• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.6
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• pp.149-159
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• 2017

There are many studies on the health and protection of Old-growth and Giant Trees, concentrating on empirical judgment and basic protection measures. The problem this study addresses is the relative importance and priority of the health evaluation indicators of Old-growth and Giant Trees. Firstly, this study exports the evaluation indicators of Old-growth and Giant Trees. The evaluation system for the degree of danger of Old-growth and Giant Trees are composed of two layers: 5 fields and 46 indicators. Secondly, using the AHP and PCA method can determine the weight of each field and each index factor. The process of AHP establishes the relative importance judgment matrix of each field and fully proves that the main cause of danger is individual aging. The PCA method suggested that trunk rot status, light conditions, tree surgeries, bacterial diseases, and soil moisture level are the most important factors in each field. These aspects should be given priority in the management and protection of Old-growth and Giant Trees. Weight values obtained in this study seemed to be useful in the evaluation of Old-growth and Giant Trees.

• 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.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.1
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• pp.73-81
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• 2017

During the 1990s, policy was put in place to create resting spaces in rural areas. This policy was associated with a government project to improve the rural residence environment and it attracted attention to outdoor spaces in rural areas. Many communities have gradually disappeared in rural areas but previous studies suggested that legally protected trees might provide resting and cultural spaces in a given rural community. The rural residential environment can be improved by legally protected trees and by doing so, these resources may then help to sustain many rural communities. Therefore, the creation of resting spaces or mini-parks created around trees that are protected by in rural communities should be considered. The value of trees that are protected by law can differ depending on the status of the trees or the surroundings. Nevertheless, there has not been systemic research regarding legally-protected trees in terms of rural communities. This study aims at evaluating the potential of these trees and at analyzing how these trees can be useful in the creation of community spaces in rural areas. The findings can be helpful in providing foundation data for creating these types of community spaces. Forty legally protected trees in Gimchon City were selected for this study. Nine items were used to evaluate the potential of the trees for creating community spaces. These items could be classified into five factors including accessibility, relation to public facilities, environment and safety, symbolism, and ease for creating community spaces. The potential of the legally protected trees was evaluated by 5-point Likert Scales in a given item. The overall potential was evaluated by the sum of individual item scores. Specifically, trees with over 20 points (max. 25 points) could be considered high potential. According to the empirical findings, the portion of legally protected trees with high potential is five percent (No.7 and No.12 trees). Therefore, the priority is to protect or use the trees for the creation of community spaces that can help make a better residential environment for rural communities.

• Journal of Korean Society of Forest Science
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• v.66 no.1
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• pp.82-94
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• 1984

The variation of stomatal density and stomatal length of four species of oaks was studied for the purpose of examining the differences among populations and among individual trees within population. Nine populations of Quercus mongolica, four populations of Q. serrata and Q. variabilis respectively, and three populations of Q. acutissima were selected in the natural stands of oaks distributed through the whole country. Twelve leaves were sampled from each of 20 trees from each population. The length of 20 stomata and ten replications of stomatal density were measured from collodion replicas of each leaf under a microscope. Average stomatal densities and lengths ranged through $600-1000/mm^2$ and $19-26{\mu}m$ respectively in all of the species studied. The stomatal densities and lengths presented significant differences statistically at the level of 1 or 5% among populations and among individual trees within population in all the species. Quercus mongolica, especially, showed large variation among populations, while Q. variabilis did very narrow variation compared to the other species. The coefficients of variation of stomatal densities and lengths among individual trees within population exhibited small values of 3.7-12.0% and 1.4-5.3% respectively in all the populations of the species. The average stomatal densities of Q. mongolica showed statistically significant correlation of multiple correlation coefficient of $R_{df{\cdot}2.6}=0.868^*$ and multiple regression equation of $Y=0.041X_1(G.M.T.S.)+0.489X_2(G.M.H.S.)+22.37$ with the sum of growing season mean daily temperature and the sum of growing season mean daily humidity of the stand studied. However the average stomatal lengths showed no relation with the same meteological variables. The figures of frequency distribution of the measurements of leaves or the mean values of individual trees did not show normal distribution curves in some populations. The curves, as well as the results of ANOVA, exhibited the differences among populations.

• Journal of Environmental Impact Assessment
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• v.17 no.5
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• pp.279-288
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• 2008

Vertical forest distribution is one of the important factors to understand various ecological mechanism such as succession, disturbance and environmental effects. LiDAR data provide information, both the horizontal and vertical distribution of forest structure. The laser scanner survey provided a point cloud, in which the x, y, and z coordinates of the points are known. The objectives of this study were 1) to analyze factors of forest structure such as individual tree isolation, tree height, canopy closure and tree density using LiDAR data and 2) to compare the forest structure between outer and interior forest. The paper conducted to extract the individual tree using watershed algorithm and to interpolate using the first return of LiDAR data for yielding digital surface model (DSM). The results of the study show characters of edge such as more isolated individual trees, higher density, lower canopy closure, and lower tree height than those of interior forest. LiDAR data is to be useful for analyzing of forest structure. Further study should be undertaken with species for more accurate results.

• Journal of Korean Society of Forest Science
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• v.34 no.1
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• pp.1-14
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• 1977

These studies were carried out to know the variation of morphological tree forms, needles, cotyledons, seed characters and top height growth of seedlings of Pinus koraiensis S. et Z. by populations in Mt. Jiri. The results are summarized as follows: 1. It was observed that the characteristics of length, needles of serration density of needles, percentage of full seeds length, of seeds, thickness, of seeds length of cotyledons, width of cotyledon, numbers of the stomata line in cotyledons and the top height growth of seedlings were significantly different in individual trees and populations. 2. The characteristics of branch angle specific gravity of wood and resin canal numbers of cotyledons were significantly different in populations. 3. It was that the characteristics of numbers of stomata line, width, of seeds weight, of seeds serration density of cotyledons, numbers of cotyledons were significantly different in individuals. 4. The resin canals of needles showed three principle resin canals in individual trees and population, and the coefficients of variation were not shown in individual trees and populations. Stem forms showed to be a straight form with all populations. 5. The characteristics of cotyledons had generally higher tendency than the characteristics of needles in comparison with coefficience of variation.

• The Korean Journal of Ecology
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• v.16 no.4
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• pp.397-408
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• 1993

Gas exchange rates and concentrations of ascorbate and glutathlone were measured in needles of eastern white pine(Pinus strohltr) trees differing in foliar sensitivity to ambient oxidant pollution during a ten month period beginning in mid-June, 1988. Current-year needle dry mass and length was 60 to 75% and 45 to 60% less, respectively, in sens~tive trees than in a tolerant tree. Net photosynthesis ($P_n$) and needle conductance ($g_n$) were greatest in the tolerant individual through late September when the rates begin to decline In trees. Needle transpiration rates showed a trend similar to $P_n$ and $g_n$. Ascorbate and total glutathione concentrations in current-year needles increased through the summer and fall, reached a maximum in mid-winter, and then decreased in the spring. Consistently throughout the year, ascorbate concentration was highest in the tolerant tree until the initial springtime decline began in April. The difference In needle ascorbate between the tolerant and sensitive individuals was greater in the summer months (25 to 30%) than in the winter months (8 to 19%). Glutathione content was similar, as was the ratio or oxidized /reduced glutathione, in both tolerant and sensitive trees.

• Health Policy and Management
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• v.16 no.1
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• pp.54-72
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• 2006

This study was conducted as the primary work to develop a customer relationship management (CRM) system to improve the performance of health screening programs. The specific aims of the study was to identify and classify the characteristics of the people who did not receive their health screening using decision trees and to propose management strategies according to their characteristics identified. The data on a total of 5,102,761 subjects of health screening provided by the National Health Insurance Program in the year of 2002 were used. The target variable was whether they underwent their health screening. The input variables included a total of 27. The SAS 9.1 version was used for data preprocessing and statistical analyses. SAS Enterprise Miner was used to develop the decision trees model. The decision trees identified the factors greatly affecting the health screening. In the non-disease group, the highest rate of non-examinees was characterized by: no experience of receiving a health screen, household's age, non-insured episode for the last one year, and patients' age. In the disease group, the one showing the highest rate of non-examinees was characterized by: no experience of receiving a health screening, no experience of going to public health center or midwife clinic for the last one year, and examinees' age. Developing CRM systems for health screening management taking into account the individual characteristics would be considerably helpful to increase the rate of receiving health screening.

• Korean Journal of Environment and Ecology
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• v.27 no.5
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• pp.544-549
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• 2013

We studied the habitat sites of Siberian flying squirrel in Guhak-ri, Sillim-myeon, Wonju-si, Gangwon-do from March to April in 2009. We were found total 30 points of inhabitation trace types; nests 15 points(Tree nest types were 13 points, used Tree hole types hole types were 2 points) and droppings 15 points. We observed 3 individuals of Siberian flying squirrels and founded that 2 individuals of them used tree holes, and another individual used tree nest which were located in branches of Pinus densiflora. Most utilized nest trees of Siberian flying squirrel were Larix leptolepis, and also used Pinus densiflora, Betula davurica, Styrax japonica, Cornus controversa, Acer mono. Droppings trees were Prunus sargentii, Cornus controversa, Quercus xmccormickii, Acer palmatum, Acer palmatum, Betula davurica. Through the observation, we defined that flying squirrels mainly used Conifer trees as nest sites, and decideous trees as droppings.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.817-819
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• 2003

Land degradation is a crucial issue in mountainous areas and is manifested in a variety of processes. For its assessment, application of existing models is not straightforward. In addition, data availability might be a problem. In this paper, a procedure for land degradation assessment is described, which follows a four-step approach: (1) detection, inventory and mapping of land degradation features, (2) assessing the magnitude of soil loss, (3) study of causal factors, and (4) hazard assessment by applying decision trees. This approach is applied to a case study in the Middle Mountain region of Nepal. The study shows that individual mass movement features such as debris slides and slumps can be easily mapped by photo interpretation techniques. Application of soil loss estimation models helps get insight on the magnitude of soil losses. In the study area soil losses are higher in rainfed crops on sloping terraces (highest soil loss is 32 tons/ha/yr) and minimal under dense forest and in irrigated rice fields (less than 1 ton/ha/yr). However there is high frequency of slope failures in the form of slumps in the rice fields. Debris slides are more common on south-facing slopes under rainfed agriculture or in degraded forest. Field evidences and analysis of causal factors for land degradation helps in building decision trees, the use of which for modelling land degradation has the advantage that attributes can be ranked and tested according to their importance. In addition, decision trees are simple to construct, easy to implement and very flexible in adaptations.