• 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.

• 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 Forest and Environmental Science
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• v.33 no.1
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• pp.74-77
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• 2017

The purpose of this study is to analyze the effect of thinning intensity on the growth of large diameter trees in Korean white pine (Pinus koraiensis S. et Z.) plantation. Eight thinning plots were analyzed by categorizing into heavy thinning, light thinning, no thinning (control) according to thinning intensity. As a result, average DBH increased more in heavy thinning plots than in light thinning or unthinned plots. The number of large trees (DBH>25 cm) were obviously shown the most in heavy thinning plots. It is considered that heavy thinning is needed for the production of the large diameter trees.

• Archives of Pharmacal Research
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• v.14 no.2
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• pp.172-175
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• 1991

Abnormality in the central noradrenergic system may be related to the seizure prone state in the genetically epilepsy prone rats (GEPR). The present work deals with the characterization of the deficit in noradrenergic system if susceptitibility and intensity of seizure are dependent on central noradrenregic activities by comparing the activities of dopamine $\beta$-hydroxylase (DBH) which hydroxylates dopamine into noradrenaline. DBH activities were measured in 5 areas of brain of normal rats, native GEPR and severe GEPR. The results suggest that lower DBH activities in the midbrain of GEPRs may positively be coupled to the susceptibility to seizure, whereas the same characteristics of the native or severe GEPR are not neccessarily in parallel with the intensity of seizure.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.5
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• pp.51-57
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• 2007

In order to study the characteristics of vegetation structure in Gundal mountain, we investigated forest community using belt transect method at 30 sites in Gundal mountain. As the result of important value' calculation on over DBH 2cm, Pinus densiflora (56.8), Quercus mongolica (48.5), Pinus rigida(41.4), Castanea crenata (22.3), Quercus variabilis (22.3), Carpinus laxiflora (16.9), Quercus aliena (11.3), Sorbus alnifolia (8.6), and Quercus acutissima (8.5) were in the order of important value. According to the ordination analysis of Gundal mountain forest, Quercus mongolica was found in north face and high of mountain. Carpinus laxiflora was found in north face steep slope and middle of mountain. As DBH analysis, the study community will be dominated by Quercus species. The correlation between the forest community and environment factor could be thought as distinction by soil nutrition etc., but we need more study about environment factors.

• Journal of Forest and Environmental Science
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• v.31 no.4
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• pp.255-260
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• 2015

Height growth models for Pinus thunbergii in Jeju Island were developed in this study using four widely used nonlinear growth models; Exponential, Modified Logistic, Chapman-Richards, and Weibull. All functions were found to be significant at the 1% level. Chapman-Richards model for height-DBH allometry and Weibull model for height-age allometry was chosen as the best model on the all validation. All the model curves showed the similar pattern. Additionally, there was no abnormal pattern when the previous studies were compared. Therefore, these models are highly expected to be used to estimate the tree height using DBH or age for Pinus thunbergii especially in Jeju Island.

• Journal of Forest and Environmental Science
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• v.27 no.1
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• pp.47-54
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• 2011

Allometry and basal area equations were developed with various tree measurement variables for the major species; Quercus variabilis, Quercus mongolica, Pinus koraiensis and Larix leptolepis in Korea. 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, and crown width), relative size (relative diameter and relative height) as well as competition measures (competition index, crown class, and live crown ratio).

• Journal of Korean Society of Forest Science
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• v.111 no.1
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• pp.125-135
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• 2022

In this study, growth changes of the diameter at breast height (DBH), height, basal area, volume, and biomass of Korean white pine (Pinus koraiensis Siebold & Zucc.) on a plantation were examined via long-term monitoring. In addition, this study was performed to provide the basic data for timber production in line with DBH class by comparing the growth of the relative DBH size. Growth characteristics according to DBH class were analyzed by categorizing trees into five classes based on sorted DBH rankings: class I (1%-20%; upper 20%), class II (21%-40%), class III (41%-60%), class IV (61%-80%), class V (81%-100%; lower 20%). A total class (0%-100%) was also used. Total increment and mean annual increment (MAI) were calculated using data from nine measurements taken over 39 years. Tree characteristics based on average values and stand characteristics based on unit area per hectare were examined. According to the total increments of variables, the differences in DBH, basal area, volume, and biomass among classes I-V increased over time, whereas the height difference did not continually increase. According to MAI, the maximum DBH value was 0.92 cm·yr^-1 at age 23 in class I, whereas the maximum value in all trees was 0.69 cm·yr^-1 at age 17. The maximum value of height MAI for class I was 0.52 m·yr^-1 at age 23, whereas that for all trees was 0.49 m·yr^-1 at age 20. In terms of basal area, volume, and biomass growth at tree-and stand-level, the maximum MAI of class I and all trees was not observed during the measurement period. Therefore, additional long-term monitoring data are required to determine the maximum MAI of the variables.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.16 no.1
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• pp.54-62
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• 2005

Objective : Attention deficit hyperactivity disorder (ADHD) is the most common childhood psychiatric disorder, affecting $3-5\%$ of school age children. Although the biological basis of ADHD is unknown, family studies provide strong evidence that ADHD has a genetic basis. Recent genetic studies have suggested associations between ADHD and Taq I polymorphism of dopamine beta hydroxylase gene(DBH) . The aim of this study is to test the association between ADHD and Taq I polymorphism of DBH in Korean population. Method : We processed DNA extraction and genotyping for 106 korean children with ADHD and their parents. Genotyping was additionally performed for 212 age and gender matched normal controls. Case-control association study was applied. And we tested the association using the transmission disequilibrium test (TDT) and haplotype-based haplotype relative risk test (HHRR). Results : There were no statistical differences of genotype distributions between cases and controls. However, we did observe preferential transmission of allele Al of DBH Taq T polymorphism in ADHD. Conclusion : On the whole, our results lend credence to the notion that the relationship between ADHD and DBH is complex. The number of cases and informative transmissions were small, therefore it would be premature to make any conclusions from our study concerning the role of DBH in ADHD. Further work is needed to support these findings.

• Korean Journal of Environment and Ecology
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• v.33 no.6
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• pp.686-694
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• 2019

This study was carried out to identify the long-term changes to beech forest due to climate change in Ulleung-do. To study the traits of the stand structure of beech forest with micro-topography, we investigated the distribution of the basal area, important values, and indicated species in a small ridge between Albong basin and Seongin-bong peak, and 1-ha stands (20 m × 20 m, 25 sites) dominated beech species including on the upper slope and valley parts. The result showed that the indicator species characterizing the vegetation communities were Tsuga sieboldii, Rhododendron brachycarpum, and Mitchella undulata in the small ridge and Celtis jessoensis, Dryopteris crassirhizoma, and Ulmus laciniata in the valley part. Moreover, the individuals with the total DBH < 10 cm were more predominant in the small ridge and upper slope than in the valley part, the individuals with DBH = 10-25 cm were predominant in the small slope, and individuals with DBH = 25-45 cm and DBH > 45 cm were predominant in the upper slope. The reason for the predominant distribution of beech stand with DBH<10 cm in all terrains is suggested to be germination by nutritional propagation rather than secondary succession caused by artificial disturbances and seed propagation.