• 대한예방의학회:학술대회논문집
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• 1999.10a
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• pp.167-168
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• 1999

• 대한예방의학회:학술대회논문집
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• 1999.10a
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• pp.177-178
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• 1999

• Journal of the Korean Statistical Society
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• v.23 no.2
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• pp.379-402
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• 1994

Graphical and numerical methods for checking the assumption of proportional hazards of Cox model for censored survival data are discussed. The strenths and weaknessess of several goodness of fit tests for the propotional hazards for the two-sample problem are evaluated with Monte Carlo simulations, and the tests of Schoenfeld (1980), Andersen (1982), Wei (1984), and Gill and Schumacher (1987) are considered. The goodness of fit methods are illustrated with the survival data of patients who had chronic liver disease and had been treated with the endoscopy injection sclerotheraphy. Two other examples of data known to have nonpropotional hazards are also used in the illustration.

• Journal of the Korean Statistical Society
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• v.32 no.2
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• pp.163-174
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• 2003

We propose a test for independence of bivariate censored data under univariate censorship. To do this, we first introduce a process defined by the difference between bivariate survival function estimator proposed by Lin and Ying (1993) and the product of the product-limit estimators (Kaplan and Meier, 1958) for the marginal survival functions, and derive its asymptotic properties under the null hypothesis of independence. We propose a Cramer-von Mises-type test procedure based on the process . We conduct simulation studies to investigate the finite-sample performance of the proposed test and illustrate the proposed test with a real example.

• The Korean Journal of Applied Statistics
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• v.19 no.3
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• pp.555-564
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• 2006

Friedman rank-sum multiple comparison procedure is often applied to nonparametric multiple comparison method under randomized block design. Since this method does not use between-block information, we propose, in this paper, nonparametric multiple comparison procedures employing aligned method suggested by Hedges and Lehmann(1962) under randomized block design. The proposed procedure and Friedman procedure are compared by Monte Carlo simulation study.

• Journal of Korean Academy of Nursing Administration
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• v.16 no.3
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• pp.267-275
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• 2010

Purpose: This study conducted to identify the effect of learning organization construction and learning orientation on organizational effectiveness among hospital nurses. Method: Data was collected from convenient sample of 296 nurses who worked for the major hospitals in Seoul, Gyeonggi-do and Gangwoen-do. The self-reported questionnaire was used to assess the general characteristics, the level of the learning organization construction, learning orientation and organizational effectiveness. The data were analyzed using descriptive statistics, pearson's correlation coefficient and multiple regression. Result: The mean score of learning organization construction was 3.61(${\pm}.32$), learning orientation got 3.26(${\pm}.39$), and organizational effectiveness obtained 3.38(${\pm}.42$). The learning organization construction affects of organizational effectiveness by 44.18% and learning orientation by 37.43%. Conclusion: This finding indicates that learning organization construction and learning orientation affects the nurses' organizational effectiveness in hospital.

• Genomics & Informatics
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• v.5 no.4
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• pp.168-173
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• 2007

In previous nuclear genomic association studies, Random Forests (RF), one of several up-to-date machine learning methods, has been used successfully to generate evidence of association of genetic polymorphisms with diseases or other phenotypes. Compared with traditional statistical analytic methods, such as chi-square tests or logistic regression models, the RF method has advantages in handling large numbers of predictor variables and examining gene-gene interactions without a specific model. Here, we applied the RF method to find the association between mitochondrial single nucleotide polymorphisms (mtSNPs) and diabetes risk. The results from a chi-square test validated the usage of RF for association studies using mtDNA. Indexes of important variables such as the Gini index and mean decrease in accuracy index performed well compared with chi-square tests in favor of finding mtSNPs associated with a real disease example, type 2 diabetes.

• Journal of the Korean Statistical Society
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• v.5 no.2
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• pp.119-127
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• 1976

By examining Table 1, it is confirmed that the two model fertility scheduels for 1960 and 1975 are close agreement with the census data in Korea. The declines of age-specific fertility are more remarkable among older women than among younger, as exhibited in Table 3 and Fig. 2. A merit of this fitted model schedule as compared to fitted conventional frequency distributions such as the Pearson Type III curve, is that the model schedule incorporates combinations of intuitively understandable demographic factors. The value of m, a measure of fertility control, increased remarkably from 0.531 in 1960 to 2.429 in 1975. Considering the fact that the average value of m for forty-three schedules shown in the 1965 Demographic Yearbook was 1.0, and the value of m in England and Wales for 1965 was 1.91, the recent level of fertility control in Korea may be considered higher than generally believed.

• 대한예방의학회:학술대회논문집
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• 2002.10a
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• pp.220-221
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• 2002

• 대한예방의학회:학술대회논문집
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• 2002.10a
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• pp.227-228
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• 2002