• Korean Journal of Plant Resources
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• v.13 no.3
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• pp.162-170
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• 2000

This study quantified the effects of urban greenspace on microclimate amelioration and atmospheric $CO_2$ reduction for several residential districts selected in Korea and Japan. The study also explored fire obstruction by urban trees to develop systematic planting guidelines. Transpiration by a Zelkova serrata tree (diameter at breast height: 15 cm) in a day of August equaled cooling effect of about 3 air conditioners running for 12 hours. Average air temperature for the growing season was 0.5$^{\circ}C$ and 1.2$^{\circ}C$ cooler, respectively, in districts with 12% and 22% cover of woody plants than in a district with no vegetation. Annual $CO_2$ uptake and $O_2$ production by woody plants were 3 times greater in a district which was 2 times higher in their cover. Woody plants played, in a district with their 22% cover, an important role through offsetting total $CO_2$ emission from the district by about 3% annually, and through producing 10% of annual $O_2$ requirement by all residents within the district. Appropriate planning strategies of residential greenspace, including species selection, planting layout, greenspace enlargement, and maintenance were suggested to improve microclimate amelioration, air purification, and fire obstruction.

• Korean Journal of Remote Sensing
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• v.33 no.6_2
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• pp.1139-1149
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• 2017

Measuring tree's volume is very important input data of various environmental analysis modeling However, It's difficult to use economical and equipment to measure a fragmented small green space in the city. In addition, Trees are sensitive to seasons, so we need new and easier equipment and quantification methods for measuring trees than lidar for high frequency monitoring. In particular, the tree's size in a city affect management costs, ecosystem services, safety, and so need to be managed and informed on the individual tree-based. In this study, we aim to acquire image data with UAV(Unmanned Aerial Vehicle), which can be operated at low cost and frequently, and quickly and easily quantify a single tree using SfM-MVS(Structure from Motion-Multi View Stereo), and we evaluate the impact of reducing number of images on the point density of point clouds generated from SfM-MVS and the quantification of single trees. Also, We used the Watertight model to estimate the volume of a single tree and to shape it into a 3D structure and compare it with the quantification results of 3 different type of 3D models. The results of the analysis show that UAV, SfM-MVS and solid model can quantify and shape a single tree with low cost and high time resolution easily. This study is only for a single tree, Therefore, in order to apply it to a larger scale, it is necessary to follow up research to develop it, such as convergence with various spatial information data, improvement of quantification technique and flight plan for enlarging green space.

• Proceedings of the Korean Institute of Landscape Architecture Conference
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• 2018.11a
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• pp.10-12
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• 2018

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.529-531
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• 2022

기후 위기가 대두되며 탄소중립에 많은 관심이 쏟아지고 있다. 탄소중립을 실천하기 위한 여러 가지 방법 중 도시의 수목을 관리하는 것은 탄소배출 저감, 대기질 개선 등의 환경적인 긍정적 효과를 얻을 수 있다. 수종별 온실가스 흡수량과 흡수 계수에는 차이가 있지만 도시 나무 캐노피를 증가시키면 온실가스 흡수량도 증가한다. 본 논문은 탄소정보공개 프로젝트(CDP)에서 제공하는 데이터를 기반으로 도시의 녹지 지대를 구글 지도(Google Map) 위성사진을 통해 찾아내고 지니 계수(Gini Coefficient)를 통해 도심 녹지 균형을 비교하였다. 향후 도시 수목과 녹지 데이터를 축적해 기초자료가 쌓이면 도시환경의 지표로 활용될 수 있을 것으로 기대된다.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.1
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• pp.49-56
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• 2019

Urban green spaces have been contributing to the improvement of environmental, mental, and physical health for humans. In addition, recent studies showed the potential role of vegetation in reducing the amount of crime in inner-city neighborhoods at the micro-scale level. However, little is known about the positive role of urban green areas in improving urban safety at the regional level. The purpose of this study is to examine the relationship between urban green areas and actual outdoor crime rates, while also considering socio-demographic factors. The study area is the city of Austin, Texas, USA, which consists of 506 block groups. This study utilized socio-demographic factors based on U.S. Census data and vegetation-related factors utilizing GIS and ENVI software. For analyses, the analysis of variance (ANOVA) and an ordinary least square (OLS) regression were utilized. The results from ANOVA showed that yearly crime rates per acre for areas having 0%~25% trees in their neighborhoods were 0.46% and 1.05% higher than those of having 25%~50% and >50% trees in the neighborhoods, respectively. The results from the OLS regression represented that income, NDVI and park rates in neighborhoods were negatively associated with the crime rate per acre, whereas the percentage of minorities and the percentage of teenage school dropouts were positively associated with the crime rate per acre. This study implies that urban green areas may help to improve the safety of urban areas.

• Korean Journal of Environment and Ecology
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• v.20 no.4
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• pp.493-502
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• 2006

This study analyzed greenspace structure focused on greenspace areas and vegetation structure for Yanggu, investigated resident attitudes to the greenspace, and explored strategies to improve greenspace functions in a rural region. Woody plant cover was approximately 29% for parks and only 3% for commercial gardens. The amount of planting for Yanggu was poor, as compared with the results of similar studies for urban areas. Trees, of which dbh was below 20cm, accounted for 91% of all trees and the tree-age structure was largely characterized by a young, growing tree population. Based on the analysis of mean importance values (MIV) of woody plant species, only a few were different in dominant species from urban areas. Four species among 10 species with highest MIV in Yanggu were very common species also ranked among 10 in cities. The most dominant species planted in residential and commercial gardens were practical plants such as fruit or edibles. Greenspace covered about 69% of parks, 39% of residential gardens, 37% of institutional gardens, 24% of streets, and 15% of commercial gardens, respectively. Tree planting potential revealed that present woody plant cover can be increased additionally by 6 times in the streets and by 2 times in the residential and commercial gardens. Based on the results of greenspace structure, planting patterns, and questionary investigation, some strategies were suggested to enlarge greenspace including its environmental functions. They included identifying each street section through setting up themes and planting appropriate species, creating multilayered vegetation structures, and promoting planting in bare grounds of gardens and around a buildings for saving energy.

• Korean Journal of Remote Sensing
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• v.38 no.6_2
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• pp.1633-1641
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• 2022

Urban population concentration and indiscriminate development are causing various environmental problems such as air pollution and heat island phenomena, and causing human resources to deteriorate the damage caused by natural disasters. Urban trees have been proposed as a solution to these urban problems, and actually play an important role, such as providing environmental improvement functions. Accordingly, quantitative measurement and analysis of individual trees in urban trees are required to understand the effect of trees on the urban environment. However, the complexity and diversity of urban trees have a problem of lowering the accuracy of single tree detection. Therefore, we conducted a study to effectively detect trees in Dongjak-gu using high-resolution aerial images that enable effective detection of tree objects and You Only Look Once Version 5 (YOLOv5), which showed excellent performance in object detection. Labeling guidelines for the construction of tree AI learning datasets were generated, and box annotation was performed on Dongjak-gu trees based on this. We tested various scale YOLOv5 models from the constructed dataset and adopted the optimal model to perform more efficient urban tree detection, resulting in significant results of mean Average Precision (mAP) 0.663.

• Korean Journal of Remote Sensing
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• v.39 no.6_1
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• pp.1437-1449
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• 2023

The purpose of this study is to analyze whether pervious and impervious areas in urban areas affect tree growth. In order to determine the differences in the growth of six species of trees planted simultaneously, the effects of pervious and impervious surfaces on tree growth were analyzed using the Normalized Difference Vegetation Index (NDVI) produced using Sentinel-2 and sub-divided land cover map from the Ministry of Environment. For this purpose, the Geospatial eXplainable Artificial Intelligence(GeoXAI) concept was applied. As a result of the analysis, the explanatory power of the model was found to be the best when considering the area of land cover included in the 10m range for Pinus densiflora, the 20 m range for Zelkova Serrata, Metasequoia glyptostroboides, and Ginkgo biloba, the 30 m range for Platanus occidentalis, and the 40 m range for Yoshino cherry trees. In addition, the wider the pervious area, the more active the growth of trees,showing a positive correlation, and the wider the impervious area, such as nearby artificial ground, showed a negative correlation with tree growth. This shows that surrounding pervious and impervious areas affect the growth of trees and that the scope of influence varies depending on the tree species.

• Korean Journal of Environment and Ecology
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• v.10 no.1
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• pp.103-112
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• 1996

By preservation of vegetation landscape in urban park, the uniqueness and attractiveness of a city can be created and maintained. In this study, the CAD simulation of Dwangju Park was implemented, and it was proved that CAD simulation can be used to preserve the vegetation landscape and to regulate the building construction. But, when simulated short range vegetation landscape, such as the position, height and forms of trees, vegetation structure, dtc., are can be important factors. And, the method of suveying and presenting trees in CAD for efficient simulation are need to be sutdied futher.

• Ecology and Resilient Infrastructure
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• v.9 no.2
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• pp.83-92
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• 2022

The 2020 summer extreme flood severely disturbed the riparian ecosystem of the Seomjin River. Some trees were killed by the flood impact, whereas others have recovered through epicormic regeneration after the disturbance. At the same time, several tree individuals newly germinated. This research aimed to explain the recovery of the riparian ecosystem by spatial proximity between each tree individual of different characteristics, such as "dead", "recovered", and "newly germinated". A spatial point pattern analysis based on K and g-functions revealed that the newly germinated trees and the existing trees were distributed in the spatially clumping patterns. However, further detailed analysis revealed that the new trees were statistically less attracted to the recovered trees than the dead trees, implying competitive interactions hidden in the facilitative interactions. Habitat amelioration by the existing trees positively affected the growth of the new trees, while "living" existing trees were competing with the new trees for resources. This research is expected to provide new knowledge in this era of rapid climate change, which likely induces stronger and more frequent natural disturbance than before. Environmental factors have been widely used for ecosystem modeling, but species interactions, represented by the relative spatial distribution of plant individuals, are also valuable factors explaining ecosystem dynamics.