• Journal of the Korea Furniture Society
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• v.22 no.3
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• pp.199-207
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• 2011

Examined the color of ten species of Korean broadleaf trees were experimented based on $L^*a^*b^*$ values and color difference (${\Delta}E^*ab$) between sapwood and heartwood, in order to analyze and determine the color, a critical visual and decorative factor of the broadleaf trees that can be used for making woodcraft and furniture. According to the result, the entire sapwood and heartwood, except the heartwood of Populus tomentiglandulosa, showed positive value in whiteness, redness, and yellowness and therefore contained yellow and red. None of the species showed color difference between sapwood and heartwood that was trace (0~0.5), slight (0.6~1.5), or very much; whereas Populus maximowiczii showed noticeable color difference (1.5~3.0); Salix koreensis, Betula platyphylla var japonica, Carpinus laxiflora, and Castanea crenata, appreciable and Populus tomentiglandulosa, Juglans mandshurica, Betula schmidtii, Alnus japonica, and Quercus variabilis, much. The color characteristics of heartwood and sapwood of the ten Korean broadleaf tree species studied in this research can be used as basic data for woodcraft or furniture production, especially when replacing foreign woods with Korean ones, and also contribute to convergence researches for science, engineering, and design fields.

• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.1
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• pp.11-17
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• 2004

This study was conducted to determine the relationship of stomatal responses, photosynthesis, and intercellular $CO_2$ concentration( $C_{i}$) of Betula Species to ozone exposure. Five Betula Species(B. costata, B. davurica, B. schmidtii, B. platyphylla var, iaponica and B, ermani) were grown in the greenhouse. One-year-old potted seedlings of the five Betula Species were exposed to ozone(100 pub) for 8 hours da $y^{-1}$ for 5 weeks in a fumigation chamber. Net photosynthesis was significantly different among species and treatments from early in the period of the fumigation. Stomatal conductance and transpiration rate differences among species and treatments became significant after three weeks of fumigation. $C_{i}$ was significantly different only among treatments; $C_{i}$ of four species, except for B. davurica, was higher than that of control plants. Carboxylation efficiency and photo-respiration rate were significantly different among species or treatments; carboxylation efficiency and photo-respiration rate of the five Betula Species were decreased by ozone treatment. It was concluded that stomatal closure of Betula Species may be the result of the reduction of photosynthesis and rubisco activity and the resulting increase of $C_{i}$. The higher $C_{i}$ likely resulted from reduced photosynthesis because of physiological processes.ocesses.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.2
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• pp.72-79
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• 2002

This study was conducted to compare the physiological and biochemical responses of four Betula species in response to ozone, and to find out the relationship between ozone uptake rate and photosynthesis or antioxidant activity. One-year-old seedlings of four Betula sp, B. costata, B. davurica, B. platyphylla var, japonica, and B. ermani, exposed to 100 pub ozone concentration for 8h day$^{-1}$ for 5 weeks in fumigation chamber. Ozone uptake rate, photosynthesis, SOD and GR activity were measured in the leaves of four species once a week. Cumulative ozone uptake rate was largest in the loaves of B. costata(53.8 mmol m$^{-2}$ ), smallest in the leaves of B. davurica(35.5 mmol m$^{-2}$ ). Photosynthesis of four Betula sp. exposed to ozone reduced relative to control, but the photosynthetic responses with changing stomatal conductance were different among species. Ozone exposure increased SOD activities of four species at the early exposing period, but after a critical point SOD activity decreased gradually. GR activity of B. costata was similar to the change of SOD activity, but the others showed the different patterns from B. costata. In conclusion, decreasing both SOD and GR activity at the critical point, B. costata may be sensitive species in response to ozone. In contrast, the others may be resistant species, which gradually increase GR activity following ozone exposure. GR activity was not always in accord with the change of SOD activity against ozone uptake, and the different responses between species were supposed to be affected by the cumulative ozone uptake.

• Journal of the Korean Institute of Landscape Architecture
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• v.19 no.3
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• pp.27-40
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• 1991

For the establishment of district planning in natural parks, vegetationin the most significant point. Consequently, district plan should be made basically under phytosociological investigations. The purpose of this paper is to conserve vegetation in the district planning at natural park(Nam Han San Sung provincial natural park). The result of vegetation survey are as follows : As an actual vegetation 13 communities are recognized. Those are Quercus mongolica-Carpinus laxiflora community, Quercus mongolica-Rhododendron schlippenbachii community, Quercus serrate community, Betula platyphylla var. Japonica community, Quercus dentata community, Quercus mongolica-Pnuus densiflora community, Quercus acutissima community, Robinia pseudo-acacia community, Alnus hirsuta community, Castanea crenata community, Quercus variabilis community, Pinus densiflora community, Pinus rigida community, weed community on cultivated land(Form land), Larix leptolepis reforested land, cut over area and non-vegetation area. The grade of vegetation naturalness was divided into five degrees by characteristics of actual vegetation. I intended to make zoning plan for protection of vegetation with a special attention to the grade of vegetation naturalness and I discussed the necessity of the improvement of existing district plan. District plan was proposed as Fig. 5.

• Journal of the Korea Furniture Society
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• v.20 no.6
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• pp.560-565
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• 2009

It is known that heat treatment decreases the hygroscopicity of wood. Thus heat-treated wood is good for outdoor construction due to its improved dimensional stability. This study is to investigate the hygroscopicity and discoloration of spruce and birch boards heat-treated above $190^{\circ}C$. The equilibrium moisture contents (EMCs) at all relative humidities decreased with the increase of heat treatment temperature and/or time for both spruce and birch. It was revealed that heat-treatment temperature affected more on the hygroscopicity thaan heat-treatment time. The average basic densities decreased for the spruce specimens, but increased for the birch specimens with an increase of the treatment time and/or temperature. The same heat treatment condition (190-8) made the birch specimens darker than the spruce specimens.

• Journal of the Korea Furniture Society
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• v.19 no.6
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• pp.460-465
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• 2008

When wood is exposed to natural weathering and UV radiation discoloration progresses. The color variation of heat-treated wood was investigated. Four domestic species were selected and heat-treated at $220^{\circ}C$ and naturally weathered for 42 days. Their colors were measured with a portable colorimeter. The color variations were different between species. The Korean red pine specimens were highly discolored by the natural weathering even though they were heat-treated. In contrast to Korean red pine, Korean pine is less discolored. The maximum color difference of larch was lower than Korean red pine. All specimens of birch exceeded the color difference criterion of 15 after 25 hours with the maximum of 28.

• The Korean Journal of Ecology
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• v.21 no.3
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• pp.283-290
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• 1998

The vegetation pattern of Mt. Odae based on the soil humidity gradient showed 3 types: (1) the forest of Pinus densiflora under the mesic or xeric conditions of the low altitudinal area, (2) the forest of Acer including A. mono, A. pseudo-sieboldianum and Tilia amurensis under the submesic or subxeric conditions and (3) the forest of Quercus including Q. mongolica of the higher elevational area and Q. variabilis of the lower elevational area under the xeric condition. Water content, organic matter and total nitrogen of soil were relatively low in Pinus densiflora and Quercus variabilis communities while they were relatively high in Betula platyphylla var. japonica and Quercus mongolica communities. According to the result of cluster analysis based on similarity indices of the communities, the proposed successional sere in the forest vegetation of Mt. Odae was as follows. P. densiflora community $\longrightarrow$ P. densiflore + Q. mongolica community $\longrightarrow$ Q. mongolica + A. pseudo-sieboldianum community. P. densiflora community $\longrightarrow$ P. densiflora + Q. variabilis community $\longrightarrow$ Q. variabilis community $\longrightarrow$ Q. mongolica + Q. variabilis community $\longrightarrow$ Q. mongolica + A. pseudo-sieboldianum community.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.4
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• pp.635-640
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• 2011

Betulae Cortex of Betula platyphylla Suk. var. japonica Hara (Betulaceae) has long been used for treatment of various inflammation, fever and cough in Eastern Asia. In order to investigate antibacterial activity of the Betulae Cortex against Streptococcus mutans or Porphyromonas gingivalis, MIC (minimal inhibitory concentration) and pH were checked, and for anti-inflammation activity, the experiments about trypsin-induced paw edema, vascular permeability and myeloperoxidase activity in rat's hind-paw tissue, were carried out with various extracts of Betulae Cortex (BCXs) respectively. The BCXs showed significant antibacterial activity, and at the dose of over 50 mg/kg, BCX showed significant inhibition on the paw edema, vascular permeability and myeloperoxidase activity. These results indicate that BCXs have antibacterial activity against oral cariogenic bacteria and anti-inflammatory effect.

• Journal of Korea Foresty Energy
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• v.21 no.3
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• pp.54-58
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• 2002

White birch bark is being called baekhwapi usually and is used urination, travail, removal of fever in Oriental medicine. Betulin had been known as main chemistry ingredient of white birch bark. So, in an experiment that see betulin and connection inorganic compounds separation and enforced to recognize antioxidative activity and anti HIV. Betulin's yield separated vast quantity for the first time in Korea by 6.9%, and 3,4-dihydrobenzoic acid in ethylacetate soluble as experiment result. Wish to utilize betulin connection derivative as each kind experiment sample ore because do composition making since.

• Journal of the Korea Furniture Society
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• v.19 no.4
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• pp.229-234
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• 2008

In a previous study, it was revealed that three major softwoods, Japanese pine, Korean pine and Japanese larch, heat-treated at $220^{\circ}C$, could produce high quality dark-colored boards. It is known that heat treatment decreases the hygroscopicity of wood. The hygroscopicity of major domestic softwoods and hardwoods heat-treated at $220^{\circ}C$ was investigated by a saturated salt solution method and compared with that of black and white charcoals. Equilibrium moisture contents of wood decreased with the increase of heat treatment time. Isotherm shapes of wood species were different from those of charcoals. Heat treatment decreases the equilibrium moisture contents of black locust more than those of Korean pine and Japanese larch. It was found that surface hardness of wood is improved by heat treatment to a certain extent, but a longer heat treatment causes thermal degradation, resulting in the decrease of the surface hardness.