• FLOWER RESEARCH JOURNAL
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• v.17 no.3
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• pp.147-151
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• 2009

The research was carried out a solution to prevent the breakage of stem resulted from stem cavity in the Dendranthema grandiflorum Ramat. 'Baekma'. Stem cavity occurred in the lower parts of stem for about 5 cm long as the stem grew to 20 cm, and the breakage increased to about 60 cm as the stem grew to 80 cm. Plant height, stem diameter, and flower stalk length were the highest in the planting density of $11cm{\times}11cm$. The light interception by plants increased as the planting density decreased (47, 99 and 143%). The strength and hardness values were the greatest, $567kg{\cdot}cm^{-2}$ and $1,339kg{\cdot}cm^{-2}$ in the planting density of $11cm{\times}11cm$. Plant height and plant weight increased in the foliage fertilization of one time, but the plants in the control flowered earlier. The strength and hardness increased in the foliage fertilization treatments and the greatest in the treatment of one time application of $60mg{\cdot}L^{-1}$ Silicate fertilization. The Si content of stems increased as the fertilization concentration and treatment time increased. The Si content in $30mg{\cdot}L^{-1}$ silicate treated twice was two times as high as that of the control.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.556-559
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• 2009

"Hongso" was originated from a cross between "Yoko" and "Hongro" in NIHHS, RDA, in 1989. "Hongso" was preliminarily selected in 2002 for its high fruit quality. After regional adaptability test at five sites from 2003 to 2006 as "Wonkyo Ga-30" it was finally selected in 2006. Optimum harvest time is early September which is similar to that of "Hongro". Fruit shape is globose conical and skin color is light red. Mean fruit weight is 295g and soluble solids content is 14.1oBrix. Fruits acidity is 0.34%, which is higher than that of "Hongro"(0.23%). It has a good taste for harmony of sugar and acidity. Storability is 3 weeks in room temperature. It is apt to russet on fruit skin. It is susceptible to Bitter rot. "Hongso" has a good cross compatibility with major cultivars such as "Fuji", "Hongro" and "Tsugaru". Tree habit is semi-spreading and tree vigor is weak. "Hongso" is high-density cultivation type cultivar, because it has a precocity, spur-type.

• Polymer(Korea)
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• v.38 no.1
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• pp.43-48
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• 2014

In this paper, we made a new polycationic polymeric liposome composed of low molecular weight polyethylenimine (PEI) and 10,12-pentacosadiynoic acid (PCDA). PCDA liposome was prepared by ultraviolet irradiation. PEI was further conjugated on the surface of the polymerized PCDA liposome using coupling reagents to make PCDA-PEI. The blue-to-red transition of PCDA liposome was observed during the coupling reaction. The size distribution of liposome and complexes with plasmid DNA was measured by dynamic light scattering (DLS). The complex formation was also identified by agarose gel electrophoresis and PicoGreen reagent assay. We confirmed the complex formation of the polymeric liposome with DNA and then performed transfection and cytotoxicity assay in HEK 293 and HeLa cells. As a result, PCDA-PEI showed significant gene transfection efficiency and low cytotoxicity. This study shows that PEI-conjugated PCDA liposome could be an efficient gene or drug delivery carrier.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.569-577
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• 2021

CFRP(Carbon Fiber Reinforced Plastic) can maintain the same strength even if the diameter is reduced by about one - third, and the weight is about one - twentieth of that of the deformed reinforcing bars that have been used in the construction industry. In particular, it is resistant to corrosion, which is the weakest part of reinf orcing bars, and there is no concern that it will deteriorate over time, It is light and durable, so transportation costs are low and it is convenient for high-rise buildings. This paper experimentally clarifies the adhesive properties of CFRP and clarifies its behavior. That is, bond strength test was conducted with the directness of CFRP and the strength of concrete as experimental variables, and the bond mechanism was clarified experimentally. Furthermore, based on the experimental results, we constructed the bond stress-slip-strain relationship of CFRP compared to the existing deformed reinforcing bars.

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.173-177
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• 2008

A new peanut variety "Pungsan" (Arachis hypogaea ssp. hypogaea L.) was developed at the Yeongnam Agricultural Research Institute, NICS, in Milyang in 2007. It was derived from a cross between a short stem cultivar "Satonoka" and a high-yielding local cultivar "Yecheon". "Pungsan" is the Virginia plant type. It has 18 branches per plant and 40 cm of main stem height. Each pod with long-ellipse shaped large kernel has two grains with light-brown testa and 100 seed weight was 95g in the regional yield trials (RYT). "Pungsan" showed more resistant to web blotch compared with check variety. In the regional yield trials "Pungsan" was outyielded in grain yield to the check variety by 16% with 4.45 MT/ha for grain.

• Korean Journal of Breeding Science
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• v.40 no.4
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• pp.461-465
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• 2008

"Green King" is a new mini kiwifruit variety developed at the National Institute of Subtropical Agriculture (NISA), RDA in 2005, which was an edible fruit without peeling. This variety was selected from seeds obtained from the cross breeding between Actinidia chinensis cv. "Apple Sensation" and A. arguta in 1998. Seedling and line selections were conducted from 1999 to 2002, and characteristic trials were carried out from 2003 to 2004. The branch of "Green King" sprouts strongly and the color of leaf is slightly dark green. The shape of fruit is cylindric and the color of peel is green or yellowish green without hair. The average weight of fruit is 15.9 g. The core is small and soft, the pericarp is light green. Soluble solids concentration is $15.4^{\circ}Brix$. The fruit is sweet with slightly acid taste, containing total acid 1.3%, and the yield is higher over twice than that of A. arguta. The content of vitamin C is higher than that of A. arguta. The harvesting time is from middle October. This variety can be planted in the central and southern region of Korea.

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.659-663
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• 2010

An Asiatic lily cultivar 'Yesol' was developed in 2005 at National Institute of Horticultural and Herbal Science (NIHHS), Rural Development Administration (RDA), Korea. The cross was made in 1992 between Asiatic lily 'White Bird', a white colored cultivar, and 'Connecticut King', yellow colored cultivar. Preliminarily selection was done as 'A94-11' in 1994. Multiplication and bulb formation, and characteristic tests were conducted from 1996 to 2004. The evaluation of this line was performed and named as 'Wongyo C1-27' in 2005 that was registered as 'Yesol' to the registration office of Korea Seed & Variety Service. 'Yesol' flowers at the end of June and grows average 32.4 cm. It flowers upward-facing, yellow (RHS, Y7D) with the size of flower 14.7 cm. The average petal length and width are 8.2 cm and 2.6 cm, respectively. Leaves are 4.8 cm long and 2 cm wide. The weight and size of bulb are 18.9 g and 11.8 cm, respectively. Year-round flowering can be obtained by storing the bulb under -1.5$^{\circ}C$ conditions.

• Journal of the Korean Geosynthetics Society
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• v.17 no.4
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• pp.29-40
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• 2018

Oil sands, which are largely distributed in Canada and Venezuela, are a mixture of crude oil and sandy soils. In order to extract crude oil from oil sands, construction of massive oil sand plants is required. Generally, the typically-used foundation types of the oil sand plant are driven piles and cast-in-place piles. Most of the oil sand plants are located in cold and remote regions. Installation of driven piles in frozen or organic surface soils is difficult due to high resistance and installation equipment accessability, while the cast-in-place pile has concrete curing problem due to cold temperature. Helical pile can be installed quickly and easily using rotation with a little help of vertical load. As the installation of helical pile is available using a small and light-weight installation equipment, accessibility of installation equipment is improved. The helical pile has an advantage of easy removal by rotation in reverse direction compared with that of installation. Furthermore, reuse of removed helical piles is possible when the piles are structurally safe. In this study, the behavior of helical piles varying helix pitch was analyzed based on the numerical analysis results. Numerical model was calibrated based on the results of model helical pile tests in laboratory. The ultimate helical pile loads, the displacement of each helix attached to the shaft of the helical pile, and the load sharing ratio of each helix were analyzed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.319-325
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• 2018

The use of 3D printing (Additive Manufacturing) technology has expanded from initial model production to the mass production of parts in the industrial field based on the continuous research and development of materials and process technology. As a representative polymer material for 3D printing, the polyamide-based material, which is one of the high-strength engineering plastics, is used mainly for manufacturing parts for automobiles because of its light weight and durability. In this study, the specimens were fabricated using Selective Laser Sintering, which has excellent mechanical properties, and the flexural characteristics were analyzed according to the temperature of the two types of polyamide 12 and glass bead reinforced PA12 materials. The test specimens were prepared in the directions of $0^{\circ}$, $45^{\circ}$, and $90^{\circ}$ based on the work platform, and then subjected to a flexural test in three test temperature environments of $-25^{\circ}C$, $25^{\circ}C$, and $60^{\circ}C$. As a result, PA12 had the maximum flexural strength in the direction of $90^{\circ}$ at $-25^{\circ}C$ and $0^{\circ}$ at $25^{\circ}C$ and $60^{\circ}C$. The glass bead-reinforced PA12 exhibited maximum flexural strength values at all test temperatures in the $0^{\circ}$ fabrication direction. The tendency of the flexural strength changes of the two materials was different due to the influence of the plane direction of the lamination layer depending on the type of stress generated in the bending test.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.3
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• pp.17-24
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• 2019

Carbon Fiber Reinforced Polymers(CFRP) has widely utilized as a material for rehabilitation because of its light-weight, deformability and workability. Because CFRP is brittle material whereas steel is ductile, it is inappropriate to apply conventional design approach for steel reinforcement. For ductile material, the behavior of combined elements is on average of that of unit element due to the stress redistribution between elements after yielding. Therefore, the mean value of the stress of combined elements is equal to that of unit element and the standard variation is smaller. Therefore, although the design value can increase, it is used as constant value because it is conservative and practical approach. However, for brittle material, the behavior of combined elements is governed by the weaker element because no stress redistribution is expected. Therefore, both the mean value and standard variation of the stress of combined elements decreases. For this reason, the design value would decrease as the number of element increases although it is eventually converged. In this paper, in brittle material, it is verified that the combination of unit element with normal distribution results in combined element with weibull distribution, so the modifying equation of mechanical properties is proposed with respect to the area load applied.