• Proceedings of the KWS Conference
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• 2002.10a
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• pp.139-144
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• 2002

Ti-50.9at%Ni wires were welded using pulsed YAG laser. The laser welded wires were tested for investigating the shape memo교 effect and the ability of super elasticity. The fatigue properties of the welded wires were investigated using the rotary bending fatigue tester specially designed for wires. Moreover, the effect of defocusing distance during laser welding on the static and fatigue properties was investigated. The shape memory effect and super elasticity of the laser welded wires were approximately identical with that of base metal at the test temperature below 353K. However, the welded wires were broken within elastic limit at the test temperature above 353k. Under the cyclic bending loading conditions, the welded wires could be useful only below the elastic limit, while the base metal had sufficient fatigue life even the stress induced M-phase region. The fatigue strength of the welded wires was about half of that of the base metal. The deterioration of the static and fatigue properties in the welded wires was proven to be from the large difference of the transformation behavior between the base metal and welded part that is caused by vaporization of Ni-content at the welded part during the welding process. The defocusing distance below 3mm acted more largely on lowering the strength of the welded wires than that of 6mm or 8mm.

• Steel and Composite Structures
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• v.25 no.2
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• pp.127-139
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• 2017

In this paper, an exact analytical solution for simply supported sandwich plate which considers the permeation effect of adhesives is presented. The permeation layer is described as functionally graded material (FGM), the elastic modulus of which is assumed to be graded along the thickness following the exponential law. Based on the exact three-dimensional (3-D) elasticity theory, the solution of stresses and displacements for each layer is derived. By means of the recursive matrix method, the solution can be efficiently obtained for plates with many layers. The present solution obtained can be used as a benchmark to access other simplified solutions. The comparison study indicates that the finite element (FE) solution is close to the present one when the FGM layer in the FE model is divided into a series of homogeneous layers. However, the present method is more efficient than the FE method, with which the mesh division and computation are time-consuming. Moreover, the solution based on Kirchhoff-Love plate theory is greatly different from the present solution for thick plates. The influence of the thickness of the permeation layer on the stress and displacement fields of the sandwich plate is discussed in detail. It is indicated that the permeation layer can effectively relieve the discontinuity stress at the interface.

• Industry Promotion Research
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• v.5 no.4
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• pp.63-72
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• 2020

This study aims to suggest the direction for improving the mental health of married women by analyzing the relationship between married women's life stress, life satisfaction, self-elasticity, and coping stances. For this study, 200 married women in their 30s~60s living in Seoul, Incheon, and Gyeonggi-do were surveyed on January 2~15, 2020, and the results were analyzed using multiple regression and regression analysis. As a result of the study, it was found that the main causes of life stress felt by married women were economic problems, relationships with their children, and conflict between mother in law and daughter in law. By analyzing the relationship with life satisfaction, it turned out that life stress had a relationship with life satisfaction, which affected the decline in their life satisfaction. In addition, it was verified that the self-elasticity and coping stances had a partial mediating effect in the relationship between the life stress and life satisfaction of married women. Accordingly, improving self-elasticity and coping stances will likely reduce the life stress of married women and boost their life satisfaction.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.1135-1141
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• 2023

The purpose of this study was to investigate the effect of Grit and Self-elasticity on Carrer Identity of nursing students. Data were collected among 193 nursing students in G city, from Sep 4 to 15 2023. The collected data was analyzed a using t-test, One way ANOVA, Pearson correlation coefficient and Stepwise multiple regression using SPSS 20.0 WIN program. The results revealed that the average score for Self-elasticity was 3.42±0.45, Grit was 3.63±0.60, Carrer Identity was 4.06±0.79. students acquired Self-elasticity by gender as per general characteristics. The Carrer Identity showed statistically significant differences in gender. There was a statistically significant positive correlation between the Carrer Identity of Self-elasticity(r=.370, p=.000), and Grit(r=.283, p=.000). Carrer Identity showed Models including the variables, Self-elasticity, Gender, Grit explained 22.6% of the variance in the Carrer Identity stress. Based on the outcome of this study, steps should be taken to design intervention program that emphasize a improve Carrer Identity for nursing students.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.3
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• pp.205-214
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• 2018

This paper deals with the experimental study on the hygrothermal ageing effect to the strength of Carbon Fiber Reinforced Plastics (CFRP) materials for marine leisure boat manufactured by vacuum assisted resin infusion method. The experiments performed consist of tensile, flexural and shear tests according to American Society for Testing and Materials (ASTM) and Korean Industrial Standards (KS) test methods. Test coupons are varied from uni-directional(UD, $0^{\circ}$, $90^{\circ}$), Bi-Directional (BD), and Double-Bias (DB) carbon fiber fabrics in conjunction with epoxy resin. The results of tensile test show that tensile strength reduces significantly while not the same degree of reduction is observed for elasticity modulus with respect to the existence of hygrothermal ageing effect. This implies that the tensile strain induced from external load holds steady values but ultimate strength values change widely under hygrothermal ageing effect. In case of the flexural test, $0^{\circ}$ UD shows more strength reduction than $90^{\circ}$ UD while BD has reduced values in both flexural strength and elasticity modulus under hygrothermal ageing effect. It is learned that the bending strain induced from external load and ultimate strength values are reduced with respect to hygrothermal ageing effect. Shear test performed only on DB materials, and the results show marginal reduction in ultimate strength and moderate reduction in elasticity modulus. This means that the shear strain varies more than ultimate shear strength with respect to hygrothermal ageing effect. The experiment conducted in this paper clearly demonstrates the differences in material properties of the CFRP for the consideration of hygrothermal ageing effect. Findings obtained from this experimental study can serve as a fundamental input data for the realistic structural responses of marine leisure boat built in CFRP materials.

• Fashion & Textile Research Journal
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• v.24 no.6
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• pp.789-800
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• 2022

This study investigates the effect of recovery elasticity of beauty college students on university life adaptation during COVID-19. Further, the mediating effect of grit in relation to recovery elasticity and university life adaptation is analyzed. Survey data of 223 students (female: 192; male: 31) were collected for multiple and intermediate regression analyses using SPSS 24.0. The results reveal a static correlation between the lower factors of resilience, glittery, and adaptation to college life and that the resilience of junior college students in the beauty department had a static effect on grit and their adaptation to college life. Passion, a subordinate factor of grit, is mediated by the effect of grit on the relationship between resilience and adaptation to university life. However, perseverance, another subordinate factor of grit, did not have any such mediating effect. These results confirm the importance of grit, particularly passion, for resilience and adaptation to college life. It was confirmed that resilience was due to college life adaptation of beauty department students, and it was confirmed that passion, a sub-factor of grit, also had a mediating effect. Therefore, it is judged that resilience induces physical and mental adaptation, interpersonal adaptation, and academic adaptation necessary for college life, and works in many ways to improve the quality of life of beauty department junior college students. Instructors should consider developing educational programs for improving recovery elasticity and grit to help students better adapt to university life.

• Journal of the Korean Wood Science and Technology
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• v.18 no.4
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• pp.86-101
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• 1990

The primary objective of this research was to investigate the strength properties of Comply, a composite panel. fabricated with particle board as core material and veneer or plywood as face and back. 20types of comply composites were manufactured according to the four specific gravity levels(0.5, 0.6, 0.7 or 0.8) of particleboard core and three veneer or two plywood thicknesses for face and back. They were tested and compared with matching particleboard (control) on moisture content. specific gravity, bending properties(MOE, MOR SPL). nail resistance and internal bond strength. The obtained results were summarized as follows: The increasing effect of modulus of elasticity was shown by the increase of face and back veneer or plywood thickness. The modulus of rupture and stress at proportional limit of the comply composites bonded with 3mm thick veneers or 3mm thick plywood face and back were higher than 2mm thick veneer or 2mm thick plywood as face and back. Both of modulus of rupture and stress at proportional limit on bending of Comply were higher than those of control board. Also the modulus of elasticity of Comply showed much higher than that of control board. The nail resistance of Comply, composed of plywood as face and back was higher than that of veneer. The nail resistance of control board was higher than that of Comply at Sp.Gr 0.7 and 0.8 core boards. Internal bond of Comply, composed of 1mm and 2mm thick veneer as face and back was higher than that of 3mm thick veneer. The increasing effect of modulus of elasticity was shown by the increase of shelling ratio in Comply composed of veneer and plywood as face and back. The modulus of rupture was increased by the increment of shellmg ratio in Compiy, composed of plywood as face and back. The modulus of elasticity and modulus of. rupture of comply were higher than those of particleboard(control) in effect of shelling ratio. Therefore it was concluded that the mechanical property values of Comply were clearly greater than those of particleboard(control).

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.27 no.1
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• pp.58-67
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• 2014

Objective : Lycii Fructus Extracts(LFE) can do Anti-hypertension activity, Antidepressant, Anti-diabetic activity. This study was designed to investigate effects of LFE on skin whitening and elasticity using melanoma cells. Methods : In this experiment, effect of LFE on cell viability, inhibition of melanin synthesis and inhibitory effect on tyrosinase and elastase. Results : More than $250{\mu}g/ml$ of LFE treated group showed lowered proliferation rates significantly compared to non-treated group. More than $125{\mu}g/ml$ of LFE treated groups were lower levels of melanin synthesis respectively. LFE showed inhibitory effect on tyrosinase activities in vitro. And, LFE suppressed tyrosinase activities in B16F10 cells significantly. Finally, LFE suppressed elastase type I and IV activities in dose-dependent manner in vitro. And LFE also slightly suppressed elastase activities in vivo. Conclusion : These results suggest that LFE can inhibit melanin synthesis through ihhibitory action on tyrosinase activity and inhibt elastase activity, and also suggest that these results can be used for the study on maintaining skin elasticity or whitening.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2007.11a
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• pp.140-152
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• 2007

Hyaluronic acid(HA) is a naturally occurring mucopolysaccharide composed of the repeating disaccharide unit of D-glucuronic acid and N-acetyl-D-glucosamine. HA exists as a high molecular weight polymer in the extracellular matrix of many tissues in the body. HA has been widely used not only for osteoarthritis and ophthalmology but also for cosmetics for skin care. Recently HA has drawin much attention for use in health foods. Bioland Corporation started production of HA t1y biotechnological process in 1990 for cosmetical use. At present Bioland produces HA for cosmetic and food use. We have done many researches to evaluate the helpful effect for skin and safety of HA as food. In order to evaluate the effect of HA on the skin after its oral intake, we measured its bioavailability, skin-care effects on anti-wrinkle, moisturization elasticity and desquamation by clinical trial. The results showed that HA is very safe and could bs helpful to improve anti-wrinkling, moisturization, elasticity, and desquamation on the skin.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.2
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• pp.169-176
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• 2023

In this study, stem cells were extracted from the callus derived from the aloe cambium, and the antioxidant activity and effect of skin elasticity improvement were assessed. The aloe cambium-derived stem cell extract, AloStem and callus showed the survival rate of each 98.27% and 71.31%. In the results of the DPPH antioxidant activity of AloStem and aloe extract, it was confirmed that the antioxidant effect of AloStem was more than twice that of Aloe extract. AloStem did not affect the cytotoxicity of normal human dermal fibroblasts (NHDF) cells up to 0.25% concentration. Also, AloStem increased elastin, COL1A1 and HAS2 mRNA expression levels dose-dependently. Furthermore, to examine lifting effect of skin elasticity using a sheet mask containing AloStem, 21 adult men and women applied the sheet mask in the face, once a day for 2 weeks. As a result, after 2 weeks the skin length was 116.75 ± 5.58 mm before the use of the sheet mask, but after 2 weeks of use, it was confirmed that 0.59% increased to 117.44 ± 5.17 mm. Thus, we concluded that the sheet mask containing AloStem can help the lifting effect of skin elasticity.