• Journal of the Society of Disaster Information
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• v.17 no.4
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• pp.694-709
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• 2021

Purpose: In this study, earthquake-induced landslide risk assessment was conducted to provide basic data for efficient and preemptive damage prevention by selecting the erosion control work before the earthquake and the prediction and restoration priorities of the damaged area after the earthquake. Method: The study analyzed the previous studies abroad to examine the evaluation methodology and to derive the evaluation factors, and examine the utilization of the landslide hazard map currently used in Korea. In addition, the earthquake-induced landslide hazard map was also established on a pilot basis based on the fault zone and epicenter of Pohang using seismic attenuation. Result: The earthquake-induced landslide risk assessment study showed that China ranked 44%, Italy 16%, the U.S. 15%, Japan 10%, and Taiwan 8%. As for the evaluation method, the statistical model was the most common at 59%, and the physical model was found at 23%. The factors frequently used in the statistical model were altitude, distance from the fault, gradient, slope aspect, country rock, and topographic curvature. Since Korea's landslide hazard map reflects topography, geology, and forest floor conditions, it has been shown that it is reasonable to evaluate the risk of earthquake-induced landslides using it. As a result of evaluating the risk of landslides based on the fault zone and epicenter in the Pohang area, the risk grade was changed to reflect the impact of the earthquake. Conclusion: It is effective to use the landslide hazard map to evaluate the risk of earthquake-induced landslides at the regional scale. The risk map based on the fault zone is effective when used in the selection of a target site for preventive erosion control work to prevent damage from earthquake-induced landslides. In addition, the risk map based on the epicenter can be used for efficient follow-up management in order to prioritize damage prevention measures, such as to investigate the current status of landslide damage after an earthquake, or to restore the damaged area.

• Water for future
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• v.45 no.9
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• pp.99-105
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• 2012

• Journal of The Geomorphological Association of Korea
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• v.27 no.3
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• pp.87-103
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• 2020

The purpose of this study is to evaluate the risk of cropland and man-made infrastructures in a landslide-prone area using a GIS-based method. To achieve this goal, a landslide inventory map was prepared based on aerial photograph analysis as well as field observations. A total of 550 landslides have been counted in the entire study area. For model analysis and validation, extracted landslides were randomly selected and divided into two groups. The landslide causative factors such as slope, aspect, curvature, topographic wetness index, elevation, forest type, forest crown density, geology, land-use, soil drainage, and soil texture were used in the analysis. Moreover, to identify the correlation between landslides and causative factors, pixels were divided into several classes and frequency ratio was also extracted. A landslide susceptibility map was constructed using a bayesian predictive model (BPM) based on the entire events. In the cross validation process, the landslide susceptibility map as well as observation data were plotted with a receiver operating characteristic (ROC) curve then the area under the curve (AUC) was calculated and tried to extract a success rate curve. The results showed that, the BPM produced 85.8% accuracy. We believed that the model was acceptable for the landslide susceptibility analysis of the study area. In addition, for risk assessment, monetary value (local) and vulnerability scale were added for each social thematic data layers, which were then converted into US dollar considering landslide occurrence time. Moreover, the total number of the study area pixels and predictive landslide affected pixels were considered for making a probability table. Matching with the affected number, 5,000 landslide pixels were assumed to run for final calculation. Based on the result, cropland showed the estimated total risk as US $ 35.4 million and man-made infrastructure risk amounted to US $ 39.3 million.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2B
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• pp.169-177
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• 2010

Recently due to the typhoon and extreme rainfall induced by abnormal weather and climate change, the probability of severe damage to human life and property is rapidly increasing. Thus it is necessary to create adequate and reliable flood risk map in preparation for those natural disasters. The study area is Seo-gu in Daegu which is located near Geumho river, one of the tributaries of Nakdong river. Inundation depth and velocity at each time were calculated by applying FLUMEN model to the target area of interest, Seo-gu in Daegu. And the research of creating flood risk map was conducted according to the Downstream Hazard Classification Guidelines of USBR. The 2-dimensional inundation analysis for channels and protected lowland with FLUMEN model was carried out with the basic assumption that there's no levee failure against 100 year precipatation and inflow comes only through the overflowing to the protected lowland. The occurrence of overflowing was identified at the levee of Bisan-dong located in Geumho watershed. The level of risk was displayed for house/building residents, drivers and pedestrians using information about depth and velocity of each node computed from the inundation analysis. Once inundation depth map and flood risk map for each region is created with this research method, emergency action guidelines for residents can be systemized and it would be very useful in establishing specified emergency evacuation plans in case of levee failure and overflowing resulting from a flood.

• Journal of Korean Neurosurgical Society
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• v.61 no.6
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• pp.761-766
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• 2018

Objective : Chronic subdural hematoma (CSDH) is a rare complication of unruptured intracranial aneurysm (UIA) clipping surgery. To prevent postoperative CSDH by reducing subdural fluid collection, we applied the modified arachnoid plasty (MAP) during the UIA clipping surgery to seal the dissected arachnoid plane. Methods : This retrospective study included 286 patients enrolled from July 2012 to May 2015. We performed arachnoid plasty in all patients, with MAP used after June 17, 2014. Patients were divided into two groups (non-MAP vs. MAP), and by using uni- and multivariate analyses, baseline characteristics, and relationships with postoperative CSDH between the two groups were analyzed. The degree of preoperative brain atrophy was estimated using the bicaudate ratio (BCR) index. Results : Ten patients (3.5%) among 286 patients had postoperative CSDH after clipping. Nine (3.1%) were in the non-MAP group, and one (0.9%) was in the MAP group. The higher BCR index showed statistical significance with occurrence of postoperative CSDH in both uni- (p=0.018) and multivariate (p=0.012; odds ratio [OR], 8.547; 95% confidence interval [CI], 1.616-45.455) analyses. MAP was associated with a lower risk of postoperative CSDH (p=0.022; OR, 0.068; 95% CI, 0.007-0.683). Conclusion : This study shows that the degree of preoperative brain atrophy is associated with an increased occurrence of CSDH after clipping and that MAP could help reduce the risk of postoperative CSDH after unruptured aneurysm clipping via a lateral supraorbital approach.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.339-344
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• 2006

Slope failures are happen to natural disastrous when they occur in mountainous areas adjoining highways in Korea. The accidents associated with slope failures have increased due to rapid urbanization of mountainous areas. Therefore, Regular maintenance is essential for all slope and conducted to maintain road safety as well as road function. In this study, we take priority of making a database of risk factor of the failure of a slope before assesment and analysis. The purpose of this paper is to recommend a standard of Slope Management Information Sheet(SMIS) like as Hazard Map. The next research, we suggest to pre-estimated model of a road slope using Logistic Regression Model.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1236-1240
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• 2006

Flooding is an inevitable problem for many cities. The study has depended on a combined approach of physically based modeling and GIS. The stream network is structured by MIKE11 for basis of a network and extended by MIKE21 to make like 2D analysis. This method is called alternative 2D analysis. In this study, one of area in Korea is used to analyze overflow of stream. Flood risk of the area looks like not so big because an elevation of this area is very high and slope is steep, but it is very dangerous area due to the typhoons. The tools to make flood risk map are MIKE11 and MIKE21 include GIS program. And map is expressed 3-D animation with MIKE Animator. As a result of this work, the flood risk map is made. And everyone who is not an expert can check dangerous area for flooding. At present, the method which is viable and easily confirmable must be promote because one of matters of common interest, which is of the general public, is the flood disaster.

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.1-10
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• 2018

Wide-area monitoring of tree-related high impedance fault (THIF) efficiently contributes to increase reliability of large-scaled network, since the failure to early location of them may results in critical lines tripping and consequently large blackouts. In the first place, this wide-area monitoring of THIF requires managing the placement of sensors across large power grid network according to THIF detection objective. For this purpose, current paper presents a framework in which sensors are distributed according to a predetermined risk map. The proposed risk map determines the possibility of THIF occurrence on every branch in a power network, based on electrical conductivity of trees and their positions to power lines which extracted from spectral data. The obtained possibility value can be considered as a weight coefficient assigned to each branch in sensor placement problem. The next step after sensors deployment is to on-line monitor based on moving data window. In this on-line process, the received data window is evaluated for obtaining a correlation between low frequency and high frequency components of signal. If obtained correlation follows a specified pattern, received signal is considered as a THIF. Thereafter, if several faulted section candidates are found by deployed sensors, the most likely location is chosen from the list of candidates based on predetermined THIF risk map.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.258-258
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• 2016

이상기후로 인한 자연 재해의 발생규모는 점차 증가하고 있다. 이는 시민의 안전과 재산을 위협하는 요인 중 하나이며, 시민 개인의 안전 침해 뿐 아니라 국가적 재산에 해당하는 SOC 시설물의 위협 역시 심각한 피해라고 할 수 있다. 이를 위해 최근 SOC 시설물에 대한 재난 대응 측면의 모니터링 시스템을 구축 및 개발 하고 있으며, 그를 지원하는 현장 지원 모바일 시스템을 연계하는 방안을 모색하는 연구가 급증 하고 있다. 하지만 현장에 있는 시설물 담당자의 측면에서는 실시간으로 모니터링 시스템을 신속하게 활용할 수 없으며, 모듈 단위가 융합하여 구동되는 무거운 사양의 시스템이 일반 PC에서 원활이 구동될 것이라는 보장이 없다. 따라서 본 연구에서는, 재난시에 발생할 수 있는 SOC 시설물에 대한 피해정보를 시뮬레이션 해주는 3차원 표출 시스템과, 그에 대한 일반 정보를 간단하게 확인 할 수 있는 모바일 어플리케이션 간의 원활한 연계 방안을 모색하고자 한다. 재난 정보는 지리정보 뿐 아니라 지리정보와 연계되는 다양한 정보들이 융합되어 있어 그에 대한 원 데이터를 실시간으로 모바일 상에 전송할 수 없으며, 이를 단순화 시킨 정보를 전송해야할 필요성이 있다. 따라서 본 연구에서는 해당하는 정보를 영상화 및 압축 하여 보다 신속하고 효율적으로 정보를 받아볼 수 있도록 하는 체계를 수립하고, 그에 맞는 시스템을 설계하고자 한다. 이를 기반으로 효율적인 재난 정보 압축방안을 마련하며, 향후 신속한 정보 송 수신 체계를 확보할 수 있다.

• Journal of the Korean Society of Safety
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• v.34 no.4
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• pp.111-118
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• 2019

Accidents occurring due to natural disasters in chemical process facilities where technologies are concentrated can cause secondary damage. The concept of the relationship between natural disasters and highly intensive technologies has evolved into the Natech (Natural Hazards Triggered Technological Disaster) research. Currently, the number of earthquakes is increasing all over the Korean peninsula. To assess the risk of Natech when an earthquake has occurred in South Korea, the Rapid Natech Risk Assessment Tool (RAPID-N) developed by the European Commission's Joint Research Center (EC JRC) was used in the present study. The RAPID-N can be used for Natech risk assessment based on mapping and can be utilized for sufficient preparation for reduction of the effects of Natech accidents. A total of 261 chemical facilities actually existing in Pohang were initially analyzed to select eight facilities and the Pohang earthquake that occurred in 2017 was implemented in the RAPID-N utilizing the shake map. High risk areas were selected through Natech risk assessments for the selected eight work places and countermeasures for the areas were suggested. High risk areas exist depending on the location, since the damage influence ranges could be overlapped and each chemical facility has an independent probability of Natech. Therefore, studies on Natech emergency plans and emergency evacuation routes should be actively conducted considering such high risk areas. The present study was conducted to demonstrate the feasibility of Natech risk assessment in South Korea through the RAPID-N. These findings can be used as a reference material to lay a foundation for Natech risk assessment and related policies in South Korea.