• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.131-135
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• 2011

To examine the sex morph, fruiting characteristics and seed viabilities of Acer palmatum var. matsumurae (Koidz.) Makino, the flowers and seed-sets of 101 trees were collected from early April to late October 2010, and floral structure and seed viability were studied. Among investigated 101 trees, 73.3% of trees were protandrous (PA: pollen is shed before stigmas are receptive) and 26.7% were protogynous (PG: stigmas are receptive before pollen is shed). Acer palmatum var. matsumurae has heterodichogamous sexual system. Number of flowers and seed-sets per inflorescence are significantly different between sex morphs, and PA has more flowers and seed-sets per inflorescence than PG. Rates of sound seeds and decayed seeds are significantly different between sex morphs. Rates of sound seeds were 46.4% in PA, but 65.6% in PG. and rates of decayed seeds were 49.6% in PA, but 23.6% in PG. The differences of decayed seeds' rates between sex morphs might be related with the timing of pistil flower blooming and insect pests' outbreak.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.585-590
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• 2011

The purpose of this research is to suggest economic feasibility of cultivating Acer Mono by using profitability analysis to forest owners. To achieve this research objective, forest owner household survey with intensive cultivating has been conducted about a sap production on its age of tree. And input costs and sap production costs are calculated with silvicultural system from plant to regeneration cutting. Total income is the sum of its sap sales and thinning and regeneration cutting. The method of profitability analysis was used on the NPV(Net Present Value) and IRR(internal rate of return). Finally, when 3% discount rate is applied, NPV is about 59,436 thousand won and IRR value is 9.22% at this point. This result, therefore, proves that cultivating Acer Mono is economical feasibility to forest owners.

• Applied Biological Chemistry
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• v.49 no.4
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• pp.322-327
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• 2006

Food constituents analysis of Acer tegmentosum. Maxim.(Acer TM) stem was carried out according to AOAC method, and the antiradical activity on DPPH and cytotoxicity on human cell lines (AGS, HepG2, A549, MCF-7 and Chang) for the 80% ethylalcohol(EtOH) extracts of Acer TM stem were studied. The antiradical activity on DPPH radical of the ethylacetate(EtOAc) fraction of the bark showed a higher activity than that of $\alpha$-tocopherol, ascorbic acid and BHT. The inhibition activity of the 80% EtOH extracts from Acer TM stem on human cancer cell lines by SRB assay indicated a dose-dependent growth inhibition on most human carcinoma cells. The growth inhibition rate of each human cancer cell line showed 91.3% to AGS, 75.0% to A549, 74.1% to HepG2, and 70.2% to MCF-7 cells, respectively, when the 80% EtOH extract(1 mg/ml) of Acer TM stem was added.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.1
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• pp.171-176
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• 2020

Reinforcement learning is a well-known method for training an artificial software agent for a video game. Even though many reinforcement learning algorithms have been proposed, their performance was varies depending on an application area. This paper compares the performance of the algorithms when we train our reinforcement learning agent for a 2D racing game. We defined performance metrics to analyze the results and plotted them into various graphs. As a result, we found ACER (Actor Critic with Experience Replay) achieved the best rewards than other algorithms. There was 157% gap between ACER and the worst algorithm.

• The Korean Journal of Ecology
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• v.17 no.3
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• pp.415-424
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• 1994

Community structure, size and age distribution of tree species of the subalpine Korean fir (Abies koreana) forest at the elevation of 1, 400~1, 700m were strudied in the north-west side of Chonwangbong Peak (1915m) in Mt. Chiri for the purpose of better understanding of the population dynamics of Abies koreana. Eight 20m X 20m permanent quadrats were established in 1991, and trees $\geq$ 2.5cm DBH for all species were marked with numbered aluminum tag, and saplings of Korean fir and Korean pine (Pinus koraiensis) were also tagged with aluminum sheet. These two conifer species comprised more than 60% of the total density and total basal area of the community. Quercus mongolica and Acer pseudo-sieboldianum were subdominats. Oridination study showed that cool temperate species such as Sorbus commixta, Betula costata, Acer tschonoskii and Acer ukurunduense occurred in close association with Abies koreana and Pinus koraiensis. Major tree species, especially Abies koreana and Pinus koraiensis, were well represented in samller size classes, indicating that they were regenerating well. Age distributuion of the Abies koreana and Pinus koraiensis showed that the former has longer physiological longevity than the latter, and that establishment were episodic and varied with sites, which implies the importance of the role of natural and artificial disturbances in this Abies kireana forest.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.5
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• pp.38-46
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• 2004

This study was carried out to analyze forest vegetation in Seodaesan of Geumsan, Chungnam Province. Employing the releve method of Braun-Blanquet and quadrat method, 36 plots were sampled in forest of Seodaesan. The sub-communities were classified into Pinus densiflora, Acer pseudosieboldianum, and Carpinus laxiflora sub-community of Quercus mongolica community. The importance values were 77.07 in Quercus mongolica, 40.79 in Pinus densiflora, 17.03 Fraxinus rhynchophylla, 14.06 in Fraxinus sieboldiana, 13.99 in Quercus serrata, 12.93 Acer pseudosiebotdianum. Coverage rate was 84.6% in tree layer, 52.8% in subtree layer, 29.1% in shrub layer, 27.9% in herb layer, respectively. Most of the DBH of Quercus mongolica and Pinus densiflora was between 5cm and 20cm. Therefore, Quercus mongolica and Pinus densiflora might be dominant species in the study area for several decades. Acer pseudosieboldianum and Carpinus laxiflora sub-communities were distributed mainly in a high-altitude and northern and north-western area. Pinus densiflora sub-community was distributed mainly in a low-altitude and western area.

• Korean Journal of Pharmacognosy
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• v.42 no.4
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• pp.371-378
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• 2011

Aldose reductase (AR) has been implicated in the development of the diabetic complications. To discover novel treatments for diabetic complications from natural sources, 65 Korean herbal medicines have been investigated for inhibitory activities on AR. Of these, 23 herbal medicines exhibited a significant inhibitory activity compared with 3,3-tetramethyleneglutaric acid (TMG). Particularly, 8 herbal medicines, Acer tataricum (twig, stem and leaf), Acer tataricum (fruit), Rhododendron schlippenbachii (twig, stem and leaf), Weigela subsessilis (twig, stem and leaf), Acer mono (branch and leaf), Ailanthus altissima (twig, stem and leaf), Lindera obtusiloba (branch and leaf), Solidago serotina (whole plant) showed three times more potent inhibitory activity than the positive control, TMG.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.5
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• pp.441-446
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• 2013

In the present study, the anti-depressant like effect of methyl gallate (MG) isolated from the stem bark of Acer barbinerve was examined in ICR mice. Body weight (BDW) and blood glucose (BDG) levels significantly decreased in the repeated restraint stress (RRS) group (2 h/day for 14 days) compared to the no stress (NS) group. To examine the effect of MG on RS-induced BDW loss and hypoglycemia, MG (10 mg/kg) and the anti-depressant fluoxetine (10 mg/kg) were administered daily for 14 days. Orally administered MG and fluoxetine significantly attenuated the RS-induced BDW loss and hypoglycemia. Interestingly, MG administered mice showed increased BDG levels in the normal and glucose feeding condition. Chronic RS-subjected mice showed immobilized and depressed behaviors. The effect of MG on the depressed behaviors was evaluated using the tail-suspension test (TST) and the forced swimming test (FST). In both tests, RS-induced immobilized behaviors were significantly reversed in MG and fluoxetine administered groups. Taken together, MG significantly attenuated the RS-induced BDW loss, hypoglycemia, and depressed behaviors. Considering that decreased BDG levels (hypoglycemia) can cause depression, MG may exert its anti-depressant like effect by preventing hypoglycemia. Our results suggest that MG isolated from A. barbinerve can exert anti-depressant like effect, and could be used as a new and natural anti-depressant therapy.

• Journal of Environmental Science International
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• v.20 no.12
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• pp.1599-1605
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• 2011

To evaluate heat environment surrounding plants diurnal change of leaf temperature in the broad-leaved deciduous and evergreen trees was measured with microclimatic environmental factors including global solar radiation, and upward and downward long wave radiation. Maximum daily solar radiation was 961.2 and 976.3 w/$m^2$ in August 9 and 23, respectively. Upward long wave radiation was slightly higher than downward long wave radiation, showing 404.2 w/$m^2$ in August 9 and 394.5 w/$m^2$ in August 23. In addition, daily maximum vapor pressure deficit was 5.42 and 6.84 kPa in August 9 and 23, respectively, indicating high evaporative demand. Quercus glauca and Acer mono was differently responded to changing light regimes. On August 9, leaf temperature at the top-positioned leaves of Acer plants was higher than air temperature as well as those of Quercus plants in the morning. This indicates that stomata in Acer plants were closed by heat stress or water stress in the morning, while Quercus plant maintained active transpiration by opening stomata. These results indicated that improved light regimes such as gap opening in the closed forest may not always affect positively in the physiology of understory plants.

• Archives of Pharmacal Research
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• v.29 no.12
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• pp.1086-1090
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• 2006

The chromatographic separation of the MeOH extract from the twigs of Acer tegmentosum led to the isolation of ten phenolic compounds. The structures of these compounds were determined using spectroscopic methods as 3,7,3',4'-tetramethyl-quercetin (1), 5,3'-dihydroxy-3,7,4'-trimethoxy flavone (2), 2,6-dimethoxy-p-hydroquinone (3), (-)-catechin (4), morin-3-O-${\alpha}$-L-lyxoside (5), p-hydroxy phenylethyl-O-${\beta}$-D-glucopyranoside (6), 3,5-dimethoxy-4-hydroxy phenyl-1-O-${\beta}$-D-glucoside (7), fraxin (8), 3,5-dimethoxy-benzyl alcohol 4-O-${\beta}$-D-glucopyranoside (9) and 4-(2,3-dihydroxy propyl)-2,6-dimethoxy phenyl ${\beta}$-D-glucopyranoside (10). The compounds were examined for their cytotoxic activity against five cancer cell lines. Compound 3 exhibited good cytotoxic activity against five human cancer cell lines with $ED_{50}$ values ranging from $1.32\;to\;3.85\;{\mu}M$.