• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.3
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• pp.45-54
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• 2012

This study intended to analyze growth condition of each object by protected tree's ground for 45 places registered to Pyeongtaek protected tree list in locational characteristics, conduct exchange analysis for impediment extent rate in crown area and tree type to the result and suggest the measures to manage artificial impediment which is an effect on protected tree condition. In this study, the tree whose area of impediment for crown area is less than 21% is tree condition of grade 1~2, less than 21~50% is grade 2~3 and more than 50% is grade 3~5. The more impediment is, the more inconvenience causes on growth and development. So, it verified that the area rate must maintain less than 21% for the root system management of protected tree. For the standard of managing artificial impediment which is an effect on the tree condition of protected trees, the below matters intend to be suggested. The first, the impediment in crown area should be less than 21%. But, if there is not artificial impediment out of crown area, the rate of impediment area is considered to increase somewhat. The second, growth space of protected tree should be maintained by crown area at least and impediment should be established out of the crown area. The third, during the national project and land development, surroundings of protected tree must be applied as park, resting place, etc. and the establishment area of impediment (artificial impediment and natural impediment) in crown area must be limited. The forth, publicity for regional people (especially, land owner) is necessary for the protection of natural inheritance and the value of dependence on local government and village which are the subject of management must be announced widely through the internet media, etc, so its importance must be recognized. The fifth, the matters related to protected tree management must be able to limit artificial damage which is for surroundings of protected tree through the mutual connection among the local governments; construction, civil engineering, architecture, water and sewage, agriculture and forest and others. Also, following studies on the effects of kinds, thickness, etc. of impediment around the protected tree on trees should be continued.

• Journal of the Korean Wood Science and Technology
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• v.26 no.3
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• pp.81-92
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• 1998

Lately public interest in tree saps of maple and birch trees has been increased for sap drink as a natural medical beverage. To ensure tree sap drink for commercial production, species which are available in resources, their ecological regeneration characteristics in the natural forest stand, and tree sap resources should be investigated. Species for the collecting tree saps and their distribution were surveyed in the areas of Mt.Sobaek, Tanyang-gun, Chungcheongbuk-do. Mt.Sobaek area was selected to the proper place to survey as the feasible area for tapping tree saps for the natural beverage. Feasible tree species of this area are Betula costata, Betula schmidtii, Comus controversa, Acer mono, and Acer pseudosieboldianum based on the estimated tree sap amounts. Average and maximum species diversities of surveyed area were 4.2 and 5.39, respectively. Its evenness 0.78 referred that there are actively progressing ecological regeneration among diverse tree species. Tree saps are mainly harvested at the areas of upper and lower Wonmanteo. In terms of species, the most high sap amounts were from birch sap, next Comus controversa, the 3rd Acer mono. Many measures were suggested ecologically and technically, for commercial or practical production of tree sap drinks, though Mt.Sobaek area was evaluated as improper place because of geographical and transportational limitation.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.6
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• pp.79-92
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• 2016

The objective of this study is to classify the types of rural areas (138 $si{\cdot}gun$) considering settlement environment by Decision Tree Method (CHAID). The CHAID method was used for decision tree algorithm and the seven dependant variables and 5 explanatory variables were selected, respectively. By decision tree method, rural areas were finally classified into six groups through three separate processes. City area, lower area in aging rate and higher area in farmland area ratio was analyzed to be relatively rich rather than other area in the case of settlement environment index. In the future, this study will be able to utilize as a reference to the planning of rural development projects.

• Spatial Information Research
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• v.16 no.1
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• pp.113-127
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• 2008

This paper proposes an efficient spatial index, named $AR^*$-tree(Area $R^*$-tree) which is a variant of the $R^*$-tree, for mobile software. A MBR(Minimum Bounding Rectangle) structure of the $AR^*$-tree has additional min and max values of area axis as well as x and y axes. The value of area axis is used to determine the significance of a spatial data. If area of a spatial data is large, then it is significant when drawing a map. To reduce complexity of a map on a small screen of mobile device, only significant spatial data can be found by the $AR^*$-tree. The result of a series of tests indicates that the $AR^*$-tree provides a method for control of readability of a map and guarantees an efficient performance at the same time.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.19-23
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• 1998

Water tree degradations have been considered as one of the most important causes of failure in underground distribution cables with polymeric insulation. Water tree growth is a preliminary step in the sequence of electrical tree initiation and electrical breakdown of the insulation. In this paper, needle electrode is made use of the etching methods and the pellet type specimen is made to observe the water tree in succession. In previous methods are able to observe the tree degradations without cutting and dyeing. The water tree image is recorded on VTR with CCD camera. The tree length of X, Y axis direction and aging area(treeing area) are calculated with image measurement. As a result of this study, water tree is observed by non-destructive method. Electrical tree is initiated from needle electrode tip only but water tree is initiated from total area of water electrode. Electrical tree owing to water treeing is initiated at low electric field and grown with discontinuously. Namely, water tree is shown up a different characteristics of tree growth.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.321-324
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• 2008

Forest fire danger rate of thinning area was lower than that of non thinning area, because height rate of leewardside in burned stem of tree, damage rate of crown and mortality of tree in thinning area were 30.8%, 37% and 48.4% lower than that in non-thinning area, respectively. Intensity of forest fire varied depending upon topographical condition up slope, down slope, aspect, location as well as species, breast height diameter and forest tree density. Especially, a mountaintop area was burned down when forest fire was spread to up slope ridge of mountain.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.153-156
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• 2008

Comparative analysis of forest fire danger rating on the forest characteristics of thinning area and non-thinning area on forest fire burnt area was studied in this work. To investigate the effect of thinning slash in forest fire, Gangneung-si Wangsan-myeon, Ulgin-gun Wonnam-Myeon, Samchok-si Gagok-Myeon, in which forest fire broke out, were selected. As a result that investigated forest fire danger ratio between thinning slash and non-thinning slash, leeward scorching ratio(36%), crown damage ratio(29%), mortality of branch at the former are higher than those at the latter, leeward scorching ratio of tree, where thinning slash is around, is 10%-20% higher than that of independent tree. So I estimate that thinning slash has a some effect on the intensity of forest fire. And the result to investigate damage of forest fire according to tree species shows that leeward scorching ratio of conifer is 5% higher than that of non-conifer, and mortality of branch of the former is 19% higher than that of the latter. It is considered that forest fire may affect directly to a tree trunk if it diffuse to piled thinning tree because there was no space between thinning trees and trees. Furthermore, it was found that re-ignition had a chance to occur due to lots of piled thinning trees.

• Electrical & Electronic Materials
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• v.8 no.5
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• pp.551-557
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• 1995

For the observation of treeing, a visual measurement with an optical microscope has been used to explain breakdown mechanism in high-voltage systems. The conventional directed visual method of tree aging observation is difficult to measure in short time processing, and it is impossible to analyze on tree degradation area, progressed direction, tree pattern, etc. By using an image processing technique, the tree features which appear immediately after the tree initiation as well as changes in the configuration of the tree can be easily measured and observed than using the conventional visual methods. In this paper, we have developed a tree observating system by using image processing for tree growth, degradation area and other treeing progress. As an experimental result, it can be concluded that the image processing method is a more effective alternative than directed visual observation method. As a matter of fact, it is possible to record the image of tree propagation immediately after its first appearance and explain the characteristics of tree growth froth the computer processing image.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.6
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• pp.605-614
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• 2015

Drone imaging, which is more cost-effective and controllable compared to airborne LiDAR, requires a low-cost camera and is used for capturing color images. From the overlapped color images, we produced two high-resolution digital surface models over different test areas. After segmentation, we performed tree identification according to the method proposed by , and computed the tree height and the canopy crown size. Compared with the field measurements, the computed results for the tree height in test area 1 (coniferous trees) were found to be accurate, while the results in test area 2 (deciduous coniferous trees) were found to be underestimated. The RMSE of the tree height was 0.84 m, and the width of the canopy crown was 1.51 m in test area 1. Further, the RMSE of the tree height was 2.45 m, and the width of the canopy crown was 1.53 m in test area 2. The experiment results validated the use of drone images for the extraction of a tree structure.

• Journal of Korean Society of Forest Science
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• v.96 no.2
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• pp.189-196
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• 2007

Allometry, basal area equations, and volume equations were developed with various tree measurement variables for the major species, Quercus mongolica and Quercus variabilis, in Korean natural hardwood forests. For allometry models, the relationships between total height-DBH, crown width-DBH, height to the widest portion of the crown-total height, and height to base of crown-total height were investigated. Multiple regression methods were used to relate annual basal area growth to tree variables of initial size (DBH, total height, crown width) and relative size (relative diameter, relative height) as well as competition measures (competition index, crown class, exposed crown area, percent exposed crown area, live crown ratio). For tree volume equations, the combined-variable and Schumacher models were fitted with DBH, total height and crown width for both species.