• Journal of Korean Society of Forest Science
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• v.84 no.1
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• pp.103-113
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• 1995

To estimate buffer capacity and sensitivity of forest ecosystem to acid rain in Taejon, ionic components of throughfall, stemflow, soil leachate, and open rain in Pinus rigida and Quercus variabilis forest were analysed. The spatial sensitivity based on parent rock and forest type was given by IDRISI of GIS which created imagery conversion from soil and vegetation map. Parent rocks and soils were classified into acidic, sedimentary, metamorphic rock and then subdivided based on $SiO_2$ content. Average pH of vegetation leachate was higher in throughfall but lower in stemflow than open rain and higher in Quercus variabilis forest than in Pinus rigida forest. The flow of $SO{_4}^{2-}$, $NO_3{^-}$ and $Cl^-$ through vegetation leaching(throughfall plus stemflow) into soil were 7.2, 4.3, and 2.5 times, respectively, higher in Pinus rigida forest and 4.4, 2, and 2.5 times, respectively, higher in Quercus variabilis forest than in open field. But the concentration of exchangeable cations was 4.1 times higher in Pinus rigida forest and 4.6 times higher in Quercus variabilis forest than in open field. Average pH of soil leachate was lower than that of throughfall, but higher than that of stemflow. The concentration of exchangeable canons and $Al^{3+}$ in soil leachate were more in Pinus rigida forest than in Quercus variabilis forest and increase signficantly with the increase of acidic deposits. Pinus forest had more deposition and canopy interception of acidic pollutants and more nutrient loss than Quercus forest, and Quercus forest had more cation exchange and proton consumption and than consequently had less nutrient loss and better buffer capacity than Pinus forest. The 69% of forest soils was distributed on acidic rock, 25% of it on metamorphic rock, and 6% of it on intermediate and basic rock. Acidic rock residuals which had low very canon exchange capacity and high sensitivity to acid rain occupied a half of total forest land in Taejon area. Therefore forests in Taejon showed high vulnerability to acid rain and will receive much more stress with the increase of acid rain precursors.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.1
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• pp.32-40
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• 2005

Recent earthquakes over magnitude 5 in the eastern coast of Korea have aroused interests in the earthquake analyses and seismic design of breakwater structures. Most of earthquake analysis methods such as equivalent static analysis, response spectrum analysis, nonlinear analysis, and capacity analysis methods are deterministic and have been used for seismic design and performance evaluation of breakwater structures. However, deterministic methods are difficult to reflect one of the most important characteristics of earthquakes, i.e. the uncertainty of earthquakes. This paper presents results of probabilistic seismic risk assessment(PSRA) of an actual caisson type breakwater structure considering uncertainties of earthquake occurrences and soil properties. First the seismic vulnerability of a structure and the seismic hazard of the site are evaluated using earthquake sets and seismic hazard map, and then seismic risk of the structure is assessed.

• Economic and Environmental Geology
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• v.32 no.2
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• pp.177-187
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• 1999

Gravity, magnetic and VLF surveys were conducted to investigat the structural stability and hazards associated with the Ubong landfill in Pohang City, which has been built to dump industrial wastes. In 1994, the collapse of a bank happened in the 6th landfill site due to sudden heavy rain, and a large quantity of waste materials flowed out to the nearby landfill sites, factories and roads. We used $10{\times}10m$ resolution DEM data for gravity reductions. The maximum variation of the terrain effect in the survey area is about 0.5 mgal and the terrain effect is large in the vicinity of bank boundary. The Bouguer gravity anomaly map shows the effect due to the variatino of thickness and type of waste materials. The small negative gravity anomaly increases from the 9th site to the 6th site. The small negative gravity anomaly of the 9th site reflects the relatively shallow dumping depth of average 14.5 m in this site and increased density of waste materials by the repeated stabilization process of soil overlaying. The 6th site is located at the center of the former valley and rainfall and groundwater are expected to flow from south-east to north-west. Therefore, considering the previous accident of mixing waste and bank materials at the north-west boundary of the landfill, there may be some environmental problems of leakage of contaminated water and bank stability. The complex inversion technique using Simulated annealing and Marquardt-Levenberg methods was applied to calculate three-dimensional density distribution from gravity data. In the case of 6th site, it is apparent that the landfill had been dumped in four sectors. However, most part of the 9th site and showed that high magnetic industrial wastes were concentrated in the 6th site. The result of magnetic survey showing low magnetic anomalies along the boundaries of two sites is similar to that of gravity data. The VLF data also reveals four divided sectors in the 6th site, and overall anomaly trend indicates the directio of former valley.

• Korean Journal of Environmental Biology
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• v.36 no.1
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• pp.21-32
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• 2018

This study was carried out to define the characteristics of the identified ground-dwelling invertebrate communities at Nari basin and Tonggumi area in Ulleungdo Island, designated as a nationally important agricultural heritage. The habitat types were divided into the following categories: crop land, forest, and ecotone, and the soil-dwelling invertebrates were collected according to habitat type. The ground-dwelling invertebrates were collected using a pitfall trap, and a self-organizing map (SOM) was applied to the invertebrates dataset to define the characteristics in invertebrates distribution. The SOM clearly classified the relevant information into four clusters, and extracted ecological information from the invertebrates dataset. The cluster II was composed of invertebrate communities which are collected in the Tonggumi area. The Tonggumi area is where mountainous areas were developed for agricultural purposes, which has geographical features commonly observed in Ulleungdo Island. It is noted that the cluster II has different characteristics as compared other clusters. The results of this study are expected to be used for the preservation of agricultural environment and maintenance of biodiversity by providing basic data, on the biotope of Ulleungdo Island designated as a nationally important agricultural heritage and information on the characteristics of the applicable ground-dwelling invertebrate communities.

• Proceedings of the KSRS Conference
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• v.2
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• pp.551-554
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• 2006

House management is very important in water resource protection in order to provide sustainable drinking water for about four millions population in northern Taiwan. House management can be a simple job that can be done without any ingredient of remote sensing or geographic information systems. Remote sensing and GIS integration for house management can provide more efficient management prescription when land use enforcement, soil and water conservation, sewage management, garbage collection, and reforestation have to be managed simultaneously. The objective of this paper was to integrate remote sensing and GIS to manage houses in a water resource protection district. More than four thousand houses have been surveyed and created as a house data base. Site map of every single house and very detail information consisting of address, ownership, date of creation, building materials, acreages floor by floor, parcel information, and types of house condition. Some houses have their photos in different directions. One house has its own card consists these information and these attributes were created into a house data base. Site maps of all houses were created with the same coordinates system as parcel maps, topographic maps, sewage maps, and city planning maps. Visual Basic.NET, Visual C#.NET have been implemented to develop computer programs for house information inquiry and maps overlay among house maps and other GIS map layers. Remote sensing techniques have been implemented to generate the background information of a single house in the past 15 years. Digital orthophoto maps at a scale of 1:5000 overlay with house site maps are very useful in determination of a house was there or not for a given year. Satellite images if their resolutions good enough are also very useful in this type of daily government operations. The developed house management systems can work with commercial GIS software such as ArcView and ArcPad. Remote sensing provided image information of a single house whether it was there or not in a given year. GIS provided overlay and inquiry functions to automatically extract attributes of a given house by ownership, address, and so on when certain house management prescriptions have to be made by government agency. File format is the key component that makes remote sensing and GIS integration smoothly. The developed house management systems are user friendly and can be modified to meet needs encountered in a single task of a government technician.

• Journal of Cadastre & Land InformatiX
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• v.50 no.1
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• pp.75-85
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• 2020

This study examines machine learning cross-validation to utilized create ROI for classification of land cover. The study area located in Sejong and one KOMPSAT-3A image was used in this analysis: procedure on October 28, 2019. We used four bands(Red, Green, Blue, Near infra-red) for learning cross validation process. In this study, we used K-fold method in cross validation and used SVM kernel type with cross validation result. In addition, we used 4 kernels of SVM(Linear, Polynomial, RBF, Sigmoid) for supervised classification land cover map using extracted ROI. During the cross validation process, 1,813 data extracted from 3,500 data, and the most of the building, road and grass class data were removed about 60% during cross validation process. Based on this, the supervised SVM linear technique showed the highest classification accuracy of 91.77% compared to other kernel methods. The grass' producer accuracy showed 79.43% and identified a large mis-classification in forests. Depending on the results of the study, extraction ROI using cross validation may be effective in forest, water and agriculture areas, but it is deemed necessary to improve the distinction of built-up, grass and bare-soil area.

• The Journal of Engineering Geology
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• v.23 no.1
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• pp.57-65
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• 2013

We developed a computer program (CDFlow v. 1.0) to design countermeasures against debris flows in natural terrain. The program can predict the probability of landslides occurring in natural terrain and can estimate the zone of damage caused by a debris flow. It can also be used to design the location and size of countermeasures against the debris flow. The program is run using the ArcGIS Engine, which is one of the most well-known Geographic Information System (GIS) tools for developers. The quasi-dynamic wetness index and the infinite slope stability equation were applied to predict landslide probability as a type of slope safety factor. The calculated safety factor was compared with the required safety factor, and areas of high probable potential for landslides were then selected and represented on the digital map. The volume of debris flow was estimated using these areas of high probable potential for landslides and soil depth. The accumulated volume of debris flow can be calculated along the flow channel. To assess the accuracy of the program, it was applied to a real landslide site at Deoksan-ri, Inje-gun, Kangwon-Province, where four debris barriers have been installed in the watershed of the site. The results of soil tests and a field survey indicate that the program has great potential for estimating probable landslide areas and the trajectory of debris flows. Calculation of the capacity volume of existing debris barriers revealed that they had insufficient capacity to store the calculated amount of debris flow. Therefore, this program enables a rational estimation of the optimal location and size of debris barriers.

• Journal of Wetlands Research
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• v.13 no.1
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• pp.95-104
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• 2011

This study was implemented to select the suitable site for Palustrine Wetland at habitat restoration for Oriental stork, red species and top-level predator in ecosystem. The evaluation items was fitted by review the antecedent studies on the suitable site selection model and evaluation items of wetland. The study sites were setted in $5,884,800m^2$ area including Yesan-gun Dae-ree, in which Oriental stork' park will be located, through DEM(Digital Elevation Model) watershed analysis. The thematic map by valuation items with secure of water resource, soil, topography, distance between roads, houses, etc., land using, wildlife corridor, and type of water resource was prepared using GIS program. The sites with high evaluation score were selected as suitable creation sites for wetland through overlapping those maps. Total 8 sites with over 18 point were selected. The characteristics of selected sites show that the soil are consisted of clay, the connectivity is valued high with surface water, the slope are gentle, and the connectivity is good with surroundings ecosystem. The result of water quality analysis, which was implement to survey available water resources and develop the solution of problem of water environment, showed that water quality at Salmok reservoir and Bogang reservoir is generally good, but the water quality at stagnant water body rising out from groundwater is not good. This study has limit to select the suitable sites of wetland only by analyzing physiotherapy environment in study area. Hereafter, the study is need to examine closely enhancement effects of biological diversity through investigation of biotic environment.

• Journal of the Korean Association of Geographic Information Studies
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• v.2 no.3
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• pp.81-90
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• 1999

The functional change of university forest have led to need more complicated techniques for forest management strategies, and more information about forest and natural environment. Therefore the systematic tools, like the so-called Forest Information System to which apply the techniques of geographic information system, are eagerly required for collecting, editing, managing, analyzing the various data about forest and environment, and for supporting the decision-making process. The digital mapping, which could be a primary step to construct the Forest Information System, was carried out using the many kinds of thematic spatial data referring to the Seongju Experimental Forest of Taegu University. As a result, various digital maps including forest type, soil type and so on were constructed. And then we made an user-interface system to link the attributive data in management plan to the thematic spatial data. This system was regarded as the effective tool capable of the more rapid query, analysis and update of related data for systematic management of university forest. Moreover, it would be a useful tool of decision-making in devising, assessing and operating the plan of forest management and development. But there would be much room for supplementation and improvement to make the more convenient and powerful system for the external demands, therefore more concerns and efforts in collecting, revising and updating the data is continuously required.

• Journal of Radiation Industry
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• v.17 no.2
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• pp.151-160
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• 2023

The International Atomic Energy Agency (IAEA) proposes 11 industries that handle Naturally Occurring Radioactive Material (NORM) that are considered to need management. A water treatment facility is one of the above industries that takes in groundwater and produces drinking water through a water treatment process. Groundwater can accumulate natural radionuclides such as uranium and thorium in raw water by contacting rocks or soil containing natural radionuclides. Therefore, there is a possibility that workers in water treatment facilities will be exposed due to the accumulation of natural radionuclides in the water treatment process. The goal of this study is to evaluate the external radiation dose according to the working type of workers in water treatment facilities. In order to achieve the above goal, the study was conducted by dividing it into 1) analysis of the exposure environment, 2) measurement of the external radiation dose rate 3) evaluation of the external radiation dose. In the stage of analyzing the exposure environment, major processes that are expected to occur significantly were derived. In the measurement stage of the external radiation dose rate, a map of the external radiation dose rate was prepared by measuring the spatial radiation dose rate in major processes. Through this, detailed measurement points were selected considering the movement of workers. In the external radiation dose evaluation stage, the external radiation dose was evaluated based on the previously derived external radiation dose rate and working time. As a result of measuring the external radiation dose rate at the detailed points of water treatment facilities A to C, it was 1.90×10^-1 to 3.75×10⁰ μSv h^-1, and the external radiation dose was analyzed as 3.27×10^-3 to 9.85×10^-2 mSv y^-1. The maximum external radiation dose appeared during the disinfection and cleaning of activated carbon at facility B, and it is judged that natural radionuclides were concentrated in activated carbon. It was found that the external radiation dose of workers in the water treatment facility was less than 1mSv y^-1, which is about 10% of the dose limit for the public. As a result of this study, it was found that the radiological effect of external radiation dose of domestic water treatment facility workers was insignificant. The results are expected to contribute as background data to present optimized safety management measures for domestic NORM industries in the future.