization and reinforcement works are used to enhance consistency. Nailing, Slope Drainage method and the surface vegetation measures can be simultaneously applied in the Mass Nail method, which is also environmental friendly reinforcement method. To demonstrate the reinforcement effect of a strengthened slope by Mass Nail, the changes in water contents by rainfall were considered while performing Scale Model Test. As a result, safety factor of reinforced slope was about 1.4~2.3 times increased on the unstrength slope. In the case of increasing water content 10% to 22%, The maximum stress was reduced to 12%~24% at the average rate of 18% on the unstrength slope and the reinforced slope by the Mass Nail Method was reduced to 4%~23% at the average rate of 14%.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.3
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• pp.53-59
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• 2010

Globally, the actual circumstance is that local downpours are occurring and the droughts are extensively continuing on and the occurrence of large-scale earthquakes is increasing as a result of changes in nature environment. It is being pointed out also in the case of Korea for the urgent countermeasures against the situation of repeated occurrence of disasters in the regions where the concept of disaster prevention has not been applied. Accordingly, the National Emergency Management Agency has been implementing the formation of disaster prevention trial towns since 2009 for the regions vulnerable to disasters and searching for plans to improve disaster prevention measures. Therefore, the concept of disaster prevention town and the program type were summarized in this study, and the development strategy for developing disaster prevention town was presented through the related laws and policies and the case analysis of domestic and international trial programs, and the basic concept of forming disaster prevention town was presented to present basic information for developing disaster prevention town.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.4
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• pp.33-46
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• 2010

The 14 cities and guns within Gangwon-do were divided into three regions (urban-rural-integrated type, urban type, and ruralcoastal type), and local voluntary disaster prevention organizations in those regions were surveyed as sample groups. As a result, the urban-rural-integrated type and the urban type were found to be lower than the rural-coastal type in all domains including recognition of disaster crisis, evacuation guidance, preparation of voluntary evacuation, maintenance of disaster prevention system, surveillance & guard, and information delivery. In particular, three types had higher information delivery but considerably lower preparation of voluntary evacuation. As for information delivery, foundations for rapid delivery of disaster information due to establishment and extension of systems for forecasting and warning of local governments were prepared, but as for preparation of voluntary evacuation, it is needed not only to perform consistent training and promotion for preparation for disasters for residents to accurately understand status of disasters but to take measures to secure safe places for evacuation beforehand.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.3
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• pp.129-136
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• 2008

All measures to cope with flooding rely on flood predictions to some extent. To investigate these predictions such as maximum water level or inundation area, a numerical model has been developed. The governing equations of the model are the two-dimensional Saint-Venant equations. The governing equations are discretized explicitly by using the leap-frog scheme and upwind scheme based on quadtree grids. The predicted numerical results have been verified by comparing to those of a Thacker problem. As a result of verifications, the present model is not only nearly four times as efficient as uniform grids but also in close agreement with the previous models. Next, the developed model is applied to several flood events in the Uiryeong basin. A general tendency is found that as a frequency is increasing, overall water levels including peak water level are increasing. At only a 500 year frequency, maximum water level is higher than 18.5 m. Therefore, it can be predictable that inundation will be generated in a 500 year frequency.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.6
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• pp.45-52
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• 2010

One of the ways to minimize damage by a slope collapse is to set up preventive measures in advance by measuring displacements in a slope and predicting a collapse. There have been many different technologies developed to predict a collapse with diverse measuring equipment. Especially recently, attempts have been made to utilize terrestrial LiDAR, a high-tech imaging equipment to measure displacements on a scope. Terrestrial LiDAR generates three-dimensional information about an object with millimeter-level accuracy from hundreds of meters away and has been used in an array of fields including restoration of cultural assets, three-dimensional modeling, and making of topographic maps. In recent years, it has been used to measure displacements in structure as well. This study monitored displacements in slopes of high collapse risk with terrestrial LiDAR. As a result, it was able to confirm the applicability of terrestrial LiDAR to the field, and proposed monitoring methods.

• Nuclear Engineering and Technology
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• v.47 no.1
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• pp.11-25
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• 2015

The accident at Japan's Fukushima Daiichi nuclear power plant in March 2011, caused by an earthquake and a subsequent tsunami, resulted in a failure of the power systems that are needed to cool the reactors at the plant. The accident progression in the absence of heat removal systems caused Units 1-3 to undergo fuel melting. Containment pressurization and hydrogen explosions ultimately resulted in the escape of radioactivity from reactor containments into the atmosphere and ocean. Problems in containment venting operation, leakage from primary containment boundary to the reactor building, improper functioning of standby gas treatment system (SGTS), unmitigated hydrogen accumulation in the reactor building were identified as some of the reasons those added-up in the severity of the accident. The Fukushima accident not only initiated worldwide demand for installation of adequate control and mitigation measures to minimize the potential source term to the environment but also advocated assessment of the existing mitigation systems performance behavior under a wide range of postulated accident scenarios. The uncertainty in estimating the released fraction of the radionuclides due to the Fukushima accident also underlined the need for comprehensive understanding of fission product behavior as a function of the thermal hydraulic conditions and the type of gaseous, aqueous, and solid materials available for interaction, e.g., gas components, decontamination paint, aerosols, and water pools. In the light of the Fukushima accident, additional experimental needs identified for hydrogen and fission product issues need to be investigated in an integrated and optimized way. Additionally, as more and more passive safety systems, such as passive autocatalytic recombiners and filtered containment venting systems are being retrofitted in current reactors and also planned for future reactors, identified hydrogen and fission product issues will need to be coupled with the operation of passive safety systems in phenomena oriented and coupled effects experiments. In the present paper, potential hydrogen and fission product issues raised by the Fukushima accident are discussed. The discussion focuses on hydrogen and fission product behavior inside nuclear power plant containments under severe accident conditions. The relevant experimental investigations conducted in the technical scale containment THAI (thermal hydraulics, hydrogen, aerosols, and iodine) test facility (9.2 m high, 3.2 m in diameter, and $60m^3$ volume) are discussed in the light of the Fukushima accident.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.4
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• pp.957-970
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• 2016

This study diagnosed the status of marine environmental impact assessment(MEIA) for project near the habitat of marine protected seagrass species such as Zostera caespitosa, Zostera asiatica, Phyllospadix iwatensis. For the preparation of a marine environmental impact statement, different monitoring parameters are used without any specific guideline for the assessment of current status. And also, both tools and techniques for MEIA are needed to improve for implementing. The monitoring plans and parameters are not considered well with the accuracy of the environmental predictions and effectiveness of any applicable mitigation measures. This study suggested the reasonable standard of the MEIA for the conservation of the marine protected seagrass species which have the habitat located near affected area. The inshore seagrasses need to be monitored including shoot count based on the "No Net Loss of Seagrass" as part of the monitoring parameters to assess the status of marine environment of environmental impact statement. In a process of effect prediction, we suggested a concentration of 10 mg/L suspended solids which added by the new developmental project near seagrasses habitat, referring to study of overseas case. But a further study for an appropriate standard is necessary effectively. In a mitigating process, priority needs to be considered in order of avoidance, minimization, reduction, compensation. In a post-monitoring process, it is necessary to monitor the seagrass species abundance to identify the variation of b/a (before and after) project. And in a case of implementing transplantation, survival rate need to be included to determine a success of project.

• Journal of the Korean Society of Hazard Mitigation
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• v.6 no.2 s.21
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• pp.37-44
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• 2006

Any vehicle and equipment whose total weight is more than 40ton and its axle weight is 10ton or above is banned to cross any bridge in our country under section 54 in the Highway law. This restriction results from the accumulation and application of safety factors about which there is type specification in the "standard design vehicle". And in "standard design vehicle", Vehicle load to bridge is assumed concentrating one. Based on this restriction, there is an issue that military tank which has a total weight of 51ton (63ton in case of the US tank) can not cross any bridge. However, many research and practical examples concerned manifest that it is possible for military tanks to cross these bridges. The reasons of this issue in the current Highway law's provisions are analyzed in this paper. Correspondingly, feasibility of military tanks passing these bridges are discussed here. At last, considering economical efficiency and practicability for military, several suggestions and improving measures are put forward. This research has certain reality significance to guide bridge design considering the passage of military heavy vehicles.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.1
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• pp.57-62
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• 2008

This study aimed at investigating elderly people's experiences and perception of flood disasters in Gangwon province, which is mainly devastated by flood disasters, and seeking to the coping strategy against vulnerability of disaster between elderly men and women. A total of 183 elderly people aged 60 and over who were directly or indirectly damaged by flood disasters of 2006 in Pyung-chang and In-je in Gangwon province were selected for this study. According to the study results, there were no statistical differences in disaster experiences between elderly men and women, however, a statistically significant difference was found in the perception of disaster among them. Although elderly women are more likely to perceive the possibility of secondary flood disasters than elderly men, elderly women are less knowledgeable than elderly men in disaster attacks and they have appeared to have low coping skills. This study showed that elderly women were more likely to live alone than elderly men and they have low income comparing to the elderly men. In conclusion, elderly women should be considered as a most vulnerable group to the disaster and gender-based approach is necessary to take measures in disaster prevention.