• Korean Journal of Environment and Ecology
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• v.33 no.4
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• pp.440-446
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• 2019

This study examined the growth and fruiting characteristics and the acorns biomass allometric equation of Quercus acuta to provide reference data related to the growth and seed supply during the restoration of evergreen forest in the warm temperate zone in Wando Island, Korea. For the growth survey, we selected and cut three sample trees having a mean diameter at breast height (DBH) to investigate the growth analysis through a stem analysis. We then developed the allometric equation (Y=aX+b) of DBH and tree height growth characteristic (Y) according to the average tree age (X) of sampled trees and estimated the DBH and tree height according to the age of Quercus acuta. For the fruiting survey, we selected and cut three sample trees with full fruit in August when, they are at the early mature fruiting stage, for the analysis. To develop the acorns/tree biomass allometric equation of Quercus acuta, we selected and cut ten sample trees of evenly divided diameters. The acorns biomass allometric equation ($Y=aX^b$) was derived by analyzing the biomass (Y) and the growth characteristics (X), such as the DBH, tree height, crown width, and crown height. The allometric equations of average tree age according to DBH and tree height were Y=0506X-2.064 ($R^2=0.999$) and Y=0.321X+0689 ($R^2=0.992$), respectively. The developed allometric equations estimated that the DBH were 3.0cm, 8.1cm, 13.1cm and 18.2cm while the tree heights were 3.9m, 7.1m, 10.3m, and 13.5m when the tree ages were 10, 20, 30, and 40 years, respectively. The analysis results of fruiting characteristics showed that the length, the diameter, the number of fruits, and the number of acorns per fruiting branch had the statistically significant difference and tended to decrease from the upper part to the lower part of crown downward. The total number of acorns was 1,312 acorns/tree in the upper part, 115 acorns/tree in the middle part, and 5 acorns/tree in the lower part of the crown. The allometric equation for the amount of acorns with DBH as an independent variable was $Y=0.003X^{4.260}$ with the coefficient of determination at 0.896. Although the coefficient of determination of the allometric equation using only DBH as the independent variable was lower than that using DBH and tree height ($D^2H$), it would be more practical to consider only DBH as the independent variable because of measurement errors.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.1
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• pp.32-38
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• 2018

Purpose: The purpose of present study was to retrospectively analyze the survival rate of narrow diameter implant less than 3.6 mm by initial stability and radiographic measurements. Materials and Methods: In total, 24 patients who received 38 narrow diameter implants (${\leq}3.6mm$ in diameter, ${\geq}7mm$ in length) were enrolled in this retrospective study. The cumulative survival rate was calculated and various factors were investigated according to the implant platform diameter, body diameter, length, position, concomitant use of guided bone regeneration in implant placement and final prosthesis type. Initial stability was investigated with implant stability quotient (ISQ) value. The mesial and distal marginal bone level (MBL) change was calculated with radiography. Results: The overall survival rate was 92.11%. Mean ISQ value and MBL change of survival implants was 66.26 and $0.14{\pm}0.31mm$, respectively. None of the implants with platform diameters larger than the body diameter failed. Conclusion: In conclusion, the findings of present study suggest that narrow diameter implant could be predictable treatment in narrow alveolar ridge.

• Journal of Korean Society of Forest Science
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• v.85 no.1
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• pp.120-129
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• 1996

This study was carried out to investigate the hydraulic architecture such as relative hydraulic conductivity, Leaf specific conductivity(LSC), Huber value, Specific conductivity of the stem, branch and Junctions of stem-to-branch in Quercus mongolica trees. The hydraulic architecture of various hydraulic conductivities of stem and branch was described. The results obtained were summarized as follows : 1. The range of relative hydraulic conductivity was $2.5526{\times}10^{-12}$ to $1.2260{\times}10^{-10}m^2$ in stems, $1.6279{\times}10^{-11}$ to $6.8378{\times}10^{-11}m^2$ in branches. The relative hydraulic conductivities increased with decreasing diameter of stem and branch. The relative hydraulic conductivity of one-year-old terminal shoots were two times greater than that of the lateral shoots. 2. LSC value was larger at the top than at the base in stem. LSC is much smaller in branches than in stem ; especially smallest at branching part. 3. Hydraulic conductivities of the branching part appeared the different values with the 4 type and 4 type. Relative hydraulic conductivity, LSC, Specific conductivity and mean vessel diameter in type branching part were larger in stem than in branch part, but not found in the branching part of Y type. 4. LSC and Specific conductivity of stem increased with decreasing diameter, but Huber value slowly increased with decreasing diameter ; especially highest at less than 1cm diameter. 5. LSC, Huber value, and mean diameter of vessels were larger at 1-year-old leader shoots than at lateral shoots. 6. The mean vessel diameter in various parts of a tree decreased with decreasing diameter of stem, but the number of vessels per unit area($mm^{-2}$) increased reversely. Mean vessel diameter in stem decreased sharply at earlywood and slowly at latewood with decreasing diameter of stem.

• Korean Journal of Environment and Ecology
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• v.14 no.3
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• pp.175-182
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• 2000

본 연구는 자연생태계 소목의 생장에 따른 탄소저장 및 흡수량 지표를 도출하고 용인시를 대상으로 임상유형의 영급별 탄소저장 및 흡수를 계량하였다. 침엽수 1주당 탄소저장 및 흡수량은 중부와 남부의 생장지역간 유의한 차이가 없었으나(p>0.05). 활엽수의경우는 남부지역에서 중부지역보다 더욱 많았다. 수목 1주당 탄소저장 및 흡수량은 활엽수가 동일 직경의 침엽수보다 더욱 많았으며, 그 차이는 직경생장과 더불어 증가하는 경향을 보였다. 용인시 자연생태계의 단위면적당 평균 탄소저장 및 흡수량은 역시 영급이 높을수록 많았으며, II 영급을 제외한 동일 영급내에서는 침엽수림보다는 혼효림이, 혼효림보다는 활엽수림이 더욱 많았다. 중부지역에서 생장하는 흉고직경 20cm 의 활엽수 1주는 약 175리터의 휘발유 소비로 인하여 배출되는 탄소량을 저장하고, 1ha의 IV 영급 활엽수림은 시민 57명이 화석연료 소비로 연간 배출하는 탄소량을 저장하였다. 본 연구의 탄소저장 및 흡수 지표는 직경 생장에 따른 삼림수목의 대기탄소농도 저감 가치를 용이하게 추정하는데 활용될 수 있다.

• Journal of Korean Society of Forest Science
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• v.98 no.3
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• pp.324-330
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• 2009

The objective of this study is to estimate the carbon sequestration in forest stands using KOMPSAT-2 imagery. For estimating the amount of carbon sequestration, the stand biomass of forest was estimated with the total weight, which was the sum of individual tree weight. Individual tree volumes could be estimated by the crown width extracted from KOMPSAT-2 imagery. In particular, the carbon conversion index and the ratio of the $CO_2$ molecular weight to the C atomic weight, reported in the Intergovernmental Panel on Climate Change (IPCC) guideline, was used to convert the stand biomass into the amount of carbon sequestration. Thereafter, the KOMPSAT-2 imagery was classified with the segment based classification (SBC) method in order to quantify carbon sequestration by tree species. This approach, estimating the amount of carbon sequestration for certain species in stand, can be available to extend plot-based carbon sequestration to stand-based carbon sequestration.

• Journal of Korean Society of Forest Science
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• v.80 no.4
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• pp.420-426
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• 1991

This study was conducted to provide fundamental information to make rational management planning in eastern seacoast forest, mainly composed of black pine (Pinus Thunbergii), Kangweon Province. Diameter distribution was estimated by the method of Weibull distribution. The results were as fallows ; 1. Average diameter in the eastern seacoast forests of Kangweon Province was 10.3cm, and the average D. B. H, of 16 study sites ranged from 6.9 to 14.6cm. 2. Parameters of the Weibull distribution were estimated in each study sites and the estimated parameters of the all study forests were a=5, b=5.6997 and c=1.4079. 3. Tested by Kolmogorov-Smirnov method for the significant differences between actual and estimated diameter distribution, the result showed that estimated values were well fitted to the actual ones at 5% significance level.

• Journal of Korean Society of Forest Science
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• v.17 no.1
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• pp.23-28
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• 1973

In this survey, to estimate volume growth of pitch pine (Pinus rigida Mill) stand, diameter growth was estimated. Among 223 sample trees, the number of rejected trees was 12, about 5 percent of total sample trees. The stand showed uniform growth and rejected trees included insect-damaged trees. Compared with reports made on forest classification basis, pitch pine a single species showed faster growth. Minimum, average and maximum value of D.B.H and mean annual diameter growth, of 16 year old pitch pine stand, were as follow. The correlation of each factors estimated by 9590 of confidence interval is shown in the table of correlation as bellow.

• Journal of Wetlands Research
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• v.21 no.4
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• pp.298-304
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• 2019

In this paper, the analytical method to derive wind fragility for urban street tree in Korea was shown. Monte Carlo Simulation method was used to determine the probability of failure for urban street tree. This probability result was used to determine wind fragility parameters for four types of tree based on the study of street tree species in urban area in Daegu, Korea. Wind fragility for street tree was presented in terms of median capacity and standard deviation of the natural logarithm of the capacity. Results showed that the dominant factor affecting the probability of failure of tree under wind load was their diameter. Moreover, amongst the four types of tree chosen, the tree with height 7m and diameter 35cm had the lowest probability of failure under wind loading, whereas the tree with height 8m and diameter 30cm could resist the least wind loading. The median failure wind speed for urban street tree with height 7m were 43.8m/s and 50.6m/s for diameter 30cm and 35cm, respectively. Also, for tree with height 8m, their median failure wind speeds were 38.7m/s and 45.4m/s for tree with diameter 30cm and 35cm, respectively.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.287-297
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• 2016

This study aims to identify the relationship between climatic factors and stand mean Diameter at Breast Height (DBH) for two major tree species; Pinus densiflora and Quercus mongolica in Andong-dam basin. Forest variables such as age, diameter distribution and number of trees per hectare from the $5^{th}$ and $6^{th}$ National Forest Inventory data were used to develop a DBH estimation model. Climate data were collected from six meteorological observatory station and twelve Automatic Weather System provided by Korea Meteorological Administration to produce interpolated daily average temperature map with Inverse Distance Weighting (IDW) method. Andong-dam basin reflects rugged mountainous terrain, so temperature were adjusted by lapse rate based correction. As a result, predictions of model were consistent with the previous studies; that the rising temperature is negatively related to the growth of Pinus densiflora whereas opposing trend is observed for Quercus mongolica.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.5
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• pp.59-70
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• 2021

This study was to investigate the measurement point of root collar diameter of landscape trees in Korea. It may contribute to avoiding disputes caused by the difference in measurement criteria of root collar diameter of landscape trees between tree growers and constructors. The difference between landscape trees' root collar diameter measurement point was 3.59cm from 6cm underground to the surface and 1.35cm from 0cm to 6cm above ground. The source root collar diameter measurement point difference was larger in the basement than in the ground. The standard deviation of the root collar diameter of the landscape tree was 0.64 from 6cm underground to the surface, and the difference in standard deviation from 0cm to 6cm above ground was 0.16. The difference by measurement point of the root collar diameter was larger in the basement than in the ground. It has been proposed to set the reasonable measurement point of the landscaping tree root collar diameter at the inflection point where the standard deviation of the tree trunk diameter is the smallest in line with the size change of the standard for each root collar diameter measurement point. By tree species, Cornus officinalis Siebold & Zucc. 18cm above the ground, Chionanthus retusus Lindl. & Paxton. 12cm above the ground, Zelkova serrata (Thunb.) Makino. 12cm above the ground, Celtis sinensis Pers. 12cm above the ground, Styrax japonicus Siebold & Zucc. 10 cm above the ground, Cornus officinalis Siebold & Zucc. 10cm above the ground, Acer palmatum Thunb. ex Murray. 6cm above the ground, Ilex rotunda Thunb. 6cm above the ground, Quercus myrsmaefolia Blume. 4cm above the ground, Lagerstroemia indica L. 2cm above the ground The above heights were shown as reasonable measurement points. The difference by landscape tree root collar diameter measurement site showed that the standard deviation was small throughout the tree species, and the reasonable average measurement point with a stable slope of the deviation was 12cm or more on average. It can be said that the reasonable measurement point of the root collar diameter of a landscape tree is set at an average of 12cm above the ground. However, recognizing 30cm, which is a familiar ruler(尺) in traditional practices, is quick, It was recommended to measure at the height of 30cm from the surface for a reasonable measurement point of the root collar diameter of a landscape tree, for the uniformity of measurement standards.