• Korean Journal of Remote Sensing
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• v.25 no.5
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• pp.445-454
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• 2009

Localized unprecedented torrential rain and heavy rainfall cause repeated damages and make it difficult to detect and predict the landslide caused by heavy rainfall. To analyze the landslide characteristics of Inje area this study used satellite images photographed after the occurrence of landslide caused by the typhoon Ewiniar occurred in July, 2006, and for GIS analysis purpose, interpreted the satellite images (SPOT5) visually to digitize into developing parts, water traveling parts and sediment parts. For analysis of spatial characteristics, landslide areas obtained from visual interpretation of digital map, 3rd & 4th forest vegetation maps and detailed soil map and grids were overlaid and analyzed. As a result, in regard to topographic features, landslide occurred at places, of which average slope is $26.34^{\circ}$, had south, south-east, south-west aspects and average altitude of 627m. From hydrological analysis, it was found out that water traveling area rapidly spread approaching water traveling area and sediment area. From forest type analysis, it was found out that landslide occurrence was high in pine woods, and in terms of girth class attribute, landslide occurred in small-sized woods, in which the crown occupancy of trees that have the diameter at breast height, 6~16cm, was greater than 50%. From the analysis of soil series, landslide areas constitute 37.85% of OdF and 37.35% of SmF, which had sandy loam soil and excellent drainage capacity. Through this study, landslides in Inje area were characterized and SPOT5 images of 2.5m resolution could be used. But there was a difficulty in determining water traveling parts adjacent to urban area.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1124-1129
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• 2011

The importance of environment-friendly agriculture is being magnified as a new growth engine industry in pursuit of low carbon, green growth policies. In order to provide technical supports for pushing ahead with the environment-friendly agriculture policies, we estimated the effects of customized fertilization on growth and yield of rice and fertilizer reduction compared to conventional fertilization and single-element fertilization. In rice plant growth and rice yield, no statistically significant difference between the three fertilization treatments was observed. In contrast, customized fertilization showed high disaster resistance reducing the damage caused by rice lodging during a typhoon. The average N application in farms showing high rice lodging amounted to $135kg\;N\;ha^{-1}$ while $135-138kg\;N\;ha^{-1}$ was known as the critical range of rice lodging in Korea. The fertilizer reduction rate of customized fertilization compared to conventional fertilization of investigated farms was on average 22.5%. We estimated the short-term effects of customized fertilization in the first year after application. In future, there is need for continuous examination of rice growth and soil environment change due to successive application of customized fertilizer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.217-223
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• 2019

In this study, the acceleration changes of the surrounding ground when crushed stones were installed in a strip-type were analyzed using the 1-G shaking table test. The ground was constructed from clay, and the foundation was installed using crushed stone of strip-type form. The response acceleration and response spectrum for various input seismic motions were analyzed. The change in acceleration was examined according to the adjacent distance to the strip-type crushed stone foundation. In the Hachinohe seismic motion results, there was no significant decrease in acceleration, but the maximum response acceleration for the two seismic motions was inversely proportional to the distance from the crushed stone foundation. As a result of the response spectrum analysis, the attenuation period in the long period and the short period input wave were different from each other, and the change in response spectrum affected the maximum acceleration value. As the distance from the crushed stone foundation was increased, the attenuation was larger in the period between 0.08 and 0.5 sec in the Hachinohe seismic motion, the attenuation was larger in the period of less than 0.2 seconds in the Northridge seismic motion.

• Korean Journal of Remote Sensing
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• v.35 no.2
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• pp.299-316
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• 2019

The purpose of this study was to analyze landslide susceptibility in the Pyeongchang area using Weight of Evidence (WOE) and Evidential Belief Function (EBF) as probability models and Artificial Neural Networks (ANN) as a machine learning model in a geographic information system (GIS). This study examined the widespread shallow landslides triggered by heavy rainfall during Typhoon Ewiniar in 2006, which caused serious property damage and significant loss of life. For the landslide susceptibility mapping, 3,955 landslide occurrences were detected using aerial photographs, and environmental spatial data such as terrain, geology, soil, forest, and land use were collected and constructed in a spatial database. Seventeen factors that could affect landsliding were extracted from the spatial database. All landslides were randomly separated into two datasets, a training set (50%) and validation set (50%), to establish and validate the EBF, WOE, and ANN models. According to the validation results of the area under the curve (AUC) method, the accuracy was 74.73%, 75.03%, and 70.87% for WOE, EBF, and ANN, respectively. The EBF model had the highest accuracy. However, all models had predictive accuracy exceeding 70%, the level that is effective for landslide susceptibility mapping. These models can be applied to predict landslide susceptibility in an area where landslides have not occurred previously based on the relationships between landslide and environmental factors. This susceptibility map can help reduce landslide risk, provide guidance for policy and land use development, and save time and expense for landslide hazard prevention. In the future, more generalized models should be developed by applying landslide susceptibility mapping in various areas.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.7
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• pp.845-857
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• 2020

Compound coastal disasters are a type of natural disaster featuring both internal and external flooding due to rises in sea-level, torrential rains, typhoons, and tsunamis. The, incidence and scale of damage from such disasters is increasing. This aim of this study was to review the current laws and systems managing the phenomenon of the coastal complex disaster, and to derive recommendations for improvements to manage and prevent them. In this study, the Framework Act on the Management of Disasters and Safety, the Countermeasures against Natural Disasters Act, the National Land Planning and Utilization Act, the Coast Management Act, the River Act, and the Sewerage Act were reviewed, with focus on the district-zoning system designated by ministries for the management of natural disasters along the coast. Through a comparison of the purpose and nature of the laws, spatial scope, and management resources, it was judged that it would be desirable to comprehensively manage compound coastal disasters based on the Countermeasures Against Natural Disasters Act. In order to overcome the limitations of the current system and to derive specific measures to improve laws and systems, a questionnaire survey on detailed factors was conducted targeting experts in natural disaster management. The results indicated that it is necessary to improve the current system or introduce a new system for the management of coastal complex disasters, with integrated management of land and sea areas through the installation and operation of integrated decision-making governance by related ministries such as MOIS, MOLIT, MOF, and ME.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.4
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• pp.117-122
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• 2021

In recent years, human damage and loss of money due to various disasters such as typhoons, earthquakes, forest fires, landslides, and wars are steadily occurring, and a lot of manpower and funds are required to prevent and recover them. In this paper, we designed and developed a disaster drone system based on artificial intelligence in order to monitor these various disaster situations in advance and to quickly recognize and respond to disaster occurrence. In this study, multiple disaster drones are used in areas where it is difficult for humans to monitor, and each drone performs an efficient search with an optimal path by applying a deep learning-based optimal path algorithm. In addition, in order to solve the problem of insufficient battery capacity, which is a fundamental problem of drones, the optimal route of each drone is determined using Ant Colony Optimization (ACO) technology. In order to implement the proposed system, it was applied to a forest fire situation among various disaster situations, and a forest fire map was created based on the transmitted data, and a forest fire map was visually shown to the fire fighters dispatched by a drone equipped with a beam projector. In the proposed system, multiple drones can detect a disaster situation in a short time by simultaneously performing optimal path search and object recognition. Based on this research, it can be used to build disaster drone infrastructure, search for victims (sea, mountain, jungle), self-extinguishing fire using drones, and security drones.

• Journal of the Korean earth science society
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• v.43 no.1
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• pp.23-29
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• 2022

Although tropical cyclones with wind speeds weaker than 17 ms^-1 (weak tropical cyclones: WTCs) can cause significant damage, particularly over the Seoul metropolitan area, only a few studies have focused on WTC activity over South Korea. In this study, we found that WTC activity is likely associated with the Pacific Decadal Oscillation (PDO). During the negative phases of the PDO, landfall frequency of WTCs increased significantly compared to the positive phases at 95% confidence level. When related to the negative phases of the PDO, a positive relative vorticity anomaly is found in the northern sector of the western North Pacific while a negative relative vorticity anomaly and enhanced vertical wind shear prevail in the southern sector of the WNP. These factors are favorable for the northward shift of the genesis location of tropical cyclones on average, thereby reducing the total lifetime of WTCs. Moreover, a high-pressure anomaly over the Japanese islands would shift a tropical cyclone track westward in addition to the landfall location. Consequently, the effects of the topographical friction and the Yellow Sea Bottom Cold Water on a tropical cyclone may increase. These conditions could result in a weaker lifetime maximum intensity and landfall intensity, ultimately resulting in WTCs becoming more frequent over South Korea during the negative phases of the PDO.

• The Journal of the Korea Contents Association
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• v.21 no.11
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• pp.490-502
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• 2021

Horticultural facility farmers subscribe to crop accident insurance and insurance products secured by horticultural facilities in preparation for possible risks in the facility. Insurance is purchased to prepare for natural disasters such as typhoons, hail, frostbite, heavy rain, and strong wind damage covered by the product. In order to find out the effect of risk perception, which is a subjective perception of the risks of a given situation, on horticultural facility farmers' intention to purchase horticultural facility insurance products, the risk perception and insurance purchase intention were analyzed. A t-test was conducted to determine the impact relationship between farm size, insurance coverage, and risk perception, and multiple regression analysis was conducted to verify the effect of personal characteristics and behavioral factors such as subjective perception, reference group, media exposure, and compensation understanding. In addition, a three-step regression analysis by Baron & Kenny was conducted to confirm the mediating role of personal characteristics and behavioral factors in the relationship between risk perception and insurance purchase intention. As a result of the study, although there was no difference in farm size, it was analyzed that policy holders had a higher degree of risk perception than non-subscribers, and that compensation understanding had the greatest influence and subjective knowledge had the smallest influence. In addition, these four factors were verified to have a mediating effect on the relationship between risk perception and insurance purchase intention. These results are expected to provide practical help to the development and marketing activities of horticultural facility insurance products.

• Journal of the Society of Disaster Information
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• v.18 no.4
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• pp.908-921
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• 2022

Purpose: As the connection between physical and non-physical structures in cities is expanding and becoming more complex, the risk of complex disaster which causes damage in a complex way is increasing. Preparing for these complex disasters, it is important to preemptively identify and manage disasters that can develop into complex disasters. Therefore, this study analyzes the disaster types studied as complex disasters by analyzing the trends of domestic and international studies related to complex disasters, and presents the direction of complex disaster management in the future. Method: We first established co-occurrence networks between disaster types based on 993 articles related to complex disasters published in disaster-related journals for the last 20 years (2002-2021). Then, through network analysis, domestic and international complex disaster research trends were compared and analyzed. Result: Research on complex disasters related to storm and flood damage, infrastructure failure and fire was high in domestic studies, and it was analyzed that research on complex disasters related to earthquakes and landslides has recently increased. However, in international studies, the proportion of studies on infrastructure failure along with storm and flood damage and earthquake was high, and various types of disasters such as tsunami and drought appeared. Conclusion: The results of this study are expected to increase the understanding of the trends in complex disaster research and provide suggestions of domestic complex disaster research in the future.

• Journal of Korean Society of Disaster and Security
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• v.16 no.1
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• pp.23-35
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• 2023

Recently, the damage caused by natural disasters such as typhoons and localized torrential rains has been increasing rapidly. The Ministry of the Interior and Safety enacted a ｢law on safety management of small sized infrastructures｣ and local governments have to register small sized infrastructures with the National Disaster and Safety Management System (NDMS) until March 31st every year. Recently, each local government has ordered Safety inspections of small sized infrastructures and maintenance plans and six types of facilities, including small streams, small bridges, farm roads, access roads to village, inlet weirs, and drop structures are being surveyed and digitized into a database. Each facility is being evaluated for risk, and for those deemed hazardous, maintenance plans are being developed. However, since the risk assessment method of small sized infrastructures is not clear so that is conducted through visual investigation by field investigators, risk assessment is conducted in a subjective and ambiguous form. Therefore, this study presented a reasonable and quantitative risk assessment method by providing a quantitative evaluation indicator for small stream, which has the highest disaster risk among other small sized infrastructures, so that small sized hazard infrastructures can be selected to secure transparent evidence for improvement plans and action plans.