• 환경생물
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• 제25권3호
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• pp.249-259
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• 2007

식장산의 현존식생과 입지환경을 고려한 식생조사구 총 114개소를 설치하여 식생구조를 분석한 결과 산지림유형, 계곡림유형, 인공림유형의 3개 유형으로 분류되었고, 총 23개의 군락으로 구분되었다. 식생 분포는 사면상부와 능선부에 신갈나무군락이, 남사면에는 소나무군락과 굴참나무군락이 각각 분포하였으며, 신갈나무군락의 점유 면적이 34,213ha로 전체 면적의 31.9%로 가장 넓은 영역을 차지하고 있었고 계곡림은 좁은 면적에 매우 많은 군락들로 구성되어 있었다. 계곡림 유형에서는 졸참나무, 갈참나무, 물푸레나무, 고로쇠나무, 까치박달, 산딸나무 등의 수종들의 층위별 중요치가 높았다. 종다양도는 인공림유형의 물오리나무군락이 0.2191로서 가장 낮았고, 계곡림 유형의 종다양도지수가 약 0.9로서 가장 높았다.

• 한국전산유체공학회지
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• 제20권2호
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• pp.52-60
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• 2015

The objective of this research lies in the effect of installation parameters influencing on the wind proof performance of the coastal forest for damage prevention. The dissipation ratio of incident wind power is developed as an assessment index to make a lumped parameter study possible. From the real field data of East, West, and South Sea bounded on the Korean peninsula, single and double storied forests were modeled in three-dimensional shape with computer aided design, and so was done the artificial structures such as wind break, sand accumulating fence, and sand dune, etc With a commercial code ANSYS-CFX, the computational result from the comparison of dissipation ratio between single and double storied forest shows the effect of composition, and also the installation effect is investigated for artificial structures with optimal dimension of distance.

• 한국환경생태학회지
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• 제26권4호
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• pp.604-619
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• 2012

독일의 산림미학(숲미학)과 영국의 산림디자인 개념에 따르면 우리나라 국립공원 인공림도 단계별로 생태적 복원이 필요하며, 본 연구는 국립공원 인공림의 식생구조를 분석하여 생태적 천이를 유도하기 위한 식생유형별 간벌 밀도 기준을 제시하고자 수행하였다. 국립공원 중 치악산, 속리산, 덕유산, 내장산에 분포하는 잣나무림, 전나무림, 편백림, 은사시나무림, 일본잎갈나무림 등 인공림 8개소와 소나무군집, 소나무-졸참나무군집, 졸참나무군집 등 자연림 3개소 등 총 11개소에 $20m{\times}20m(400m^2)$ 크기의 방형구를 설정하였다. 식생구조 특성을 고려하여 인공림을 천이미발달형, 외래종치수발달형, 천이초기형으로 유형화하였다. 종다양도(H')는 천이미발달형 0.9681~1.1323, 외래종치수발달형 1.0192~1.1870, 천이초기형 1.3071~1.3892, 자연림 1.2202~1.3428로 침엽수 단일수종 위주의 단층구조의 인공림보다 천이초기형 인공림과 다층구조의 자연림의 종다양도가 다소 높았다. 단계별 간벌 밀도는 30~60% 범위로 하되, 천이미발달형은 외래종 우점치가 88~90%로 높으므로 대경목부터 3단계에 걸쳐 간벌하고, 외래종치수발달형은 외래종 우점치가 60~97%로 높고 아교목층과 관목층에 치수가 발달하고 있어 조기에 외래종 치수를 제거하고 1단계 또는 2단계에 걸쳐 간벌하며, 천이초기형은 외래종 우점도가 30% 이하로 자생종과 경쟁하는 외래종을 우선적으로 간벌하고 1단계 또는 2단계에 걸쳐 간벌할 것을 제시하였다.

• 한국정보시스템학회지:정보시스템연구
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• 제29권2호
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• pp.287-306
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• 2020

Purpose Youth unemployment is a social problem that continues to emerge in Korea. In this study, we create a model that predicts the employment of college graduates using decision tree, random forest and artificial neural network among machine learning techniques and compare the performance between each model through prediction results. Design/methodology/approach In this study, the data processing was performed, including the acquisition of the college graduates' vocational path survey data first, then the selection of independent variables and setting up dependent variables. We use R to create decision tree, random forest, and artificial neural network models and predicted whether college graduates were employed through each model. And at the end, the performance of each model was compared and evaluated. Findings The results showed that the random forest model had the highest performance, and the artificial neural network model had a narrow difference in performance than the decision tree model. In the decision-making tree model, key nodes were selected as to whether they receive economic support from their families, major affiliates, the route of obtaining information for jobs at universities, the importance of working income when choosing jobs and the location of graduation universities. Identifying the importance of variables in the random forest model, whether they receive economic support from their families as important variables, majors, the route to obtaining job information, the degree of irritating feelings for a month, and the location of the graduating university were selected.

• 한국조경학회지
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• 제26권2호
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• pp.15-27
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• 1998

The purposes of this study were to investigate vegetation structure and present management planning of mountain type green space using the green space changes during the 20 years, actual vegetation, and plant community structure in land area of Inchon, Korea. The actual vegetation area in survey sites was consisted of Quercus acutissima community, Robinia pseudoacacia forest, Pinus rigida forest, Q. mongolica-Pinus rigida community, P. rigida-Q. mongolica community, Q. monogolica community and so on. According to the classification by TWINSPAN, 61 survey plots were divided into 9 groups; Q. mongolica-Alnus japonica-R. pseudoacacia-P. densiflora, R. pseudoacacia-Styrax japonica, P. rigida-R. pseudoacacia-Q. mongolica, R. pseudoacacia-P. rigida-Q. mongolica-A. hirusta, Q. mongolica-P. thunbergii, and prunus sargentii-Zelkova serrata community. From this result, ecological succession trend of vegetation seems to be change from artificial result, ecological succession trend of vegetation seems to be change from artificial planting forest to native plant community which was dominated by Quercus spp.. This study area need to manage for the increase of biodiversity through the restoration of naturalness by ecological management of artificial planting forest and ecological planting of injured green space.

• Journal of Forest and Environmental Science
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• 제29권2호
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• pp.173-180
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• 2013

Berries of Korean mistletoe (Viscum album var. coloratum [Kom.] Ohwi) contained one seed, which have, in general, one or two embryos but very rarely three embryos. Mucilaginous substances in berries may help them adhere to the branches of host trees. It was observed that seeds need more than one and half years to develop into normal and healthy seedlings from the time of inoculation. Many factors such as adhesion of berry, thickness of host branch, orientation of haustorial root, etc. influenced the successful development of mistletoe plants. Through the application of six-year observation results on the germination of seeds and growth of seedlings, about 80% of germination rate for mistletoe seeds and 61% of survival ratio for germinated seeds, which is more than 23 times higher in natural conditions, were obtained after inoculation of seeds on the one-year-old branches of Malus pumila var. dulcissima and Quercus mongolica trees. The technological aspects of the success can be applied to other host plants and provide a critical clue to an artificial propagation system, for this medicinally valuable genus. This is the first successful report on artificial inoculation and plant development of Korean mistletoe.

• 전기학회논문지
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• 제60권10호
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• pp.1966-1971
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• 2011

Generally, the characteristics of the conductor that was affected by forest fire can be analyzed only when the forest fire is accurately modeled and its effect is identified. Few studies have been conducted with a forest fire model for transmission lines, and no results of the examination of the actual test specimens that were exposed to forest fire have been reported. As the deterioration characteristics of a forest fire are difficult to analyze in the actual field, an environment that was similar to that in the field was used in this study. Deterioration was deposited on a wire using an artificial flame experiment device, to analysis the temperature, surface and component characteristics. It seems that this analysis data in this study can be used as the basic data for the database that can be utilized to analyze wires exposed to forest fire and deterioration and to predict the ACSR wire refurnishment life.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.436-437
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• 2006

Porcelain insulators have generally been used in Korea but polymer insulators which are superior in that they are light weight, explosion proof, impact proof, economical with construction characteristics, have been in use for the 154kV transmission line since 1999 following a worldwide trend towards the reduced weight, simplification and compact usage of new material insulators. However there have been approximately 500 cases of forest fires in Korea, so the transmission lines that for the most part pass through mountainous areas have been highly effected and the highly polymerized compound polymer insulator has raised concern about reliability in cases of exposure to forest fires. Therefore for the reliability assessment of the effect of forest fires on polymer insulators, mechanical and electrical characteristics are analyzed by an artificial flare test device and transmission facility surrounding conditions along with forest fire characteristics are surveyed. In addition to this, actual 90kV energized transmission line was tested with an artificial forest fire and the expanded usage of polymer insulators is presented through the analysis of mechanical and electrical characteristics and physical properties, and a study on the influence of forest fires on polymer insulators.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.298-301
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• 2004

The aim of this study is to cross-validate of spatial probability model, artificial neural network at Boun, Korea, using a Geographic Information System (GIS). Landslide locations were identified in the Boun, Janghung and Youngin areas from interpretation of aerial photographs, field surveys, and maps of the topography, soil type, forest cover and land use were constructed to spatial data-sets. The factors that influence landslide occurrence, such as slope, aspect and curvature of topography, were calculated from the topographic database. Topographic type, texture, material, drainage and effective soil thickness were extracted from the soil database, and type, diameter, age and density of forest were extracted from the forest database. Lithology was extracted from the geological database, and land use was classified from the Landsat TM image satellite image. Landslide susceptibility was analyzed using the landslide­occurrence factors by artificial neural network model. For the validation and cross-validation, the result of the analysis was applied to each study areas. The validation and cross-validate results showed satisfactory agreement between the susceptibility map and the existing data on landslide locations.

• 한국환경복원기술학회지
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• 제4권1호
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• pp.41-51
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• 2001

'The Ecological Forest' in Youido Park was intended to be an artificial forest in urban center, following the form of natural forests in central Korea. This study was to investigate the planting plan and the vegetation change of 'the Ecological Forest' and to compare it with natural forests of similar plant composition. The natural forests had slopes between $12^{\circ}$ and $21^{\circ}$, whereas 'the Ecological Forest' had slopes between $2^{\circ}$ and $6^{\circ}$. It was unlikely that the slope condition was adequate to show 'toposequence succession' at 'the Ecological Forest'. The soil bulk density and soil hardness of 'the Ecological Forest' were higher than those of the natural forests. The soil pH of 'the Ecological Forest' was 7.45, which was greater than that of the natural forests. There were some changes in plant composition and amounts 2 years after the construction : the number of conifers was reduced from 383 to 338 ; the number of deciduous trees was reduced from 4717 to 1158. It was because of the young trees dead in the sub-tree layer. The herbaceous species planted were 14 families, 31 species, which increased to 37 families, 93 species after 2 years. In case of horizontal structure of vegetation, trees and shrubs were distributed evenly in the natural forests, whereas 'the Ecological Forest' showed uneven distribution with higher total density. In case of vertical structure of vegetation, the natural forests had distinctive layers with dominant species distributed in each layers. In 'the Ecological Forest', however, dominant species were only in tree layer. The natural forests had greater average tree height, tree density, however, and basal area than 'the Ecological Forest'. The results showed that there were some differences in the structure between 'the Ecological Forest' and natural forests. The management plan should be applied in order that the natural condition be restored in 'the Ecological Forest' by competition between plant species and natural processes.