• Journal of the Korean Society of Safety
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• v.25 no.2
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• pp.71-77
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• 2010

According to the Korea National Statistical Office data in 2008, the population over ages of 65 years would possess to 10.7% whole population of Korea in 2009 denoting Korea is already in the aging society. In addition, the office also expected that Korea would enter in the aged population over 65 years: 14.3% and post-aged 20.8% society in 2019 and 2026 respectively, and which suggests that an averaged age of workers in Korean industries may increase rapidly in future. The main purpose of this study is to assess the work ability and the job stress of each age group in order to identity the influential factors on those items. To this end, Questionnaires about work ability and job stress were distributed to practitioners in shipbuilding industry and statistical analysis was performed to assess work ability and the job stress based on the responses from the practitioners.

• Anxiety and mood
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• v.2 no.1
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• pp.9-16
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• 2006

As an aging population is increasing, more elderly people are exposed to traumatic stress. Although this issue has received more attention in some literature, it is clear that numerous questions exist in aftermath of trauma exposure in elderly people. In case of Korean elderly suffers, traumatic experience includes the Korean war, military dictatorship and violent demonstration. Studies regarding elderly PTSD is not active and a lot of patients are not still engaged in treatment. We suggest that concerns that are unique to this population are necessary.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.10 no.3
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• pp.345-353
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• 2003

Purpose: The purpose of this study was to explore the stress-coping process used by elderly people. Method: This study was based on the grounded theory methodology of Strauss & Corbin. The participants were 15 elders selected by theoretical sampling. Over a period of 3 months, in-depth interviews using audiotape recording were used to collect the data. The data were analyzed simultaneously by a constant comparative method in which new data were continuously coded in categories and properties according to Strauss and Corbin's methodology, Result: Stress in elderly people is caused by illness, family conflict, and loss of economic power. Stress occurred in connection with aging and limitation of social activity. The central incidents for stress were fear, alienation and anxiety. It was found that action/interactional strategies of stress-coping behavior were related to social support and mobility disorders. Action/interactional strategies to stress-coping in elderly people were dependent on medical treatment, mind control, participation of social activity, and renunciation of offensive behavior. Stress-coping in elderly people resulted in stability or instability in body and mind. Conclusion: It is suggested that the results of this study may contribute to the development stress-coping strategies for elderly people. There is need to develop social support systems and a positive environment to avoid negative coping strategies.

• Transactions on Electrical and Electronic Materials
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• v.15 no.5
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• pp.284-289
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• 2014

The effects of additives (Nb, Bi and Cr) on the microstructure, varistor properties, and aging behavior of V/Mn/Co/ La/Dy co-doped zinc oxide ceramics were systematically investigated. An analysis of the microstructure showed that all of the ceramics that were modified with various additives were composed of zinc oxide grain as the main phase, and secondary phases such as $Zn_3(VO_4)_2$, $ZnV_2O_4$, and $DyVO_4$. The $Bi_2O_3$-modified samples exhibited the lowest density, the $Nb_2O_5$-modified sample exhibited the largest average grain size, and the $Cr_2O_3$-modified samples exhibited the highest breakdown field. All additives improved the non-ohmic coefficient (${\alpha}$) by either a small or a large margin, and in particular an $Nb_2O_5$ additive noticeably increased the non-ohmic coefficient to be as large as 36. The $Bi_2O_3$-modified samples exhibited the highest stability with variation rates for the breakdown field and for the non-ohmic coefficient (${\alpha}$) of -1.2% and -26.3%, respectively, after application of a DC accelerated aging stress of 0.85 EB/$85^{\circ}C$/24 h.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1759-1761
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• 2004

In this paper, we studied on life-decision of underground cable of live-line state. Data of CV 6.6kV and 22kV cable's life is got data measured insulation resistance by D.C. overlapped current. We confirmed that D.C resistance reduced by time. Aging of cable could be occurred by electrical, thermal, mechanical stress and complex aging confirmed that proceeded by Weibull plot. In the result, life of 6.6kV cable remained 21 years till light caution and 35 years till heavy caution, so aging of 6.6kV XLPE cable was not occurred. Life of 22kV cable remained 10 years till light caution and 22 years till heavy caution. We confirmed that the designed life of 22kV cable is similar to the measured life.

• Korean Journal of Pharmacognosy
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• v.41 no.1
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• pp.26-30
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• 2010

The root of Korean ginseng (Panax ginseng C.A. Meyer) is a commonly used herbal medicine in China, Korea, Japan. However, the compositions and effects of Korean ginseng berry are not clear to date. In order to investigate the anti-aging effects in the skin, Korean ginseng berry was extracted with 70% ethanol and tested the biological effects. In the results, Korean ginseng berry extract showed an excellent anti-oxidant effect against oxidative stress and decreased MMP-1 over-expression induced by UV irradiation. Especially the main component of Korean ginseng berry extract, ginsenoside Re, increased hyaluronic acid in HaCaT keratinocytes. We improved Korean ginseng berry could be a good material for the anti-aging effect of skin.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.445-450
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• 2001

The paper investigates the relationships between dynamic elastic modulus and static elastic modulus or compressive strength according to curing temperature, aging, and cement type. Based on this investigation, the new model equations are proposed. Impact echo method estimates the resonant frequency of specimens and uniaxial compression test measures the static elastic modulus and compressive strength. Type I and V cement concretes, which have the water-cement ratios of 0.40 and 0.50, are cured under the isothermal curing temperature of 10, 23, and 50 $^{\circ}C$. Cement type and aging have no large influence on the relationship between dynamic and static elastic modulus, but the ratio of dynamic and static elastic modulus comes close to 1 as temperature increases. Initial chord elastic modulus, which is calculated at lower strain level of stress-strain curve, has the similar value to dynamic elastic modulus. The relationship between dynamic elastic modulus and compressive strength has the same tendency as the relationship between dynamic and static elastic modulus. The proposed relationship equations between dynamic elastic modulus and static elastic modulus or compressive strength properly estimates the variation of relationships according to cement type, temperature, and aging.

• Proceedings of the KIEE Conference
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• 2004.11d
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• pp.77-79
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• 2004

It is caused that insulation paper, which had got a lot of thermal stress by over-load after installation, should have been deteriorated in electrical and mechanical characteristics. Beside, insulation material is decreased the insulating property and accelerated aging of them in case of dielectric loss when transformers are manufactured with some moisture or transformers would have been them because of moisture-permeation. Therefore, in this study we experienced the influence of moisture content in case of the thermal aged insulation paper. we have measured tan 6 and breakdown voltage in the ratio of paper' moisture content before the aging and then taken the same tests again after insulation paper thermally accelerating-aged. There is a purpose to gain data for a life-design and to establish aging mechanism in order to continuously study life expectancy of the insulation paper

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.4
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• pp.38-43
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• 2011

For the efficient and safe operation of nuclear power plant, evaluating quantitatively aging phenomenon of major components is necessary. Especially, typical aging parameters such as stresses and cumulative usage factors should be determined accurately to manage the lifetime of the plant facility. The 3-D finite element(FE) model is generated to calculate the aging parameters. Mechanical and thermal transfer functions called Green's functions are developed for the FE model with standard step input. The stress results estimated from transfer functions are verified by comparing with 3-D FE analyses results. Lastly, we suggest an effective fatigue evaluation methodology by using the transfer functions. The usefulness of the proposed fatigue evaluation methodology can be maximized by combining it with an on-line monitoring system.

• Journal of the Korean Ceramic Society
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• v.27 no.8
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• pp.971-978
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• 1990

The ifluence of transformability and stabilized effects in tetragonal phase on the isothermal phase transformation of Y-TZP at low temperature were investigated. The transformability of Y-TZP powders were gradually increased with calcination temeprature and reached maximum at critical temperature, but when the Y-TZP powders were calcined above critical temperature, transformability of Y-TZP were gradually decreased with increasing calcination temperature. It was concluded that maximum transformability was appeared because particle size effects decreased and constrain effects increased with calcined temperature. The isothermal phase transformation during aging at 25$0^{\circ}C$ only observed in Y-TZP stabilized by constrain effects and the amounts of transformation during aging at 25$0^{\circ}C$ only observed in Y-TZP stabilized by constrain effects and the amount of transformed monoclinic phase during aging decreased with increasing constrain effects. From these results, the mechanism of isothermal phase transformation and degradation behaviors at low temperature in Y-TZP was concluded that occurred by decreasing of constrain effects due to stress relaxation at grian boundary.