• Journal of Digital Convergence
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• v.15 no.2
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• pp.493-501
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• 2017

This study aimed to present cosmetic countermeasures for preventing fast aging process in the middle age and accepting healthy aging both physically and mentally by investigating the perception of aging according to the health condition, lifestyle and psychological condition targeting mid-aged women in 40s to 50s residing in Seoul and Gyeonggi-do Province. The data collection period was from July 25 to Sept 1, 2015. The data was analyzed by descriptive statistics, t-test, ANOVA, Pearson's correlation coefficients, and stepwise multiple regression. It was shown that as the age was higher, the menopause ratio was higher, drinking, exercise volume and hours of sleep were reduced and the stress and psychological pressure were higher. According to the menopausal status, the status of facial aging showed a significant difference (${\chi}^2=39.692^{***}$, p<.001), and it also showed a difference according to the status of leisure (hobby) activity (${\chi}^2=22.470^{***}$, p<.01). Also, as higher the age and closer to the menopause in items including the progress of aging, anxiety about aging and improvement efforts, more negative perception was shown, indicating that it is necessary to prepare cosmetic countermeasures for mid-aged women in like a second puberty 40s to 50s although aging and menopause around 50s are very natural. If a beauty alternative is provided, it will help them to have a successful retirement.

• International Journal of Safety
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• v.1 no.1
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• pp.36-42
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• 2002

This paper is aimed at predicting the life of rubber insulating gloves under normal operating stresses from relatively rapid test performed at higher stresses. Specimens of rubber insulating gloves are subject to multiple stress conditions, i.e. combined electrical and thermal stresses. Two modes of electrical stress, step voltage stress and constant voltage stress are used in specimen aging. There are two types of test for electrical stress in this experiment: the one is Breakdown Voltage (BDV) test under step voltage stress and thermal stress and the other is lifetime test under constant voltage stress and temperature stress. The ac breakdown voltage defined as the break-down point of insulation that leakage current excesses a limit value, l0mA in this experiment, is determined. Because the very high variability of aging data requires the application of statistical model, Weibull distribution is used to represent the failure times as the straight line on Weibull probability paper. Weibull parameters are deter-mined by three statistical methods i.e. maximum likelihood method, graphical method and least squares method, which employ SAS package, Weibull probability paper and FORTRAN, respectively. Two chosen models for predicting the life under simultaneous electrical and thermal stresses are inverse power model and exponential model. And the constants of life equation for multistress aging are calculated using numerical method, such as Gauss Jordan method etc.. The completion of life equation enables to estimate the life at normal stress based on the data collected from accelerated aging test. Also the comparison of the calculated lifetimes between the inverse power model and the exponential model is carried out. And the lifetimes calculated by three statistical methods with lower voltage than test voltage are compared. The results obtained from the suggested experimental method are presented and discussed.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.2
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• pp.160-168
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• 2003

Statement of problem : Direct denture reline resins tend to discolor during service in the oral environment by intrinsic and extrinsic factor. Purpose : This study was designed to evaluate the color stability of direct denture reline resins. Material and methods : Mild Rebaron(GC Corp., Japan), Meta Base M(Sun medical Co., Japan), Mild Rebaron LC(GC Corp., Japan) and as a control group, Vertex SC(Dentimex Zeist, Holland) were chosen for this study. Ten specimens of each direct denture reline resins were fabricated. Treatment methods designed for this study were the coffee staining test(7days) and the accelerated aging test(100hours). The color changes before and after treatment were measured by Tristimulous colorimeter(Yasuda seiki seisakusho, Ltd. Japan) and analyzed. Results All the direct denture reline resins subjected to the coffee staining test and the accelerated aging test showed noticible difference in color change. After coffee staining test, Meta Base M showed the highest color change followed by Vertex SC. Mild Rebaron LC and Mild Rebaron. There were no statistical differences between Meta Base M and Vertex SC and between Mild Rebaron LC and Mild Rebaron(p>0.05). After accelerated aging test. Mild Rebaron LC showed the highest color change followed by Vertex SC, Meta Base M and Mild Rebaron. There were no statistical differences only between Mild Rebaron and Mata Base M(p>0.05) but among the others, there were statistical differences(p<0.05). Conclusion : Within the limitation of this study, all the direct denture reline resins subjected to the extrinsic and intrinsic factors showed noticible difference in color change, and there were differences among manufacturers.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.8
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• pp.580-586
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• 1999

Aging characteristics of 13 years service-aged distribution cable terminations which dismounted from 3 regions were investigated by material characterization and electrical test. All dismounted terminations have propagating micro-cracks on the surface of weathershed and chalking fillers from bulk. Elemental analysis of these terminations showed that the carbon was decreased and the oxygen was increased on the surface of weathershed due to a little oxidation reaction. Contact angle of terminations was abnormally increased with time. In the analysis of anti-oxidation ability and chemical structure, there were no differences between new and dismounted terminations. All terminations showed satisfactory results in electrical test. Therefore, itcan be considered that aging is only propagating on the surface of dismounted terminations. Also, it was confirmed that environmental factors such as UV, pollution and salt have an effect on the aging through the observation of polymer composition change.

• Journal of the Korea Institute of Building Construction
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• v.9 no.1
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• pp.81-87
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• 2009

The purpose of this study is to investigate the sulfate attack resistance of concrete using the EAF(electric arc furnace) Slag as fine aggregate. In order to figure out the effects of magnesium sulfate solution on the durability of concrete using the EAF Slag as fine aggregate, the experiments for the immerging test in the 10% magnesium sulfate solution was executed by selecting factors such as aging processes, replacement ratio(0, 10, 20, 30, 50%), and duration of immerging. The specimens were made with various EAF slag replacements for fine aggregates and with W/C ratio fixed 0.45. compressive strength and S.D.F(Sulfate Deterioration Factor), weight change, and SEM(Scanning Electron Microscope) were tested. From the test results, EAF slag aggregate treated with accelerated aging is better than treated with air aging. The compressive strength and resistance to the sulfate attack is slightly improved with an increase in the EAF slag aggregate treated with accelerated aging replacement for aggregate.

• Journal of Electrical Engineering and Technology
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• v.13 no.3
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• pp.1355-1362
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• 2018

In order to obtain a better understanding of the ageing process of the field composite insulators, it is necessary to explore a quantitative-valuation method for the aging state evaluation. And the linear relationship between volume resistivity and temperature is proposed. In this paper, the composite insulators with different lengths of operating lives from two manufacturers were tested. The relationship between trap characteristics and volume resistivity-temperature characteristics were analyzed based on Thermal Stimulated Current (TSC), volume resistivity-temperature test, Scanning Electron Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). Furthermore, the application of trap characteristics in the quantitative evaluation of aging state of composite insulators was discussed. The results showed that there was a general negative correlation between the relative variation ratio of trap charges and the volume resistivity-temperature characteristics. Meanwhile, the physicochemical properties would change with the aging time, which would result in the increasing of electron traps. Combined with the TSC and volume resistivity test results, the trap characteristic thresholds which indicated the serious age of the composite insulators had been proposed.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.2
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• pp.176-182
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• 2022

Since the various characteristics of the polymer electrolyte membrane are not clearly identified, it is difficult to predict and design applications for various conditions. In this study, as a previous study on the aging of the polymer electrolyte membrane, a study was conducted on the change of mechanical properties according to the aging of the polymer electrolyte membrane. Through the tensile test of Nafion 117, the mechanical properties change due to aging was confirmed. As a result of the tensile test, it was confirmed that the aged Nafion 117 had reduced tensile strength. Through DSC measurement, aged Nafion confirmed that the glass transition temperature and enthalpy change were low, which is thought to be the effect of molecular motion and transition due to the lapse of time. The effect is thought to cause a difference in the amount of change in enthalpy, resulting in a difference in mechanical properties during tension.

• The Journal of the Korea Contents Association
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• v.18 no.10
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• pp.575-583
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• 2018

The purpose of this study is to examine Mediating effects of aging anxiety on the relationship between social activities and successful aging and Moderating effects of social support in relation to aging anxiety and successful aging. A total of 513 respondents participated in the questionnaire, 450 of which were used for the analysis. The analysis used mediating effect and regulatory effect test using regression analysis. The results showed that social activities lowered aging anxiety and helped to improve successful aging. Aging anxiety showed a mediating effect on the relationship between social activity and successful aging and confirmed the moderating effect of social support on the relationship between aging anxiety and successful aging. On the basis of this, the social activity providers diversify the social activity programs, reorganize the business system so that aging anxiety can be mitigated, and establish a mutual support system among the participants, so that successful aging through social activities will be more effective It is necessary to be managed so that.

• Elastomers and Composites
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• v.47 no.3
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• pp.201-209
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• 2012

Grommet is one of the Automotive rubber components and is made from EPDM(Ethylene Propylene Diene monomer M-class) rubber and the nonlinear hyperelastic material properties of rubber are important to predict the behavior of rubber product. In this study, the stable stress-strain relations were obtained from the uni-axial tension test and the equi-biaxial tension test. Finite element analysis for grommet was carried out and heat aging test for the lifetime prediction of grommet was introduced.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.5
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• pp.805-810
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• 1994

Relationship between pungency and allicin content of pickled garlic during aging was examined . Degree of pungency of pickled garlic during aging at 20 $^{\circ}C$ was determined by the sensory evaluation. A panel of 10 members evaluated seven samples of pickled garlic which were aged for 0, 10 , 20, 40 , 50 or 60 days by using scoring test (seven point scale). The sensory evaluation results showed that pungency of pickled garlic decreased gradually during aging, and scored at 3.07 on the 40 th day of aging. Content of allicin, which was a major pungent component of garlic homogenate, was quantitatively analyzed by HPLC. The level of allicin in homogenate of pickled garlic was found to decrease gradually, and to 5.9% on the 40 th day of aging compared with that of fresh garlic. Relationship between the pungency score results and the content of allicin demonstrated a highly positive correlation (r=0.9648).