• Journal of Aerospace System Engineering
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• v.12 no.3
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• pp.64-69
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• 2018

The high-velocity electromagnetic forming (EMF) process is based on the Lorentz force and the energy of the magnetic field. The advantages of EMF include improved formability, wrinkle reduction, and non-contact forming. In this study, the electromagnetic-structural interlocking analysis was performed in order to analyze the moldability of aluminum pipe using electromagnetic molding. The magnetic flux density was decreased due to increasing electrical resistance as the temperature increased, and the stress-strain curve decreased. The higher the temperature, the lower the flow stress, increasing deformation.

• Journal of Fashion Business
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• v.13 no.1
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• pp.102-114
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• 2009

Chitosan is a polysaccharide with cationic amino groups in its structure and has useful properties as functional materials. Various end-use developments of chitosan are in progress. When the cotton fabric is pretreated with chitosan, the hand property of cotton fabric may be improved expecially for the summer apparel. In this study, as a cross-linking agent to introduce chitosan into cotton, BTCA(butane-1,2,3,4-tetracarboxylic acid) or CA(citric acid) was added in order to prevent detachment of chitosan by the cross-linking. During the cross-linking procedure, via the padding-drying-heat setting, amino groups of chitosan and hydroxyl groups of cotton, carboxyl groups of BTCA/CA are cross-linked by forming anhydrous cyclic rings. Since BTCA has four carboxyl groups, cross-linking by thermal treatment is easy, leading to the trials in wrinkle-recovery treatment of cotton fabrics. However, the high price of the BTCA reagent has been a shortcoming in the actual application for industrial use. Therefore, in this study, we tried the application of CA having three carboxyl groups, which is relatively low priced, as the substituting cross-linking agent. The hand of the treated fabrics were evaluated by measuring physical properties. In addition, based on the physical properties, three-dimensional images were introduced by using 3D CAD systems and results were compared.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.12
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• pp.92-100
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• 2005

An aircraft wing or fuselage panel of skin-stringer assembly can fail in a variety of instable modes under compression loads. Instability modes can be buckling of the panel, local buckling of the stringer, flexure, torsion, wrinkle and combined flexural/torsional buckling of the panel assembly. Although researches on these buckling behaviors have been carried out for a long time, there are some difficulties to apply to the practice because of complex theoretical and empirical equations. Accordingly, It is well known that leading aerospace companies are using their own in-house programs for the convenience of practical usage, but our domestic situation is that no such program has been ever developed. In this study a comprehensive program has been developed, which can identify the instability modes and the magnitude of reserve factor of the modes for the skin/stringer panel assembly under compression load. The developed program is based on the theory manual of the Airbus program APA114. For the verification, calculation of the instable reserve factors for the A320 wing panel and A380 low wing panel sections were carried out and compared with results by APA114.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.741-762
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• 2003

Ginsenosides, the major active ingredients of ginseng, show a variety of biomedical efficacies such as anti-aging, anti oxidation and anti-inflammatory activities. To understand the effects of compound K (20-O-D-glucopyranosyl-20 (S)-protopanaxadiol), one of the major metabolite of ginsenosides on the skin, we assessed the expression level of ∼ 100 transcripts in compound K-treated HaCaT cells using cDNA microarray analysis. Compound K treatment induced differential expression of 21 genes, which have been reported to be involved in the organization of ECM structure as well as defense responses in human skin cells. One of the most interesting findings is 2-fold increase in hyaluronan synthase2 (HAS2) gene expression by compound K. We found that change in expression of HAS2 gene represents a specific response of HaCaT cells to compound K because hyaluronan synthase 1, 3 was not changed by treatment with compound K. We also demonstrated that the compound K effectively induced hyaluronan synthesis in human skin cells and hairless mouse skin. The human clinical study indicates that topical application of compound K-containing oil-in-water emulsion showed improvement of xerosis, wrinkle and fine lines in the aged skin. We concluded that compound K has anti-aging effects by the induction of HAS2 gene expression and following hyaluronan synthase.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.24 no.3
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• pp.116-122
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• 1998

It is well known that all-trans-retinol is not only very unstable in heat, light, air, and water, but also skin-irritant despite a good anti-wrinkle effect. Therefore, it is very difficult to stabilize retinol and make the safe retinol containing cosmetics by using a certain concentration of retinol with real effect. In order to dissolve these problems and apply retinol for skin care cream, firstly retinol is to be encapsulated in the vesicle called Liposphere (pseudo-liposome) which is made by homogenizing under high pressure the mixtures of lecithin, retinol, caprylic/capric triglyceride, and hydroalcoholic solution ; and then this retinol containing Liposphere is to be intercalated in lamellar liquid crystal layer which is prepared by emulsifying in an optimal ratio the mixtures composed of non-ionic emulsifier (cetearyl glucoside, sorbitan stearate & sucrose cocoate etc), cetearyl alcohol, stearic acid, cholesterol, and ceramide. In addition, the stability of the retinol containing oil in water cream by adding the polymeric emulsifier such as acrylate /C10-30 alkyl alkylate crosspolymer is to be ensured even at 55 C. Retinol containing oil in water cream prepared through above procedure could be very stable at 45 C for at least 50 days. The structure identification of lamellar liquid crystal was determined using polarized light microscope and electron microscope Conclusively, we could make the very stable retinol containing oil in water cream by triple procedure, that is, encapsulation of retinol in Liposphere, intercalation of retinol in lamellar liquid crystal layer, and assurance of the high temperature stability of cream even at 55 C.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.3
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• pp.479-485
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• 2007

In this paper, a hierarchical simulation with an approximate implicit method is proposed in order to efficiently and plausibly animate mass-spring based cloth models. The proposed hierarchical simulation method can generate realistic motion of extremely fine mesh in interactive rate. The proposed technique employs a fast and stable simulation method which approximates the implicit integration. Although the approximate method is efficient, it is extremely inaccurate and shows excessively damped behavior. The hierarchical simulation technique proposed in this paper constructs multi-level mesh structure in order to represent the realistic appearance of cloth model and performs simulation on each level of the mesh with constraints that enforce some of the mass-points of current level to follow the movement of the previous level. This hierarchical method efficiently generates a plausible movement of a cloth model composed of large number of mass points. Moreover, this hierarchical method enables us to generate realistic wrinkles on the cloth, and the wrinkle pattern on the cloth model can be easily controlled because we can specify different contraction resistance force of springs according to their hierarchical level.

• Composites Research
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• v.36 no.5
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• pp.321-328
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• 2023

This study developed the in-situ stamp-forming process using the multi-axis robotic arm to fabricate thermal composite parts. Optimal fabrication parameters with the multi-axis robotic arm were determined using finite element analysis and these parameters were further refined through the practical manufacturing process. A comparison between the manufactured parts and finite element analysis results was conducted regarding thickness uniformity and wrinkle distribution to confirm the validity of the finite element analysis. Additionally, to evaluate the formability of the manufactured composite parts, measurements of crystallinity and porosity were taken. Consequently, this study establishes the feasibility of the In-situ stamp-forming consolidation using a robotic arm and verifies the potential for producing composite parts through this process.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.2
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• pp.173-181
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• 2016

Skin basement membrane (BM) is a specialized structure that binds dermis and epidermis of the skin and plays an important role in maintaining skin structure. Structural change and destruction of BM is reported to appear due to UV exposure and aging, which may contribute to skin aging including wrinkle formation and a decrease in elasticity of the skin. One of the key components of the BM is laminin-332 (LN-332), and is a major contributor to epidermal-dermal attachment. In this study, we elucidated the effects of Meladrium firmum hexane fraction (MFHF) on LN-332 expression in HaCaT, a human keratinocyte cell line. Quantitative real-time PCR (RT-PCR) and immunoblot analysis revealed that MFHF induced upregulation of LN-332 gene and protein expression. Next, cells were treated with p38 MAPK inhibitor (SB202190) prior to MFHF treatment to analyze the signaling pathway contributing to LN-332 expression. The mRNA and protein levels of LN-332 expression were suppressed completely by pretreatment with p38 MAPK inhibitor. Furthermore, MFHF also increased the mRNA level of collagen type VII and integrin ${\alpha}6$ of skin BM component. These results collectively suggest that MFHF may have potential as an effective agent to stimulate the synthesis of BM components, and could be used to improve phenomenon of skin aging ascribed to the structural and functional impairments of BM in aged human skin.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.12
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• pp.1873-1882
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• 2009

Hospital patient clothing material was treated with a mixture of chitosan in order to enhance functionality, such as the durability and dimensional stability of the cotton fabric used. Chitosan is a natural polymer with excellent biocompatibility, however there is a deteriorating adherence efficiency. The addition of a nanosilver colloidal solution in accordance with a prescribed ratio can further increase the performance of chitosan. Changes in the structural characteristics and physical properties of the chitosan/nanosilver treated fabric were observed in a comparison with fabric treated only with chitosan. The add-on ratio increased when the mixing ratio of nanosilver colloidal solution was higher; however, the crystalline structure of the treated fabric remains similar. In the case of CH3/NS1 treated fabric (where the mixing ratio of chitosan and nanosilver solution was 3:1) the K/S value, whiteness index, wet tensile strength, and wrinkle recovery angle were superior. The dimension stability, pilling resistance, and abrasion resistance of the fabric treated with a mixed solution increased in comparison to the fabric treated only with chitosan. The chitosan/nanosilver treated cotton fabric used for patient clothing material has excellent physical properties.

• Journal of Life Science
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• v.28 no.4
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• pp.408-414
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• 2018

Actein is the well-known active ingredient of Cimicifugae rhizoma (Black cohosh). In this study, we investigated and compared the binding affinity of tubocurarine, actein, and actein derivatives on the B&C domain of the acetylcholine binding protein through in silico computational docking studies. The three-dimensional crystallographic structure of the acetylcholine binding protein B&C domain was obtained from the PDB database (PDB ID: 2XYT). An in silico computational autodocking analysis was performed using PyRx, Autodock Vina, Discovery Studio Version 4.5, and NX-QuickPharm based on scoring functions. The actein showed an optimum binding affinity (docking energy), with the acetylcholine binding protein at -10.50 kcal/mol as compared to the tubocurarine (-9.80 kcal/mol). The interacting amino acids tryptophan 84 and tryptophan 147, in the B domain of the acetylcholine binding protein active site, significantly interacted with the actein and 27-deoxyactein, and (26R)-actein. The centroid XYZ grid position of the tubocurarine was X=38.300689, Y=112.053467, and Z=51.991022, but the actein and its derivatives showed values around X=26.4, Y=127.3, Z=43.7. These results clearly indicated that actein and its derivatives could be a more potent antagonist to the acetylcholine binding protein than tubocurarine. Therefore, the extract of Cimicifugae rhizoma or actein containing biomaterials can substitute for the botulinum toxin-mediated acetylcholine receptor regulation, and be applied to the anti-wrinkle cosmetics industry.