• Journal of Oral Medicine and Pain
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• v.19 no.2
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• pp.221-231
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• 1994

Age determination in children have been criticized because they rely on subjective estimations of tooth development, as seen in radiographs. This study was undertaken to obtain the objective estimation of developing teeth. The panoramic radiograph of 254 males and 254 females ranging from 6 to 14 years of age were studied. The structures measured were crown height, apex width and root length. The data weree statistically investigated with SPSS/PC + package. The results were as follows : 1. With the aid of a multiple regression model, a linear relationship between some of these distances and age was shown. 2. In th total material(6-14yr) and four-yr. intervals, linear equations are as follow : Boys : 6-14 age = 683 + 145.6 44RL + 126.6.45RL + 71.1 46DRL - 161.3 46DAW 6-10 age = 1202 + 72.6 46DRL + 100.2 44RL + 75.1 45RL 8-12 age = 3818 + 75.9 45RL - 190.9 44AW 10-14 age = 4151 + 58.6 45RL - 84.0 45AW - 130.6 44AW Girls : 6-14 age = 1587 + 104.9 45RL + 113.4 44RL - 233.1 46DAW + 81.4 47DRL - 255.9 46MAW 6-10 age = 1821 + 55.8 46DRL + 67.2 45RL - 184.2 46MAW + 56.3 44RL 8-12 age = 2435 + 68.2 45RLL + 71.3 44RL 10-14 age = 3485 + 49.9 47DRL - 51.3 45AW - 179.9 47DAW + 33.4 45RL + 39.4 44RL (DRL, length of distal root in molars. RL, root length in premolars. DAW, width of distal apex in molars. MAW, width of mesial apex in molars. AW, width of apex n molars)

• Journal of Forest and Environmental Science
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• v.32 no.1
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• pp.74-81
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• 2016

Classified into sub-tree of the growth-form, Acer pseudosieboldianum and Carpinus cordata hardly reach the uppermost canopy with limited height growth potentiality in the natural deciduous forest. However, the two species usually dominate lower stories of the forest, playing an important role in overall ecological characteristics in the forest. Based on the vegetation data of 106 $20m{\times}20m$ sample plots in Mt. Jumbong area, this study was carried out to evaluate ecological constitution by several quantitative analysis so as to understand the mechanism of the natural deciduous forest. The results indicated that individuals of A. pseudosieboldianum and C. cordata were absent or few in overstory, but emerged the most dominant species in midstory and understory, providing adequate proof of the ecological importance. The comparison of indices of succession between presented and predicted values in midstory did not make much difference, suggesting that the species composition would not change much and come close to steady state in midstory and understory. The pair combination of species association noted that A. pseudosieboldianum had significant positive association with C. cordata, Quercus mongolica, and Tilia amurensis had significant positive association with A. pseudosieboldianum, A. pictum subsp. mono and Fraxinus mandshurica but negative association with F. rhynchophylla. Being compared with other major canopy tree species in the study forest, the target species of A. pseudosieboldianum and C. cordata had strong regeneration strategies, partially characterized by large number of saplings and pole sized trees and high ratio of live crown, which indicated high shade tolerance to survive in the limited amount of light under the canopy. Even though A. pseudosieboldianum and C. cordata do not reach and occupy the canopy layer mainly due to the inherent growth form, they would have highest competitive potentiality to prosper and dominate in the midstory of the natural deciduous forest.

• Korean Journal of Environment and Ecology
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• v.12 no.3
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• pp.242-252
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• 1998

The inhabitation environments and growth conditions of Machilus thunbergii community in the Pyonsanbando located at southwestern area in Korea were examined and analyzed to provide some practical data to be used to establish measures for long term succession monitoring, protection and sustainable management. The Machilus thunbergii community are located at Kyokpo-ri, Pyonsan-myon, Puan-gun(35$^{\circ}$35′24"N~35$^{\circ}$ 42′30"N, 126$^{\circ}$28′18"E~126$^{\circ}$40′40"E). Within the Pyonsanbando area the mean temperature is 12.4$^{\circ}C$, the warmth index 101.5$^{\circ}C$.month, the coldness index -12.3$^{\circ}C$ month and the annual precipitation 1,016mm. The soil within the community is silt loam or clay loam and so fertile. 30 species and 1 varieties of 21 families inhabited at the community. There were 18 grown trees and 131 saplings of Machilus thunbergii within the community. The mean basal diameter, mean height, and crown width of grown trees was measured to be 57.4cm, 7.4m and 9.0~9.8m respectively. And 9 trees were full flowering, 2 trees small flowering here and there, and 7 trees non flowering in 1998. The mean branch growth length was 8.3cm, mean leaf area 18.3$\textrm{cm}^2$, mean inflorecence length 9.3cm, mean fertilization 14.5％ and mean seed diameter 7.6mm. Further rich management measure and investigation were recommended such as sapling protection, signboard construction, soil erosion controlling and regular monitoring within the community.

• Journal of Ginseng Research
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• v.7 no.2
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• pp.172-192
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• 1983

Light environment and growth of Panax ginseng In habitat and cultivation under natural shade were renewed. Grower's experiences on ginseng stand In relation to light environment were assessed. Change of shading method and grower's concepts on light requirement of ginseng plant in Korea, Manchuria and Japan was counted. Growth of wild ginseng was better under rich light. Optimum crown density index appeared to be 0.7 In natural habitat and 0.4 to 0.7 for the cultivation in forest. Change of light Intensity in forest was greatest in May and reached near to constant value (from 40% to 3% for broad leaf deciduous forest and loom 4% to 2% for pine forest). Insufficient light condition induced long and thin stem, poor flowering and seed bearing, and sequent dormancy. Relation between light and ginseng strand was not clear but light Interception with cool weather was effective. Topography and orientation of bed have been deeply considered for light environment. Panel or bark of won were used for shading in deep forest manly In Manchuria while reed blind and straw thatch were used in Korea. Kinds and number of shades material and seasonal or daily schedule have been simplified probably by labor pressure due to eulargement of plantation. Post height has been greater while width of roof, bed and ditch has changed lisle. Scientific survey in the past omitted important light control methods (complete light hardening etc) which has been practiced in specific areas. The concept and technique of light control in the past in Korea were delicate and intensive including the control of temperature and moisture. For the application of old concept in modem cultivation precise Investigation of the technique including the measurement of light, temperature and moisture is needed.

• Journal of Korean Tunnelling and Underground Space Association
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• v.5 no.3
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• pp.217-226
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• 2003

This study is focused on the finding out load transfer mechanism in the ground near the tunnel during tunnel excavation in the jointed sandy ground. Laboratory model tests were performed on various cases of the overburden heights above tunnel crown, location, and degree of discontinuity planes. For model tests, a movable plate was installed in the midst of the bottom of sandy ground. This plate, moving downwards, was intended to model the stress relaxation during tunnel excavation. The load transfer was measured at the fixed separated bottom plates adjacent to the movable plate. As the result, the loosening zone and the load-transfer form around the tunnelling site were affected by the overburden height and the characteristics of discontinuous planes. And large loosening zone was developed along the discontinuous planes which were close to the tunnel.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.6
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• pp.1-15
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• 2013

The present Namgang Dam had been completed in 2000, Salix subfragilis communities began to form in 2003 and their distribution area have been rapidly extended into nine times in 2010. In order to deduce correlation between water level and distribution of Salix subfragilis communities under this background in Namgang-dam reservoir, distribution characteristics and widening direction of Salix subfragilis communities have been analyzed by aerial photographs and water levels has been reviewed, also heights and ages of Salix subfragilis have been surveyed in field. The water levels of Namgang-dam related germination of Salix subfragilis have been analyzed in May and June from 2000 to 2010, mean water level, minimum water level and maximum water level were 37.87m, 36.99m and 38.82m, respectively. The oldest ages were 9-13 years, average diameters of breast height, average heights, average numbers and average crown area were respectively 3.9-8.8cm, 3.8-7.5m, $0.53/m^2$ and $0.98m^2/m^2$ in sites. Therefore, this results showed that the first recruitment of Salix subfragilis was in May 2002 when water levels have been maintained as 38.76-41.31m and the widening of Salix subfragilis communities was in May 2004 and 2005 when mean minimum water levels have been maintained as 38.76-41.31m. Salix subfragilis communities formed climax forest in Namgang-dam shore, this phenomena were different from the succession processes of Salix in rivers appeared landforming by deposition of sediment.

• The korean journal of orthodontics
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• v.50 no.1
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• pp.13-25
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• 2020

Objective: The aim of this study was to compare the accuracy and reliability of measurements performed using two different software programs on digital models generated using two types of plaster model scanners (a laser scanner and a computed tomography [CT] scanner). Methods: Thirty plaster models were scanned with a 3Shape laser scanner and with a Flash CT scanner. Two examiners performed measurements on plaster models by using digital calipers and on digital models by using Ortho Analyzer (3Shape) and Digimodel^® (OrthoProof) software programs. Forty-two measurements, including tooth diameter, crown height, overjet, overbite, intercanine and intermolar distances, and sagittal relationship, were obtained. Results: Statistically significant differences were not found between the plaster and digital model measurements (ANOVA); however, some discrepancies were clinically relevant. Plaster and digital model measurements made using the two scanning methods showed high intraclass coefficient correlation values and acceptable 95% limits of agreement in the Bland-Altman analysis. The software used did not influence the accuracy of measurements. Conclusions: Digital models generated from plaster casts by using laser and CT scanning and measured using two different software programs are accurate, and the measurements are reliable. Therefore, both fabrication methods and software could be used interchangeably.

• Fashion & Textile Research Journal
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• v.8 no.1
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• pp.80-88
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• 2006

This study attempted to undertake comparative analysis of woman's jacket pattern and details based on the Crinoline and Bustle style of the 19th century, comprehend the relation and differences between the two styles. And it also presented the resultant characteristics and attempted reproducing the original dress of the past for the development of modern woman's jacket design. Larger portion was occupied for the breast front width than the back width for both Crinoline and Bustle style, which indicated the remarkable difference between these styles and modern jackets in terms of pattern size. Circumferences also showed that both styles had larger size for the front region than for the back. Divided by two types of pattern shape. The Crinoline style has a waist line and flare. On the other hand, the Bustle style does not have a waist line and has pleats. These two styles shows distinct differences of patterns even if they seem similar. It was essential to undertake the designing of models by giving a consideration to the characteristics of patterns of the two styles. With respect to how to sketch the study models which will be applied for the reproduction to modern body sizes were as follows: the front bust circumference; B/4 +1+1 cm, the back bust circumference; B/4 +1-1 cm, front waist circumference; W/4 +1+1 cm, back waist circumference; W/4 +1-1 cm, the height of sleeve crown; AH/3, armhole line; B/4, the back width /2; 17.5 cm, the breast front width /2; 16.5cm. And for the rest parts, sizes reflecting the characteristics of the patterns of two styles have been applied.

• Journal of Korean Society of Forest Science
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• v.7 no.1
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• pp.35-39
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• 1968

1. The Fall webworm, Hyphantria cunea was widely distributed ranging from Seoul to Kangnung, Yung-ju, Taegu, Iri and Kwang-ju in 1967. 2. Heavily infested tree species by the Fall webworm were Sycamore, Cherry, ash-leaved maple, poplar, and elm. 3. The average number of larval masses per damaged garden tree and roadside tree was 7.0 and 3.4 respectively. 4. Trees of 6-10m in height had most number of larval masses and were most heavily infested. 5. More larval masses were found in the median and lower parts than higher parts of the crown. 6. The ratio of damaged by second generation was 55% higher than by first generation. The ratio of damage by 3rd generation is 18% less than by first generation.

• Journal of the Korean Geotechnical Society
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• v.23 no.8
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• pp.87-95
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• 2007

This study analyzed ground settlement and ground stress depending on tunnel excavation and the ground reinforcing grouting methods for double line road tunnel through deep weathered zone. Diameter of double line road tunnel was approximately 12m and umbrella arch method and side wall reinforcing grouting were applied. The ring-cut split excavation method and CD-cut excavation method for excavation method were applied. Analyses of failure rate and vertical stress ratio show that the tunnel for which the height of the cover (H) was higher than four times the diameter, can be considered a deep tunnel. Comparisons of various excavation and ground reinforcement methods showed that CD-cut method results in lower surface and crown settlement, and lower failure rate than that obtained by Ring-cut split method. In addition, the side wall reinforcing grouting resulted in reduction of tunnel displacement and settlement.