• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.693-697
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• 2005

This study was performed to develop accelerated life test method of the wind-turbine gearbox using accumulated damage theory that used to model the fatigue of parts that receive variable load. The accumulated damage theory was introduced, and the estimation of life and calculation of accelerated life test time was illustrated. As the actual application example, accelerated life test method of the gearbox was described. Life distribution of the wind-turbine gearbox was supposed to follow Weibull distribution and life test time was calculated under the conditions of average life (MTBF) 140,600 hours and 99% reliability for one test sample According to the accumulated damage theory, because test time can shorten in case increase test load, test time could be reduced by 1.2 years when we put the load 1.2 times of rated load than 0.93 times of rated load that is equivalent load calculated by load spectrum of the wind turbine. This time, acceleration coefficient was 21.3. This accelerated test method was used to develop accelerated test method of gear reducer, gear and bearing as well as the industrial gearbox and it is considered to be applied comprehensively to mechanical parts the fatigue of which is happened by load or pressure etc.

• 연구논문집
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• s.32
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• pp.35-43
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• 2002

This study was performed to develop accelerated life test method of machanical parts using cumulative damage theory that used to model the fatigue of parts that receive variable load. The cumulative damage theory was introduced, and the estimation of life and calculation of accelerated life test time was illustrated. As the actual application example, accelerated life test method of agricultural tractor transmission was described. Life distribution of agricultural tractor transmission was supposed to follow Weibull distribution and life test time was calculated under the conditions of average life (MTBF) 3,000 hours and 90% reliability for one test sample. According to the cumulative damage theory, because test time can shorten in case increase test load, test time could be reduced by 482 hours when we put the load 1.1 times of rated load than 0.73 times of rated load that is equivalent load calculated by load spectrum of the agricultural tractor. This time, acceleration coefficient was 11.7. This accelerated test method was used to develop accelerated test method of gear reducer, hydraulic hose and bearing as well as agricultural tractor transmission and it is considered to be applied comprehensively to machanical parts the fatigue of which is happened by load or pressure etc.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.7
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• pp.607-611
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• 2000

The characteristics on the interface between Epoxy and EPDM which are materials of the underground insulation systems of power delivery have studied. The breakdown strength of specimens are observed by applying high AC voltage at the room temperature. The breakdown times under the constant voltage below the breakdown voltage were gained. As constant voltage is applied the breakdown time is proportion to the breakdown strength. The life exponent n is gained by inverse power law and the long breakdown life time can be evaluated. AC breakdown strength and life time is improved by oiling to the interface. When the low viscosity oil is spread interface has the highest life time.

• Journal of Korean Society of Rural Planning
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• v.18 no.4
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• pp.91-101
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• 2012

The time management and allotments for various activities of daily life is much different by age groups. This study analyzes time allotments of different age groups for various activities of daily life to figure out the change of main activity by aging through 2009 time use survey by National Statistical Office. Especially we focus on time allotments of rural elderly population and intangible factors for life quality of people instead of physical and environmental elements. The results show that there is a large gap of time allotments for paid and unpaid working time of rural and urban elderly population. Whereas the time for leisure of elderly women in rural areas is much shorter than that of urban elderly women and rural elderly men spend more time to provide community services and help to other households. However, the percentage leisure time of rural elderly people for passive activities such as TV, radio, magazine etc. is longer than that of urban elderly people. We hope that our analysis data could be used for developing new policies and project to improve the life quality of rural elderly population.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.6
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• pp.772-776
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• 2006

The purpose of this study was to examine the differences in satisfaction of leisure life and quality of life using standardized evaluation tools developed by WHO. Resource availability when dining out was measured by objective index(time of dining out, dining out expense) and subjective index(perceived satisfaction with time of dining out and dining out expense). In this study, 500 questionnaires(male & female adults) located in Seoul and the metropolitan area were sampled by convenience sampling and gather in 433 sheets of questionnaire. Data was analyzed by frequency analysis, factor analysis, reliability analysis, correlation analysis and regression analysis using SPSS Win 12.0. As a result there was high positive correlation between time of dining out, dining out expense and perceived satisfaction with time of dining out and dining out expense. Moreover, dining out resources impact on leisure life satisfaction and quality of life. Leisure life satisfaction had fairly high effects on quality of life. Since there is an increase in leisure time the desire to improve quality of life while enjoying dining out as a part of leisure life is increasing and as various forms of consumption takes place, it suggests that segmentation of dining out market is necessary and marketing strategy should be established.

• The Korean Society of Law and Medicine
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• v.11 no.1
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• pp.297-329
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• 2010

The bioethics as a comprehensive and normative control method of life sciences including the technology of advanced medical care, on the one hand, it has modified the conditions for allowing the progress of life sciences. On the other hand, it has put the brakes on attempts of life sciences violating the dignity and value of human beings, natural order. Positively, bioethics presents ethical bases, suggests organization of the legal and institutional conditions, and enables elimination of the legal and institutional obstacles, for the progress of life sciences. Negatively, it has presented justifiable prospects and road maps of life sciences, not to take indiscreet and intemperate turn of violating the dignity and value of human beings, natural order, and its such roles must be carried on.

• Journal of Family Resource Management and Policy Review
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• v.4 no.2
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• pp.57-73
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• 2000

The Purpose of this study is to scrutinize the time structure and time use pattern of North Korean and to identify the differences of time use patterns between South and North Korean Societies. To carry out this Purpose in-depth interviews with ten people who escaped from North Korea after 1990 and empirical survey with 158 subjects were conducted. The findings are as follows. The characteristics of time life of North Korean are uniform time use pattern in tightly scheduled daily life and shortage of disposable time and constraint of free time due to job related labor, extra job activities including learning, meeting and evaluation, and labor mobilization. Women are faced with heavy burden of doing job and housework in the continuing patriarchal way of thinking and in the circumstances of poor housing environment. In North, Leisure time is constraint and leisure facilities are poor and the concept of leisure is totally different as that of South. North Korean think leisure as connecting with work and education and as public sphere, not private sphere. I this context leisure is considered as means for the strengthening of the communist society. Differences in the perception of time life through defectors are as follows. In South, there are plenty of leisure time and man can control his own time. Man spend his free time for various activities, especially for cultural activities such as sports, recreation, eating out with families and spend time till late in the outdoors. This study revealed differences in many aspects of time life between South and North Korean societies. These results will provide useful informations for the overcome of differences of cultural life of South and North Korean societies and accomplishment of the real integration of two societies.

• Journal of Family Resource Management and Policy Review
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• v.18 no.2
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• pp.75-102
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• 2014

This study classified the current work-life balance of full-time female paid workers and tested the typology by using the 2009 Korean Time Survey. The categorization demographic and psychological characteristics of women belonging to each type were comparatively analyzed. It was found that full-time female paid workers used an average of 435.7 minutes for work, 146.4 minutes for family, 104.5 minutes for leisure, and 17.7 minutes for growth. On the basis of times used in each area of work and life, individuals were classified into family-oriented type, work-leisure parallel type, work-oriented type, work-growth parallel type, and work-family parallel type. Psychological characteristics were examined by type. The work-oriented type women experienced feelings of lack of time and fatigue the most compared with women of other types. From examining the influence that the amount of time used in each area of work and life had on psychological characteristics, it was shown that the activity time relevant to leisure influenced psychological characteristics the most. Lastly, based on the limitations of this study, future assignments are discussed.

• KIEAE Journal
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• v.14 no.5
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• pp.5-12
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• 2014

Building has been deteriorated gradually owing to geographic, physical complex and other factors. School living condition has a key role to improve the learning ability, life attitude and qualifications to adopt to social life. Therefore, it is important for school environment to keep the living condition. Repair time and scope of school facilities are required to maintain the function and performance to plan the long term repair. But there are little information about the school maintenance such as repair time and function. In this paper, it aimed at providing the service life to suggest the repair time and scope in the roof-proofing and floor finishing which used the three estimation method in probabilistic approach. The service life has a key role to decide the repair time and to make the plan for the repair maintenance. Results of this study are as follows ; First, the 1st repair time were taken through three methods in probabilistic and deterministic functions to eliminate the estimation bias. Second, the service life is suggested 36 years of an elementary school, 34 years of a middle school and 41 years of a high school. Third, the service life of a floor finishing is 43 years of an elementary, 39 years of a middle school and 41 years of a high school. The above study could not include the detailed information about the materials and repair works. Therefore it needs a further study to reflect the detailed information and to make a repair strategy.

• Elastomers and Composites
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• v.52 no.4
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• pp.237-241
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• 2017

The tensile strength (TS) and elongation-at-break (EB) loss of a CR/CB rubber composite sample prepared for the automotive parts were measured after accelerated thermal ageing at temperatures of 100, 120, 140, and $150^{\circ}C$. The change in TS was observed to be linear from the master curve prepared using the time-temperature superposition-principle (TTSP). An Arrhenius type of shift factor, $a_T$ was used to predict the life time of the sample, and a plot of ln $a_T$ vs. 1/T was also shown to be linear. The activation energy ($E_a$) of the sample was calculated as 70.30 kJ/mole from the Arrhenius plot. The expected life time of the sample was predicted at the given operating conditions by applying Arrhenius analysis. Assuming the $E_a$ value was constant at lower operating condition, life time of the sample was calculated as 2.3 years when the life limit was set as time to reach the 20% decrease of the initial TS value at operating temperature of $40^{\circ}C$.