• Korean Journal of Remote Sensing
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• v.36 no.2_1
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• pp.217-229
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• 2020

Recently, weather changes in Korea have intensified due to global warming, and the five major natural disasters that occur mostly include heavy rains, typhoons, storms, heavy snow, and earthquakes. Busan is vulnerable to snow disaster, given that the amount of natural disaster damage in Busan accounts for more than 50% of the total amount in the entire metropolitan cities in Korea, and that the Busan area includes many hilly mountains. In this study, we attempted to identify vulnerable areas for snowfall disasters in Busan areas using the geographic information system (GIS) with the data for both geographical and anthropogenic characteristics. We produced the maps of vulnerable areas for evaluating factors that include altitude, slope, land cover, road networks, and demographics, and overlapped those maps to rank the vulnerability to snowfall disasters as the 5th levels finally. To weight each evaluating factor, we used an entropy method. The riskiest areas are characterized by being located in mountainous areas with roads, including Sansung-ro in Geumjeong-gu, Mandeok tunnel in Buk-gu, Hwangnyeongsan-ro in Suyeong-gu, and others, where road restrictions were actually enforced due to snowfall events in the past. This method is simple and easy to be updated, and thus we think this methodology can be adapted to identify vulnerable areas for other environmental disasters.

• The Journal of Engineering Geology
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• v.30 no.3
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• pp.315-325
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• 2020

This study was performed to develop a model to predict landslides and determine the variable importance of landslides susceptibility factors based on the probabilistic prediction of landslides occurring on slopes along the road. Field survey data of 30,615 slopes from 2007 to 2020 in Korea were analyzed to develop a landslide prediction model. Of the total 131 variable factors, 17 topographic factors and 114 geological factors (including 89 bedrocks) were used to predict landslides. Automated machine learning (AutoML) was used to classify landslides and non-landslides. The verification results revealed that the best model, an extremely randomized tree (XRT) with excellent predictive performance, yielded 83.977% of prediction rates on test data. As a result of the analysis to determine the variable importance of the landslide susceptibility factors, it was composed of 10 topographic factors and 9 geological factors, which was presented as a percentage for each factor. This model was evaluated probabilistically and quantitatively for the likelihood of landslide occurrence by deriving the ranking of variable importance using only on-site survey data. It is considered that this model can provide a reliable basis for slope safety assessment through field surveys to decision-makers in the future.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.501-511
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• 2018

As a result of the recent revision of the 'Guideline for Installation and Management of Fire Prevention Facility in Road Tunnels', the thermal buoyancy has to be taken into account when calculating the capacity of jet fans for smoke control in tunnel fires. However, there is no detailed methodologies for considering thermal buoyancy, so further study is needed. In this study, the thermal buoyancy in the tunnel is calculated by 3-D numerical simulation to consider the thermal buoyancy in case of fire in tunnels, and the relationship between heat buoyancy and vehicle drag, And the method of calculating the capacity of the jet fan for smoke control in tunnels. According to the analysis results, heat buoyancy acts as a resistance force in the case of a down-slope tunnel, and the pressure rise of jet fan for smoke control is not simply determined by the value of heat buoyancy at the entrance of the tunnel and the value of the vehicle drag at the exit. And it is analyzed that it is necessary to carry out a comprehensive review according to the location of the fire vehicle in tunnels.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.1
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• pp.59-77
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• 2003

This study is to validate the use of macro language for the land suitability analysis aiming to help to resolve land use conflicts. The silver-town suitability analysis is conducted on the Geejang Gun, Busan Metropolitan city. Such digital maps as terrain, road, facility, and water body were created for various cartographic models. A cartographic model identified the best suitable areas for silver-town development based on the such site selection variables as a distance to facility and road, slope and aspect of terrain, land use etc. Then, the other cartographic model identified the most favorable site among the candidate sites based on the comparison of the aspect of proximity, usage and environmental quality. Macro language was used for these modeling process and was used for the manipulation of all these spatial variables used in the models to resolve land use conflicts relating to the decision making process of the final site selection. This study will improve the effectiveness and rationality of the traditional site suitability analysis.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.6
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• pp.63-70
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• 2011

A bicycle is different from vehicles in the structure that a rider is fully exposed to the surrounding environment. Therefore, it needs to make use of prior information about local weather, air quality, trail road condition. Moreover, since it depends on human power for moving, it should acquire route property such as hill slope, winding, and road surface to improve its efficiency in everyday use. Recent mobile applications which are to be used during bicycle riding let us aware of the necessity of development of intelligent bicycles. This study aims to develop a riding state (up-hill, down-hill, accelerating, braking) recognition algorithm using a low-power wrist watch type embedded system which has 3-axis accelerometer and wireless communication capability. The developed algorithm was applied to 19 experimental riding data and showed more than 95% of correct recognition over 83.3% of the total dataset. The altitude and temperature sensor also in the embedded system mounted on the bicycle is being used to improve the accuracy of the algorithm. The developed riding state recognition algorithm is expected to be a platform technology for intelligent bicycle interface system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.395-406
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• 2016

Population and development are concentrated by urbanization. Consequently, the usage of underground area and the riverside area have been increased. By increasing impermeable layer, the urban basin drainage is depending on level of sewer. Flood damage is occurred by shortage of sewer capacity and poor interior drainage at river stage. Many of researches about flood stress the unavailability of connection at the river stage with the internal inundation organically. In this study, flood calculated considering rainfall and combined inland-river. Also, using urban runoff model analyze the overflow of sewer. By using results of SWMM model, using flood inundation analysis model analyzed internal drainage efficiency of drainage system. Applying SWMM model, which results to flood inundation analysis model, analyzes internal drainage efficiency of drainage system under localized heavy rain in a basin of the city. The results of SWMM model show the smoothness of internal drainage can be impossible to achieve because of the influence of the river level and sewer overflow appearing. The main manholes were selected as the manhole of a lot of overflow volume. Overflow reduction scenarios were selected for expansion of sewer conduit and instruction retention pond. Overflow volume reduces to 45% and 33~64% by retention pond instruction and sewer conduit expansion. In addition, the results of simulating of flood inundation analysis model show the flood occurrence by road runoff moving along the road slope. Flooded area reduces to 19.6%, 60.5% in sewer conduit expansion scenarios.

• Korean Journal of Plant Resources
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• v.23 no.2
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• pp.187-196
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• 2010

A total of 10 islands (Kumodo and Komundo in Yeosu City; Oinarodo in Goheung County; Chongsando, Soando, and Pogildo in Wando County; Chodo in Jindo County; Uido, Huksando, and Hongdo in Shinan County) were surveyed to confirm distribution of naturalized plants from June 2006 to December 2008. A total of 100 naturalized plants taxa from 25 families were recorded. The highest number of naturalized plant species (82 taxa) was recorded on Oinarodo, while the lowest number was recorded on Hongdo (42 taxa) and on Uido (34 taxa). A total of 26 naturalized species taxa (such as Dactylis glomerata, Lolium perenne, Bromus unioloides, Rumex obtusifolius, Chenopodium album, Phytolacca americana, Barbarea vulgaris, Lepidium apetalum, Robinia pseudo-acacia, Trifolium repens, Erigeron annuus, Erigeron canadensis, Senecio vulgaris, Xanthium strumarium) was recorded in all study areas. Distribution of naturalized plants were categorized into 7 habitat types based on ecological traits: afforested land, beach, port, and vacant land, road boundary, road cut and slope area, waste arable land, landfill area, and wetland. Systematic management is required to conserve unique landscape, species diversity, vegetation and ecosystem of Dadohae National Park. In order to manage the naturalized plants in Dadohae National Park, basic surveys are most needed to understand distribution and dispersal of naturalized plants communities based on ecological features of each habitat type.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.2
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• pp.23-38
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• 2022

This study investigates the characteristics and physical habitat requirements for each Bufo gargarizans life history through a literature survey. After deriving variables for each component of Bufo gargarizans, in order to reduce regional deviations from eight previously studied literature research areas for deriving the criteria for variables, a total of 12 natural habitats of Bufo gargarizanss are selected as spatial ranges by selecting four additional sites such as Umyeonsan Ecological Park in Seoul, Wonheungibangjuk in Cheongju in the central region, Changnyeong Isan Reservoir in the southern region, and Mangwonji in Daegu. This study presents Bufo gargarizans SI, a species endemic to Korea, whose population is rapidly declining due to large-scale housing site development and road development, and develops a Bufo gargarizans HSI model accordingly to improve the function of the damaged Bufo gargarizans habitat and to present an objective basis for site selection of alternative habitat. At the same time, it provides basic data for adaptive management and follow-up monitoring. The three basic habitat requirements of amphibians, the physical habitat requirements of Bufo gargarizans, synthesized with shelter, food, and water, and the characteristics of each life history, are classified into five components by adding space and threats through literature research and expert advice. Variables are proposed by synthesizing and comparing the general characteristics of amphibians, among the previously studied single species of amphibians, the components of HSI of goldfrogs and Bufo gargarizans, and the ecological and physical environmental characteristics of Bufo gargarizans. Afterwards, through consultation with an amphibian expert, a total of 10 variables are finally presented by adjacent forest area(ha), the distance between spawning area and the nearest forest land(m), the soil, the distance from the wetland(m), the forest layered structure, the low grassland space, the permanent wetland area(ha), shoreline slope(%), PH, presence of predators, distance from road(m), presence or absence of obstacles. n order to derive the final criteria for each of the 10 variables, the criteria(alternative) for each variable are presented through geographic information analysis of the site survey area and field surveys of the previously studied literature research area. After a focus group interview(FGI) of 30 people related to the Bufo gargarizans colony in Cheongju, a questionnaire and in-depth interviews with three amphibians experts are conducted to verify and supplement the criteria for each final variable. Based on the finally developed Bufo gargarizans HSI, the Bufo gargarizans habitat model is presented through the SI graph model and the drawing centering on the Bufo gargarizans spawning area

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.4
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• pp.41-53
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• 2007

The Baekdudaegan Mountain Range is a backbone of the Korean Peninsula which carries special spiritual and sentimental signatures for Koreans as well as significant ecological values for diverse organisms. However, in spite of importance of this region, the forests of Baekdudaegan have been damaged in a variety of human activities by being used as highland vegetable grower, lumber region, grass land, and bare land, and are still undergoing destruction. The existing researches had determined the details of the damage through on-site and recent observations. Such methods cannot provide quantitative and integrated analysis therefore could not be utilized as objective data for the ecological conservation of Baekdudaegan forests. The goal of this study is to quantitatively analyze the forest damage in the Baekdudaegan preservation region through land cover categorization and change detection techniques by using satellite images, which are 1980s, and 1990s Landsat TM, and 2000s Landsat ETM+. The analysis was executed by detecting land cover changed areas from forest to others and analyzing changed areas' spatial patterns. Through the change detection analysis based on land cover classification, we found out that the deforested areas were approximately three times larger after the 1990s than from the 1980s to the 1990s. These areas were related to various topographical and spatial elements, altitude, slope, the distance form road, and water system, etc. This study has the significance as quantitative and integrated analysis about the Baekdudaegan preservation region since 1980s. These results could actually be utilized as basic data for forest conservation policies and the management of the Baekdudaegan preservation region.

• Journal of the Korean GEO-environmental Society
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• v.21 no.12
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• pp.17-21
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• 2020

Over 60% of South Korea's land consists of mountainous topography, and recently, due to earthquakes, localized heavy rains and road development, the risks of rockfalls are getting higher. As of now, rockfall prevention facilities are being constructed in 70% of Korean roads cut slope and rockfall protections account for about 20% of them. Rockfall protection's supporting capacity is defined by combining performance of wire mesh, pillars and wire ropes. For the existing constructed rockfall protection, standards of pillars that can absorb 48~61 kJ amount of energy, wire ropes and wire mesh are presented in Guidelines for the installation and management of traffic safety facilities, Rockfall prevention facilities by Ministry of Land, Transport and Maritime Affairs (2008). However, each factor's correlation of absorption energy is not presented so it is uncertain. This study will conduct vertical drop test and identify adequacy of rockfall protection net of displacement quantity calculation factor which is delta and evaluate rockfall protection net's absorbable energy through standards of overseas performance evaluation criteria.