• Journal of the Korean Society for Precision Engineering
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• v.17 no.6
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• pp.143-152
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• 2000

The comer filling in shaped drawing process is an important characteristic, unlike the round drawing. It has also influence on the dimensional accuracy of the product. In this study, therefore, the shaped drawing process has been simulated by the three dimensional rigid-plastic finite element method in order to investigate the effect of process variables such as reduction in area and semi-die angle to the corner filling. The artificial neural network has also been introduced to reduce the number of simulations. To verify the results of simulations, experiments have been performed on the real industrial products. According to the results, the main process variable on the corner filling is the combination of semi-die angle in the irregular shaped drawing processes, but in the case of regular shaped drawing processes, reduction in area has great influence on the corner filling.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.3
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• pp.22-27
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• 2018

One problem of the Discrete Element Method is the assumption of a spherical particle shape, which reduces the computing time but significantly limits the application of the DEM to analysis. This limitation can be overcome by a recently developed rigid-rod model. However, the rigid-rod model has an essential problem related with friction: it always contains friction error because of the bumpy surface. To overcome this issue, we suggest a superposed rigid-rod model in this paper. The superposed rigid-rod model is notably consistent with the theoretical value in terms of the velocity and angular velocity after the collision. The estimated error is negligible(less than 2%). Then, the developed model is applied to hopper discharging. The developed model shows no problem in the discharging flow from the hopper.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.338.2-338.2
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• 2016

Al doped ZnO (AZO) thin films were deposited on Si substrates with rod-shaped-surface by pulsed laser deposition method (PLD). Si-rods were prepared through chemical etching. To analyze the influence on the formation of the rod structure, samples with various chemical etching conditions such as AgNO3/HF ratio, etching time, and solution temperature were prepared. The morphology of Si-rod structures were examined by FE-SEM. Fig. 1 shows a typical structure of n-AZO/p-Si-rod juncions. The fabricated n-AZO/p-Si-rod devices exhibited p-n diode current-voltage characteristics. We compared the I-V characteristics of n-AZO/p-Si-rod devices with the samples without Si-rod structure.

• Journal of Species Research
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• v.7 no.3
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• pp.222-230
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• 2018

Six bacterial strains 18JY42-3, 18SH, 18JY76-11, 17J11-11, 18JY14-14, and 18JY15-11 assigned to the phylum Proteobacteria, Firmicutes, and Actinobacteria were isolated from soil samples in Korea. The Cohnella species, strain 18JY42-3 was Gram-stain-positive, short rod-shaped and beige-colored. The Methylobacterium species, strains 18SH and 18JY76-11 were Gram-stain-negative, short rod-shaped and pink-colored. The Microterricola species, strain 17J11-11 was Gram-stain-positive, short rod-shaped and yellow-colored. The Paenarthrobacter species, strains 18JY14-14 and 18JY15-11 were Gram-stain-positive, short rod-shaped and white-colored. Phylogenetic analysis based on 16S rRNA gene sequence showed that strains 18JY42-3, 18SH, 18JY76-11, 17J11-11, 18JY14-14, and 18JY15-11 were most closely related Cohnella rhizosphaerae (MH497628; 98.8%), Methylobacterium goesingense (MH497632; 99.1%), Methylobacterium populi (MH497635; 99.9%), Microterricolagilva (MH504108; 98.4%), Paenarthrobacter nicotinovorans (MH497641; 100%), and Paenarthrobacter nitroguajacolicus (MH497646; 99.2%), respectively. All the six unrecorded strains showed resistance to UV radiation. This is the first report of these six species in Korea.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.10 no.1
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• pp.13-23
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• 1984

The fluorescence intensity rations (F2.F1) of excimer (F2) to monomer (F1) of pyrene were measured as a function of the concentration of sodium dodecyl sulfate (SDS). It was found that there were not gross changes in size and shape of sphere-shape micelles in the first micelle concentration, while at concentrations above the second critical micelle concentration (CMC) the micelles grew in size with increasing concentration. Fluorescence intensities of 8-anilinonaphthalene 1-sulfonate (ANS) were also monitored as a micellar probe with varying concentrations of SDS. Results suggested that a phase transition from sphere-shaped micelles to hemicapped rod-like micelles occurred at the second CMC (17). A general formula for the axial ratio of ellip-soil-shaped micelle in the first micelle concentration was suggested. According to this general formula, the axial ratio of SDS, sodium lauryl ether sulfate and sodium laurate were 1:1, 5:2, and 5:3, respectively. The electrolyte-induced phase transition from spherical to hemicapped rod-like micelles occurred and the size of hemicapped rod-like micelles grew with increasing electrolyte concentrations. The maximum concentrations of solubilzed benzene in sphere-shaped micelles and hemicapped rod-like micelles were measured by differential spectrohpotometry. The hemicapped rod-like micelles in the presence of electrolytes grew in size with increasing amount of benzene solubilized.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.99-102
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• 1999

In this study, to investigate the effect of process variables such as reduction in area, semi-die angle and the rectangular ratio to the corner filling which influences the dimensional accuracy of the final product in the drawing of the cluadrangle rod from a round bar, it has been simulated by three dimensional rigid-plastic finite element method. In order to reduce the number of simulation artificial neural network has been introduced. Also, through the experimental investigation, the present results have been implemented on the industrial product. In results, the main process variable is the combination of the semi-die angle in case of the irregular shaped drawing process and reduction in area in the event of regular shaped drawing process, respectively.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.1 s.232
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• pp.14-21
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• 2005

Laser chemical vapor deposition can be an effective technique for a rapid prototyping with ceramic materials, in particular. The objective of the study is to fabricate several 3-dimensional objects by stacking multi-layers as well as to find out some basic aspects of a rapid prototyping with laser chemical vapor deposition such as deposition characteristics with traversing speed of the laser, possible problems in stacking multi-layers etc. The limit speed of the laser that can grow a tilted SiC rod was found in this study, and laser directing writing that occurs over the limit speed was also investigated. Finally, a zigzag-shaped rod, a spiral-shaped rod, a wall and a square duct were successfully fabricated with laser chemical vapor deposition of tetramethylsilane

• Fashion & Textile Research Journal
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• v.16 no.5
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• pp.698-705
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• 2014

This study classifies features of women's hair adornments with the functional and decorative aspects in the Three Kingdoms Period and analyses in regards to their contemporary social and cultural surroundings. First, the tree-shaped and Rod-like hairpins in the Three Kingdoms Period are not as similar as to the hairpins found in China or other northern countries. It is farming lives and the wood-worship religion established the wearing of high-bun hair styles and tree-shaped hairpins. Second, high-bun hair styles and -shaped hairpins were basic hair decorations during the Three Kingdoms Period. Common high-bun styles finally became one of the cultures that reflected the contemporary thinking. High-bun hair styles, not excessively-decorated, became harmonized with the costume beauty and later developed along with with various-shaped hairpins. Third, Buyao (made of metals and based on flower subjects)in the Three Kingdoms Period was a unique style not been seen in the Han and Wei-jin-nam-bei-chao Period. Flowers in Buyao of the of the Three Kingdoms Period show an elegant sway, which is not excessively-decorated that developed into unique features.

• Transactions of Materials Processing
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• v.8 no.4
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• pp.331-339
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• 1999

In this study, to analyze the shaped drawing process from round bar, the practical conical die with considering die radius and bearing was defined by a mathematical expression, and also a simple technique for initial mesh generation to the shaped drawing process was proposed. The drawing of rectangular section from round bar, one of the shaped drawing process, has been simulated by using non-steady state 3D rigid plastic finite element method in order to evaluate the influence of semi-die angle and reduction in area to corner filling. Other process variables such as friction constant, rectangular ratio, die radius and bearing length were fixed during the simulation. An artificial neural network has been introduced to obtain the optimal process conditions which gave rise to a fast simulation.

• Applied Microscopy
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• v.35 no.4
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• pp.42-54
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• 2005

This study described the spermatozoa of the discoglossidae Bombina orientalis using light, scanning and transmission electron microscopes. Sperm head possess a crescent or leaf shape, with a moderately flexible head, and with a sharp anterior and posterior tips. The nucleus are a thick cone shaped in the widest middle part of nucleus, and a slender anterior and posterior of nuclear tips. The chromatin is not completely compact, but irregularly imbricated such as roof. Some nuclear lacunae, irregular in shape, are scattered within the nucleus. No neck and middle piece were developed. The flagellum is composed of 9+2 axoneme, axial rod and undulating membrane. The mitochondria were distributed only in cytoplasmic membrane around the nucleus. In particular, the nuclear rod contains bundles of fibers, the rod penetrating from anterior portion to the middle of the nucleus, is extended roughly two-thirds of the nucleus such as eyelashes shaped.