• The Journal of Engineering Geology
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• v.33 no.1
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• pp.69-83
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• 2023

Forest fires increase the risk of subsequent soil erosion and mass movement in burned areas, even under rainfall conditions below landslide alert thresholds, by destroying plants and vegetation and causing changes to soil properties. These effects of forest fires can alter runoff in burned areas by altering soil composition, component minerals, soil water repellency, soil mass stability, and soil fabric. Heat from forest fires not only burns shallow organic matter and plants but also spreads below the surface, affecting soil constituents including minerals. This study analyzed X-ray diffraction and physical properties of topsoil and subsoil obtained from both burned and non-burned areas to identify the composition and distribution of clay minerals in the soil. Small amounts of mullite, analcite, and hematite were identified in burned soils. Vermiculite and mixed-layer illite/vermiculite (I/V) were found in topsoil samples from burned areas but not in those from non-burned areas. These findings show changes in soil mineral composition caused by forest fires. Expansive clay minerals increase the volume of soil during rainfall, degrading the structural stability of slopes. Clay minerals generated in soil in burned areas are therefore likely to affect the long-term stability of slopes in mountainous areas.

• Journal of Korean Society of Forest Science
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• v.112 no.4
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• pp.405-416
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• 2023

In this study, the sustainability of Abies nephrolepis in the presence of Tripterygium regelii was analyzed. To accomplish this, a field survey of140 stands was conducted. Based on the presence or absence of T. regelii, as well as the layer in which it was present (where appropriate), the type of T. regelii presence wasclassified as follows: TP type, indicating the presence of T. regelii in the tree and sub-tree layers; SP type, indicating its presence in the shrub layer; and A type, indicatingits absence from all layers. The indicator species analysis revealed T. regelii to be an indicator species of the TP type and SP type. The MRPP test was used to examine the differences among the types. Moreover, the seedling and DBH class analysis indicated there to be a difficulty in terms of the status competition, as the number of young trees generated by A. nephrolepis was the lowest in the TP type. The findings of this study enhanced our understanding of the vegetation structure of A. nephrolepis, thereby contributing to efforts concerningits conservation and management.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.6
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• pp.641-650
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• 2011

Airborne LIDAR system, utilized in various forest studies, provides efficiently spatial information about vertical structures of forest areas. The tree height is one of the most essential measurements to derive forest information such as biomass, which can be estimated from the forest terrain model. As the terrain model is generated by the interpolation of ground points extracted from LIDAR data, filtering methods with high reliability to classify reliably the ground points are required. In this paper, we applied three representative filtering methods to forest LIDAR data with diverse characteristics, measured the errors and performance of these methods, and analyzed the causes of the errors. Based on their complementary characteristics derived from the analysis results, we have attempted to combine the results and checked the performance improvement. In most test areas, the convergence method showed the satisfactory results, where the filtering performance were improved more than 10% in maximum. Also, we have generated DTM using the classified ground points and compared with the verification data. The DTM retains about 17cm RMSE, which can be sufficiently utilized for the derivation of forest information.

• Journal of Mushroom
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• v.9 no.4
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• pp.194-197
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• 2011

The transitivity of Chemical constituents by Pleurotus ostreatus cultivated in different raw sawdusts, which are Acer tegmentosum MAX, Rhus verniciflura, was investigated. The HPLC chromatography patterns on the chemical constituents of P. ostreatus showed the similar chromatography patterns in the different raw sawdusts and control sawdust. The unknown chemical constituents of P. ostreatus cultivated in the mixed medium added 10 %, 20% raw sawdusts, respectively, were increased. But the significance results in the mixed medium added 50% raw sawdusts were not showed. The chromatography patterns of mycelia grown in media added the 80% MeOH extracts of A. tegmentosum and R. verniciflura showed the similar patterns in comparison with control mycelia. In the results, the secondary metabolites of functional media were not degrade and changed to other derivatives compounds by P. ostreatus.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.2-2
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• 2021

최근들어 하천내 식생이 차지하는 비율이 크게 증가하고 있으며, 이러한 현상은 하천의 규모나 위치, 댐 유무에 관계없이 전국적으로 발생하고 있다. 식생 면적 비율의 증가는 하천의 육역화로 이어질 뿐만아니라 홍수위를 상승시켜 홍수 안전에 영향을 미칠 수 있다. 본 연구에서는 2020년 8월 섬진강에서 발생한 홍수를 대상으로 식생이 홍수위에 미치는 영향을 분석하였다. 섬진강에는 초본류 뿐만아니라 버드나무류의 목본류가 상당히 분포하고 있으며 이와 같은 식생이 홍수흐름에 큰 영향을 미친 것으로 보인다. 분석을 위해 홍수 이후 섬진강 현지 답사를 통해 식생분포 현황 및 홍수로 인한 영향을 조사하였다. 섬진강의 식생분포 조사를 위해서는 2020년 4월 조사된 유럽 우주국 Sentinel-2 위성영상을 사용하였으며, 정규식생지수(NDVI)와 정규수분지수(NDWI)를 이용하여 하천내 식생밀도를 단계별로 구분하였다. 군집된 식생지수에 따라 USGS의 매닝계수 산정표를 기본으로 식생분포 군집별 조도계수를 산정하여 대상 구간내에 2차원으로 분포시켰다. 수치모형은 NAYS2D 모형을 사용하였으며 대상구간은 섬진강 고달교에서 구례교까지 21.5km이다. 계산조건은 2020년 8월 홍수중 구례교 수위관측소를 기준으로 최대수위가 발생한 시점의 자료를 활용하였다. 고달교에서는 홍수통제소에서 제공하는 홍수량을 상류경계 조건으로 입력하였고 구례교에서는 해당 시각의 수위를 하류경계조건으로 입력하였다. 모형의 검증을 위해 대상구간의 중간에 있는 압록수위관측소 수위를 활용하였다. 식생 유무에 따른 홍수위변화는 조도계수 값에 의해 반영되도록 하였는데 식생이 있는 경우는 현재 상태, 식생이 없는 경우는 모든 지점에 모래와 자갈이 분포하는 것으로 가정하여 계산된 홍수위를 비교하였다. 분석 결과 대상구간에는 전체 면적중 약 56%를 식생이 차지하고 있으며 이로 인해 0.5~1.0m의 홍수위 상승이 발생하는 것으로 분석되었다. 수목으로 인해 2020년 8월과 같은 큰 홍수시에도 홍수위가 크게 상승하는 것으로 분석되었는데 이와 같은 점을 고려하면 하천내 식생이 홍수위에 미치는 영향을 감안하여 적극적인 식생관리 방안이 시행될 필요가 있을 것으로 판단된다.

• Korean Journal of Plant Resources
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• v.23 no.4
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• pp.261-273
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• 2010

This study intended to investigate the environmental factors including soil and vegetation in order to understand the environmental and ecological characteristics of seven different habitats of Viola websteri. These habitats, according to investigations, are mostly located on the slope of mountains facing north at an altitude of 343 m to 991 m above sea level with angle of inclination from 1 degree to 33 degrees. The type of soil is mostly sandy loam and the average field capacity of soil is 28.97%. Their average organic matter is 16.63%, soil pH 5.62, and available phosphorus is 14.75%. A total of 133 vascular plants are identified in 18 quadrates of seven habitats. Dominant species of woody plants in seven habitats are represented as Acer pictum subsp. mono and Quercus mongolica in tree layer, and Acer pictum subsp. mono in subtree layer. Importance value of Viola websteri is 9.66%, as regards the herbaceous layer, and five highly ranked species such as Meehania urticifolia(8.53%), Pseudostellaria heterophylla(6.51%), Hylomecon vernalis(5.15%), Oxalis obtriangulata (4.52%), and Pseudostellaria davidii(4.15%) are considered to be an affinity with Viola websteri in their habitats. The degree of their average species diversity is 1.32, and that of dominance and evenness are 0.08 and 0.89, respectively. Correlation coefficients analysis based on environmental factors, vegetation and soil analysis shows that the coverage of Viola websteri is correlated with silt and sand ratio, and coverage of tree layers are correlated with species richness and altitude. Cluster analysis based on vegetation structure of each habitats are forms a three groups.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.3
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• pp.46-58
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• 2024

The purpose of this study is to understand the current status of the pet plant kit industry and determine the priorities for support policies to revitalize the industry. SWOT analysis assessed the industry's current state, and the Analytic Hierarchy Process (AHP) was used with industry professionals to prioritize support policies. The SWOT analysis results indicated that SO strategies involve leveraging government support policies to enhance marketing and developing eco-friendly DIY products. WO strategies include launching advertising campaigns to increase market recognition and establishing strategic partnerships to expand distribution. ST strategies focus on strengthening price competitiveness and proposing unique values, while WT strategies involve improving production processes and enhancing product quality based on consumer feedback. The AHP analysis identified 3 top-level and 12 sub-level evaluation items, with data collected from 17 expert surveys. The results showed the 'entry phase' (0.482), 'activation phase' (0.397), and 'advanced phase' (0.121) were prioritized, with 'organizing seminars' (0.181) as the most crucial subcategory and 'support for kit development' (0.020) as the least. The pet plant kit industry is in its early stages, and appropriate policy incubation can help activate the garden industry. This study provides foundational information on the industry's needs for activation.

• Korean Journal of Environment and Ecology
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• v.34 no.6
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• pp.573-588
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• 2020

The study investigated the forest vegetation structure of Kongju National University Forests in the vicinity of Seokjangri-dong to provide the information needed for efficient use and management. It conducted a Z-M phytosociological vegetation survey in 60 quadrate plots in August 2019 and generated the actual vegetation map by analyzing the physiognomic community classification and mean importance value. The physiognomic community classification showed five vegetation community types: Quercus acutissima community, Pinus densiflora community, Quercus variabilis community, Pinus rigida community, and Quercus serrata community. The relative importance value in the Q. acutissima community was 31.4% for Q. acutissima, 9.6% for Prunus spp., and 9.0% for Q. variabilis. In the P. densiflora community, it was 24.9% for P. densiflora, 12.4% for Q. acutissima, and 11.5% for Q. serrata. In the Q. variabilis community, it was 25.3% for Q. variabilis, 9.8% for Prunus spp., and 8.5% for Q. acutissima. In the P. rigida community, it was 28.4% for P. rigida 28.4%, 10.0% for Q. acutissima, and 9.3% for P. densiflora. In the Q. serrata community, it was 27.0% for Q. serrata, 11.3% for Q. aliena, and 11.5% for Styrax japonica. The actual vegetation map based on the uppermost dominant species to identify the forest vegetation's spatial distribution characteristics indicated that the natural vegetation covered the most with 87.5%, the number of vegetation patches was 87, and the average area per patch was 1.46ha.

• Journal of the Korean Institute of Gas
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• v.6 no.1 s.17
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• pp.66-73
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• 2002

In this study a new SIS evaluation method based on the reliability analysis has been developed. It evaluates the Safety Integrity Level (SIL) using the Fault Tree Analysis (FTA), and when the SIL falls short of the systems target level, through the reliability analysis and system retrofit, this method will satisfy the aimed SIL. A hazard evaluation was carried out on the 415V Diesel BUS to verify the SIL evaluation method based on the reliability analysis. The availability of the original 415V Diesel BUS was $99.40\%$, which comes under the category of SIL 2. After exchanging the diesel generator and the isolator switch using the developed evaluation method, the availability rose to $99.94\%$, SIL 3. By applying the method presented in this study, not only will it reduce the maintenance cost due to the prevention of accidents and reduction of loss, but also maximize the reliability of the system.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.6
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• pp.137-147
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• 2016

The purpose of this study was to analyze the perception factors of a pedestrian environment that affect pedestrian environment satisfaction(PES) and determine the relationship between PES and the expected effects of health promotion. The targeted areas of study are neighborhood parks in Suseong-gu, Daegu city. First, regarding the results for the evaluation of pedestrian environment perception, 'Gentle slope' was rated the highest, while factors regarding pedestrian safety such as 'Lots of unpleasant elements', 'Risk from biking and motorcycling' and 'Many obstacles on sidewalks' were rated low. A stepwise regression analysis showed that factors such as 'Fresh air', 'Beautiful scenery', 'Continuity of the sidewalks', 'Various attractions', 'The shade of trees' and 'Lots of unpleasant elements' influenced the PES. Therefore, creating fresh air and shade trees by planting trees and removing unpleasant elements from pedestrian areas are important. Also, it is necessary to cultivate beautiful scenery and attractions through street improvement and improve the continuity of the sidewalks. Finally, in terms of path analysis, PES influenced the frequency of park use, the expected effects of physical and mental health promotion both directly and indirectly.