• Journal of Radiation Protection and Research
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• v.29 no.2
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• pp.129-139
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• 2004

Recently, much attentions are paid to the risk associated with increased uses of medium size radiation sources in medical and industrial fields. In this study, radiation risks to the worker and to the general public due to $^{99m}Tc$ generator were assessed for both normal and accident conditions. Based on the event tree technique, exposure scenarios for various situations were derived. Uncertainty analysis based on the Monte-Carlo technique was applied to the risk assessment for workers and members of the public in the vicinity of the work place. In addition, sensitivity analysis was performed on each of the five independent input parameters to identify importance of the parameters with respect to the resulting risk. Because the frequencies of normal tasks are fat higher than those of accidents, the total risk associated with normal tasks were higher than the accident risk. The annual dose due to normal tasks were $0.6mSv\;y^{-1}$ for workers and $0.014mSv\;y^{-1}$ for public, while in accident conditions $3.96mSv\;y^{-1}\;and\;0.0016mSv\;y^{-1}$, respectively. Uncertainty range of accident risk was higher by 10 times than that of normal risk. Sensitivity analysis revealed that source strength, working distance and working time were crucial factors affecting risk. This risk analysis methodology and its results will contribute to establishment of risk-informed regulation for medium and large radioactive sources.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.4
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• pp.54-61
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• 2017

Strengthening the protection and management of very old trees is an important aspect of urban site preservation, urban design and construction. Rating various danger factors to evaluate the degree of danger posed can help to create the correct protective countermeasures. In order to develop the danger evaluation index, this study performed four round surveys by using the Delphi method and collected opinions from experts in related fields. Necessary indexes were fully added in the first and second round while the indexes falling beyond the guidelines were deleted. From the final analysis results, five areas derived a total of forty-one indicators to create a degree of danger index from vigour status, growth and development status, diseases and insect pests, soil status, and management status. The degree of danger evaluation index can provide basic data for the protection of very old trees.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.4 s.34
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• pp.27-32
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• 2005

DEM is needed for urban modeling, forecasting of floods and the analysis of slope and aspect. It has been generated using digital maps, aerial photos or satellite imageries. Recently, however, many studies on DEM generation from LiDAR data has been conducted because of its efficiency and accuracy. Filtering is said to be the process of making DEM by eliminating non-ground points from LiDAR data. In most researches, some input parameters such as the size of filter are required. The purpose of this investigation is to automatically obtain DEM by eliminating objects of various sizes without the knowledge of the objects' sizes. The experimental results show that most of objects on steep terrain are eliminated by the proposed method.

• Journal of the Korean Wood Science and Technology
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• v.43 no.6
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• pp.721-729
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• 2015

Wood properties depend on not only environmental factors such as soil, climate change, or forest stand characteristics, but also silviculture practices such as thinning, regeneration, or selection. This study report influences of the extent of thinning intensity from no thinning, moderate and heavy thinning to the wood property of Quercus acuta forest stands in Wan-do arboretum, Jeollanam-do Province. The results showed that there were close relationships between thinning intensity and anatomical, physical or mechanical properties of Quercus acuta wood. Especially, there are close relationships between thinning intensity and ring width or mechanical properties of wood. As a result, this study showed high correlations between Quercus acuta wood properties and thinning intensity of Quercus acuta forest stand. These findings are expected to be very useful as fundamental data for the implementation of silviculture practices of this specie to produce timber.

• Journal of the Korean Wood Science and Technology
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• v.29 no.4
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• pp.89-96
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• 2001

Three isoflavones and one isoflavanone were isolated from the wood of Sophora japonica (Leguminosae) which has been selected due to its high antifungal activity among the tested species, Four compounds were identified as 5,7-dihydroxy-4',6-dimethoxyisoflavone (irisolidone), 5,7-dihydroxy-4'-methoxyisoflavone (biochanin A), 7-hydroxy-4'-methoxyisoflavone (formononetin) and 7-hydroxy-4'-methoxy-isoflavanone by Mass and NMR spectroscopic analysis. The antifungal activity of the isoflavonoids was tested by medium dilution method and showed low antifungal activity indicating that the other compounds may contribute to high activity of the wood extractives of S. japonica.

• The Journal of the Convergence on Culture Technology
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• v.8 no.2
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• pp.59-67
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• 2022

The main purpose of this study is to quantitatively grasp the effectiveness of the gardening program by conducting a gardening program to induce active activities of the elderly and to induce healing functions and social activities, and then observing the results before and after implementation. In order to achieve the purpose of the study, as a result of conducting 30 gardening programs for 20 elderly people at two elderly care facilities, the measure of depression was found to have an improvement effect as a practice-oriented program, and it was found to revitalize the elderly. In addition, it was found that the quality of life was improved by the gardening program, and it was found to be helpful in activating the brain.

• Journal of Cadastre & Land InformatiX
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• v.54 no.1
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• pp.5-17
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• 2024

In this study, we examined the applicability of UAV LiDAR for cadastral surveying and proposed the results. For this purpose, an experimental area was selected and point cloud data was created by scanning the terrain using UAV LiDAR. Since there is no comparative verification target in the forest area, the coordinates of the verification points were obtained by directly surveying the ridge and valley lines prescribed by the current law. Based on these points, the point cloud density within a 7cm radius was analyzed. As a result, an average of 46 point clouds were generated within a circle with a radius of 7 centimeters, which can build a more precise topography of the forest area, proving that precise cadastral surveying is possible. In the case of UAV LiDAR, it is expected that the boundaries of forest areas can be extracted more accurately and efficiently without the influence of trees compared to the existing cadastral survey method. This is expected to have many advantages in various fields that want to use it in the future, such as the creation of stereoscopic maps of forest areas and terrain modeling for disaster safety in the forest areas.

• Korean Journal of Environment and Ecology
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• v.18 no.3
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• pp.306-315
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• 2004

Yangjae stream, stretching through Seocho-gu and Gangnam-gu, is a representative city stream with its environmentally friendly stream makeover project model, launched in 1995. The district of Gangnam-gu, the subject of this study, is under high pressure from the residents for its use as a huge residential areas close to the stream. The study has two main purposes. The first is to identify the condition and characteristic of utilization of Yangjae stream which is currently being increased in use by the stream restoration. Secondly, the study aims to suggest the environment-friendly management to accomplish arrangement of the naturally friendly stream based on the identification survey, The result from the user survey with 303 valid answer sheets show that the people from neighboring residential areas use this stream a lot doing exercising(51.8%) and taking a walk(24.4%) in their free time. Also regular use rate is high, and people are likely to use it alone(30.4%) or as a family(28.4%). With regard to the need of facility increase, even though the respondents required resting places in the shade(80.8%) most, overall, additional introduction of facilities was analyzed as unnecessary(78.8%). safety issue(22.0%) and a lack of convenience facilities(17.6%) and resting places in the shade(16.6%) are pointed as main problems while the users are generally satisfied(59.5%) with the stream. Improving walk-way and planting trees for shade on the slope were designed as a solution for these problems. For securing safety through improvement of walk-way, the scattering of pressure of current walk with building new walk using berms was presented. In order to increase safety on the walk-way(see above figure), the study proposes to build a new walk-way with berms to disperse excessive pressure. It also suggests the tree planting to provide shade in the stream and to make a provision for the planting of forest trees in the current law.

• Korean Journal of Environment and Ecology
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• v.27 no.6
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• pp.718-732
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• 2013

The purpose of this study was to provide data for the basic research to found the effective conservation and management plan for the Geumdangsil Pine Forest of Yecheon designated as Natural Monument No. 469. Furthermore, this paper suggest efficient sustainable forest preservation and using. In order to achieve the sustainable forest preservation, this study was to analyse topography, land use, tree growth, soil environment, forest usage and forest management, etc. According to analysis the results, the site area is located in the flatlands where is from 130 to 140 m above sea level. The around forest was transformed into agricultural land. The 565 individuals of Pinus densiflora grows in the forest, whereas, 25 trees was cut down or died. There are signs of 25 stumps. The most of 565 trees' diameter at breast height(DBH) was centerized between 30 cm and 50 cm, moreover, the average life expectancy of trees were 85.4 years. The oldest age of tree was estimated to be 200 years. The Sample trees of rate of branch growth is from 4.3 cm to 5.1 cm per year. The middle branch which is more vigorous growth grow 24.2 cm for 3 years. Moreover, the result of soil physico-chemical properties analysis of 7 plots, 4 categories which is soil organic matter, total nitrogen, available phosphoric acid, specific electrical conductance was generally good, however, the 2 categories which is soil pH, exchangeable cation needed improvement. Currently, the site was not pressured by facilities and usage, however, there might be threaten by agriculture such as encroaching on forest. Therefore, there should establish comprehensive ecosystem management such as facility management, visitors management and operation management In this paper considered 4 fields that is ecosystem management, facility management, visitors management and operation management for sustainable management.

• Korean Journal of Environment and Ecology
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• v.22 no.2
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• pp.173-183
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• 2008

This research was aimed at looking into the vegetation structure of Abies holophylla forest distributed between Iljumun of Woljeong Temple and Keumgang bridge in Odaesan National Park. It was found that existed a total of 977 tree of Abies holophylla which are more than 20cm in DBH within the target site, and in 2006 when the survey was made, the number of fallen trees and poor growth trees was about 96, accounting for 9.8% of all. The age of Abies holophylla ranged from 41 years to 135 years($11\sim82cm$ in DBH). The number of Abies holophylla over 100cm in DBH was 8 and the largest Abies holophylla was 175cm in DBH and 31m in height. Its density was 5.9 individuals per $400m^2$. As a result of the analysis of the plant community structure using the TWINSP AN classification, Abies holophylla was divided into four community types. Firstly, Pinus densiflora-Abies holophylla community was predicted to vary into Abies holophylla community. In case of other three other communities, Abies holophylla communities were predicted to compete with deciduous broadleaf trees, such as Tilia amurensis and Acer pictum subsp. mono. Abies holophylla forest adjacent to Woljeong Temple of Odaesan National Park has a high value as sustainable resources for culture, landscape and tourism. Thus, it is necessary to clarify the reason for the incidence of poor growth trees and fallen trees among all trees of Abies holophylla and take counter-measures against it for the preservation and management of Abies holophylla forest. In addition, a more aggressive managrment like getting rid of the deciduous broadleaf trees, such as Tilia amurensis and Acer pictum subsp. mono, which appear mostly on understory layer or shrub layer within Abies holophylla, and continuous management is also needed for the young trees of Abies holophylla which are feared to be pressurized outside from their neighboring trees because their initial growth after germination is very slow.