• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.709-712
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• 2010

본 논문은 개미군락최적화 알고리즘을 이용한 트러스 구조물의 설계최적화에 대한 이론적 배경과 수치해석 결과를 기술하였다. 트러스의 설계최적화를 수행하기 위하여 구조물의 중량을 최소화하는 것을 목적 함수로 하고 구조물에서 발생하는 응력과 변위의 허용치를 초과하지 않는 것을 구속조건으로 이용하였다. 본 연구에서는 개미군락알고리즘을 구조물의 최적화에 적용하기 위하여 외판원문제(travelling salesman problem: TSP)를 재 정의하는 방법을 사용하였으며 최대-최소개미시스템(max-min ant system)을 도입하여 트러스 구조물의 최적설계를 수행하였다. 이때 이산화 된 설계변수를 사용하였으며 구속조건을 처리하기 위해서 벌점함수를 사용하였다. 본 연구를 통하여 개미군락최적화 알고리즘은 구조최적화에 그 적용 가능성이 높았으며 전통적인 최적검색 기법의 새로운 대안으로 이용될 수 있는 것으로 나타났다.

• Korean Journal of Environment and Ecology
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• v.25 no.4
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• pp.540-561
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• 2011

We carried out a study for ecological management and ideal vegetation structure selection on the shrine forest of 'Miwhang-sa' considering the species diversity and the vegetation structure analysis associated with global warming. We carried out the analyses of phytosociological vegetation structure, correlation between vegetation units and environmental variables, life form, species diversity, and species evenness. This study identified the vegetation units as 3 communities. The identified vegetation units are as follows: Quercus acuta community(DQ), Quercus serrata-Quercus variabilis community(QQ) and Celtis sinensis community(CS). According to the basis on the environmental variables; Ca, Mg and P, Celtis sinensis community and other communities were classified. Quecus serrata-Quercus variabilis comm. and Quercus acuta comm. were classified, according to the basis on the environmental variables; organic matter(OM), Ni and Zn. Sasa borealis as life form R1-2, dominated the herb layer and will dominate the herb and shrub layers. Species simplification is formed on herb layer and will be formed on shrub layer. The species diversity of Quercus serrata-Quercus variabilis community is higher than the one of Quercus acuta community, and the species diversity of shrine forest around Miwhang-sa was higher than the shrine forest around Nameun-sa where evergreen broad-leaved forests dominate. It is essential that the long-term vegetation management considering the vegetation units by phytosociological analysis, the species simplification problem of low layers by S. borealis and the species diversity and evenness in the shrine forest, Miwhang-sa.

• Korean Journal of Environment and Ecology
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• v.20 no.2
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• pp.103-113
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• 2006

To investigate the forest structure and to suggest basic data for forest management in the Mookdong area of the Weolchulsan National Park, thirty plots, each size is $100m^2$, were set up and surveyed. According to analysis of classification by TWINSPAN, the community was divided by five groups of Quercus variabilis-Q. mogolica(I), Q. variabilis(II), Q. variabilis-Pinus densiflora(III), P. densiflora(IV), Q. acutissima(V). The structure of communities were investigated using importance value. From the above results, it was anticipated that Quercus spp. will be dominance species instead of Pinus densiflora.

• Korean Journal of Environment and Ecology
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• v.25 no.3
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• pp.378-388
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• 2011

This study was done to classify the vegetation structure and ecological characteristics in Nakdong-jeongmaek. Therefore, we set up 34 plots($100m^2$) in 9km range. As a result of vegetation analysis, the vegetation of Seongsi valley was classified into the type of 6 communities i.e. Pinus densiflora community, Quercus variabilis community, Q. mongolica community, Q. serrata community, Betula schmidtii community, Larix leptolepis community. The average number of species and individuals were ranged from 8.5~10.5 and 27.5~75.6 respectively. Species diversity index(H') of groups were ranged from 0.6061~0.8736 per units, and it was highest and lowest in B. schmidtii and P. densiflora communities respectively. Similarity index of groups were slightly low. It was low in P. densiflora community, Q. mongolica community and L. leptolepis community, and lowest in Q. variabilis-Q. mongolica community.

• Applied Biological Chemistry
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• v.15 no.1
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• pp.41-47
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• 1972

Comparative study on dynamic change of canopy structure during ripening period were carried out by using newly bred high yield rice cultivar (IR 667-Suwon 213) and a commercial variety, Jinhung in relation to nitrogen nutrition. The results were as follows. 1. Canopy structure pattern (vertical distribution of dry matter density at heading)was vertical type for Jinhung and horizontal type for IR 667. 2. The vertical distribution pattern of leaf area density (or weight) in the canopy was central dominant type for IR 667 while apical dominant type for Jinhung. 3. Canopy conservation pattern and percent distribution pattern of leaf area density followed the vertical distribution pattern of leaf area density. 4. Canopy persistence was weaker in IR 667, thus they have smaller canopy conservation ratio indicating faster senescence. 5. Slow supply of nitrogen (sulfur coated urea) showed a trend to change the apical dominant pattern into the central dominant pattern by the conservation of central portion, and it-resulted in higher yield though nitrogen nutrition did little affect canopy pattern. 6. The central and apical dominant pattern appeared to be well matched to the upper leaf-dependent type and the lower leaf-dependent type of grain yield, respectively.

• Korean Journal of Environment and Ecology
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• v.18 no.2
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• pp.131-141
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• 2004

To investigate the vegetation structure of mountain ridge from Namdeogyusan to Sosajae in Baekdudaegan which is the greatest chain as well as the major ecological axix of the Korean Peninsula, sixteen sites(size 500$m^2$) were set up and surveyed. By using TWINSPAN technique, the plants community was divided and summarized into five groups, those are four Quercus mongolica dominated communities and Quercus mongolica-Pinus densiflora community. Four Quercus mongolica dominated communities have differentiated from subtree dominant species. Vegetation structure of each community have explained using important percentage by layer. In descriptive analysis, average number of species is 27.8$\pm$7.5 and average number of individuals is 687.6$\pm$326.8 at unit area(500$m^2$).

• Korean Journal of Environment and Ecology
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• v.15 no.3
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• pp.237-246
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• 2001

To investigate the forest structure and to suggest the basic data of forest in the Dongwol Valley, the Gyeryongsan National Park, forty one plots were set up and surveyed. According to the analysis of classification by TWINSPAN, the community was divided by seven groups of Carpinus taxinora(I), Styrax japonica(II), Pinus densiflora A type(III), Quercus acutissima(IV), P. densinora-Q. valiabilis(V), p. densinora B type(Ⅵ) and Q. mongolica community(Ⅶ). The structure of communities were investigated using importance value. The survey results were summarized as follows: 1) the results of annual ring analysis revealed that the age of forest in the Dongwol Valley was about 30~50 years old,2) number of the average species was 15.6$\pm$4.7 and number of average individual was 124.9$\pm$36.4 per a plot(100$\textrm{cm}^2$). From the above results, it was anticipated that C. laxiflora will be climax species instead of Q. spp. and P. densinora.

• Journal of Wetlands Research
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• v.23 no.2
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• pp.133-143
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• 2021

This study aims to classify the plant communities of the Gudam wetland, a riparian wetland in Nakdong River basin, and to identify the characteristics of the communities according to the veritical structure to prepare management plan. In the Gudam wetland, a total of 19 plant communities were found through physiognomical vegetation, and were analyzed by dividing into tree dominant community, shrub dominant community, and herbaceous dominant community according to the vertical structure. When examining the results of the community characteristics analysis, the species diversity index was the highest in the tree dominant communities but there was concern about a decrease in species diversity due to the influx of exotic plants such as Sicyos angulatus. The shrub dominant community tended to have a biased species diversity index on shrub plants. The herbaceous dominant communities ware divided into wetland herbaceous communities and dryland herbaceous communities according to the species diversity index, and measures were needed to reduce the species diversity index due to artificial disturbances. The importance value was the highest in the arboreal Salix genus in the tree dominant communities, and the exotic plants such as Amorpha fruticosa were the highest in the shrub dominant communities. In the herbaceous dominant communities, wetland herbaceous plants such as Phragmites japonicus were high. As a result of the analysis according to ordination the tree dominant communities and shrub dominant communities were differentiated by exotic plant factors, and the herbaceous dominant communities were differentiated by hierarchy number and slope.

• Korean Journal of Heritage: History & Science
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• v.43 no.1
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• pp.100-117
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• 2010

This study analyzed vegetation structure of natural monuments Koelreuteria paniculata community in search of a conservation and management plan. Plant sociological analysis of Koelreuteria paniculata community indicates that it can be classified into Achyranthes japonica subcommunity and Rhodotypos scandens subcommunity and Trachelospermum asiaticum var. intermedium subcommunity. While Koelreuteria paniculata community of Ahnmyeondo is composed of sub tree layer and herb layer, those of Pohang and Wando are composed of tree layer, Sub tree layer, shrub layer, herb layer. The results of tree vitality analysis showed that those in Ahnmyeondo appeared to be relatively low when compared to those in Pohang and Wando-gun. This can be understood in two different aspects: disease and insects vulnerability due to a relatively simple structure and lack of competitive species, and decreased vitality / natural branch losses due to crown competition arising from high density. The result of soil characteristics analysis showed that soil texture, soil pH, organic matter, $p_2O_5$, exchange positive ion were sufficient for tree growth while total nitrogen was not, so that discretion would be needed for fertilizer application. As there were damages of disease and inscet, but only for 10~15% of the entire area; it still requires consistent preconsideration. The study suggests the management methods for preservation of Koelreuteria paniculata community. First, securing designated areas is necessary in order to minimize environment deterioration due to surrounding development. Especially, for sections with decreased areas, expansion of designated areas through land purchase should also be considered. Second, artificial interference may affect the livestock. Therefore, monitoring of artificial interference is necessary, based on which protection projects must be conducted. Third, from analysis of young plants which influence the maintenance mechanisms of Koelreuteria paniculata community, a decrease compared to the prior year was observed; investigation is needed. Therefore, an active management policy through status examination of livestock such as germination and young plants is necessary.

• Journal of agriculture & life science
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• v.45 no.3
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• pp.1-7
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• 2011

This study was carried out to provide the basic information for effective preservation and management of forest community of Nari basin in Ulleung Island. Forest community in Nari basin was classified into Fagus engleriana community, Sorbus amurensis community, Pinus densiflora community, Celtis jessoensis community and Alnus maximowiczii community. As the result of DCCA ordination analysis, sea level among environmental factors had high correlation with community distribution. Fagus engleriana community and Sorbus amurensis community correlated highly with aspect, Na content, and C/N ratio. There was a high correlation between Celtis jessoensis community and the content of Ca and K. Alnus maximowiczii community was distributed in site where CEC content is high. Pinus densiflora community was distributed in site where the content of Ca and CEC is high.