• Korean Journal of Materials Research
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• v.9 no.12
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• pp.1245-1251
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• 1999

Phase-change optical disk very rapid recording, high densification of data, resulting in high feedback rate and good C/N(carrier to noise) ratio of a feedback signal. However, repetitive thermal energy may cause the deformation of a disk or the lowering of an eliminability and a cyclability of the recording. The lowering of the cyclability can be reduced by insertion of thin layer of ZnS-$SiO_2$ dielectric thin film in appropriate disk structure between the upper and lower part of the recording film. Using the Taguchi method, optimum conditions satisfying both the optimized quality characteristic values and the scattering values for film formation were found to be the target R.F. power of 200W, the substrate R.F. power of 20W, the Ar pressure of 6mTorr, and the electrode distance of 6cm. From the refractive index data, the existence of the strong interaction between the electrode distance and Ar pressure was confirmed, and so was the large effect of the electrode distance on transmittance. According to the analysis of TEM and XRD, the closer the electrode distance was, the finer was the grain size due to the high deposition rate. However, the closer electrode distance brought the negative effect on the morphology of the film and caused the reduction of transmittance. AFM and SEM analyses showed that the closer the electrode distance was, the worse was the morphology due to the high rate of the deposition. Under optimum condition, the deposited thin film showed a good morphology and dense microstructure with less defects.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.789-795
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• 2015

The new garden chrysanthemum (Dendranthema grandiflorum Ramat.) cultivar 'Nuri Ball' was developed at Yesan Chrysanthemum Experiment Station of Chungcheongnam-do Agricultural Research and Extension Services in 2011. 'Nuri Ball' was bred through a cross between the '02-145-01' line as the female parent with yellow flower color and '02-04-32' as the male plant with white flower color in 2004. Three years of adaptation trials were conducted from 2006 to 2009 under natural conditions. This study compared the external shape type with that of 'White Miri' and conducted ploidy and RAPD (Random amplified polymorphic DNA) marker analyses. These tests showed that 'Nuri Ball' cultivar has its own characteristics compared with the control 'White Miri'. 'Nuri Ball' was a shrub type variety with semi-double flowers of 4.0 cm in width with white petals. It could produce 1025.2 flowers per plant in autumn. Compared with the control 'White Miri', 'Nuri Ball' was similar in terms of shape and color of flowers, but was different in flower size and number. The natural flowering time of 'Nuri Ball' was late September. It had very vigorous growth and an early budding plant. 'Nuri Ball' was demonstrated to be a new cultivar based on ploidy test and RAPD analysis. 'Nuri Ball' is intended for use as a bed chrysanthemum and expected to contribute to farm incomes in landscaping.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2396-2401
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• 2009

This study is on development of UV-cured hard coating compounds which have more improved abrasion resistance than existing UV-cured urethane-acrylic resin, to prevent a surface of a widely used PVC tile as a constructive material from being scratched. To make a high abrasion resistant hard coating solution compared to UV-cured urethane-acrylic resin which has no abrasion resistance and been used for PVC tiles, we added powder substances of different abrasion resistant level, $Al_2O_3$(Al-160SG-3), $Al(OH)_3$(SH-8W), $SiO_2$(KS-5000), etc., to the resin, changing their contents from 10% to 30% against quantities of resin, and compounded it using Ring-Mill. After coating PVC tiles with the hard coating solution using bar-coating method that can adjust a thickness, we estimated some surface properties-abrasion resistance, pencil hardness, adhesive power, thickness of coating, and so on. As a result, a hard coating solution added 30% $Al_2O_3$ powder to the resin had the finest surface properties-the first grade in abrasion resistance, H in pencil hardness, 100% in adhesive power, and a hard coating solution which showed excellent solidity and abrasion resistance has smaller particle size, higher powder content, and thicker coating thickness.

• Journal of Yeungnam Medical Science
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• v.12 no.1
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• pp.1-9
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• 1995

A monoclonal antibody to PCNA, which can be used on routinely processed tissue, was applied to 25 cases of gastric adenomas and 64 cases of gastric adenocarcinomas in order to diffentiate adenoma and adenocarcinoma and also to evaluate the prognostic value in adenocarcinoma. The results were summerized as follows: The peNA labelling index was $29.14{\pm}12.77%$ in control, $44.09{\pm}17.11%$ in adenoma and $80.15{\pm}10.69$ in adenocarcinoma, resulting in significant increase in adenocarcinoma compared to adenoma. In adenocarcinoma, no significant correlation was observed between PCNA labelling index and histologic grade, and there was increased tendency of PCNA labelling index in proportion to depth of invasion without statistical significance. The PCNA index was significantly increased in advanced adenocarcinoma compared to early gastric carcinoma, and also in positive nodal metastasis group than in negative group. From above results, the PCNA stain will be able to provide a helpful method for the differential diagnosis between gastric adenoma and adenocarcinoma, and could be a useful prognostic factor in adenocarcinoma if other factors are considered together.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.3
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• pp.330-337
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• 2021

3D printing is not only at the fundamental study and small-scale level, but has recently been producing buildings that can be inhabited by people. Buildings require a lot of cost and labor to work on the form work, but if 3D printing is applied to the building, the construction industry is received attention from technologies using 3D printing as it can reduce the construction period and cost. 3D printing technology for buildings can be divided into structural and non-structural materials, of which 3D printing is applied to non-structural materials. Because 3D printing needs to be additive manufacturing, control such as curing speed and workability is needed. Since cement mortar has a large shrinkage due to evaporation of water, cement polymer dispersion is used to improve the hardening speed, workability, and adhesion strength. The addition of polymer dispersion to cement mortar improves the tensile strength and brittleness between the cement hydrate and the polymer film. Cement mortar using polymer materials can be additive manufacturing but it has limited height that can be additive manufacturing due to its high density. When light-weight materials are mixed with polymer cement mortar, the density of polymer cement mortar is lowered and the height of additive manufacturing, so it is essential to use light-weight materials. However, the use of EVA redispersible polymer powder and light-weight materials, additional damage such as cracks in cement mortar can occur at high temperatures such as fires. This study produced a test specimen incorporating light-weight materials and EVA redispersible polymer powder to produce exterior building materials using 3D printing, and examined flame resistance performance through water absorption rate, length change rate, and cone calorimeter test and non-flammable test. From the test result, the test specimen using silica sand and light-weight aggregate showed good flame resistance performance, and if the EVA redispersible polymer powder is applied below 5%, it shows good flame resistance performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.273-280
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• 2021

The purpose of this study was to identify groups depending on the four years of changing trajectories in self-efficacy and its relationship with life satisfaction and interpersonal competence of adults with disabilities who were aged above 25. The 1st to 4th year of the second wave from Panel Survey of Employment for the Disabled (PSED) was used to identify the groups and explore their relationship with life satisfaction and interpersonal competence through growth mixture modeling. The results identified three latent classes according to changing trajectories in self-efficacy: a 'high level-increasing group', an 'average level-increasing group', and a 'low level-stable group'. These three groups showed different characteristics in life satisfaction and interpersonal competence. For example, life satisfaction for groups decreased from the 'high level-increasing group' to the 'low level-stable group' and interpersonal competence increased in both 'high level-increasing group' and 'average level-increasing group', whereas it was stabilized in the 'low level-stable group'. These findings suggest that the life satisfaction and interpersonal competence of adults with disabilities are associated with their self-efficacy.

• Journal of Adhesion and Interface
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• v.24 no.1
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• pp.26-35
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• 2023

Generally, solvent-type coatings generate a large amount of volatile organic chemicals(VOC), which are carcinogenic substances, in the manufacturing process, and their use is regulated due to environmental problems. There is also the problem of resource depletion due to limited fossil fuels. Therefore, in this study, UV-curable urethane acrylate oligomers were synthesized with different contents of isosorbide, which is a biomass material, and proceeded to evaluate the physical properties of coatings. As the isosorbide contents increased, the viscosity, glass transition temperature, tensile strength, stain resistance, and pencil hardness increased, but elongation and flexibility decreased, and BOI-3 showed the best adhesion. The isosorbide content of the oligomer fixed at 20%, UV-curable urethane acrylate oligomer was synthesized according to the content ratio of polycaprolactone diol(PCL) and Ecoprol H1000(Ecoprol). As the PCL/Ecoprol content ratio increased, the glass transition temperature, elongation, and flexibility increased, but the tensile strength and pencil hardness decreased. It was confirmed that the adhesion and stain resistance increased by improving the surface bonding strength of PCL. All films of oligomers synthesized were transparent without discoloration.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.10a
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• pp.107-110
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• 1998

카네이션 품종은 200여종의 다양한 원종을 이용하여 품종을 만들었기 때문에 품종별 생리도 아주 다르며 양액재배를 했을 때는 더욱 다른 품종별 생육반응을 나타낸다. 그러므로 품종별 생육반응을 검토하기 위해 국내외에서 많이 재배되고 있는 품종, 화색과 화형을 달리한 품종과 원예연구소에서 육성한 품종 및 계통을 시험재료로 하여 순환식 양액재배를 실시하였다. (중략)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.475-476
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.839-840
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• 2013