• Korean Journal of Child Studies
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• v.15 no.2
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• pp.181-193
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• 1994

The purpose of this research was to study differences between reciprocal and unidirectional friendships and to examine evidence on whether certain constituents of friendship can predict the termination of friendships. A total 375 subjects- 190 elementary and 185 middle school children in Pusan- were administered questionnaires two times at an interval of 3 months. Frequency, factor-analysis, t-test, discriminant-analysis, and cross classification analysis were applied for data analysis. The results of the study were as follows: 1) The different constituents of reciprocal and unidirectional friendships were statistically significant. That is, children in reciprocal friendships perceived their relationships more positively, felt closeness more strongly, and evaluated their friend more highly than the children in unidirectional friendships. 2) The termination of reciprocal friendships was predicted by the constituents of friendship. The most powerful predictor was the degree of closeness and the second powerful predictor was the degree of commitment to the relationship and the 3rd powerful predictor was perceived characteristics of the friend. The last powerful predictor was perceived characteristics of the relations. 3) There were no sex differences in the rate of termination of reciprocal relationships. 4) There were age differences in the rate of friendship termination of reciprocal relationships. That is, the rate of termination of reciprocal relationships among older children was higher than among younger children.

• Journal of the Korean Statistical Society
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• v.30 no.2
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• pp.281-290
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• 2001

Symmetric estimation and recursive mean adjustment are considered to construct tests for the doble unit root hypothesis for both parametric and semiparametric time series models. It is shown that simultaneous application of symmetric estimation and recursive mean adjustment yields the most powerful test. Moreover, size property of the semiparametric test based on the simultaneous application is bet among all semiparametric tests.

• Journal of Korean Society for Quality Management
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• v.26 no.4
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• pp.79-87
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• 1998

This paper considers the problem of testing a one-sided hypothesis under the generalized sampling plan which is defined by a sequence of independent Bernoulli trials. A certain lexicographic order is defined for the boundary points of the sampling plan. It is shown that the family of probability mass function defined on the boundary points has monotone likelihood ratio, and that the test function is uniformly most powerful.

• Journal of the Korean Statistical Society
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• v.33 no.2
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• pp.149-157
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• 2004

The stationarity is one of the most important properties of a time series. We propose robust sign tests for seasonal autoregressive processes to determine whether or not a time series is stationary. The proposed tests are robust to the outliers and the heteroscedastic errors, and they have an exact binomial null distribution regardless of the period of seasonality and types of median adjustments. A Monte-Carlo simulation shows that the sign test is locally more powerful than the tests based on ordinary least squares estimator (OLSE) for heavy-tailed and/or heteroscedastic error distributions.

• Proceedings of the Korean Statistical Society Conference
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• 2003.05a
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• pp.281-286
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• 2003

The stationarity is one of the most important properties of a time series. We propose robust sign tests for seasonal autoregressive process to determine whether or not a time series is stationary. The tests have an exact binomial null distribution and are robust to the outliers and the heteroscedastic errors. Monte-Carlo simulation shows that the sign test is locally more powerful than the OLSE-based tests for heavy-tailed and/or heteroscedastic error distributions.

• Journal of Korean Academy of Nursing
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• v.15 no.2
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• pp.49-61
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• 1985

It is assumed that the more society advances in its complexity and development, the more people pay attention to their health and accordingly the more people tend to practice health protective behavior. Most of human behavior is based on social inter-actions. The concept in Locus of Control has been developed from social learning theory to help better understanding the social phenomena affecting human behavior. Multidimensional Health Locus of Control is consisted of three dimensions: Internal, Powerful Others and Chance. This study was conducted to find out the health protective behavior patterns of the people and its relationship with Health Locus of Control as an influencing factor to their behavior. All the subjects in this study were the ones of the bank employees in Seoul, Among the total of 1,430 bank employees, 761 were chosen as a sampled subjects. Questionnair survey was conducted from March 4 to March 13, 1985. Research instruments used in this study were two kinds, one was the Health Locus of Control Scale developed by Wallston & Wallston and the other was the Measuring Scale for Health Protective Behavior developed by the investigator. Analysis of data was done by using Descriptive Statistics, X²-test, t-test, ANOVA, Pearson's correlation coefficient. The results of this study are summarized as follows: The mean score of Internal was 24.1, Powerful others was 19.7 and Chance was 15.3 out of maximum range of 6-30 respectively. The mean score of Health Protective Behavior Scale fell as 53.2 out of a maximum range of 18-90. Internals were more likely closely related with sex, educational levels and religion, Powerful others were related with age, educational levels and the number of family members. Chances were related with edu cational levels. The older the subjects were, the more concerned about their health. They tended to practice more favorable health protective behaviors. Furthermore, married people tended to fay more attention to their health than single individuals. Also, the number of family members and religion affected their attitudes in the health protective behavior patterns. Internals and Powerful Others were related with health protective behaviors. If one believes he can do something about his health and others play a significant role on his health, he is more apt protective patterns more suitable for health and actually shows that he is better off.

• Journal of the Korean Data and Information Science Society
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• v.27 no.5
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• pp.1399-1412
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• 2016

We compare many normality tests consisting of different sources of information extracted from the given data: Anderson-Darling test, Kolmogorov-Smirnov test, Cramervon Mises test, Shapiro-Wilk test, Shaprio-Francia test, Lilliefors, Jarque-Bera test, D'Agostino' D, Doornik-Hansen test, Energy test and Martinzez-Iglewicz test. For the purpose of comparison, those tests are applied to the various types of data generated from skewed distribution, unsymmetric distribution, and distribution with different length of support. We then summarize comparison results in terms of two things: type I error control and power. The selection of the best test depends on the shape of the distribution of the data, implying that there is no test which is the most powerful for all distributions.

• Communications for Statistical Applications and Methods
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• v.21 no.4
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• pp.309-316
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• 2014

Testing normality is very important because the most common assumption is normality in statistical analysis. We propose a new plot and test statistic to goodness-of-fit test for normality based on the generalized Lorenz curve. We compare the new plot with the Q-Q plot. We also compare the new test statistic with the Kolmogorov-Smirnov (KS), Cramer-von Mises (CVM), Anderson-Darling (AD), Shapiro-Francia (SF), and Shapiro-Wilks (W) test statistic in terms of the power of the test through by Monte Carlo method. As a result, new plot is clearly classified normality and non-normality than Q-Q plot; in addition, the new test statistic is more powerful than the other test statistics for asymmetrical distribution. We check the proposed test statistic and plot using Hodgkin's disease data.

• Communications for Statistical Applications and Methods
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• v.8 no.1
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• pp.137-145
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• 2001

There are many situations in which the well-known tests such as log-rank test and Gehan-Wilcoxon test fail to detect the survival differences. Assuming large samples, these tests are developed asymptotically normal properties. Thus, they shall be called asymptotic tests in this paper, Several asymptotic tests sensitive to some specific types of survival differences have been recently proposed. This paper compares by simulations the test levels and the powers of the conventional asymptotic tests and their random permutation versions. Simulation studies show that the random permutation tests possess competitive powers compared to the corresponding asymptotic tests, keeping exact test levels even in the small sample case. It also provides the guidelines for choosing the valid and most powerful test under the given situation.

• Journal of Korean Academy of Nursing Administration
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• v.12 no.4
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• pp.604-614
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• 2006

Purpose: This study was to identify factors that influence the organizational commitment and job satisfaction of nurses. Method: The data were collected from 1st, August until 7th, August, 2005. The subjects were 238 nurses from a general hospital in Busan. Data were analyzed with descriptive statistics, t-test, one-way ANOVA, Pearson correlation coefficient, and stepwise multiple regression using SPSS program. Result: The organizational commitment and job satisfaction was significant positive correlations with flexibility, satisfaction, competence factors and significant negative correlations with empathy factors and centralization factor. The most powerful predictors of Nurses's organizational commitment and job satisfaction was managerial strategy of organizational characteristics. And, satisfaction factors of professional self-concept, affiliative-dominant culture and conservative- dominant culture and innovative-dominant culture were powerful predictor factors. The Other powerful predictors of nurses's job satisfaction were satisfaction factors of professional Self-concept, communication and centralization factor of organizational characteristics, affiliative-dominant culture and conservative-dominant culture, professional image factor of nurse image. Conclusion: This study revealed that important factors for nurses's organizational commitment and job satisfaction. Consequently, the manager should be make effective managerial strategy and encourage that nurse have more satisfy to professional self-concept. And the manager make constant efforts to create an affiliative culture in hospital.