• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.1
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• pp.49-55
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• 2022

Recently, the automobile industry has continued to demand lighter materials owing to international environmental regulations and increased convenience. To address this demand, aluminum parts have increased in popularity and are mainly developed and produced through hot forging and cold pressing. However, because this method has low yield and low production efficiency, a new manufacturing method is desirable. In this study, the water capacity efficiency of an aluminum inner tie rod socket was investigated using cold forging that provided a high yield and excellent production efficiency. Mechanical properties were derived through tensile testing of 6110A aluminum materials, and critical fracture factor and process analysis based on experimental data were carried out. The optimized process was applied as a prototype using cold multi-stage forging, and based on the derived results, the formability, productivity, and material efficiency of aluminum inner tie rod socket parts using this cold forging process was verified.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.9
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• pp.1355-1359
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• 2014

To detect goat vascular endothelial growth factor (VEGF)-mediated regrowth of hair, full-length VEGF164 cDNA was cloned from Inner Mongolia cashmere goat (Capra hircus) into the pET-his prokaryotic expression vector, and the recombinant plasmid was transferred into E. coli BL21 cells. The expression of recombinant $6{\times}his-gVEGF164$ protein was induced by 0.5 mM isopropyl thio-${\beta}$-D-galactoside at $32^{\circ}C$. Recombinant goat VEGF164 (rgVEGF164) was purified and identified by western blot using monoclonal anti-his and anti-VEGF antibodies. The rgVEGF164 was smeared onto the dorsal area of a shaved mouse, and we noted that hair regrowth in this area was faster than in the control group. Thus, rgVEGF164 increases hair growth in mice.

• Journal of computational fluids engineering
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• v.21 no.3
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• pp.110-117
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• 2016

It is a essential to minimize production of by-products for economically effective petrochemical process. In order to find key factor to achieve the effective process, 2-dimensional computational fluid dynamics considering a variety of physics such as convective and radiative heat transfer and thermal cracking of ethane are carried out. The reactor is modeled as an isothermal tube, whose length is 1.2 m and radius is 0.01 m, respectively. At first, the axial distribution of representative by-products in ethane thermal cracking are investigated in each inner wall temperature conditions. Then the comparison between concentration of propene($C_3H_6$) and ethane conversion is discussed with respect to inner wall temperature conditions too. Finally, both reaction rate and turbulent kinetic energy are used to identify the production mechanism of $C_3H_6$ under the intersection point in the plot for $C_3H_6$ molar concentration and ethane conversion.

• Journal of architectural history
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• v.22 no.4
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• pp.7-18
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• 2013

Integrated-Salmi can be suggested as a character of Da-po type Kong-po in Korea's traditional architecture. However, only few studies are made on this subject yet. This study is to investigate the integration process of Salmi through cases of certain Kong-po which have the same number of inner and outer Chul-mok and are also known to precede in time. The results of the study are like below. First, Integrated-Salmi is more dominant in inner and outer 3 Chul-mok Kong-po than in inner and outer 2 Chul-mok Kong-po. Second, While inner and outer 2 Chul-mok prevail in Yeong-nam region, inner and outer 3 Chul-mok prevail in Ho-nam region. Third, integrated Salmi of Inner and outer 3 Chul-mok, first appeared in internal Jusangpo to be carried over to internal Juganpo then eventually to outer Salmi. Fourth, the reason why integrated form precede in internal salmi of inner and outer 3 Chul-mok Kong-po is due to 2 main factors. First of which is the impact of integrated Boaji that developed in Da-po type since the early 16th century. The second factor is downward expansion of Cho-gak's Boaji which was adopted to cope with disorders made in structure of Chum-Cha, due to inner and outer 3 Chul-mok type buddhist temples' wide reconstruction throughout Jeolla region following the Japanese invasion of Korea in 1592. This study is to disclose the regularity of development process of Salmi's Cho-gak(草刻) which is a characteristic of Korea's Da-po type Kong-po.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6201-6206
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• 2015

The epithelial-mesenchymal transition (EMT) is a cellular process though which an epithelial phenotype can be converted into a phenotype of mesenchymal cells. Under physiological conditions EMT is important for embryogenesis, organ development, wound repair and tissue remodeling. However, EMT may also be activated under pathologic conditions, especially in carcinogenesis and metastatic progression. Major signaling pathways involved in EMT include transforming growth factor ${\beta}(TGF-{\beta})$, Wnt, Notch, Hedgehog and other signaling pathways. These pathways are related to several transcription factors, including Twist, Smads and zinc finger proteins snail and slug. These interact with each other to provide crosstalk between the relevant signaling pathways. This review lays emphasis on studying the relationship between EMT and signaling pathways in carcinogenesis and metastatic progression.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.4
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• pp.155-160
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• 2008

End part of the brake tube formed with the shape of snake head is important for the braking of automobile in safety because it has to prevent crack, fracture and defects occurred during the forming process. Especially, the shape of tube end has influence on the ability of brake. Based on the procedure of process design, in this paper, the forming operation is done by finite element method and the design variables are analyzed by Taguchi method. Design variables such as the outer angle of tube end with the shape of snake head(A), the inner angle to make a hole at tube end with the shape of snake head(B) and the forming distance at tube end(C) are used. Optimization of design variables is performed to minimize the damage factor of the tube end occurred during the forming process. The value of damage factor of 0.327 was obtained under the optimal condition like $A=114^{\circ},\;B=80^{\circ}$ and C=5.3mm, respectively.

• 연구논문집
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• s.29
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• pp.173-183
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• 1999

The vacuum investment casting process for a large gas turbine component, Inner Preswirl Support (IPS), was simulated by using commercial FEM package ProCAST(TM) with view factor radiation method. The solid fraction in mushy zone was directly measured by Differential thermal analysis(DTA-DSC mode). Three types gating design. considering liquid flow and heat release through it. were proposed. Solidification had begun at the ribs or thin sections of the IPS casting and advanced further through the upper and lower gates. The computed temperature gradient G and G/R values at 70% solidified temperature were used for prediction of microshrinkage formation during casting. The effect of mold preheat on the thermal history of the casting displayed minute effect on the microshrinkage formation.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.10a
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• pp.124-127
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• 2000

The finite element analyses of the wrinkling initiation and growth in the sheet metal forming process provide the detailed information about the wrinkling behavior of sheet metal. The direct analyses of the wrinkling initiation and growth, however, bring about a little difficulty in complex industrial problems because it needs large memory size and long computation time. For the description of wrinkling growth, the mesh elements should be sufficiently small and the size of finite element matrix becomes large. In the static implicit finite element method therefore, the direct analysis of wrinkling growth in a complex sheet metal forming process is rather difficult. From the industrial viewpoint of tooling design, the readily available information of possibility and location of wrinkling is sometimes more preferable to the detailed time-consuming information. In the present study, therefore, the wrinkling factor that shows locations and relative possibility of wrinkling initiation is proposed as a convenient tool of relative wrinkling estimation based on the energy criterion. The location and relative possibility of wrinkling initiation are predicted by calculating the wrinkling factor in various sheet metal forming processes such as cylindrical cup deep drawing, spherical cup deep drawing, and elliptical cup deep drawing. The wrinkling factor is also implemented in the analysis of the door inner stamping process to predict wrinkling.

• Tribology and Lubricants
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• v.32 no.1
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• pp.18-23
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• 2016

The effective case depth for case-hardened rolling bearing has been discussed. For this purpose, rolling contact fatigue tests for ball bearings built with inner race of various hardness values were conducted until L₁₀ calculating rating life using a bearing life test machine under radial loading. Then, the distribution of residual stress below the inner raceway, which depended on the hardness value, was measured by X-ray diffraction. As a result, the linear relationship was established between the hardness value of the inner race and the theoretical shear stress evaluated at the depth where the residual stress disappeared below the inner raceway. Based on the relationship, it could be found that the factor of safety in bearing manufacturer’s rules for the effective case depth of case hardened rolling bearings was set higher. However, it could be also found that the hardness values at the depth where the maximum shearing stress acted below the raceway surface in a tapered roller bearing hardened by the carburizing process, were not sufficient for preventing plastic deformation under the basic dynamic load rating. Consequently, further efforts were still required to reduce or to disperse the contact load on the material design of a rolling bearing in order to prolong its life.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.1
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• pp.1-12
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• 2016

In Korea, small and medium sized domestic enterprises(SMEs) play an pivotal role in the national economy, accounting for 99.9% of all enterprises, 87.5% of total employment, and 47.6% of production. and SMEs was driving a real force of the development of national economy in many respects such as job creation, innovation, balanced regional development, industrial diversity. The government has strengthened a variety of policy support to support SMEs. However, due to the mismatch between the difficulties of SMEs and benefits of government's policy, the policy implementation has not come out effectively. In order to effectively support SMEs, government must be a priority to know about the factors that experiencing difficulties in the technology commercialization process. The purpose of this study is thus to identify the major evaluation criteria through 3 level AHP analysis. First, 12 Critical elements are extracted from previous studies and professional interview and these elements are tied into 3 factors; technological factor, inner-organizational factor and Outer-organizational factor. The results of AHP analysis show that inner-organizational factor is more important and 'Market environment' in the inner-organizational factor is the most important element. The results of this research will be useful for public R&D institutions policy makers when establishing technology commercialization support policies and strategic planning of small and medium sized domestic enterprises.