• Journal of the Korean Wood Science and Technology
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• v.52 no.2
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• pp.191-203
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• 2024

Persimmon wood (Diospyros kaki) is a seasonal fruit-producing plant with a beautiful dark pattern in its wood that is suitable for high-quality furniture, sculptures and musical instruments. The utilization of persimmon wood can be improved by determining its anatomical characteristics, such as juvenile and mature wood. This study aimed to determine the boundaries between juvenile and mature wood and observe the anatomical properties of juvenile and mature wood and their variations in the axial direction. Three 30-year-old persimmon (D. kaki) trees grown in Karo, North Sumatra, Indonesia, were used in this study. The boundary between juvenile and mature wood was determined by measuring the fiber length and vessel element length from near the pith to near the bark. Anatomical observations were conducted in the juvenile and mature wood areas. The results showed that the average boundaries between juvenile and mature wood were 44.11 mm from the pith and were not significantly different in the axial direction of the trees. Furthermore, the wood anatomy categories of juvenile and mature wood differed significantly in terms of fiber diameter, fiber proportion, vessel proportion, and axial parenchyma proportion. In the axial direction, vessel diameter, ray parenchyma frequency, and ray parenchyma proportion at the base, middle, and top of the tree were significantly different.

• Journal of Korea Multimedia Society
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• v.10 no.11
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• pp.1483-1495
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• 2007

Thanks to IEEE 802.11 technique, accessing Internet through a wireless LAN(Local Area Network) is possible in the most of the places including university campuses, shopping malls, offices, hospitals, stations, and so on. Most of the APs(access points) for wireless LAN are supporting 2.4 GHz band 802.11b and 802.11g protocols. This paper is introducing a C# library function which can be used to read RSSIs(Received Signal Strength Indicator) from APs. An LBS(Location Based Service) estimates the current location of the user and provides useful user's location-based services such as navigation, points of interest, and so on. Therefore, indoor, LBS is very desirable. However, an indoor LBS cannot be realized unless indoor position ing is possible. For indoor positioning, techniques of using infrared, ultrasound, signal strength of UDP packet have been proposed. One of the disadvantages of these techniques is that they require special equipments dedicated for positioning. On the other hand, wireless LAN-based indoor positioning does not require any special equipments and more economical. A wireless LAN-based positioning cannot be realized without reading RSSIs from APs. Therefore, our C# library function will be widely used in the field of indoor positioning. In addition to providing a C# library function of reading RSSI, this paper introduces implementation of indoor positioning modules making use of the library function. The methods used in the implementation are K-NN(K Nearest Neighbors), Bayesian and trilateration. K-NN and Bayesian are kind of fingerprinting method. A fingerprint method consists of off-line phase and realtime phase. The process time of realtime phase must be fast. This paper proposes a decision tree method in order to improve the process time of realtime phase. Experimental results of comparing performances of these methods are also discussed.

• Journal of Korean Society of Forest Science
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• v.84 no.1
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• pp.22-30
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• 1995

Responses of Pospam-injected chestnut and pine trees to drill wound were examined. Pospam was injected into the stem by just filling up the drill wound in September 10, 1993. The diameter of the injection wound were 0.5 and 1cm. DBH of chestnut trees and pine trees injected were 10, 15, 20 and 10, 20, 30cm, respectively. The results of tree response were examined in June, 1994. None of them showed any symptom of decay by the time. However, sapwood under the bark was remarkably discolored. The discoloration was more severe in 1cm-injection wound than in 0.5cm one. The severity of discoloration was not differed between species and among DBH applied. The sapwood split was longer in 1cm-injection wounded trees than in 0.5cm trees and longer in chestnut trees than in pine trees. From the split, callus grew out and almost closed the splits. In the trunk injection tested, the damage was mare severe in 1cm injection wound of chestnut trees than in any other combination.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.3
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• pp.102-106
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• 2008

This study was carried out to evaluate the relationships between stand attributes and litterfall amounts in a 28-year old Quercus acutissima stand. Eighteen sampling plots of $20m{\times}20m$ were chosen and litterfall was collected from May 2005 to December 2006. There was no correlation between stand attributes(tree density, mean diameter at breast height, mean height, basal area) and litterfall amounts except for flower and miscellaneous litter for the study period. There were no significant relationships between leaf litter and basal area(r=0.02, 0.05; P=0.93, 0.83) and between leaf litter and tree density(r=-0.10, 0.05; P=0.85, 0.69). Also, leaf litter was affected neither by mean diameter at breast height(r=-0.08, 0.30; P=0.73, 0.22) nor by mean height(r=-0.24, 0.09; P=0.34, 0.70). Other litter amounts such as bark, branch, and acorn showed no relationships with the stand attributes (P>0.05). The lack of significant relationships between litterfall amounts and stand attributes could be due to the closed canopy with a complete crown cover in this mature oak stand.

• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.170-175
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• 2013

This study was conducted to investigate the effect on the habitation of Monochamus alternatus, a vector insect of Pine wood nematode by the tended sound stumps for the developing forestry control methods of Pine wilt disease controls. Field cage plots (1 m ${\times}$ 1 m ${\times}$ 1 m) were established 12 units (Experiment1:4 units, Experiment2:8 Units) and were treated 4 kinds(February in 2010, February, April, June in 2011). The adults of M. alternatus were put into 4~5couples each the cage June in 2011. Presence or absence of the larva entrance holes and larva were detailed November in 2011. The larva were appeared in the sound stumps of sapling and young trees tended at February, April, June, the current emergence year of M. alternatus, but were not appeared in the sound stumps of sapling and young trees tended February in 2010, one year before the emergence of M. alternatus. The larva habitated in stumps of sapling were likely to be smaller in size in compare to the larva in stumps of young trees. In case of young tree, the larva were found at the cleft part of bark, but were not found at ridge part of bark. All observed larva appeared at part of bark and between the bark and the woody parts, but were not found at the woody parts. To develop the control guiding principal of sound stump after forest tending practice, further experiment need is in existence oviposition and larvae of vectors by height of stemps.

• Korean Journal of Heritage: History & Science
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• v.42 no.1
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• pp.122-142
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• 2009

This study explored all domestic and international theories for maintenance and health enhancement of an old and big tree, and carried out the anatomical survey of the operation part of the tree toward he current status of domestic surgery and the perception survey of an expert group, and drew out following conclusion through the process of suggesting its reform plan. First, as a result of analyzing the correlation of the 67 subject trees with their ages, growth status. surroundings, it revealed that they were closely related to positional characteristic, damage size, whereas were little related to materials by fillers. Second, the size of the affected part was the most frequent at the bough sheared part under $0.09m^2$, and the hollow size by position(part) was the biggest at 'root + stem' starting from the behind of the main root and stem As a result of analyzing the correlation, the same result was elicited at the group with low correlation. Third, the problem was serious in charging the fillers (especially urethane) in the big hollow or exposed root produced at the behind of the root and stem part, or surface-processing it. The benefit by charging the hollow part was analyzed as not so much. Fourth, the surface-processing of fillers currently used (artificial bark) is mainly 'epoxy+woven fabric+cork', but it is not flexible, so it has brought forth problems of frequent cracks and cracked surface at the joint part with the treetextured part. Fifth, the correlation with the external status of the operated part was very high with the closeness, surface condition, formation of adhesive tissue and internal survey result. Sixth, the most influential thing on flushing by the wrong management of an old and big tree was banking, and a wrong pruning was the source of the ground part damage. In pruning a small bough can easily recover itself from its damage as its formation of adhesive tissue when it is cut by a standard method. Seventh, the parameters affecting the times of related business handling of an old and big tree are 'the need of the conscious reform of the manager and related business'. Eighth, a reform plan in an institutional aspect can include the arrangement of the law and organization of the old and big tree management and preservation at an institutional aspect. This study for preparing a reform plan through the status survey of the designated old and big tree, has a limit inducing a reform plan based on the status survey through individual research, and a weak point suggesting grounds by any statistical data. This can be complemented by subsequent studies.

• Journal of Korean Society of Forest Science
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• v.9 no.1
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• pp.55-60
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• 1969

In order to understand the growth percentage of red pine, author had 207 trees cut and made stem analysis on them and there by studied and analysed volume growth percentage, bark volume percentage, diameter growth percentage and the relation between diameter growth percentage and volume growth percentage and so forth. The result was as follows. 1. The volume growth percentage decreased as the age class increased and it was about 3% at the cutting age. 2. Bark volume percentage was about 5~15% and it seemed to be about constant irrespective of the age class. 3. The diameter growth percentage gradually decreased as the age class increased and it would be constant from a certain age class on. 4. As for the relation between the diameter growth percentage and volume growth percentage, the correlation ratio showed to increase with the age class increase generally the value of b was between 2.0~3.6.

• Journal of Life Science
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• v.25 no.11
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• pp.1298-1303
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• 2015

Machilus thunbergii (Lauraceae) is an evergreen tree cultivated in Korea and Japan. M. thunbergii has long been used as a traditional medicine in Korea, China, and Japan to treat various diseases, including edema, abdominal pain, and abdominal distension. In this study, dried stem bark of M. thunbergii extracted in methanol and extract was partitioned into n-hexane, CHCl₃, and BuOH. The CHCl₃-soluble extracts chromatographed on silica gel column using a CHCl₃/acetone and n-hexane/EtOAc mixture to afford Compound 1 and 2. Two dibenzylbutane lignans, macelignan (1) and meso-dihydroguaiaretic acid (2), were isolated from the CHCl₃-soluble extract of M. thunbergii stem bark. The structures of 1 and 2 were determined by ¹H- and ¹³C-NMR spectroscopic data analyses and a comparison with literature data. The tyrosinase inhibitory activity of the isolated compounds was evaluated. Among these compounds, Compound 2 strongly inhibited the monophenolase (IC₅₀=10.2 μM) activity of tyrosinase. A kinetic analysis showed that Compound 2 was a competitive inhibitor. The apparent inhibition constant (K_i) for Compound 2 binding to free enzyme was 4.8 μM. Based on these results, it can be concluded that meso-dihydroguaiaretic acid (2) is a potential candidate for the treatment of melanin biosynthesis-related skin diseases.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1242-1247
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• 2012

Acer barbinerve Maxim belongs to the Aceraceae tree family and is often consumed as an Oriental medicine. In this study, we investigated whether or not ethanol extract from the bark of A. barbinerve Max. (EBA) inhibits lipopolysaccharide (LPS)-induced inflammatory responses in Raw264.7 macrophages. EBA was fractionated using n-hexane, $CH_2Cl_2$, ethyl acetate (EtOAc), and water. Raw264.7 cells were treated with 20 ${\mu}g/mL$ of EBA and the EBA fractions. EBA inhibited LPS-induced nitric oxide (NO) production. Among the three fractions, EtOAc fraction of EBA (EFEBA) was the most effective in inhibiting LPS-induced NO production without significant cytotoxicity in Raw264.7 cells. EFEBA futher reduced LPS-induced expression of inducible NO synthase (iNOS) proteins and its corresponding mRNA. Additionally, EFEBA decreased the mRNA levels of interleukin (IL)-6, IL-$1{\beta}$, and tumor necrosis factor-${\alpha}$ in LPS-treated Raw264.7 cells. Lastly, EFEBA inhibited LPS-induced degradation of the inhibitor of kappaBalpha ($I{\kappa}B{\alpha}$) as well as phosphorylation of p65 nuclear factor-${\kappa}B$ (NF-${\kappa}B$). These results indicate that EFEBA exhibits strong anti-inflammatory effects and can be developed as a potential anti-inflammatory agent.

• Korean Journal of Environmental Agriculture
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• v.15 no.1
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• pp.77-85
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• 1996

Chestnut(Castanea crenata) were trunk-injected by two methods to check the changes around the injection wound. In September 1993, high concentration of oxytetracycline(OTC) was injected through the injection wound of 1cm diameter and low concentration of OTC through 0.5cm diameter. Trunk diameter of injected trees ranged from 10cm to 20cm. All trees were in their vigorous conditions. Tree reaction was examined in June, 1994. None of them showed any sign of decay by the time. However, under the bark, sapwood was remarkably discolored. But, more severe discoloration was found in 1cm-injection wound than in 0.5cm one. Sapwood of some trees split from the injection wound, and the split was longer in 1cm-injection wounded trees than in 0.5cm trees. From the split, callus grew out and the split was closing. In this kind of trunk injection, the damage was more severe in 1cm-injection wound than in 0.5cm-injection wound.