• 한국항공운항학회지
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• 제24권1호
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• pp.41-46
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• 2016

This paper reviews and summarizes overall fatigue substantiation method of aircraft. The fatigue substantiation method has been studied using the related regulation and examples of industry application. And the comparisons of fatigue substantiation procedure between safe-life and damage tolerance design have been performed. Fatigue substantiation methods have wide variability depend on design methodology and type of aircraft such as fixed wing and rotorcraft. In this study, fatigue substantiation methodologies have been reviewed using analysis and test methods.

• International Journal of Reliability and Applications
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• 제14권1호
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• pp.27-39
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• 2013

In this article, a new model based on the Rayleigh distribution is introduced. This model is useful and practical in physics, reliability, and life testing. The statistical and reliability properties of this model are presented, including moments, the hazard rate, the reversed hazard rate, and mean residual life functions, among others. In addition, it is shown that the distributions of the new model are ordered regarding the strongest likelihood ratio ordering. Four estimating methods, namely, method of moment, maximum likelihood method, Bayes estimation, and uniformly minimum variance unbiased, are used to estimate the parameters of this model. Simulation is used to calculate the estimates and to study their properties. Finally, the appropriateness of this model for real data sets is shown by using the chi-square goodness of fit test and the Kolmogorov-Smirnov statistic.

• 농업생명과학연구
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• 제44권1호
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• pp.33-42
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• 2010

본 연구는 일당증체량, 90kg 도달일령, 등지방두께, 등심단면적 및 정육율에 영향을 미치는 품종, 성, 농장 규모 및 환경요인의 효과를 추정하였다. 2004년부터 2008년까지 농장 검정된 Landrace종 5,902 두 Yorkshire종 18,022두 및 Duroc종 6,601두 등의 3개 품종 총 30,525두의 자료를 이용하였다. 검정종료일령에 대한 보정을 위하여 모델에 공분산 항목을 포함하여 분석하였다. 일당증체량, 90kg 도달일령 및 정육율은 중간규모의 농장에서 유의적으로 우수하게 나타났다. 반면 등지방두께와 등심단면적은 소규모의 농장에서 유의적으로 우수하게 나타났다. 결론적으로 본 연구에서는 품종, 성, 검정종료년도, 검정종료계절 및 농장 규모간의 유의적 차이를 나타내었고, 추후 농장규모에 관한 더 많은 연구가 이루어져야 할 것으로 사료되어지며, 이러한 연구가 양돈 산업의 발전에 이바지 할 수 있을 것이다.

• 한국정밀공학회지
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• 제18권4호
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• pp.151-159
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• 2001

As huge energy transfer systems like a nuclear power plant, steam power plant and petrochemical plant are operated for a long time, mechanical properties are changed by degradation. The life time of the systems can be affected by the mechanical properties. BI(Ball Indentation) test has a potential to replace conventional fracture tests like a uniaxial tensile test, fracture toughness test, hardness test and so on. In this paper, we would like to present the ageing evaluation technique by the BI method. The four classes of the thermally aged 1Cr-!mo-0.25V specimens were prepared using an artificially accelerated aging method. Tensile tests, fracture toughness tests, hardness tests and BI tests were performed. The results of the BI tests were in good agreement with fracture characteristics by a standard fracture test method within 5%. The IDE(Indentation Deformation Energy) of a BI technique as a new parameter for evaluating a degradation was suggested and the new IDE parameter clearly depicts the degradation degree.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.171-176
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• 2000

As huge energy transfer systems like a nuclear power plant, steam power plant and petrochemical plant are operated for a long time, mechanical properties are changed by degradation. The life time of the systems can be affected by the mechanical properties. BI(Ball Indentation) test has a potential to replace conventional fracture tests like a uniaxial tensile test, fracture toughness test, hardness test and so on. In this paper, we would like to present the aging evaluation technique by the BI method. The four classes of the thermally aged 1Cr-1Mo-0.25V specimens were prepared using an artificially accelerated aging method. Tensile tests, fracture toughness tests, hardness tests and BI tests were performed. The results of the BI tests were in good agreement with fracture characteristics by a standard fracture test method. The IDE(Indentation Deformation Energy) of a BI technique as a new parameter for evaluating a degradation was suggested and the new IDE parameter clearly depicts the degradation degree.

• 성인간호학회지
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• 제17권3호
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• pp.400-410
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• 2005

Purpose: The purpose of this study is to examine the relationship between the living arrangement, life satisfaction and depression in the elderly. Method: The subjects consisted of 371 elderly who has at least one adult child classifying two groups(living with children and not living with children). The data were collected by a structured questionnaire that included general characteristics, Geriatric Leisure Activity Scale, Geriatric Life Satisfaction Scale, Geriatric Depression Scale, from March to December, 2004. The collected data were analyzed by SPSS program including descriptive statistics, ${\chi}^2-test$, t-test, Pearson Correlation Coefficient and Hierarchical Regression. Result: In hierarchical regression, the elders who live with their children showed more life satisfaction than elders who lived by themselves. However, living arrangement showed no effect on the level of depression of the elderly parents. Significant leisure activity interaction effect was found on the depression among the elderly: The elderly with no leisure activity reported lower levels of depression when they lived with their adult child. Conclusion: It is necessary to explore further the various relationship among living arrangement and life satisfaction of the elderly, their preferences and expectations regarding inter-generational obligations and living arrangements.

• 근관절건강학회지
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• 제13권2호
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• pp.94-107
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• 2006

Purpose: The purpose of this study was investigate the empowerment, health behavior and life satisfaction in elderly home residents according to living situations. Method: Data were collected from September to October, 2005. The participants were 240 elderly people who lived at home. Date were collected using structured questionnaire and analysed using t-test, ANOVA, Sheffe test. Result: Empowerment in elderly home residents according to living situations was significantly different(F=3.35, p=.006). Health behavior in elderly home residents according to living situations was not different significantly(F=.88, p=.492). However, questionnaire of "only the elderly couple lives" showed the highest health behavior score as an average 3.05$({\pm}.24)$. Life satisfaction in elderly home residents according to living situations was not different significantly(F=1.67, p=.143). There was a positive correlation between empowerment, health behaviors and life satisfaction. Conclusion: Considering that the single home which only the elderly people reside is the one of general family patterns of the aged people, the elderly people shall acknowledge the difference of values between a family pattern which takes a serious view of family or sons/daughters and a family pattern which reflects a weak supporting consciousness by a nuclear family. Based on above facts, Nurses should develope the nursing strategies to promote life satisfaction in the elderly.

• 종양간호연구
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• 제7권2호
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• pp.131-139
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• 2007

Purpose: This study was to compare the perceptions about hospice and the meaning of life between the participants and non-participants of the hospice volunteer education program. Method: Descriptive survey research design was used. Participants were 63, and the data collecting period was from October to December, 2006. Instrument developed by Jung-Hee Kim(1990) and Eun-Ja Lee(1998) was modified to measure the perceptions about hospice. To measure the meaning of life, P.I.L (Purpose In Life) instrument by Crumbaugh and Maholick(1969) was utilized. The data were analyzed using $X^2-test$, t-test and Pearson-Correlation Coefficient. Results: 1. The participants in the hospice volunteer education program demonstrated higher perception scores about hospice than the non-participants (t=5.193, p= .001). 2. The program participants also showed higher scores of the meaning of life than non-participants (t=3.084, p=.005). 3. The perception about hospice and the meaning of life had positive correlation (r= .46, p= .01). Conclusion: Therefore, hospice education program must be established in a continual and systematic way in order to standardize the hospice system in Korea.

• 대한간호학회지
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• 제37권5호
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• pp.676-683
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• 2007

Purpose: This study was conducted to understand the degree of vitality, meaning in life and self-efficacy and to elucidate the factors influencing this vitality in the nurses of Korea. Method: A cross-sectional survey of nurses from 4 hospitals was conducted by convenience sampling. Data collection was conducted through the use of questionnaires which were constructed to include a Vitality Self Test, Purpose in Life Test and Self-efficacy Scale. Results: The degree of vitality in nurses was in the middle range. The nurses of this study had few goals towards meaning in life, and an existential vacuum state. A positive relationship was found between vitality and the research variables. The significant predictors influencing vitality in nurses were meaning in life, self-efficacy, and clinical career, and these variables accounted for 28.7% of the variance in vitality. Conclusions: This results support that vitality is an important link with meaning in life and self-efficacy. There should be a comprehensive study in the future for in-depth understanding of the vitality of nurses.

• 국제강구조저널
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• 제18권4호
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• pp.1284-1296
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• 2018

Carbon fiber reinforced polymer (CFRP), plates bonding repair method is one of the simple repair methods for cracked steel structures. In this study, the influence of width of CFRP plates on bending fatigue life of out-of-plane gusset joint strengthened with CFRP plates was investigated from the experimental and numerical point of view. In the bending fatigue test of cracked out-of-plane gusset joint strengthened with CFRP plates, the effect of width of CFRP plates on crack growth life was clarified experimentally. Namely, it was revealed that the crack growth life becomes larger with increasing the width of CFRP plates. In the numerical approach, the stress intensity factor (SIF) at the surface point of a semi-elliptical surface crack was estimated based on the linear fracture mechanics. Furthermore, the extended fatigue life of cracked out-of-plane gusset joint strengthened with CFRP plates was evaluated by using the estimated SIF at the surface point and the empirical formula of the aspect ratio of semi-elliptical crack. As the results of numerical analysis, the estimated fatigue life of the specimen strengthened with CFRP plates showed the good agreement with the test results.