• Journal of the Ergonomics Society of Korea
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• v.33 no.5
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• pp.423-432
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• 2014

Objective and Background: The objective of this study was to evaluate the association of individual characteristics, work-related factors, lifestyle factors, and health problems with work ability among aging workers in Korea. Method: In this cross-sectional survey, the study population consisted of 1,594 workers who had participated in a voluntary health promotion center and private workplace. Participants completed the work ability index. Results: The mean WAI score was 37.4, while the mean age of the sample was 43.25. In the age group over 50 showed 36.26. The majority of participants rated their work ability as 'good' to 'excellent', one-third moderate and about 7.5% poor. Work ability decreased significantly with age among the men. The younger group had higher scores on the work ability index than the age group over 50, except for mental resources. By work characteristics, work ability was analyzed to be the lowest in the case of work handling heavy stuff. Lastly, as a result of health factors analysis, the good management and retention of current health status can be the measure helpful to the improvement of work ability. Conclusion and Application: According to the results, it can be a basic principle to devise and enforce preventive measures on the factors for which improvement or action is possible, together with workplace-level systematic approach, in order to improve work ability. For such measures to be realized, it is necessary to check trends in change for several years.

• Journal of the Ergonomics Society of Korea
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• v.29 no.1
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• pp.101-105
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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. It is well-known that the possibility to work longer and to live better is highly related to the work ability of individuals. The objective of this study is to evaluate the work ability of each aged group using the Work Ability Index(WAI) in the shipbuilding industry, machinery industry and Korea housing corporation, and to assess the effect of the type of business, age and job on the WAI score. The results showed that no significant difference was identified on the effect of aging although work ability of some group(over 55 years) was a little higher than that of others. Also, type of business and job had a significant effect on WAI score. These results suggested that the work ability is not necessarily related to aging in Korean society. One possible explanation for this might be different cultural characteristics of Korean society.

• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.132-135
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• 2009

The population over 65 years of age in Korea will be 10.3% of the entire population in 2008 indicating that Korea is already in an aging society. In addition, it is expected that Korea will be in an aged society in 2018 (population over 65 years of age : 14.3%) and that it will be in a post-aged society in 2026 (20.8%). Consequently, aged workers may also increase. It is well-known that the possibility to work longer and to live better is highly related to the work ability of individual. The objective of this study was to evaluate the work ability of each age group using the Work Ability Index(WAI) in the shipbuilding industry, and to assess the effects of social psychological stress, drinking characteristics, smoking characteristics, etc. on the WAI score. The results showed no significant difference on the effects of aging, drinking, and smoking characteristics. Interestingly, a statistical analysis on the effects of social psychological stress revealed a significant difference by stress levels. The difference of the average WAI score between the healthy group and the high risk group was about 10 points. Based on this result, it can be concluded that the stress level is an influential factor on WAI.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.5
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• pp.1-10
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• 2011

In this study, 13 water soluble polymers(6 natural polymer, 7 synthetic polymer) were treated on Hanji. Mechanical properties, morphology and oxidation index with thermal aging were measured on the aged Hanji, dewaxed Hanji and polymer treated Hanji. 3 natural polymer(such as CMC, EC, MC) and 3 synthetic polymers(such as PVA 1500, 2000, PEG 1500) treated Hanji had higher strength than other polymer treated Hanji. The oxidation index of 3% methyl cellulose solution treated Hanji did a little increase with thermal aging. Finally, methyl cellulose was found to be the most efficient method for strengthening the dewaxed Hanji. The best aging safety and thermal stability were obtained at the methyl cellulose 3% water solution.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.1
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• pp.1-9
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• 2012

In this study, 5 solvent soluble polymers were treated on Hanji. Mechanical properties, morphology and oxidation index with thermal aging were measured on the aged Hanji, dewaxed Hanji and polymer treated Hanji. Synthetic polymers(such as polylactic acid, polybutylene succinate, polystyrene) treated Hanji had higher strength and thermal stability than cellulose derivatives(such as cellulose nitrate and cellulose acetate) treated Hanji. Polymer treated Hanji showed a little bit of color change. The oxidation index of PS treated Hanji did not increase with thermal aging because it did not have a carboxyl group in chemical structure. Finally, polystyrene was found to be the most efficient method for strengthening the dewaxed Hanji. The best aging safety and thermal stability were obtained at the polystyrene 3% solution.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1216-1216
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• 2015

In this study, the author apply the VLF(Very Low Frequency) tan-delta data that has been measured at each office of the KEPCO 2012 to the Weibull distribution which is the statistical analysis as previous studies for the remaining life prediction through the improvement of the sensitivity and reliability of the degradation state assessment of underground distribution power cables. Also, in this paper, UCD(Used Cable Diagnosis) Matrix proposed by KEPCO was applied to the hierarchy of assessment prioritization. it suggests Aging Index for condition assessment and high reliability of proper economic replacement cycle using the weight according to the assessment prioritization.

• Korean Journal of Materials Research
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• v.30 no.6
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• pp.315-320
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• 2020

This study deals with the yielding behavior and strain aging properties of three bake hardening steels with dual-phase microstructure, fabricated by varying the annealing temperature. Bake hardening and aging tests are performed to examine the correlation of martensite volume fraction with yielding behavior and strain aging properties of the bake hardening steels with dual-phase microstructure. The volume fraction of martensite increases with increasing annealing temperature. Room-temperature tensile test results show that the yielding behavior changes from discontinuous-type to continuous-type with increasing volume fraction of martensite due to higher mobile dislocation density. According to the bake hardening and aging tests, the specimen with the highest fraction of martensite exhibited high bake hardening with low aging index because solute carbon atoms in ferrite and martensite effectively diffuse to dislocations during the bake hardening test, while in the aging test they diffuse at only ferrite due to lower aging temperature.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.3
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• pp.39-53
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• 2014

The Korean population is aging rapidly and a disproportionate share of older people(aged 65 and older) lives in rural areas. The rural population is aging more rapidly than the population in urban area. However, the majority of studies on aging population focuses on an urban area rather than a rural area. Rural areas have been alienated from the priority of the national policy. For these reasons, this study is to show the level of population aging and to analyze the spatial spillover patterns of aging population in rural areas for the establishment of localized policy on population aging. The main findings of this study can be summarized as follows. First, the level of population aging varies in different localities such as socio-economic and locational characteristics. Secondly, there are distinct differences between hot spot region(clustering of high aging index) and cold spot region(clustering of low aging index) in spatio-temporal spillover patterns. This study intends to suggest an useful information to establish the area-specific policy on aging population through the results of analysis.

• Polymer(Korea)
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• v.31 no.4
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• pp.335-342
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• 2007

The goal of this study is to investigate the effect of molecular structure modifications on the kinetics of physical aging of thin films formed from 6FDA-based polyimides with time. The permeability for 6FDA-based polyimide thin films containing carboxyl acid groups commonly decreased 20-50% after the isothermal aging and the selectivity gained anywhere from 10% to 30% while the rate of permeability loss on the change of polymer structure showed different reciprocal relationship between 6FDA-6FpDA based polyimides and 6FDA-DAM based polyimides. The Lorenz-Lorentz equation was used to relate changes in refractive index to densification and volume relaxation with aging time. The permeability as a function of aging time fits the expected form $P=Ae^{(-B/f)}$. The results matched well with the data for different polymer membranes.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.420-422
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• 2003

Aging and failure of motor insulation depend on the stresses imposed on it. The insulation life time depends on the severity of the stresses. The electrical aging by transient surge is very important to traction motor in EMU(electric multiple unit). This paper Presents the insulation characteristics of stator coil by transient surge from inverter. There are several nondestructive tests available for checking the condition of motor insulation, the probable extent of aging,. and the rate of which aging is taking pace. So the insulation characteristics of stator coil were each analyzed by measurement of leakage current, dielectric loss($tan{\delta}$), capacitance, polarization index(PI) and partial discharge. The method of diagnosis is able to analyze the aging condition and Predict the life of the traction motor in EMU.