• Structural Engineering and Mechanics
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• v.54 no.1
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• pp.189-198
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• 2015

We present a torsion analysis of single-bent leaf flexure that is partially restrained, subject to a torsional load. The theoretical equations for the torsional angle are derived using Castigliano's theorem. These equations consider the partially restrained warping, and are verified using finite element analysis (FEA). A sensitivity analysis over the length, width, and thickness is performed and verified via FEA. The results show that the errors between the theory result and the FEA result are lower than 6%. This indicates that the proposed theoretical torsional analysis with partially restrained warping is sufficiently accurate.

• Journal of the Korean Society of Tobacco Science
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• v.3 no.2
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• pp.103-108
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• 1981

This experiment was carried out to investigate effects of soil moisture content on the growth of tobacco plant at early stage after transplanting. Soil moisture was controlled to be 30%, 45%, 60%, 75% and 90% of the maximum water holding capacity (38.7%), and treated for 10, 20 and 30 days. Budding flowering and topping were delayed in the 30% and 45% treatment where soil moisture was deficient. Plant height, number of leaves, and length and width of the largest leaf were the best in the 75% treatment for 10 days, and development of the root and top was the best also in the same treatment. As the duration of low soil moisture treatment prolonged, intercellular space , became small. Nitrogen and potassium of the cured leaf showed the highest value in 30% and 45% treatments. Nicotine content of the cured leaf was high in the 90% treatment, and reducing sugar content of that was high in the 75% treatment for 10 days.

• Horticultural Science & Technology
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• v.34 no.4
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• pp.596-606
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• 2016

The growth and contents of anthocyanins and ascorbic acid in lettuce(Lactuca sativa L., 'Jeokchima') as affected by supplemental UV-A LED irradiation under different light quality and photoperiod conditions were analyzed in this study. Five light qualities, namely B (blue LED), R (red LED), BUV (blue LED+UV-A LED), RUV (red LED+UV-A LED) and Control (white fluorescent lamps) with photoperiods of 12/12 hours (day/night), 16/8 hours, or 20/4 hours were provided to investigate the effects of light quality and photoperiod on the growth and accumulation of anthocyanins and ascorbic acid in lettuce leaves. As measured 28 days after transplanting, the number of leaves, leaf length, leaf width, leaf area, shoot fresh weight and dry weight of lettuce were significantly affected by light quality and photoperiod. The number of leaves, leaf length, leaf width, leaf area, shoot fresh weight and dry weight of lettuce grown under R treatment increased with increasing light period. By contrast, leaf development was inhibited, but chlorophyll content increased, under B treatment. Supplemental UV-A irradiation significantly decreased leaf length, leaf width, leaf area and shoot fresh weight. Anthocyanins in lettuce increased significantly with decreasing dark period under B treatment. A synergistic effect of supplemental UV-A LED irradiation on anthocyanins accumulation was found for lettuce leaves grown under R treatment but not B treatment. Ascorbic acid in lettuce was greatly affected by photoperiod. Ascorbic acid content at BUV and RUV treatments increased by 20-30% compared to without UV-A LED irradiation. From these results, it was concluded that growth and contents of anthocyanins and ascorbic acid in lettuce are significantly affected by supplemental UV-A LED irradiation. The results obtained in this study will be informative for efforts to improve the nutritional value of leafy vegetables grown in plant factories.

• Journal of Korean Society of Forest Science
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• v.53 no.1
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• pp.37-43
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• 1981

This study was aimed at expanding the tea plant culture in Korea to further north, and the leaf-form and the cold resistance of the tea plants selected form 7 districts(around Korea) were investigated. 1. The length of tea leaf is 5.1cm to 8.4cm, the width of the leaf is 2.3cm to 3.6cm, but the area of tea leaf in Mt. Mudung is $26.88cm^2$ and that is the widest of all. 2. The tooth number of the tea leaf in 43 to 73 but the number of Mt. Borim is remarkably number of all. The tooth number is increased or decreased in proportion to the leaf width and to the leaf length. 3. The lateral vein number is generally 13 to 19. The vein number of Mt. Borim is especially number of all. That is also increased or decreased in proportion to the leaf width and to the leaf length. 4. In general, the number of leaf formation index is 2 to 3, and ablong. 5. In general, those which come upper lands are remarkably small in length and width of the tea leaf and those which come from level lands are large. 6. All kinds of tea plant which is growing in Korea, area, are the same as those imported from China : Thea sinensis Linne var. Bohea. 7. I supposed that the external form of tea plant has a little changed by geography or climate for many a long day, since the tea plant had been transplanted in Mt. Samsin. 8. In the treatment of low temperature and duration of vernalization of their plants, those selected from Mt. Mudung and Mt. Hwaun were the coldest resistance, those from Mt. Samsin and Mt. Borim were medium and those from Mt. Joge and Nursery were cold sensitive. 9. The critical temperature of the tea plant from Mt. Mudung, Mt, Hwaum, Mt, Samsin and Mt. Borim was about $-10^{\circ}C$, and that from Mt. Joga and Nursery was about $-5^{\circ}C$. The critical temperature of frost injury of all tea plants in this experiments was $-15^{\circ}C$. 10. In spite of increasing the vernalization time, the critical temperature was not effected, but the treatments over critical temperature were increased their frost injuries. Based on these results, the coldest resistance, Mt. Mudung tea plant, was considered expanding their culture to further north improvement yields of the tea plants in Korea.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2004.10a
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• pp.56-56
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• 2004

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.88-96
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• 2010

Zoysiagrass, especially Jungji implicating medium-leaf type zoysiagrass has been widely used in South Korea recently. This study was carried out to classify 36 selected medium-leaf type zoysiagrass accessions compared to 5 basic zoysiagrass species using RAPDs. Morphological characteristics such as leaf width, leaf angle, leaf sheath length, existance of trichomes and stolon color were measured as useful characteristics for identification of species in Zoysia genus. Nineteen RAPD markers were identified using 8 selected random primers. The dissimilarity coefficient of variants ranged from 0 to 0.736. Three zoysiagrass groups were clustered by dissimilarity coefficient analysis. Group 1 consisted of Z. japonica and some US varieties including 'Zenith' and 'Meyer'. Group 2 consisted of Z. sinica, Z. macrostachya and Korean commercial varieties such as 'Anyang', 'Samdeock', and 'Pyeongdong' medium-leaf type grasses. Group 3 was genetically distinct from Group 1 and Group 2, and included Z. matrella and Z. tenuifolia. 'Anyang', 'Samdeock', and 'Pyeongdong' medium-leaf type zoysiagrasses showed very close genetic relationship with Z. sinica and Z. macrostachya.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.6 s.107
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• pp.109-116
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• 2005

This study was conducted to examine the growth and physiological characteristics of Asplenium scolopendrium native fern as affected by irrigation times and soil media as an environment modeled on habitate where was sunken-condition. 1. Light intensity was lower in sunken than in non-sunken, but air humidity was higher in sunken about $2040\%$. Soil moisture content was higher with the leaf mold in sunken irrigating 2 times/week. The results of chemical analysis of medium showed that EC, pH, organic matter content, total nitrogen, CEC, Exch-Ca, Exch-Mg and Exch-K were higher with leaf mold than sud: leafmold and field soil: sud: leaf mold. 2. In the case of irrigation 2 times/week Asplenium scolopendrium grew well sunken more than non-sunken. As non-sunken condition similar with, 7 times/week irrigation, plant height, frond width, frond length and stipe length increased. In case of soil media, growth of Asplenium scolopendrium was better with leaf mold than that of sand: leafmold or field soil: sand: leaf mold. 3. In the case of irrigation 2 times/week photosynthetic rate, $CO_2$ absorption rate and water efficiency were higher with non-sunken than that of sunken, expect of stomatal conduction, $CO_2$ use efficiency. The physiological characteristics of Asplenium scolopendrium were highest in non-sunken irrigating 7 times/week In case of soil media, physiological activity was higher with leaf mold than sand: leafmold or field soil: sand: leaf mold.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.499-504
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• 2005

This experiment was conducted to identify the effect of several plant growth retardants on growth of Sedirea japonica seedlings cultured in vitro and their changes of invertase activities. When seedlings of Sedirea japonica were treated with ancymidol and paclobutrazol, as the concentrations were increased, leaf length was gradually shortened and leaf width became wider than that of control. On the other hand, root length was shorter, but the number of root and the root's diameters were greatly increased, compared with control. In 0.05mg/L uniconazole, growth of leaf and root were enhanced, compared with the control and higher concentrations of uniconazole. As concentration of each growth retardants was increased, leaf shape became round and smaller. Both soluble acid invertase activity and soluble alkaline invertase activity in leaf were decreased in higher concentrations of each growth retardant, but those of the root were contrary to those of the leaf. To confirm the estimated invertase activities, starch content of leaf was higher in low concentration treatments in each growth retardant, but in the root was contrary to content that of the leaf.

• Journal of Environmental Science International
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• v.11 no.10
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• pp.1001-1009
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• 2002

Vegetative characters (e.g. habitat, root, ramification and habit of stem, phyllotaxy, leaf sape, shape of leaf margin, shape of division and lobe of division, number of division, thick and texture of leaf and shape of stipule) on 35 species of Asian Geranium were reviewed to discussion propriety of taxonomic character and evolutionary trends. Wilfordii group is characterized by three divided leaf, Farreri group was grown a high altitude, and Maculatum group is grouped by life cycle of anneal. Arrangement state of leaf is alternate type G, tripartitum, G. eriostemon, and G. erianthum is thought the more primitive than the other taxon, and regarded as more advanced group the sibiricum group and pseudosibiricum group which divided of leaf deeply. Shape of leaf, division degree of lobes, shape of leaf margin and number of division are considered a good identification characters because width of change are fixed between population.

• Journal of the Korean Society of Tobacco Science
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• v.4 no.2
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• pp.23-30
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• 1982

Six flue- cured cultivars of Nicotiana tabacum L., 15 possible $F_1$ hybrids and $F_2$ Populations among them, and 15 haploid Populations from Fl hybrids and haploids from Parents, were evaluated. Comparisons of the $F_1$, hybrids and $F_2$ Populations with the Parents indicated that heterosis values were small but significant for yield, plant height, days to flower, leaf length and width and total alkaloids from-6.0% to 5.4% in $F_1$ hybrids, and from -3.4% to 3.6% for Plant height days to flower leaves per plant in $F_2$ populations, respectively. There were positive correlations for yield, plant height, days to flower, leaves per plant and total alkaloids between diploid and haploid populations. Increase or decrease ratio of haploids to diploids of total alkaloids was appeared to 30.3%. Those for yield, leaf length and width, value arid reducing sugar were ranged from -4.1% to -27.6%.