• 대한인간공학회지
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• 제33권5호
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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.

• 대한인간공학회지
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• 제29권1호
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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.

• 한국안전학회지
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• 제24권6호
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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.

• 펄프종이기술
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• 제43권5호
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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.

• 펄프종이기술
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• 제44권1호
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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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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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.

• 한국재료학회지
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• 제30권6호
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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.

• 한국지리정보학회지
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• 제17권3호
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• pp.39-53
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• 2014

우리나라의 인구 고령화 현상은 매우 빠르게 진행되고 있으며 농촌지역의 인구 고령화가 도시지역보다 더욱 빠르게 진행되고 있다. 그러나 지금까지 인구 고령화에 관련한 정책이나 연구들은 농촌지역보다 주로 도시지역에 초점을 두고 있다. 이에 본 연구에서는 농촌지역의 고령화 문제에 대한 심각성을 일깨우고, 나아가 지역 맞춤형 인구 고령화 정책을 수립하기 위한 기초정보를 제공한다. 이를 위해 농촌지역의 인구 고령화 수준을 미시적으로 제시하고 인구 고령화 현상의 공간적 확산 패턴을 분석하였다. 분석 결과 첫째, 읍면 단위의 농촌지역에 따라 인구 고령화 수준과 공간적 확산 패턴이 각각 다르게 분석되었다. 둘째, 고령화의 시공간적 확산 측면에서 인구 고령화 지수가 높으면서 공간적으로 집중되어 있는 지역(High-High, hot spot 지역)과 지수가 낮으면서 집중되어 있는 지역(Low-Low, cold spot 지역)은 뚜렷하게 구분되었다. 이상의 분석결과를 통해, 본 연구는 지역 맞춤형 인구 고령화 정책, 특히 농촌지역의 인구 고령화 정책을 수립하는데 기여하고자 한다.

• 폴리머
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• 제31권4호
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• pp.335-342
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• 2007

장시간에 걸친 에이징이 carboxyl acid group을 포함한 수 백 나노 두께의 6FDA계 폴리이미드 박막에 미치는 영향을 박막의 가스투과도와 굴절률의 변화를 통하여 측정하였다. 에이징 시간에 따른 가스투과도의 변화는 carboxyl acid group을 포함한 박막이 이를 포함하지 않은 박막보다 빠른 투과도 감소와 선택도의 증가를 보였으며, 박막 특성의 정량적 분석을 위해 Lorent-Lorentz 이론을 통하여 volume relaxation을 정량화하였다. 박막의 밀도와 부분자유부피는 에이징 시간의 증가에 따라 지속적인 증가 혹은 감소의 경향을 보였으며, 에이징 시간에 따른 가스투과도와 부분자유부피간의 상관관계를 $P=Ae^{(-B/f)}$을 통하여 예측할 수 있었으며, 그 결과는 다른 고분자 분리막이 보인 경향과 일치하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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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.