• 한국환경복원기술학회지
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• 제22권6호
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• pp.1-14
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• 2019

Carbon storage is one of the regulating ecosystem services provided by urban street trees. It is important that evaluating the economic value of ecosystem services accurately. The carbon storage of street trees was calculated by measuring the morphological parameter on the field. As the method is labor-intensive and time-consuming for the macro-scale research, remote sensing has been more widely used. The airborne Light Detection And Ranging (LiDAR) is used in obtaining the point clouds data of a densely planted area and extracting individual trees for the carbon storage estimation. However, the LiDAR has limitations such as high cost and complicated operations. In addition, trees change over time they need to be frequently. Therefore, Structure from Motion (SfM) photogrammetry with unmanned Aerial Vehicle (UAV) is a more suitable method for obtaining point clouds data. In this paper, a UAV loaded with a digital camera was employed to take oblique aerial images for generating point cloud of street trees. We extracted the diameter of breast height (DBH) from generated point cloud data to calculate the carbon storage. We compared DBH calculated from UAV data and measured data from the field in the selected area. The calculated DBH was used to estimate the carbon storage of street trees in the study area using a regression model. The results demonstrate the feasibility and effectiveness of applying UAV imagery and SfM technique to the carbon storage estimation of street trees. The technique can contribute to efficiently building inventories of the carbon storage of street trees in urban areas.

• Journal of the Korean Data and Information Science Society
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• 제13권1호
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• pp.97-104
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• 2002

Regression trees, a technique in data mining, are constructed by splitting function-a independent variable and its threshold. Lee (2002) considered one-sided purity (OSP) and one-sided extreme (OSE) splitting criteria for finding a interesting node as early as possible. But these methods cannot be crossed each other in the same tree. They are just concentrated on OSP or OSE separately in advance. In this paper, a new splitting method, which is the combination and extension of OSP and OSE, is proposed. By these combined criteria, we can select the nodes by considering both pure and extreme in the same tree. These criteria are not the generalized one of the previous criteria but another option depending on the circumstance.

• 한국산림과학회지
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• 제71권1호
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• pp.27-32
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• 1985

한 임분(林分)에 있어서 개체목(個體木)의 생장(生長)은 그 임목(林木) 주변(周邊)의 주변목(周邊木)들에 의하여 커다란 영향(影響)을 받는다. 무간벌(無間伐) 임분(林分)의 경우 이러한 경향(傾向)은 임목(林木) 상호간(相互間)의 경쟁(競爭)을 통하여 더욱 현저(顯著)하게 나타난다. 본(本) 연구(硏究)는 1962년(年) Spurr가 제안(提案)한 각도합산법(角度合算法)(angle-summation method)을 이용(利用)하여 낙엽송림(落葉松林)의 개체목(個體木) 생장(生長)과 주변목(周邊木)들과의 기본적(基本的)인 생장관계(生長關係)를 조사(調査)하였으며, 이것을 기초(基礎)로 중심목(中心木)으로 선정(選定)된 각(各) 임목(林木)들의 최근(最近) 5년간(年間)의 직경생장량(直徑生長量)을 추정(推定)하기 위해 중회귀식(重回歸式)을 적용(適用)하고 그 결과(結果)를 분석(分析) 검토(檢討)하였다.

• 한국조경학회지
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• 제31권2호
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• pp.94-101
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• 2003

The purpose of this paper is to analyze the correlation between Death Rate of Trees (DRT) and the Physiological Characteristics of Trees(PCT) in POSCO Gwangyang works, which is a reclaimed area. To analyze the DRT, 15 species of deciduous trees were selected, for example Ulmus davidiana var., Zelkova serrata, Melia azedarach var. etc. Though there were numerous factors to affect the growing of trees, 5 PCT were considered to be main factors, soil salt tolerance, wind salt tolerance, water needs, transplanting difficulty, and nutrient needs. According to two kinds of soil-base: mound and pot area, we tested the relationship between 5 PCT and DRT by use of t-test and multiple regression analysis. The results are as follows. 1. The DRT of Acer palmatum, Cornus kousa, Magnolia kobus, Liriodendron tulipifera, and Albizzia julibrissin were high by more than 20%. On the other hand, Chionanthus retusa, Ulmus davidiana var. japonica Celtis sinensis, and Lagerstroemia indica were low by less than 10% in the DRT and are considered to be species suitable for planting in reclaimed areas. 2. The DRT of trees in pot areas was meaningfully higher than in mound areas; for this reason the mound technique is desirable as a soil-base for planting in reclaimed areas. 3. In the pot area, the independent variables, in the order of soil salt tolerance, wind salt tolerance, transplanting difficulty, had an effect on the DRT more significantly than in mount area. On the other hand, wind salt tolerance and soil salt tolerance affected the DRT in mount areas. This means that soil salt tolerance, wind salt tolerance, and transplanting difficulty have to be considered as significant factors to the DRT. Although the researchers tried to interpret how the PCT affected the DRT in order to analyze the relationship between the two in reclaimed areas, it was neglected at an experimental level. Therefore, future research should work on this aspect in detail.

• 한국환경과학회지
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• 제19권3호
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• pp.305-312
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• 2010

The purpose of this study is to compare the relative growth of annual ring width of red pine(Pinus densiflora), black pine(Pinus thunbergii) and pitch pine(Pinus rigida) by means of multiple regression method according to Graybill hypothesis. The obtained results are as follows. 1. The changes of rainfall have affected to tree growth during the periods of 1975 through 1978. 2. Among these pine trees, red pine was mostly influenced by environmental factors. 3. The growth of annual ring width was sensitively responded to the changes of rainfall and air temperature. 4. Among the heavy metals analyzed, the concentrations(ppm) of Lead(Pb) and Copper(Cu) were negatively effected on the growth of annual ring width of pine trees. 5. The analytical technique of annual ring width may be useful for estimation of the pollution in forest areas near industrial complexes.

• 한국산림과학회지
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• 제96권2호
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• pp.160-169
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• 2007

The data used to develop distance-independent individual models for natural mixed forests were collected from 712 remeasured permanent sample plots (25,526 trees) of 10-year periodic from 1990 to 2000 in Baihe Forest Bureau of Changbai Mountains, northeast China. Based on analyzing relationship between diameter increment of individual trees with tree size, competitive status, and site condition, the diameter growth models for individual trees of 15 species growing in mixed-species uneven-aged forest stands, that have simple form, good predicting precision, and easily applicable, were developed using stepwise regression method. The main variables influencing on diameter increment of individual trees were tree size and competition, however, the site conditions were not significantly related with diameter increment. The tree size variables (lnDBH and $DBH^2$) were the most significant and important predictors of diameter growth existing in all 15 growth models. The diameter increment was directly proportional to tree diameter for each species. For the competitive factors in growth model, the relative diameter (RD), canopy closure (P), and the ratio of diameter of subject tree with maximum diameter (DDM) were contributed to the diameter increment at a certain extent. Other measures of stand density, such as basal area of stand (G) and stand density index (SDI), were not significantly influenced on diameter increment. Site factors, such as site index, slope and aspect were not important to diameter increment and excluded in the final models. The total variance explained by the final models of squared diameter increment ($R^2$) for all 15 species ranged from 35% to 72% and these results compared quit closely with those of Wykoff (1990) for mixed conifer stands. Using independent data set, validation measures were evaluated for predicting models of diameter increment developed in this study. The result indicated that the estimated precision was all greater than 94% and the models were suitable to describe diameter increment.

• 한국환경복원기술학회지
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• 제24권4호
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• pp.15-29
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• 2021

Urban green spaces offer a variety of benefits to living things and humans. However, existing green spaces have been reduced and fragmented due to urbanization, and there is a limit to creating new large green spaces in densely developed cities. Street trees have fewer restrictions on land use, which can be a measure to secure green areas in cities. In Korea, excessive pruning is being done on some street trees for reasons such as blocking of building signboards, contact with electric wires, and restrictions on sidewalk widths. Therefore, it is necessary to quantitatively understand the relationship between the benefits provided by street trees and their structures to come up with an efficient and systematic planning and management plan for urban street trees. In this study, we quantitatively analyzed the relationship between the thermal comfort improvement by the shades of street trees and the vertical structure, planting environment, and types of street trees. To calculate the thermal comfort felt by human body, we calculated UTCI (Universal Thermal Climate Index) of each street tree. For the vertical structure of street trees, we used Terrestrial LiDAR and the point clouds of street tree's crown was sliced vertically at 1m intervals. We conducted a multiple regression analysis on the thermal comfort improvement using the variables we obtained from fields. As a result, in the case of a street tree's vertical structure, the lager the volume of tree's crown located 3-4m (β=0.298, p<.05) and 6-7m (β=0.568, p<.001) above clear length, the better the cooling effect. In addition, the thermal comfort improvement was assessed to decrease as the DBH increased (β=-0.435, p<.001). In general, the crown diameter and DBH are positively correlated, with a cooling effect occurring as crown diameter increases. In this study, the opposite result was obtained due to the small number of trees measured, so additional research is needed by increasing the number of tree samples. In the case of the planting environment, the effect of improving thermal comfort was higher in the shaded area of trees planted to the south (β=-0.541, p<.001). Since unsystematic management of street trees can deteriorate the function of them, quantitative evaluations of the vertical structure of street trees are required, which can provide specific measures for planning and management of urban street trees with thermal comfort effect.

• 한국환경생태학회지
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• 제29권4호
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• pp.590-598
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• 2015

소나무재선충병에 대한 다양한 방제방법에도 고사목은 해마다 급격히 증가하고 있다. 그러나 현 방제방법 문제에 대한 연구는 매우 미흡한 실정이다. 재선충 확산 방지를 위해 가장 널리 쓰이는 방법은 병의 매개충인 솔수염하늘소 유충 폐사를 위한 감염목 훈증처리방법이다. 본 연구는 산림 내 소나무재선충 감염목 훈증처리지역에서 훼손 정도를 확인하고자 경상남도 밀양시 일대에 $100m^2$의 조사구 32개소를 설치하여 근원단면적과 수관단면적을 분석하였다. 훼손되지 않은 수목에서 도출한 근원단면적과 수관단면적의 회귀식(침엽수: $R^2=57.4$, 낙엽활엽수: $R^2=63.8$)을 바탕으로 훼손된 수목의 수관단면적을 유추하였다. 분석결과 수관단면적을 기준으로 재선충감염목은 18.7%이었으며 재선충과 무관하게 베어진 수목은 35.5%에 달했다. 소나무류의 경우 8.4%가 재선충과 관계없이 훼손되었으나 참나무류를 포함한 낙엽활엽수류는 훼손비율이 62%에 달했다. 소나무재선충 방재를 위한 훈증처리작업에 따른 아교목층 낙엽활엽수의 무분별한 제거는 산림의 온도저감, 습도조절 등 공익적 기능을 저하할 우려가 높았다.

• 한국컴퓨터산업학회논문지
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• 제2권2호
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• pp.203-210
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• 2001

이진 트리 검색에 관한 관계 모형들을 추정하고 이론 가설들을 검정하기 위하여 중복되지 않는 자연수들을 자료로 하는 3개 이상 7개 이하의 노드를 가진 모든 가능한 이진 검색 트리 들을 생성하였다. 노드 개수 별로 높이 및 균형도 에 따른 이진 검색 트리 생성 확률들을 추정하였으며 노드 개수와 트리의 높이, 검색에 필요한 비교 횟수의 관계를 나타내는 회귀 모형이 구축되었고 이진 검색 트리의 O(1g(n)) 이론이 적합도 검정 절차에 의하여 실험적으로 채택되었다. 이진 검색 트리의 균형에 따른 검색 성능의 유의적 차이들을 통계적으로 증명하기 위하여 균형도에 따라 확률적으로 생성된 이진 검색 트리들을 세 그룹으로 그룹화하고 그룹간의 검색 비교 횟수를 분산 분석 모형에 의하여 비교 분석하였다.

• 환경영향평가
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• 제6권1호
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• pp.67-76
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• 1997

The purpose of this research is to draw out the factors affecting the residents' evaluation on valuable animal and vegetation and the naturality of vegetation seen near regional environment. With this purpose, Questionnaire research and vegetation survey focusing on area of types of vegetation and species of big trees were made in 30 points of midstream of Tama River, Tokyo, Japan. The questionnaire research was based on basin environment units in order to be reflective of regional natural environment. The vegetation was classified into 5 types according to its flora and observed the covering area of each points and types through the aerial photograph. In addition, the species of big trees in habitat were listed by the survey. Results as below came out by analyzing the outcome of the questionnaire research and vegetation survey by multiple regression. First, residents are most likely not to distinguish precisely between the quantitative and qualitative aspects of vegetation. Both of the researches are apt to be influenced by quantitative factors of vegetation. Second, residents are assumed to consider forest of big trees, inhabitant of groups of big trees, highly natural.