• Journal of Environmental Science International
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• v.17 no.3
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• pp.287-296
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• 2008

A comprehensive quality survey for heavy metals, organophosphorous and organochlorine residual pesticides, and coplanar PCBs in samples such as water, sediments and soils as well as spiders has been implemented. The samples were undertaken at nine stream sites and their vicinity in August 2006, representing different surrounding environments. The levels of PCBs were expressed as concentrations and WHO-TEFs. Among 12 coplanar PCBs as target compounds in this study, 2,3', 4,4', 5-PentaCB (IUPAC # 118) was the congener with the highest concentration. The total concentrations and TEF values of coplanar PCBs in Siheung stream sediment (heavy industrial complex site located in Ansan city) were 3915.50 pg/g and 0.8366 pg-TEQ/g on a dry weight basis, respectively. Such levels were around 40 times higher compared to sediment from Gapyung stream (green site located in the upper of Myunggi mountain). It is probably due to the direct input of PCBs trom PCBs treatment materials. Organophosphorous (EPN, dementon-s-methyl, diazinon, parathion, and phenthoate) and organochlorine (alpha-BHC, aldrin, 4,4'-DDT, 4,4'-DDE, endosulfan alpha and etc.) pesticides were not detected above 5 ppb of detection limits. The concentrations of Cu and Cd in water and sediment samples from Siheung stream were 44.11 and $0.17ug/m\ell$ and $713.42{\mu}g/g$ and $3.73{\mu}g/g$, respectively, which contained $20\sim40$ times higher concentrations than those from Gapyung stream. In addition to the water and sediment samples, the levels of heavy metals in spider from designated sampling sites were also determined. Heavy metals in spider collected near Siheung stream was appeared to be equivalent and/or a little higher levels with respect to other spiders. Furthermore, the ratio of relative heavy metals (Cu, Cd, and Pb) in spider from each stream site showed a correlation as similar as that of heavy metals in soil samples.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1982-1990
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• 2010

Excepting tunnel of dorimstream - ccachimountain station section, the subway line No.2th section was build using ASSM and NATM methods because of soil pressure and land condition. The way of dealing underground water was selected without sufficient preconsideration of geographical features, ground condition, influence of lowing underground water, and long-term cost of running maintenance so that the form of undrained tunnel was build having decreased construction characteristics and technically improper elements. The form of partial drainage is very difficult to manage structures of tunnel, because water leakage, water pressure causing cracks of lining concretes and scaling are constantly happened. so partial drainage suggest that setting reinforced Anchor Bolt to prevent buoyancy and should increase center drainage way up to height of railroad. Partial drainage suggest that holey pipe(${\phi}$350mm) manhole, drainage checking pipe manhole are should be regularly dredged, when changing roadbed(gravel${\rightarrow}$concrete) drainage checking pipe manhole should be build and setting a limitation of entering underground water's quantities. Beside drainage degree in changed section of structures causing instability of structures is continuous degree. so if efficient drainage way and the patterns of flaws, problems are considered in survey, it will be expected to have a advantage condition in maintenance part.

• The Journal of Engineering Geology
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• v.14 no.4 s.41
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• pp.443-450
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• 2004

This study developed a prediction model of debris flow to predict a landslide probability on natural terrain composed of the Tertiary sedimentary and volcanic rocks using a logistic regression analysis. The landslides data were collected around Pohang, Gyeongbuk province where more than 100 landslides were occurred in 1998. Considered with basic characteristics of the logistic regression analysis, field survey and laboratory soil tests were performed for both slided points and not-slided points. The final iufluential factors on landslides were selected as six factors by the logistic regression analysis. The six factors are composed of two topographic factors and four geologic factors. The developed landslide prediction model has more than $90\%$ of prediction accuracy. Therefore, it is possible to make probabilistic and quantitative prediction of landslide occurrence using the developed model in this study area as well as the previously developed model for metamorphic and granitic rocks.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.4
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• pp.245-255
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• 2008

Korea Hydro and Nuclear Power Company(KHNP) conducted site investigations for a low and intermediate-level nuclear waste repository in the Gyeong Ju site. The site characterization work constitutes a description of the site, its regional setting and the current state of the geosphere and biosphere. The main objectives of hydogeological investigation aimed to understand the hydrogeological setting and conditions of the site, and to provide the input parameters for safety evaluation. The hydogeological characterization of the site was performed from the results of surface based investigations, i.e geological mapping and analysis, drilling works and hydraulic testing, and geophysical survey and interpretation. The hydro-structural model based on the hydrogeological characterization consists of one-Hydraulic Soil Domain, three-Hydraulic Rock Domains and five-Hydraulic Conductor Domains. The hydrogeological framework and the hydraulic values provided for each hydraulic unit over a relevant scale were used as the baseline for the conceptualization and interpretation of flow modeling. The current hydrogeological characteristics based on the surface based investigation include some uncertainties resulted from the basic assumption of investigation methods and field data. Therefore, the reassessment of hydrostructure model and hydraulic properties based on the field data obtained during the construction is necessitated for a final hydrogeological characterization.

• Economic and Environmental Geology
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• v.43 no.4
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• pp.381-391
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• 2010

Probabilistic prediction methods of landslides which have been developed in recent can be reliable with premise of detailed survey and analysis based on deep and special knowledge. However, landslide susceptibility should also be analyzed with some reliable and simple methods by various people such as government officials and engineering geologists who do not have deep statistical knowledge at the moment of hazards. Therefore, this study suggests an evaluation chart of landslide susceptibility with high reliability drawn by accurate statistical approaches, which the chart can be understood easily and utilized for both specialists and non-specialists. The evaluation chart was developed by a quantification method based on canonical correlation analysis using the data of geology, topography, and soil property of landslides in Korea. This study analyzed field data and laboratory test results and determined influential factors and rating values of each factor. The quantification analysis result shows that slope angle has the highest significance among the factors and elevation, permeability coefficient, porosity, lithology, and dry density are important in descending order. Based on the score assigned to each evaluation factor, an evaluation chart of landslide susceptibility was developed with rating values in each class of a factor. It is possible for an analyst to identify susceptibility degree of a landslide by checking each property of an evaluation factor and calculating sum of the rating values. This result can also be used to draw landslide susceptibility maps based on GIS techniques.

• Analytical Science and Technology
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• v.29 no.6
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• pp.293-299
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• 2016

$^{137}Cs$ was investigated in river bottom sediments located in South-Han River basin and it was compared with international case studies to estimate the concentration level of $^{137}Cs$ in river sediment of Korea. The obtained values of $^{137}Cs$ which was analyzed by gamma-ray spectrometry were in the range of <$MDA{\sim}3.80{\pm}0.14Bq/kg{\cdot}dry$ and similar to the $^{137}Cs$ activities in soil of Korea. According to international case studies, $^{137}Cs$ activities were between 3.7 to $15,396Bq/kg{\cdot}dry$, when pollutants such as nuclear power plant accidents and radiation leaks were present near the rivers. The $^{137}Cs$ activities showed a variety of distribution depending on the country, when pollution occurs and survey time. Also, $^{137}Cs$ activities of river sediments without pollution sources were mostly less than $10Bq/kg{\cdot}dry$ in other countries. It was comparable with the obtained $^{137}Cs$ activities in this study. The obtained values provide useful information on the background concentration of $^{137}Cs$ in river sediment and will be able to use a basis for determining contamination of $^{137}Cs$ in the river.

• Horticultural Science & Technology
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• v.17 no.6
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• pp.737-741
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• 1999

We surveyed the physiological disorders of fruit vegetables grown in the greenhouse in Kyungbuk province in 1998. Greenhouses used for cultivation were mostly single or multi-span iron pipe houses covered with polyethylene film. Single span greenhouses were used for strawberry, oriental melon and watermelon. Fifty six percent of the surveyed farms was a mono-cropping system for oriental melon and tomato. There were greenhouses used for successive cultivation for 10 years or more for strawberry and oriental melon in Koryeong and Seongju. Varieties of fruit vegetables cultivated were diverse, especially in cucumber and watermelon. In strawberry, malformed fruits were observed most frequently in March and the small fruits at late harvest period. Leaf chlorosis, stunt plants and runner outbreak were also found during the growing season. In tomato, occurrence of malformed fruits was severe from March to May, and occurrence of cracked fruits and blossom- end rot was also severe in October and November. The self topping and abnormal stem in tomato were problem in hydroponic cultures in August and November, respectively. Malformed cucumber fruits, such as curved, club shaped, irregular shaped and narrow necked, occurred at late season. Umbrella-shaped leaf in cucumber in summer were caused by calcium deficiency. Most serious disorders were fermented and malformed fruits occurring from March to May in oriental melon, and cracked fruits occurring from April to May in watermelon. At late growing stage of melons the leaf chlorosis occurred with complex symptoms of leaf disease. Growers had little knowledge on physiological disorders, and also on diagnose and measures to cure the disorders. Most growers pointed out that poor soil environment and temperature management in the greenhouse as the main causes of physiological disorders.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.1
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• pp.87-96
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• 2011

Carbon emissions and storages that are strongly related to global warming has have emerged as one of the important issues while many governments and researchers have been interested in climate change and pollution. In this regards, forest biomass estimation is quite importance since forest biomass works as an important medium of the global carbon cycle between the atmosphere and soil. Forest biomass estimation through field survey needs lots of time and labors, and has accessibility issues. Hence, many researchers have focused on the forest biomass approaches based on remotely sensed data. This research comprehensively reviewed forty one international studies using remote sensing data according to five different categories (i.e., location of study area, size of study area, biome, used remote sensing data, and estimation technology). It would be expected that the results of this study can be used for suggesting domestic research directions; domestic research in this field is at the beginning stage in terms of level of technologies and useful materials. As results, 39% out of the reviewed studies used the areas located in North America. 59% out of the researches dealt with small size of the study areas (less than 3,600km2). In case of biome, around 30% of the studies focused on the boreal/taiga areas. Moreover, 35% and 16% of the studies were carried out using Landsat series and Lidar data, respectively. Finally, regression analysis method was most frequently used for forest biomass estimation by 71% out of 41 studies.

• Journal of Environmental Impact Assessment
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• v.28 no.6
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• pp.525-535
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• 2019

In this study, 49 major WCS(Wildlife Crossing Structure), including Baekdu-daegan, were evaluated for the effectiveness of WCS on using the daily average frequency index and diversity Index comparing the number of species that appear with the surrounding habitats. According to the analysis, the average use frequency of the entire WCS was 1.4 times, and the average number of WCS exceeded the average was 17 and 34.7 percent of the total. There were 18 WCS with the same number of habitats and species that appeared in the same area, or 36.7 percent of the total. The daily average use frequency and variety were all analyzed at 10 efficient WCS, accounting for 20.4 percent of the total. According to the results of an site survey on the compliance rate of 4 efficient WCS, the compliance rate of the Deoksanjae overpass was the best in location selection, specifications, vegetation cover and soil, fence. The results of this research will be used as basic data for the study of WCS effectiveness, including the improvement of functions of new and installed WCS.

• Geophysics and Geophysical Exploration
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• v.19 no.4
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• pp.187-199
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• 2016

In order to delineate the soft ground distribution, an integrated geostatistical analysis was performed using the MASW (Multichannel Analysis of Surface Wave) which has the information of overall region and CPTu (Piezo Cone Penetration Test) which provides the direct information of the measuring point of the ground. MASW results were known to have close relationship with the ground stiffness. This correlation was confirmed through the comparison of MASW data obtained from two survey lines to the laboratory test with extracted soil samples. 3D physical property distribution in the study area was acquired by geostatistical integrated analysis with the data of tip resistance ($q_c$) and pore pressure (u) from the CPTu obtained at 6 points within the study area. The integrated analysis was conducted by applying the COSGSIM (Sequential Gaussian Co-Simulation) technology which can carry out the simulation in accordance with the spatial correlation between the MASW results and both tip resistance and pore pressure. Besides the locations of CPTu, borehole investigations were also conducted at two different positions. As a result, the N value of SPT and borehole log could be secured, so these data were used for the analysis of the geotechnical engineering accuracy of the integrated analysis result. For the verification of reliability of the 3D distribution of tip resistance and pore pressure secured through integrated analysis, the geotechnical information gained from the two drilling areas was compared, and the result showed extremely high correlation.