• 대한수학회지
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• 제43권2호
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• pp.225-239
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• 2006

In [5], Csorgo and Zitikis exposed the strong $uniform-over-[0,\;{\infty}]$ consistency, and weak $uniform-over-[0,\;{\infty}]$ approximation of the empirical mean residual life process by employing weight functions. We carry on the uniform asymptotic behaviors of the empirical mean residual life process over the whole positive half line by representing the process as an integral form. We compare our results with those of Yang [15], Hall and Wellner [8], and Csorgo and Zitikis [5].

• 설비공학논문집
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• 제10권6호
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• pp.658-665
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• 1998

This paper investigates local exhaust effectiveness in a room with a supply and an exhaust slots on the ceiling. The mean age of air is an indicator of supply effectiveness, while the mean residual life time can be used as an indicator of exhaust effectiveness. The distribution of local mean residual life time in a space is calculated by four different numerical procedures. The reverse-flow calculation method has been proved to show quite accurate results while it can save considerable amount of computation time and efforts, compared to the method by its original definition. It is concluded that the diffusion term in the equation of mean residual life time can be neglected. The spatial and temporal diffusion characteristics of the contaminant are also discussed.

• 한국항공우주학회지
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• 제39권7호
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• pp.612-617
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• 2011

동합금 Elbrodur-NIB 재질에 대해 평균응력을 포함한 응력제어시험을 수행하였으며, 그 결과 라체팅 거동에 응력진폭, 평균응력, 응력속도가 어떠한 영향을 주는지에 대해 시험을 통해 알 수 있었다. 라체팅 변형률은 같은 평균응력에서 응력진폭이 증가할수록, 또한 같은 응력진폭에서 평균응력이 증가함에 따라 같이 증가하는 것을 볼 수 있었다. 그러나, 응력속도가 증가함에 따라 라체팅 변형률은 감소하는 것을 알 수 있었다. $10^2-10^5$ 영역에서 3가지 평균응력을 포함한 피로수명예측모델을 검토하였으며, 그 결과 Smith-Watson-Topper가 제안한 모델과 Walker가 제안한 모델이 매우 신뢰성 있는 결과를 보여주었다.

• 대한기계학회논문집
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• 제12권4호
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• pp.790-805
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• 1988

본 연구에서는 유리섬유 강화 에폭시 복합재료의 파괴 강도와 피로 수명을 정 규분포, 로그 정규 분포와 2모수 및 3모수 Weibull 분포 함수의 기대값으로 살펴 보았 다. 2연속 응력 피로 실험 [작은 응력에서 큰 응력으로의 실험(low-high test), 큰 응력에서 작은 응력으로의 실험(high-low test)]의 결과도 분포 함수들을 사용하여 분 석하였다. 비통계학적 누적 손상 법칙들(non-statistical cumulative damage rules) 을 2연속 응력 피로 수명 분산 예측에 이용하기 위해서 동등 순위 가정(equal rank assumption)을 확장하여 수정하였다. 수정한 누적 손상 모형은 Miner의 법칙, Brou- tman과 Sahu의 손상모형 및 Hashin과 Rotem의 모형 등이다.

• Asian Pacific Journal of Cancer Prevention
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• 제17권4호
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• pp.1677-1684
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• 2016

Background: Among the factors reported to determine the quality of life of breast cancer patients are socio-demographic background, clinical stage, type of treatment received, and the duration since diagnosis. Objective: The objective of this study was to determine the quality of life (QOL) scores among breast cancer patients at a Malaysian public hospital. Materials and Methods: This cross-sectional study of breast cancer patients was conducted between March to June 2013. QOL scores were determined using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and its breast cancer supplementary measure (QLQ-BR23). Both the QLQ-C30 and QLQ-BR23 assess items from functional and symptom scales. The QLQ-C30 in addition also measures the Global Health Status (GHS). Systematic random sampling was used to recruit patients. Results: 223 breast cancer patients were recruited with a response rate of 92.1%. The mean age of the patients was 52.4 years (95% CI = 51.0, 53.7, SD=10.3). Majority of respondents are Malays (60.5%), followed by Chinese (19.3%), Indians (18.4%), and others (1.8%). More than 50% of respondents are at stage III and stage IV of malignancy. The mean Global Health Status was 65.7 (SD = 21.4). From the QLQ-C30, the mean score in the functioning scale was highest for 'cognitive functioning' (84.1, SD=18.0), while the mean score in the symptom scale was highest for 'financial difficulties' (40.1, SD=31.6). From the QLQ-BR23, the mean score for functioning scale was highest for 'body image' (80.0, SD=24.6) while the mean score in the symptom scale was highest for 'upset by hair loss' (36.2, SD=29.4). Two significant predictors for Global Health Status were age and employment. The predictors explained 10.6% of the variation of global health status ($R^2=0.106$). Conclusions: Age and employment were found to be significant predictors for Global Health Status (GHS). The Quality of Life among breast cancer patients reflected by the GHS improves as age and employment increases.

• 한국신뢰성학회지:신뢰성응용연구
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• 제18권3호
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• pp.220-228
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• 2018

Purpose: The purpose of this study is to investigate the tail behavior of the life distribution which exhibits an increasing failure rate or other positive aging effects after a certain time point. Methods: We characterize the tail behavior of the life distribution with regard to certain reliability measures such as failure rate, mean residual life and reliability function and derive several stochastic properties regarding such life distributions. Also, utilizing an L-statistic and its asymptotic normality, we propose new nonparametric testing procedures which verify if the life distribution has an increasing tail failure rate. Results: We propose the IFR-Tail (Increasing Failure Rate in Tail), DMRL-Tail (Decreasing Mean Residual Life in Tail) and NBU-Tail (New Better than Used in Tail) classes, all of which represent the tail behavior of the life distribution. And we discuss some stochastic properties of these proposed classes. Also, we develop a new nonparametric test procedure for detecting the IFR-Tail class and discuss its relative efficiency to explore the power of the test. Conclusion: The results of our research could be utilized in the study of wide range of applications including the maintenance and warranty policy of the second-hand system.

• Asian Journal for Public Opinion Research
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• 제2권1호
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• pp.15-31
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• 2014

This descriptive study evaluated the satisfaction in daily life of Thai people according to participants' socioeconomic characteristics. The accidental sample included 676 Thai people aged 20 and older who lived in Bangkok and urban Saraburi. The satisfaction in daily life questionnaire (${\alpha}=0.86$) was used to collect data. The ranking for each aspect of daily life satisfaction arranged from high to low are: family life (mean=3.39), human relations, housing, food, job, health, and income (mean=2.99). Females were found to have a significantly higher satisfaction with daily life than males (mean=22.81 vs. 21.91). Those who lived in Saraburi province were found to have a higher satisfaction with daily life than those in Bangkok. Married participants, participants age 50-59, participants from two-generation households of parents and unmarried children, participants who stated that they took better care of their health now compared to one year ago, and participants who consulted a doctor in the past month were found to have higher satisfaction with daily life than their counterparts.

• 재활간호학회지
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• 제4권2호
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• pp.219-231
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• 2001

The purpose of this study was to investigate the relationship among percieved social support, hope and quality of life of the cancer patients and to gain the baseline data for development of nursing intervention program for promoting quality of life in cancer patients. The design of this study was a cross sectional correlational survey. The subjects were 220 out and in-cancer patients in 5 general hospitals in Pusan. The data were collected from July 2 to August 1, 2001. The instruments were the Percieved social support scale(16 items, 5 point scale) had developed by Tae(1986), Hope scale(12 items, 4point scale) developed by Nowotny(1989) and Quality of life scale(31 items, 10 point scale) developed by Tae et al.(2000). The data was analyzed by the SPSS/PC+ program using frequency & percentage, item mean & standard deviation, t-test, ANOVA & Scheffe test, Pearson's correlation coefficient. The results of this study was as follows: 1) The item mean score of quality of life was $6.05{\pm}1.16$ (range 0-10). The highest score of subarea of the quality of life was the spiritual wellbeing area ($7.09{\pm}1.63$) and the lowest score was social wellbeing area ($5.53{\pm}1.65$). The mean score of perceived social support was $52.65{\pm}10.32$ (최저 1, 최고 80). The mean score of family support was $32.71{\pm}6.66$ (range 1-40) and the mean score of medical team support was $19.93{\pm}5.95$ (range 1-40). The mean score of Hope was $37.02{\pm}5.64$ (range 1-48). 2) There were statistically significant difference in the score of quality of life according to the life effect of religion(F=3.97, p=0.00), treatment method(F=2.94, p=0.01), area of diagnosis(F= 3.48, p=0.01), stage of disease (F=13.74, p=0.00). 3) There was significant correlation between perceived social support(r=0.44, p=0.000 ; family support ; r=0.334, p=0.000, medical support; r=0.395, p=0.000), hope(r=0.563, p=0.000) and quality of life. In conclusion, there was a significant relationship among perceived social support, hope and quality of life. Therefore perceived social support, hope intervention programs should be developed to improve the quality of life in cancer patients.

• International Journal of Reliability and Applications
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• 제7권1호
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• pp.1-11
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• 2006

The better mean residual life at $t_0\;(BMRL-t_0)$ class of life distribution is introduced by Kulasekara and Park (1987). They proved that the $BMRL-t_0$ class contains the DMRL class, but it is a proper subclass of the NBUE class. In this paper we develop a new family of tests for testing exponentiality against the $BMRL-t_0\;(WMRL-t_0)$ alternatives based on the goodness of fit approach. It is shown that the suggested test is better than the one introduced by Kulasekara and Park (1987) in the sense of Pitman asymptotic efficiency values.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.255-260
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• 2003

Most of the fatigue test were achieved in fully reversed condition that mean stress is zero. But, generally, mean stress can not be zero. This research was achieved the bending fatigue test that changes mean stress to spring steel and was studied relation with the mean stress and the fatigue life. The method to search effect about mean stress was extended S-N graph in two cases. One method was extended S-N graph using modified Miner's rule with considering damage. Another was extended using tendency of S-N graph. The exponential value(${\alpha}$) of mean stress-alternating stress equation is converged between the Goodman's and the Gerber's value even if fatigue life increases.