• Structural Engineering and Mechanics
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• v.59 no.3
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• pp.527-537
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• 2016

We describe a stress analysis of a single leaf flexure under torsion in which the warping effect is considered. The theoretical equations for the warping normal stress (${\sigma}_{xx}$) and shear stresses (${\tau}_{xz}$ and ${\tau}_{xy}$) are derived by applying the warping function of a rectangular cross-sectional beam and the twist angle equation that includes the warping torsion. The results are compared with those of the non-warping case 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 of warping stress results and the FEA results are lower than 4%. This indicates that the proposed theoretical stress analysis with warping is accurate in the torsion analysis of a single leaf flexure.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.4
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• pp.332-336
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• 1981

Seven soybean varieties and 21 F 2 hybrids of a diallel cross among these varieties were used as the materials, and genetic studies were conducted to evaluate the frequency and distribution of genes governing the characters of soybean leaf shapes. Partial dominance was exhibited by petiole length of trifoliates, petiole length of terminal leaflets, length of terminal leaflets, length of lateral leaflets, width of terminal leaflets Mean values of length of terminal leaflet were higher than those of lateral leaflets and length of leaflets were higher than width of leaflets, but mean values of width of terminal leaflets were shorter than those of lateral leaflets.

• Korean Journal of Plant Resources
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• v.36 no.3
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• pp.225-236
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• 2023

Stomatal traits such as stomata density (SD), aperture length (APL) and width (APW), guard cell length (GCL) and width (GCW), and distance between stomata (DIS) were investigated to identify correlation with agronomic traits for 35 Korean wheat cultivars. Flag leaf width (FLW) of Korean wheat cultivars was the widest in Ol-mil, and the narrowest in Keumkang. SD tended to be higher on the adaxial side than on the abaxial side in Korean wheat cultivars. SD of adaxial and abaxial sides was classified into a cultivar with a significantly different or not. In APL, 18 wheat cultivars showed significant differences according to leaf side, and APL of adaxial was longer than APL of abaxial in 13 wheat cultivars. In APW, 15 wheat cultivars showed a significant difference, and APW of abaxial was wider than APW of adaxial among them. In GCL, 14 wheat cultivars showed a significant difference, and the GCL of abaxial was longer than the GCL of adaxial in 10 wheat cultivars. In GCW, 10 wheat cultivars showed a significant difference, GCW of adaxial was wider than GCW of abaxial and in 6 wheat cultivars. FLW of adaxial and abaxial showed a negative correlation with GCL and a positive correlation with grain number per panicle. FLW of only abaxial showed a positive correlation with DIS. The SD of the adaxial showed a negative correlation with GCL, while the SD of the abaxial showed a negative correlation with APL. APL of both sides of the leaf showed a positive correlation with GCL, and APW of only abaxial showed a negative correlation with GLC. DIS of adaxial showed a negative correlation with tiller number (TN), while DIS of abaxial showed a positive correlation with GNP.

• Journal of the Korean Society of Tobacco Science
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• v.26 no.1
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• pp.7-12
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• 2004

Effect of Decyl Alcohol Emulsifiable Concentrate on sucker control and phytotoxicity to tobacco plants were tested on flue-cured tobacco and burley tobacco. There were no significant differences of sucker inhibition effect between Decyl Alcohol EC and Choline Salt of Maleic Hydrazide Soluble Concentrate(control chemical). Tobacco plants applied with Decyl Alcohol EC showed no visible symptoms of phytotoxicity and no significant differences of number of leaves, leaf length, leaf width, and stalkt height. Yields increased considerably with no difference from ones of plants treated with control chemical.

• Asian Journal of Turfgrass Science
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• v.26 no.1
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• pp.1-7
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• 2012

Field experiments were conducted to evaluate the morphological characteristics and growth rates of 101 medium-leaf type zoysiagrasses (Zoysia spp.) collected at the major sod production area (Jang Seong Gun) in South Korea. Collected lines with distinctive morphology and visual growth rate were planted in plastic pots and measured morphological characteristics under the plastic house conditions. Variation of leaf width, plant height, leaf angle, length of leaf sheath, trichome, stolon length, and color were measured. Six lines were selected by evaluating growth rates from one hundred one collected lines. Eight standard cultivars and three other superior lines previously collected were compared to 7 selected lines form Jang seong area by checking growth rates and morphological characteristics. Average leaf blade width was 3.4 mm, leaf angle was 45.8 degree, plant height was 21.6 cm, height of lowest leaf was 5.0 cm, and length of leaf blade was 14.1 cm. Ground cover rates of selected lines 'CY6097' and 'CY6069' were 70% and 68.3%, respectively. These are believed to be faster than 60% ground cover rate of zoysiagrass 'Anyang', and also, twice as faster than the 31.7% ground cover rate of Z. matrella. Selected line 'CY6069' showed fast growth rate with shorter internode length (5.1 cm) compared to zoysiagrass 'Anyang'. Based on the results of this study, we could select useful fast growing zoysiagrass breeding lines from the major sod production area (Jang Seong Gun) in Korea.

• Korean Journal of Plant Resources
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• v.32 no.1
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• pp.29-37
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• 2019

This study was conducted to provide a basic data such as leaf morphological characteristics, total 110 individual trees selected from 11 wild population, for selective breeding. As a result of investigation of the twenty morphological characteristics of the leaf, there were statistically significant differences in all leaf characteristics among the populations. Especially, Mt. Mani population had larger leaf length (LL), width (LW) and area (LAR) than other populations. On the other hand, Mt. Beakwoon and Mt. Duryun had smaller leaf size (LL, LW and LAR) among the populations. Its principal component analysis (PCA) results showed that it represented 72.9% accumulated explanation from three principal component. The characteristics such as leaf area, leaf length and leaf width were highly contributed for classification among populations. According to the cluster analysis, the natural S. alnifolia populations were classified into five groups and Mt. Mani population was different from the other population.

• Korean Journal of Plant Resources
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• v.7 no.2
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• pp.109-114
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• 1994

Followings are resulted through the analysis of the maln characters and the leaf ingredients, which is on the purpose of getting the basic materials to improve jaso and increase its production.Of the introduced varieties, Jukyeubjaso-stem length is 180cm, ear length is 37cm, No. of branches ofstem is 27, leaf length Is 16cm, leaf width Is 15cm-has better character than any other. Gurye local-stem length is 179cm, ear length is 38cm-is taken to be the best in the Geo-ecotypic.In the yield of leaf and seed, JukyeubJaso Is 727kg/10a, the greatest of all. In the leaf softness, allthe Inirorluced varieties are about 3.5 degrees, the Geo-ecotypic, about 2. The qualify of the introducedvat'ieties is better· than that of the Geo-ecotypic. Estimating on the chemical analysis of leaf,Jukyeubjaso has Protein 21.84%, Total carbohydrate 7.91%, Fe 126ppm, and Gurye lacal has Protein21.7 a, Total carbohydrate 8.4%, Fe 148ppm, expressing the highest. In correlation coefficients of leafchemical components, between protein and Total carbohydrate, Protein and Mn, protein and Fe, Pro-tein and Cu all the sorts show the positive correlation. Among them the Geo-ccoyplcs show the hlghestsignificance.

• Korean Journal of Environmental Biology
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• v.20 no.1
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• pp.66-72
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• 2002

The intraspecific variability, habitats, and morphological characteristics of eelgrass (Zostera marina L.) along the eastern coast of Korea were examined during June to August 1998. Morphological characteristics including shoot height, leaf length, leaf width, number of leaf veins, and shape of leaf apex were measured, and eelgrass habitats were analyzed using character correlation, principal components and cluster analyses. The morphological characteristics varied with the habitat types and water depth. Eelgrass beds distributed mostly in lagoons, ports and bays along the east coast of the Korean peninsula. The quantitative morphological features that enabled recognition of the two phonetic groups were short- narrow and long-broad leaf types. Leaf apex in particular varied with the habitat characteristics.

• Composites Research
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• v.17 no.2
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• pp.1-8
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• 2004

The present paper is concerned with the optimum design of taper spring, in which the static spring rate of the fiber-reinforcement composite material spring is fitted to that of the steel leaf spring. The thickness and width of springs were selected as design variables. The object functions of the regression model were obtained through the analysis with a common analytic program. After regression coefficients were calculated to get functions of the regression model, optimal solutions were calculated with DOT. E-glass/epoxy and carbon/epoxy were used as fiber reinforcement materials in the design, which were compared and analyzed with the steel leaf spring. The result of the static spring rates show that optimized composite leaf springs agree with steel leaf spring within 1%.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.6
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• pp.104-111
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• 2008

Plant growth and variegated leaf color changes of three leaf variegated Sedum spectabile varieties 'Variegatum', 'Frosty Morn', red colored 'Washfield Ruby', and one Sedum lineare variety 'Variegatum' and Sedum sarmentosum under three levels of shading conditions were examined for leaf ornamental value improvement. Shading levels were 40%($1,500{\mu}mol{\cdot}m-^2{\cdot}s-^1$), 70%($750{\mu}mol{\cdot}m-^2{\cdot}s-^1$) and 85%($375{\mu}mol{\cdot}m-^2{\cdot}s-^1$). Improvements of leaf ornamental value of 'Variegatum' 'Frosty Morn' and 'Washfield Ruby' were observed at 40% shading level and plant heights and leaf sizes were also increased. Plant height of S.sarmentosum were shorten under direct sun light condition and leaf color changed to greenish yellow(RHS143B) but deep green color(RHS144A) was observed under shading conditions. Endurance of S.sarmentosum was stronger than other species and leaf ornamental values remained well at 70% shading level. Leaf width of S.lineare 'Variegatum' were not changed under shading conditions but leaf length was increased. Leaf color was Deep green color was greenish yellow under direct sun light but deepest green color was observed at 85% shading level. Consider all ornamental value criteria, best shading conditions for S.lineare 'Variegatum' were ranged 40% to 70%.