• Journal of computational fluids engineering
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• v.15 no.4
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• pp.85-91
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• 2010

In this study, aerodynamic analyses based on unsteady computational fluid dynamics (CFD) have been conducted for a 2-bladed vertical-axis wind turbine (VAWT) configuration. Reynolds-averaged Navier-Stokes equations with standard $k-{\varepsilon}$ and SST $k-{\varepsilon}$ turbulence models are solved for unsteady flow problems. The experiment model of 2-bladed VAWT has been designed and tested in this study. Aerodynamic experiment of the present VAWT model are effectively conducted using the vehicle mounted testing system. The comparison result between the experiment and the computational fluid dynamics (CFD) analysis are presented in order to verify the accuracy of CFD modeling with different turbulent models.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.2
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• pp.105-108
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• 1979

Compared with ordinary varieties, the cold resistant lines were heavy in fresh weight of seedling, low in stalk elongation. Their leaf-types were complete runner types, and they were high in wintering rate, and were abundant in the branch number and in pod numbers per branch. They were high in the seed yield.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.28B no.5
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• pp.421-430
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• 1991

This paper investigated the errect of the right-half-plane zero on stability in the buck-boost DC-DC converter which is one type of the switching regulator and the stability region for the variation of the output current is obtained by evaluating the feedback gain. And it is clarified that the damping ratio decreases gradually by increase of the feedback loop gain and the regulation system of the converter becomes unstable, and from the transient response analysis we obtainedthe stability region about this converter. From above result it is known that the stability decreases by the existence of the right-half-plane zero. For the improvement of stability, we carried out one pole compensation in feedback circuit and obtained the avaliable stability region in relation to the gain bandwidth product from the stability and transient response analysis. These results were established experiment.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2005.11a
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• pp.62-62
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• 2005

• Proceedings of the Plant Resources Society of Korea Conference
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• 2005.11a
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• pp.63-63
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• 2005

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.1
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• pp.95-106
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• 1992

For commercial application of the MCFC, the life time of the MCFC should exceed 40,000 hours, But the life time of the state-of-the-art MCFC was limited to 15,000 hours. The main reasons of the life time limit can be classified as the deficiency of the electrolyte and cathode dissolution. It has been found that the electrolyte deficiency is caused by the continuous evaporation of the electrolyte. However a recent reaserch shows that an electrolyte pumping phenomenon, which implies, the migration of the electrolyte through the gasket material of the external gas manifold, is also the reason of the electrolyte deficiency. Due to the electrolyte pumping phenomenon, positive end cell of the stack suffers the electrolyte deficiency and negative end cell of stack is flooded with electrolyte. Therefore, the cell performance is degraded. The author invented a new manifoldcasing, which prevents the contact between the wet seal and the gasket of the manifold, and gives a complete elimination of an electrolyte pumping effect.

• Korean Journal of Plant Taxonomy
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• v.34 no.3
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• pp.265-271
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• 2004

A new species of Corydalis sect. Corydalis (Fumariaceae), C. namdoensis B.U. Oh et J.G. Kim, is described from the central and southern part of Korea. The new species is distinct from its close relative C. albipetala in having very variable leaf shapes, broadly flattened fusiform fruits, seed arrangement nearly in two rows in capsule, V-shaped inner petal apex and limited distribution area.

• Korean Journal of Breeding Science
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• v.41 no.1
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• pp.16-24
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• 2009

Although leaf characters are important in soybean [Glycin max (L.) Merr.] breeding and development of cultural methods, very little information has been reported. The objectives of this study were to evaluate and analyze the relationships among leaf characters and suggest possible classification criteria for cultivating and wild (Glycin soja Sieb. & Zucc.) soybeans. Total of 94 cultivating and 91 wild soybean accessions from the Soybean Germplasm Laboratory of Chungbuk National University were used for this study. Central leaflet of the second leaf from the top of the plant was selected to measure leaf characters. Average leaf length, leaf width, leaf area, leaf shape index (LSI) of cultivating and wild soybeans were 12.3$\pm$1.25 cm and 6.6$\pm$1.35 cm, 6.8$\pm$1.241 cm and 2.9$\pm$0.92 cm, 55.6$\pm$15.75 $cm^2$ and 14.3$\pm$7.83 $cm^2$, and 1.9$\pm$0.38 and 2.4$\pm$0.53, respectively. Based on LSI, three categories of leaf shape, i.e., oval, ovate and lanceolate, were defined as LIS$\leq$2.0, LSI 2.1~3.0 and 3.1$\leq$LSI, respectively. Percentage of oval, ovate and lanceolate leaf types among cultivating and wild soybean accessions were 78.7%, 17.0% and 4.3 %, and 40%, 15.4% and 4.4%, respectively. Based on leaf length, three categories for cultivating, i.e. short leaf ($\leq$11.0 cm), intermediate (11.1~13.0 cm), and long (13.1 cm$\leq$), and four categories, i.e. short ($\leq$5.0 cm), intermediate (5.1~7.0 cm), long (7.0~9.0 cm), and very long (9.1 cm$\leq$) for wild soybeans were defined. Short, intermediate and long leaf types were about 1/3, 1/2 and 1/6, respectively, in cultivating soybeans, and 15.4%, 40.7% and 39.5%, plus 4.4% of very long leaf type in wild soybean. Cultivating and wild soybeans had leaf thickness, leaf area ratio (LAR), angle and petiol length of 0.25$\pm$0.054 mm and 0.14$\pm$0.032 mm, 40.1$\pm$8.22 and 53.7$\pm$12.02, $37.6{\pm}5.89^{\circ}$ and $54.6{\pm}10.77^{\circ}$, and 23.9$\pm$5.89 cm and 5.9$\pm$2.33 cm, respectively. There were highly significant positive correlations between leaf length and leaf width, and negative correlation between LSI and leaf width both in cultivating and wild soybeans. Although leaf area showed significant correlations with leaf length, leaf width and LIS in cultivating soybeans, wild soybeans showed no significant relationships among these characters. In general, soybeans with oval, ovate and lanceolate leaves were significantly different in leaf width and thickness. Cultivating soybean with oval leaf had greater leaf area, while wild soybeans with oval or ovate leaf had longer petiol than with lanceolate leaf.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.449-455
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• 2010

'Moulinrouge' was selected as the best regenerating cultivar among 18 different spray-type chrysanthemum cultivars bred in the Gyeongnam Flowers Breeding Research Institute. When the leaf explants from standard- and spray-type chrysanthemum 'Jinba' and 'Moulinrouge' were incubated on MS basal medium supplemented with $0.5mg{\cdot}L^{-1}$ BA and $1.0mg{\cdot}L^{-1}$ NAA, both 'Jinba' and 'Moulinrouge' induced adventitious shoots that can be regenerated into plantlets. Based on these regeneration conditions, we developed an efficient $Agrobacterium$-mediated chrysanthemum 'Moulinrouge' transformation method by using sequential selection of shoots from low ($10mg{\cdot}L^{-1}$) to high ($30mg{\cdot}L^{-1}$) concentrations of kanamycin after co-cultivation of leaf explants with $Agrobacterium$ for 10 days and induction of shoots. All kanamycin resistant plants investigated with genomic PCR analysis carried the report gene, $AtSICKLE$, in their genome. Although expression levels of the report gene in the transgenic plants investigated with RT-PCR were relatively low because of inefficiency of CaMV 35S promoter in chrysanthemum, transgenic lines expressing $AtSICKLE$ efficiently showed leaf epinasty phenotype. We expect that our results will provide a useful method that can perform a high-throughput investigation of genes isolated and studied well in model plants for molecular breeding of chrysanthemum.

• Korean Journal of Plant Resources
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• v.20 no.1
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• pp.7-11
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• 2007

This study was conducted by estimate of leaf characteristics and growth performance among selected 20 families progenies of Hovenia dulcis var. koreana Nakai. Mean seedling height and root-collar diameter in whole progenies showed 61.6cm, 6.98mm, respectively. Mean seedling height of KW 2-5 family was 79.3cm and it was higher than that of other families. JN 2-2 family had highest value, 9.16mm, in mean of root-collar diameter. Growth performances of KW 2-5 and JN 2-2 families showed 57% (in seedling height), 53% (in root-collar diameter) superior to those of lowest marked families. The selection level based on growth performances, which are seedling height over 75.0cm and root-collar diameter over 8.0mm, were applied on whole families, and two families selected (KW 2-5, JN 2-2). The selection effects from selected families was evaluated as 125% compared to the mean of whole families. The coefficient of variation (C.V) appeared wide range, $9.4{\sim}42.4%$, in estimated leaf characteristics. Particularly, C.V of petiole length (PL) and petiole diameter (PD) showed 42.4% and 28.7%, respectively. Their were higher value than other leaf characteristics. Analysis of variance for all leaf characteristics were significantly different among families. Also, there had positive correlation between most leaf characteristics except the correlation between leaf length (LL) and leaf morphological index (LMI, LW/LL). Particularly, the correlation between leaf length and leaf width (LW) showed the highest correlation.