• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.396-399
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• 2006

This study was conducted to investigate the desalinizing effect of some vegetable crops (beet, crown daisy, kale, lettuce, spinach, sweet com, and tomato) in salinized soil. The soil was treated with highly concentrated nutrient solutions and the growth of these crops was compared and soil salinity was monitored. The plant height of lettuce and crown daisy inhibited severely in with EC $5dS{\cdot}m^{-1}$ salinized soil. Soil EC level was the lowest in soil where tomato was cultivated followed by corn and kale. The residual level of $NO_3$ was higher in soils used for cultivation of corn, tomato, and kale, that of K was higher in soils used for cultivation of corn, tomato, and beet, and That of $P_2O_5$ was higher in soils used for cultivation of corn and tomato. Although the desalinizing effect was greatest by tomato and corn after 60 days of cultivation. Quality of the these crops was low and the cultivation periods of these crops overlapped with that of the main crops. Kale, on the other hand showed less growth inhibition in salinized soil, greatest desalinating effect based on fresh weight. In addition this crop only needs 30 days of cultivation period. Therefore, kale was most efficient crop in desalinizing considering crop quality, a short cultivation period, and nonoverlapping cultivation time with the main crops.

• Journal of Korean Society of Forest Science
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• v.90 no.5
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• pp.650-662
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• 2001

The growth and yield models for five different kinds of natural forest types were systemically developed in the natural Broadleaved-Korean pine Forests in Northeast China. The data were collected from 359 temporary plots and 58 permanent plots with area ranged from 0.06 ha to 1.0 ha, ranging in stand age from 43 to 364 years. The Site Class Index (SCI) was introduced to evaluate site quality and the Crown Competition Factor (CCF) was selected as a measure of stand density for the mixed natural forest. The Chapman-Richards function was adopted to develop SCI equation and height-diameter curve. The Schumacher growth function was selected as base model to develop the DBH, basal area, and stand volume growth models by using re-parameterized method. In modeling mean DBH and basal area growth, it was found that the asymptotic parameter A of Schumacher function was exponentially related to site quality (SCI) and stand density (CCF). The rate parameter k was related to stand density and it was independent of SCI. Several validation measures for predicted stand variables were evaluated in the growth and yield models using independent data sets. The results indicated that relative mean errors (RME) in predicted stand attributes were less than ${\pm}5%$ and the estimated precision values of the stand variables were all greater than 95%.

• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.502-510
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• 2022

In the national greenhouse gas inventory, a settlements category has never been included owing to the lack of activity data. Therefore, this study was conducted to obtain basic data for estimating biomass carbon storage in settlements. Nondestructive stem analysis with a laser dendrometer was performed on four major street tree species (Metasequoia glyptostroboides, Prunus armeniaca, Ginkgo biloba, and Acer buergerianum) in Wonju city, South Korea. Allometric equations of the aboveground volume were developed using five models, and allometric equations of crown area were developed with diameter at breast height (DBH) as an independent variable. The best performing allometric equations were aD²+bD+c for M.glyptostroboides and G. biloba, aD+bD² for P. armeniaca, and a+bD² for A. buergerianum. Regarding the allometric equations of crown area with DBH as an independent variable, G. biloba and A. buergerianum exhibited low coefficients of determination (R²), i.e., < 0.364, whereas M. glyptostroboides and P. armeniaca exhibited satisfactory R² values, i.e., > 0.767, probably due to different street tree management practices. The allometricequations in this study will support the carbon inventory of settlements and urban tree monitoring in management practices.

• Journal of Korean Society of Forest Science
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• v.77 no.3
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• pp.303-314
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• 1988

Tong-ri beach has not enough vegetation to be enjoyed by the sea bathers and to be satisfied with preventing the disaster-damages, but mixed forest near the beach can work its funtions and the old forest of Pirus thunbergii $P_{ARL}$. near the beach do a Little. Therefore it is very urgent to plant more trees near the beach for bathers and disaster-damage prevention. This study was carried out for planning an afforestation, with reporting upon the crown amounts and soil properties of disaster-damage prevention forests of P. thunbergii $P_{ARL}$. planted on the coast sand dunes in 1970 and 1976, and with reporting upon the valuation on soil properties of the lands near the beach in order to set the afforestation site. The results are as follows : 1. In disaster-damage prevention forests, crown surface area and crown volume became increasingly greater in proportion to the height. To D.B.H., crown volume also became increasingly greater in proportion, but crown surface area was directly proportional. 2. In comparison to sail characteristics of sand dune, those of the forests were in large quantity in OM, T-N and avail. $SiO_2$, and almost in the same in avail. $P_2O_5$, but in small quantity in exchangeable canons : K, Ca, Mg and Na. 3. EC, Cl and pH were in small value in the forest soils, but CEC was in large value in those soils. 4. Above facts showed that the forests fulfill their functions for preventing disaster-damages and improve their soil properties. 5. The forests have naturally been thinned up to 34% in 17 years and 39% in 11 years, and one can easily pass through the forest(planted in 1970), because of its sufficient clear-length(2.71m) and its space to pass. 6. A plan for afforestation was oracle nut after judging several sites by the evaluation on the soil properties and considering the best relaxation and the prevention of the various disaster-damages upon which were reported in the last issue. 7. Afforestation should be kept for maintaining its appropriate density for best relaxation and disaster-damage prevention.

• Journal of Korean Dental Science
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• v.4 no.1
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• pp.1-5
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• 2011

Purpose: Exact knowledge of the location and dimension of the pulp chamber help to maintain the pulp healthy during operative procedure and also reduces the risk of perforation of pulp chamber during root canal treatment. This in-vivo study was carried out to measure critical morphology of pulp chamber of mandibular molar using intra-oral periapical radiograph. Materials and Methods: Mandibular molar teeth of 56 patients were evaluated. The mandibular molar teeth whose pulp chamber was not violated by caries, restoration, fracture crown and those having closed apex were included in the study. The intraoral periapical radiographs were taken with paralleling angle technique using radio-opaque grid with 1 mm space. This grid was placed directly on the film. Results: In 94% of the mandibular first molars specimens the pulp chamber ceiling was at the level of the cemento-enamel junction. The measurements showing the lowest percentage variance were buccal cusp to furcation (approximately 11%) and buccal cusp to pulp chamber ceiling (approximately 15%). The distance from the cusp tip to pulp chamber ceiling height was approximately 6.0 mm, the distance from the pulpal floor to the furcation was approximately 3.0 mm, and the average height of a pulp chamber was 1.5 to 2.0 mm. Conclusion: The exact knowledge of distances of pulp chamber from various anatomical landmarks helps in proper assessment of root canals and ultimately avoids the failure of root canal treatment.

• Journal of Korean Society of Forest Science
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• v.86 no.2
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• pp.208-213
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• 1997

Tree form characteristics and biomass distribution and volume increment for Quercus spp., Larix leptolepis and Pinus koraiensis growing in Kwangju-Gun, Kyunggi-Do were investigated. P. koraiensis showed higher crown percentage than L. leptolepis, indicating that P. koraiensis maybe shade-tolerant species. Biomass allocation by tree height showed significant difference among three species. Stem biomass distributed more dimminishing along tree height with Quercus spp. and P. koraiensis than L. leptolepis. The allometric pattern of leaf-and branch biomass appeared as normal distribution. Present biomass was highest in L. leptolepis showing 171.1tons/ha and followed by P. koraiensis and Quercus spp, with 75.3tons/ha and 61.6tons/ha, respectively.

• Journal of Korean Society of Forest Science
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• v.90 no.4
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• pp.445-449
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• 2001

The objective of this study was to develop a new technique to control crown form of Hiscus syriacus to be used for an upright street tree with a single stem. Fertilization and raising the clear-bole length were the main treatments to compare the diameter and height growth of this species. The trees maintained with clear-bole length of 100, 150, and 200cm showed diameter growth of 15.7. 13.8, and 10.8mm, respectively, indicating the reduced diameter growth of trees with increasing clear-bole length, which is known as a typical characteristics in tending trees in silviculture. The effects of fertilization was not shown in this study. At the end of the two-year study from 1999 to 2,000, optimum diameter growth was obtained with the treatments of clear-bole length of 80-120cm, or 121-150cm. It is concluded that height and clear-bole length should be considered first in raising Hibiscus syriacus for street trees. Further study may be needed to obtain the effects of fertilization and raising the clear-bole length on uprightness of this species.

• Journal of Korea Foresty Energy
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• v.17 no.1
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• pp.1-7
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• 1998

This study was to investigate the productivity of 24-year-old Larix leptolepis plantation in the Experimental Forest of Chungbuk National University located in Mt. Worak, Chungchungbuk-do, Korea. Eight plots(l0m x l0m) were established in the larch plantation in the 9th compartment. Eight sample trees were selected and cut off. Stem, branches and leaves were weighed respectively with the stratified clipping method, and analyzed for productive structure. The allometric regression equations between dry weight of each component(stem, branches. and needles) and D$^2$H were obtained. The results obtained are summarized as follows; (1) Photosynthetic layer of Larix leptolepis was shown at about 13m in height, and maximum needle amount of crown at 15-l6m in height. (2) The total biomass of aboveground was 186.25tons/ha(86.3% from stem, 9.9% from branches and 3.8% from needles). (3) Annual net production of aboveground was 12.17tons/ ha/yr, and the ratios of stem, branches and needles to that of aboveground, 0.835, 0.12, and 0.045, respectively.

• The korean journal of orthodontics
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• v.47 no.5
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• pp.277-288
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• 2017

Objective: Treating Class II subdivision malocclusion with asymmetry has been a challenge for orthodontists because of the complicated characteristics of asymmetry. This study aimed to explore the characteristics of dental and skeletal asymmetry in Class II subdivision malocclusion, and to assess the relationship between the condyle-glenoid fossa and first molar. Methods: Cone-beam computed tomographic images of 32 patients with Class II subdivision malocclusion were three-dimensionally reconstructed using the Mimics software. Forty-five anatomic landmarks on the reconstructed structures were selected and 27 linear and angular measurements were performed. Paired-samples t-tests were used to compare the average differences between the Class I and Class II sides; Pearson correlation coefficient (r) was used for analyzing the linear association. Results: The faciolingual crown angulation of the mandibular first molar (p < 0.05), sagittal position of the maxillary and mandibular first molars (p < 0.01), condylar head height (p < 0.01), condylar process height (p < 0.05), and angle of the posterior wall of the articular tubercle and coronal position of the glenoid fossa (p < 0.01) were significantly different between the two sides. The morphology and position of the condyle-glenoid fossa significantly correlated with the three-dimensional changes in the first molar. Conclusions: Asymmetry in the sagittal position of the maxillary and mandibular first molars between the two sides and significant lingual inclination of the mandibular first molar on the Class II side were the dental characteristics of Class II subdivision malocclusion. Condylar morphology and glenoid fossa position asymmetries were the major components of skeletal asymmetry and were well correlated with the three-dimensional position of the first molar.

• Journal of Korea Foresty Energy
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• v.25 no.1
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• pp.39-45
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• 2006

This study was conducted to understand the biomass and the energy content of 36-year-old Pinus rigida stand planted in Mt. Taehwa, Gwangju-si, Gyeonggi-do, Korea. The total biomass of aboveground was 252.0 ton/ha (65.9% from stemwood, 8.9% from stembark, 20.6% from live branches, 1.5% from current leaves, 2.6% from previous leaves, and 0.5% from cones). Annual net production (ANP) of aboveground was 27.4 ton/ha/yr, and the ratio of stemwood, stembark, live branches, current leaves, and cones to ANP of aboveground total, 56.3%, 6.1%, 19.1%, 13.9%, and 4.6%, respectively. Energy content of aboveground was 5,434 GJ/ha, and annual energy accumulation was 597 GJ/ha/yr. Photosynthetic layer of P. rigida was shown at about 5.2 m in height, and maximum needle amount of crown at 11 to 13 m in height.