• Journal of Advanced Marine Engineering and Technology
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• v.41 no.1
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• pp.1-7
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• 2017

When implementing butt joint welding of two plates, it is useful to attach end-tabs made of a metal with high heat conductivity (e.g., copper) at the front and back sides of the welded plates to prevent the bead from rolling down and prevent defects that may occur at the tips of the weld zone. In this study, the fin shape, which is known to have good heat discharging characteristics by natural convection, has been applied to enhance the cooling performance of the end-tab. From both experiment and numerical analysis, it was confirmed that end-tabs with fin-shaped holes have better heat discharging performance than end-tabs without holes. Through thermal and fluid flow analysis, the cooling rates of end-tabs with different hole shapes were estimated in order to figure out characteristics of shape factor that are important for the heat discharging performance. As a result, we found that the structure including vertical fins with optimal fin gap was the best-performing shape.

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.6
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• pp.569-575
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• 1984

The characteristics of the stress corrosion cracking of SUS 304 stainless steel weldments were studied with the speciments of the constant displacement type under the environment of 42% MgC $l_{2}$ boiled solution (143.+.-.2.deg.C). The susceptibility of initiation and propagation of the stress corrosion crack was quantitatively inspected in the weld metal, heat affected zone and heat affected zone with including the reinforcement shape, respectively. Also, those susceptibility were discussed in connection with the change of mechanical and microstructural characteristics caused by heating cycle of welding. Main results obtained are as follows: (1)Stress corrosion cracking is easiest to initiate and propagate in the heat affected zone of weldment. (2)The susceptibility of stress corrosion cracking of the weldment is largely improved by eliminating the reinforcement part of the weld bead. (3)The dominant factor of the cracking susceptibility of the heat affected zone appeared to be the phenomenon of softening and sensitizing caused by welding heat cycle. (4)Under the low loading conditions, the behavior of stress corrosion cracking of the SUS 304 steel weldment is largely influenced by the pitting phenomenon in the front region of the main crack.

• Journal of Welding and Joining
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• v.26 no.5
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• pp.49-59
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• 2008

Hastelloy C-276, corrosion resistant alloy at high temperature, is used in chemical plant and power generation industry. In this study, process parameter of laser welding for welding property in Hastelloy C-276 using a continuous wave Nd:YAG laser was studied. As the result of experiment, laser welding did not show segregation or crack at heat affected zone compared to conventional GTWA welding. The melting zone showed cell dendritic structure along with welding line. In addition, planer front solidification is occurred from welding structure, and it was progressed to cellular solidification. Optimal process parameter for butt welding was 1.2kW and 2.0 m/min for laser power and welding speed, respectively. While heat input, output density, tensile stress, and longitudinal strain was $441.98{\times}103$ J/cm2, $29.553{\times}103$ W/cm2, 768 MPa, and 0.689, respectively. Lap welding of the same material showed greater discrepancy in tensile property during 1 line and 2 line welding. For 1 line welding, tensile stress was about 320 MPa, and 2 line showed slightly larger tensile stress. However, strain was decreased by 20%. From this result, lap welding of the same material, Hastelloy C-276, with 2 line welding is considered to be more effective process than 1 line welding with consideration of mechanical property.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.2
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• pp.217-228
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• 2003

Co-ordinate growth of the brain and skull is achieved through a series of tissue interactions between the developing brain, the growing bones of the skull and the sutures that unite the bones. Craniosynostosis, the premature fusion of cranial sutures, presumably involves disturbance of these interactions. Bmp2, one of bone morphogenetic proteins (Bmps), is involved in the regulation of the shapes of individual bones and the relative proportions of the skeleton. Mutations in the homeobox gene Msx2, known as a downstream gene of Bmp, cause Boston-type human craniosynostosis. The phenotype of Dlx5 homozygote mutant mouse presents craniofacial abnormalities including a delayed ossification of calvarial bone. These facts suggest important roles of Bmp2, Msx2 and Dlx5 genes in the cranial bone growth and suture morphogenesis. To elucidate the function of these molecules in the early morphogenesis of mouse cranial sutures, we first analyzed by in situ hybridization the expression of Bmp2(E15-18), Msx2 and Dlx5 genes in the developing sagittal suture of calvaria during the embryonic stage. Bmp2 mRNA was intensely expressed in the osteogenic fronts and also at the low level in the periosteum of parietal bones during embryonic stage, Msx2 mRNA was intensely expressed in the sutural mesenchyme and mildly expressed in the dura mater during the embryonic stage. Dlx5 mRNA was intensely expressed osteogenic fronts and parietal bones. To further examine the role of Bmp signaling in cranial suture, we did in vitro experiments in E15.5 mouse calvarial explants. Interestingly, implantation of Bmp2-soaked beads onto the osteogenic fronts after 48 hours organ culture resulted in the increase of the tissue thickness and cell number around Bmp2 beads, compared to BSA control beads. In addition Bmp2 induced etopic expressions of Msx2 and Dlx5 genes. On the other hand, overexpression of FGF2 did not induce the expression of Msx2 and Dlx5. Taken together, these data indicate that Bmp2 signaling molecule has a important role in regulating the cranial bone growth and early morphogenesis of cranial suture. We also suggest that Bmp signaling is involved in all the stages of osteogenesis of cranial bones and the maintenance of cranial suture by regulating Msx2 and Dlx5 genes, and that Msx2 and Dlx5 genes are specific transcription factors of Bmp signaling pathway.

• Korean Journal of Heritage: History & Science
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• v.43 no.4
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• pp.24-55
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• 2010

Jangmyeongdeung Lantern (貞陵長明燈) refers to the stone lantern placed in front of the royal tomb. It serves both symbolic and decorative purposes; symbolic because it is supposed to guard and illuminate the buried, and decorative because it is a work of sculpture that adorns the entire graveyard. The Jangmyeongdeung of Jeongneung was the earliest stone lantern to be produced during the Joseon period. Its square shape is unique among those from the early to mid-Joseon period. The three major parts of Jangmyeongdeung - the stand, the lantern, and the roof-shaped cover parts - are square in shape, differing from the octagonal shaped Jangmyeongdeung. The stand consists of three single stone blocks, the Hadaeseok(下臺石), Ganjuseok(竿柱石), and Sangdaeseok(上臺石). The Hwasaseok(火舍石), or the lantern part, is also a single stone block. Jangmyeongdeung of Jeongneung succeeds the style of those of Hyeon-neung and Jeongneung(玄正陵) of the Goryeo period and is of a better artistic quality. As the first Jangmyeongdeung lantern, it is a refined work of art that marks the foundation of the Joseon Kingdom. This paper tries to ascertain the stylistic origin of the square-shaped Jangmyeongdeung of Jeongneung and compare it with those of Buddhist temples. Consequently, similarities were found among the stone lanterns of Zen priests 'Jigong'(指空) and 'Nawong'(懶翁) in the Hweamsa Temple(檜巖寺) site from the late Goryeo period, those of Zen priest 'Muhak'(無學) of the Hweamsa Temple site, and those of national priest 'Bogak'(普覺) of Cheongnyongsa Temple(靑龍寺) from the early Joseon period. Primarily, this is because the three components(the stand, the lantern part, and the roof-shaped cover) are essentially square-shaped. Second, as the Ganjuseok(one of the components of the stand) became shorter, the stand took a more stable form. Third, the Hwasaseok(the lantern part) consists of two stone blocks joined together. Fourth, the roof-shaped cover is also in square in shape. Similarly, the Jangmyeongdeung of Jeongneung contains Buddhist elements as well. The three-bead pattern that decorates the Ganjuseok stand is an example. The three-bead pattern is one of the symbolic elements related to Tantric Buddhism. It is found on the diadems worn by Bodhisattvas from the Goryeo and early Joseon periods. The Jangmyeongdeung of Jeongneung in early Joseon directly influenced the production of the square-shaped stone lanterns used to decorate the tombs during the Joseon period. After the latter half of the 15th century, however, the octagonal-shaped Jangmyeongdeung style began to prevail. The Jangmyeongdeung of Jeongneung reflects the succession of the tradition of royal tombs from Goryeo to Joseon, the introduction of square-shaped stone lanterns to Buddhist temples, and the influence of the Buddhist philosophy of the time. It is a living testimony to various elements of each time and corresponding cultural trends.

• Journal of Fashion Business
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• v.8 no.1
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• pp.16-33
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• 2004

Up to now, image of femme fatale has undergone constant transformation to be inherited and developed through various genres of movies. With few exceptions such cases have represented sensuality of women by costumes with the most distinctive and exaggerated sexuality. Temptresses in movies are mostly drawn as extravagant and gorgeous one or a gloomy and dreary woman. Such an image is reinforced with make-up, hair style, accessories, attitude and manner of talking. The movie 'Chicago' is a musical film that crosses the boundaries of reality and fantasy with dancing and singing. Its lighting, stage setting, powerful and sexy dancing augmented already exaggerated and sensual costumes. Following is the analysis of costumes for two heroines as images of femme fatale. Strong contrast of color among black, red and blue on see-through & stickingly tight body suit signifies liberal mind and arrogant charisma of Velma. The contrast, haughty gestures, cropped black hair and thick makeups represent sex appeal, aggressive image, and fearlessly determined character of femme fatale. Roxie wears decent dresses in front of public and gorgeous stage costume in fantasy to convey two images of bad girl and angel. Her body suit, showing off lustering materials and dazzling bead decoration, is rather loose but still displays her bodyline to emphasize sexiness for representation of desire in fantasy. Chastity and innocence are implied with the decency of dresses in reality. They were specially chosen to draw public sympathy and indicate cunning disguise of Roxy who desperately wants to realize her desire. These dauntless costumes, which sufficiently express inside aspirations of Velma and Roxie later denote open and realistic social yearning rather than fatal desire hidden behind sensual beauty. It doesn't exist as imperfect, unrealistic and socially disdainful ambition as the image of femme fatale of paintings and movies did before in history. Femme fatale is expressed with deep cleavage, silk dresses that explicitly display bodyline, sexiness of mesh stockings with garter belts. All of these won't be utilized as a negative tool to seduce and destroy someone anymore but rather, they should represent rightful and fair nature of humans such as men's curiosity who secretly steal a look at them or female sexuality that women spontaneously want to show off.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.2
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• pp.300-308
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• 2000

The Fibroblast growth factors(FGFs) plays an important role in the control of osteogenesis during skeletal development. Especially, FGF-2 is a potent mesodermal inducer during embryogenesis and FGF receptors (FGFRs) messages are strongly expressed in developing bones. In this study, we investigated the effect of bFGF on osteopontin(OPN) gene expression in ST-2 cells and tried to elucidate the mechanism of its stimulatory effects. The obtain results were as follows; The treatment of bFGF(1ng/ml) upregulates OPN, fibronectin mRNA levels and downregulates type I collagen mRNA levels. But, there was no remarkable difference in alkaline phosphatase mRNA levels between two groups. The OPN gene expression increased in a dose-dependent manner up to 10ng/ml and OPN gene began to occur at around 3h with continuous increase up to 24h then decreased to basal level at 48h. 30 minutues pretreatment with cycloheximide (500ng/ml), a protein synthesis inhibitor, prior to addition bFGF resulted in blocking bFGF induced OPN expression. These results suggest that bFGF increased the level of OPN mRNA in a dose and time-dependent manner via the synthesis of certain transcriptional regulatory proteins.