• Journal of Korean Society of Environmental Engineers
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• v.27 no.2
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• pp.130-137
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• 2005

This research programme include investigation of the adsorption behavior of heavy metals and VOCs by Pyrolysis char for using landfill cover material. The volatile potions in the sludge gasified during the pyrolysis period and gave birth to porosity throughout the matrix. The result of the ad/desorption experiment of nitrogen to find out the formation of some pore by the gasification of the volatile matter, we can certify that the pyrolysis char($14.56\;m^2/g$) has increased twice more than the organic wasted sludge($6.68\;m^2/g$) in specific surface area. The pyrolysis char has the adsorption characteristic of medium type of Type II and V in BDDT classification, and showed a little micro pore. In the adsorption experiment of ethylbenzene and toluene, as a result of applying the Freundlich adsorption isotherms, the pyrolysis char was higher in the adsorptivity of ethylbenzene and toluene than the granite and the organic wasted sludge. The results of the heavy metal adsorption test for the char indicated that it had some ability of adsorption. It is suggest that pyrolysis char has some advantages for utilizing as landfill covers because the pyrolysis char can adsorb/absorb hazardous substances from the landfill sites and inhibit the ground water and soil contamination.

• Journal of Navigation and Port Research
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• v.33 no.5
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• pp.315-321
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• 2009

The Very Large Marine Structure has been widely used new method of ocean space instead of method for reclamation Therefore, VLFS is proposed to coincide on such request. It can be established regardless of nature of soil and height of water, and stream of flow exists under the floating structure, there is seldom effect in natural environment. Fuertherrnore, it can do easily to do assembly and taking to pieces due to expansion or removal. Based on the regulation by class, VLFS have to possess more than enough structural strength against severe wave loading induced by green sea condition Therefore, There are performed structural simulation as well as experimental test about expected loading scenario in order to examine the safety of structure. Up to now, various examinations based on the strength limit value of the main structural material have been done based on the elasticity response analysis. However, there is little finding about the collapse behavior and the safety when the load that exceeds the collapse of the material acts. In the present study, we investigated the collapse behavior based on the ultimate limit state calculated by FE-analysis.

• Asian Journal of Turfgrass Science
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• v.24 no.1
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• pp.9-15
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• 2010

During 2008~2009 winter season, yellow patch and gray snow mold occurred on turfgrass plants in golf courses in Kangwon and Jeonbuk provinces, respectively. The fungi associated with the diseases were identified as Rhizoctonia cerealis Van der Hoeven and Typhlua incarnata Lasch ex Fr., based on the morphological characteristics of hyphae and sclerotia. R. cerealis and T. incarnata were pathogenic to most turfgrass and crop species tested. R. cerealis infected crown, stem and leaf tissue of the host plants, and the symptom was light yellow circular patch. Individual infected leaf near the margin of patch developed red color first and finally turn brown. The symptoms caused by gray snow mold pathogen are water-soaked spots, and became a watery soft rot. Infection parts became yellow and then turned brown followed by death of the whole plant. White mycelia were developed on higher petioles, leaves, and on soil where these plant parts lay, and black sclerotia of variable size and shape formed in the mycelial mass. All isolates tested were pathogenic on most turfgrass and crop plants, and significantly different in aggressiveness. Disease severity increased with longer snow cover days on target plants, suggesting that disease severity was expressed over snow cover days. There were significant differences in disease severity among the graminious species, and among cultivars within each species, indicating varying levels of susceptibility to R. cerealis and T. incarnata.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.2
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• pp.71-78
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• 2012

Eupatilin, one of representative medical components of mugwort, can be efficiently extracted from the 'Gangwha Sajabalssuk'. The Eupatilin content may depend on environmental factors such as soil and regional climate in addition to a genetic factor and Gangwha region has a profitable environmental condition for the mugwort growth. In this study, the climatological characteristics of Gangwha was analyzed in order to find the environmental condition of mugwort containing high Eupatilin in term of atmospheric, oceanographic and land variables. The climate of Gangwha is characterized by the relatively low daily temperature and large diurnal variation with plenty of solar radiation, long sunshine duration and less cloudiness. According to our correlation analysis, the long sunshine duration and the large diurnal temperature variation are highly correlated with the Eupatilin contents. The result implies that Gangwha has the favorable conditions for the cultivation and the habitat of the high-Eupatilin concentrated mugwort. Because of the sea surrounding Gangwha Island with low salinity and moderate wind, the salt contained in sea breeze is relatively low compared to other regions. Furthermore, Gangwha has clean atmospheric environment compared to other regions because the concentrations of toxic gases harmful to crop growth such as nitrogen dioxide ($NO_2$), sulfite gas ($SO_2$) and fine dust (PM-10) are lower in the air. The ozone ($O_3$) concentration is moderate and within the level of natural production. It is also found that moderately coarse texture or fine loamy soils known as good for water drainage and for the growth and cultivation of the 'Gangwha-mugwort' are distributed throughout the areas around mountainous districts in Gangwha, coinciding with those of mugwort habitat.

• Korean Journal of Remote Sensing
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• v.35 no.5_1
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• pp.751-761
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• 2019

Mt. Baekdu, Mt. Aso, Mt. Sakurajima, Mt. Kikai and etc are distributed around the Korean Peninsula. Recently signs of eruption of Mt. Baekdu are increasing, raising concerns over possible damage to volcanic ash from seasonal winds during the winter eruption. Therefore, detailed procedures for investigation and countermeasures for volcanic ash spread and damage are required. But the standards for the warning and alarm signal of volcanic ash presented by Korea Ministry of Government Legislation are vague, with "when damage is expected" and "when serious damage is expected". In this study, to analyze the damage threshold and to apply the cases of overseas damage to the country, a survey was conducted on the establishment of domestic spatial information by public institutions with public confidence. As a result of the investigation of damage from volcanic ash overseas, the details of the damage cases were different depending on the type of life or income sources of each country. Therefore, instead of applying the volcanic ash damage cases abroad in Korea, spatial information analysis was performed to reflect domestic social and natural characteristics. In addition, we selected the areas to be considered in the event of volcanic ash damage in Korea. Finally, domestic volcanic ash damages should be classified as health, residential, road, railroad, aviation, power, water, agriculture, livestock, forest, and soil. When establishing the volcanic ash alarm optimized for Korea in the future, overseas volcanic ash damage cases and domestic spatial information construction in this study will be helpful in policy establishment.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.419-430
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• 2021

This study investigated spatiotemporal trends of sediment-related disasters in North Korea from 1960 to 2019 and post-disaster recovery cases based on a literature review and satellite images. Results showed that occurrence status of sediment-related disasters was initially externally reported in 1995 (during the Kim Jongil era); their main triggering factor was heavy summer rainfall. Furthermore, forest degradation rate was positively correlated with population density (R² = 0.4347, p = 0.02) and occurrence number of sediment-related disasters was relatively high on the west coast region, where both variables showed high values. This indicates that human activity was a major cause of forest degradation and thus, significantly affected sediment-related disasters in mountain regions. Finally, sediment- related disasters due to shallow landslides, debris flow, and slow-moving landslides were observed in undisturbed forest regions and human-impacted forest regions, including terraced fields, opencast mines, forest roads, and post-wildfire areas, via satellite image analysis. These disaster-hit areas remained mostly abandoned without any recovery works, whereas hillside erosion control work (e.g., treeplanting with terracing) or torrent erosion control work (e.g., check dam, debris flow guide bank) were implemented in certain areas. These findings can provide reference information to expand inter-Korean exchange and cooperation in forest rehabilitation and erosion control works of North Korea.

• Korean Journal of Organic Agriculture
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• v.26 no.4
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• pp.629-647
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• 2018

This study was carried out to investigate the economic value of organic rice production using gelatin chitin microorganisms in eco-friendly complex, Gongsan, Naju city. The soil condition of experiment paddy field was Jeonbuk series and silt loam with a slightly poor drainage. Except for the high effective silicate, the chemical characteristics of soils used were included in the optimum range of paddy soils in Korea. In growth, plant length, tiller number, ear number, and ear length were observed to be higher in conventional paddy fields than organic paddy fields. However, number of grain per panicle and grain filling ratio (%) were higher in organic paddy fields than conventional paddy fields. Incidences of diseases and insect pests were slightly higher in the organic paddy fields. Water weevil, sheath blight, rice leaf roller and rice blast were more occurred in organic paddy field. On the other hand, false smut was higher occurred in conventional paddy field. There was a significant negative correlation between rice sheath blight and rice leaf roller, and rice yield. In the milled rice quality, the quality of organically cultivated milled rices was lower by the increase of broken rice than that of conventionally cultivated milled rices. The quality and palatability of rice were higher in organic cultivation with decreasing of protein content. Net income of conventionally and organically cultivated rice was 360,000 won/10a and 610,000 won/10a, respectively. Premium net income of the organically cultivated rice was 68%.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.1
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• pp.3-14
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• 2018

An apartment complex is a building use with great potential to contribute to solving problems related to urban ecological environment and climate change. The first goal of this study is to grasp the current situation of application and limitations of the ecological area rate, which is a representative evaluation index used to evaluate the environmental performance of the external space of an apartment complex in Green Standard for Energy and Environmental Design (G-SEED). The second goal is to propose a prototype of the evaluation index for evaluating greenhouse gas (GHG) reduction performance in order to supplement the evaluation index for the environmental performance of the external space in terms of response to climate change. We analyzed 43 cases of apartment complexes certified according to G-SEED, which was enforced since July 1, 2010, and found application characteristics of each space type and the limitations of ecological area rate. We analyzed overseas green building certification systems such as LEED and BREEAM that derived implications for supplementing the limitations of ecological area rate, which is focused on the evaluation of soil and water circulation function, and set up a development direction of complementary measures. Through analysis of previous studies, relevant regulations and standards, and technical documents of the manufacturer, the heat island mitigation performance of the pavement and roof surfaces of the apartment complex and the carbon uptake performance of the trees in the apartment complex was selected as parameters to yield the GHG reduction performance of the external space of the apartment complex. Finally, a quantitative evaluation method for each parameter and a prototype of the evaluation index for the GHG reduction performance were proposed. As a result of applying the prototype to an apartment complex case, the possibility of adoption and applicability as an evaluation index of G-SEED were proved.

• Journal of Wetlands Research
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• v.24 no.4
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• pp.354-366
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• 2022

To analyze the distribution of plant communities growing in river wetlands and the relationship between biotic and abiotic environmental factors, plant communities and environmental factors were investigated in river wetlands in the Boseong River. The Boseong River Wetland, the research site, consists of Hwapyeong Wetland, Bangujeong Wetland, and Seokgok Wetland. From June to September 2022, a plant community survey was conducted from the perspective of physiognomical vegetation, and the coverage of the emerging species followed the Braun-Blanquet scale. Plant species and the coverage of each species were recorded in the quadrant for plant community survey, and the cover of the quadrant, the total number of species, and the number of exotic species were measured as biological factors. As abiotic factors, altitude, orientation, inclination, soil texture, litter layer depth, dominant species diameter at breast height, and topography were recorded. In a total of 50 square plots, the most common Salix koreensis and Phragmites japonicus communities were found, and the community with the highest Shannon species diversity index was Phragmites japonicus-Echinochloa caudata community. As a result of ordination analysis by DCCA, the most significant clusters were separated according to topographic factors such as leeve, leeve slope, upper floodplain, lower floodplain, upper waterside, middle waterside, lower waterside, river island and opem water. As rare plants that need to be preserved in river wetlands, Hydrocharis dubia and Penthorum chinense were found in lower waterside, and it was found that the management of the river in the reservoir is necessary in line with the topographical distribution of ecosystem-disrupting plants, such as Paspalum distichum var. indutum.

• Journal of Environmental Impact Assessment
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• v.31 no.5
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• pp.321-333
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• 2022

In this study, the concentration and distribution characteristics of BTEX (benzene toluene, ethylbenzene, and xylene) emitted from Daesan Petrochemical Industrial Complex were examined to determine their potential hazards to local residents. Residents living nearby the complex areas may be exposed to the chemicals through various media (air, water, and soil), especially by air. This study evaluated human health risks by inhalation using both deterministic and probabilistic risk assessment approaches. As a result of the deterministic risk assessment, the non-cancer risk was much lower than the regulation limit of hazard index (HI 1.0) for all the points. However, in case of cancer risk evaluation, it was found that the risk of excess cancer for benzene at point A located in the industrial complex was 2.28×10^-6, which slightly exceeded the standard regulatory limit of 1.0×10^-6. In addition, the probabilistic risk assessment revealed that the percentile exceeding the standard of 1.0×10^-6was found to be 45.3%. The sensitivity analysis showed that exposure time (ET) had the greatest impact on the results. Based on the risk assessment study, it implied that ethylbenzene, toluene, and xylene had little adverse effects on potential human exposure, but benzene often exceeded the cancer risk standard (1.0×10^-6). Further studies on extensive VOCs monitoring are needed to evaluate the potential risks of industrial complex areas.