• Communications for Statistical Applications and Methods
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• 제3권2호
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• pp.129-138
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• 1996

We propose a smoothing estimator of mean residual life function based on Ghorai and Susarla's (1990) smooth estimator of distribution function under random censorship model and provide the asymptotic properties of this estimator. The Monte Carlo simulation is performed to compare the proposed estimator with the other estimators and an exmple is also given using the real data.

• 품질경영학회지
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• 제27권1호
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• pp.91-100
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• 1999

In this paper we propose a smooth nonparametric estimator of mean residual life based on a complete sample. This estimator is constructed using the maximum likelihood estimate of cumulative failure rate in the class of distributions which have piecewise linear failure rate functions between each pair of observations. We derive the asymptotic properties of our estimator. Examples using simulated data are used to illustrate the performance of this estimation.

• 품질경영학회지
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• 제30권4호
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• pp.78-85
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• 2002

The problem of trend change in the mean residual life is great interest in the reliability and survival analysis. In this paper, a new test statistic for testing whether or not the mean residual life changes its trend is developed. It is assumed that neither the change point nor the proportion at which the trend change occurs is known. The asymptotic null distribution of test statistic is established and asymptotic critical values of the asymptotic null distribution is obtained. Monte Carlo simulation is used to compare the proposed test with previously known tests.

• 품질경영학회지
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• 제22권3호
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• pp.111-118
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• 1994

In this paper we propose a parametric and a nonparametric small sample estimators for the mean residual life (MRL) under the random censorship model using the partial moment approximation. We also compare the proposed nonparametric estimator with the well-known nonparametric MRL estimator based on Kaplan-Meier estimator of the survival function, and present the efficiency of the nonparametric method relative to the Weibull model for small samples.

• 대한간호학회지
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• 제37권4호
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• pp.459-466
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• 2007

Purpose: This study was to identify predictors of quality of life in breast cancer patients. Physical and pscyhological factors like stress, mood, and fatigue with sociodemographic factors like education, income, job and stage of disease were used to predict quality of life. Methods: One hundred eleven patients with breast cancer participated in this study? The functional Assessment of Cancer Therapy-Breast(FACT-B) was used to assess quality of life. Results: The mean age of the patients was 46.7 years. The FACT-B mean score was 89.89(SD:17.31) Education, income, job and stage of disease were significantly associated with QOL. In a regression analysis, mood, income, and fatigue were significant predictors for QOL where as, stress was not significant. Among the subscales of QOL, physical well-being, functional well-being, emotional well-being, and the breast cancer subscale were included as predictors of QOL Conclusion: Physical and psychological factors were strong predictors of QOL. These results demonstrate the need for interventions to improve QOL in breast cancer survivors.

• Journal of the Korean Statistical Society
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• 제18권2호
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• pp.125-134
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• 1989

This paper presents optimum simple step-stress accelerated life test plans for the case where the test process is observed periodically at intervals of the same length. Two types of failure data, periodically observed complete data and periodically observed censored data, are considered. An exponential life distribution with a mean that is a log-linear function of stress, and a cumulative exposure model for the effect of changing stress are assumed. For each type of data, the optimum test plan which minimizes the asymptotic variance of the maximum likelihood estimator of the mean life at a design stress is obtained and its behaviors are studied.

• 대한안전경영과학회지
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• 제14권3호
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• pp.167-174
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• 2012

In the manufacturing process the most widely used $\bar{X}$ chart has been applied to control the process mean. Also, Accelerated Life Test(ALT) is commonly used for efficient assurance of product life in development phases, which can be applied in production reliability acceptance test. When life data has lognormal distribution, through censored ALT design so that censored ALT data has asymptotic normal distribution, $ALT\bar{X}$ control chart integrating $\bar{X}$ chart and ALT procedure could be applied to control the mean of process in the manufacturing process. In the situation that process variation is controlled, $Z_p$ control chart is an effective method for the very small fraction nonconforming of quality characteristic. A simultaneous control scheme with $ALT\bar{X}$ control chart and $Z_p$ control chart is designed for the very small fraction nonconforming of product lifetime.

• 대한간호학회지
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• 제31권5호
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• pp.912-920
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• 2001

The purpose of this study is to identify the correlation that exists between quality of life and self-efficacy of schizophrenic patients, focusing on the influence of related factors on these varables. Method: The subjects of this study were 151 schizophrenic patients. The data were collected using questionnaires. The instruments used for this study were the general self-efficacy scale developed by Sherer ＆ Maddex(1982), the specific self-efficacy scale modified and complemented by these co-researchers on the basis of the past studies and modified SIP by Voruganti(1996). The period of data collection was from July. 2000 to Jan. 2001. Data analysis was done by SPSS, t-test, ANOVA and the Pearson Correlation Coefficient. Result: 1. The level of self-efficacy showed a mean score of 60.0 and the level of quality of life, a mean score of 47.0. 2. The general characteristics affecting the self-efficacy of schizophrenic patients were staying with family (p=0.05) and employment (p=0.00). 3. The general characteristics affecting the quality of life of schizophrenic patients were staying with family (p=0.04), employment (p=0.05) and duration of illness (0.03). 4. A positive correlation was identified between self-efficacy and quality of life (r=-0.469, p=0.000). Conclusion: The study suggests that nursing intervention strategy should be worked out to develop a psychiatric rehabilitation program that can promote self-efficacy and thus enhance the quality of life of schizophrenic patients.

• Asian Pacific Journal of Cancer Prevention
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• 제16권9호
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• pp.4089-4094
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• 2015

The purpose of the research was to determine the effect of home care service on the quality of life in patients with gynecological cancer. This randomized case control study was carried out in a womans hospital between September 2011 and February 2012. Women undergoing gynecological cancer treatment were separated into intervention and control groups, of 35 patients each. The intervention group was provided with nursing care service through hospital and home visits ($1^{st}$, $12^{th}$ weeks) within the framework of a specifically developed nursing care plan. The control group was monitored without any intervention through the hospital routine protocols ($1^{st}$, $12^{th}$ weeks). Data were collected using An Interview Form, Home Visit Monitoring Form and Quality of Life Scale/Cancer Survivors. Effects of home care service on the quality of life in gynecological cancer patients were investigated using chi-square tests, McNemar's test, independent t-test and ANOVA. This study found that the intervention group receiving home care service had a moderately high quality of life (average mean: $6.01{\pm}0.64$), while the control group had comparatively lower quality (average mean: $4.35{\pm}0.79$) within the 12 week post-discharge period (p<0.05). This study found home care services to be efficient in improving the quality of life in patients with gynecological cancer.

• 대한가정학회지
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• 제39권2호
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• pp.57-72
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• 2001

This study was designed to investigate the relationships among adolescent′s study load, peer relationships, school violence and their level of satisfaction with school life. Its purpose was not only to identify and describe their overall school life, but most importantly, to provide baseline data to develop intervention programs that shall improve the level of adolescents′satisfaction with school life. The analysis of data revealed the following results: 1. Adolescents felt highly stressed by their studies. The mean score was 3.40 out of 5 points. 2. Adolescents were highly intimate and relatively low confident with their friends, 4.28 and 3.82 respectively. 3. Approximately half of the respondents(45.4%) had an experience of making their classmates feel "exclusive". In connection, 27% had been involved in school violence. 4. The mean score of adolescents′ level of satisfaction with school life was 2.33. The resets of the study also revealed that students in the rural areas are more satisfied with their school life than in Seoul area Similarly, those in vocational schools are more satisfied than those in regular schools.