• 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 the Korea Society of Computer and Information
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• v.27 no.6
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• pp.167-174
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• 2022

In this paper we investigate the permutation test for the equality of correlation coefficients in several independent populations. Permutation test is a non-parametric testing methodology based upon the exchangeability of observations. Exchangeability is a generalization of the concept of independent, identically distributed random variables. Using permutation method, we may construct asymptotically exact test. This method is asymptotically as powerful as standard parametric tests and is a valuable tool when the sample sizes are small and normality assumption cannot be met. We first review existing parametric approaches to test the equality of correlation coefficients and compare them with the permutation test. At the end, all the approaches are illustrated using Iris data example.

• The Korean Journal of Applied Statistics
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• v.15 no.2
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• pp.355-366
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• 2002

Nonparametric statistical inference for the parameter of logit model were examined. Usually nonparametric approach is milder than parametric approach based on normal theory assumption. We compared the two nonparametric methods for legit model, the bootstrap and random permutation in the sense of coverage probability. Monte Carlo simulation is conducted for small sample cases. Empirical power of hypothesis test and coverage probability for confidence interval estimation were presented for simple and multiple legit model respectively. An example were also introduced.

• The Korean Journal of Applied Statistics
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• v.14 no.1
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• pp.191-199
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• 2001

본 소고는 n명의 심사자가 k개의 객체를 평가하여 얻어진 불완전 순위자료에서 객체간 선호도에 있어 차이가 없다는 영가설을 검정하는 방법에 관한 연구이다. 주어진 자료에서 결측값들을 다중대체하는 방식을 제안하고 이들을 평균 p-값으로 묶는 몬테칼로방식의 임의순열 검정을 제안한다.

• The Korean Journal of Applied Statistics
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• v.31 no.2
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• pp.241-251
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• 2018

The analysis of gene sets in microarray has advantages in interpreting biological functions and increasing statistical powers. Many statistical methods have been proposed for detecting significant gene sets that show relations between genes and phenotypes, but there is no consensus about which is the best to perform gene sets analysis and permutation based tests are considered as standard tools. When many gene sets are tested simultaneously, a large number of random permutations are needed for multiple testing with a high computational cost. In this paper, several parametric approximations are considered as alternatives of the permutation distribution and the moment based gene set test has shown the best performance for providing p-values of the permutation test closely and quickly on a general framework.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.12
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• pp.641-652
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• 2016

This paper proposes a method to generate test scripts in an automatic manner, based on checklist used for testing embedded systems in the fields. The proposed method can reduce the mistakes which may be introduced during manual generation. In addition, it can generate test scripts to test various mode combinations, which is not possible to be tested by the typical checklist. The test commands in a checklist are transformed into a test script suit referencing the signal values defined in a test command dictionary. In addition, the method to generate test scripts in sequential, double permutation and random manners is proposed useful to test the inter-operations between modes, a series of operations for a specific behavior. The proposed method is implemented and the feasibility is shown through the experiments.

• Korean Journal of Adult Nursing
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• v.14 no.1
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• pp.114-124
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• 2002

Purpose: This study was conducted to investigate whether a self-efficacy information resources program based on the self-efficacy theory of Bandura (1986) would increase self-efficacy and self-care in patients with CAD. Method: The study was a one group, pretest-posttest pre-experimental design research. The Self-Efficacy Information Resources Program was composed of a video tape program and a telephone coaching program and based on vicarious experiences and verbal persuation. The Program was used as an experimental treatment from February 27. to May 27, 1999. Twenty patients participated from a university hospital located in Seoul. Three days later after a pretest the telephone coaching program was given. It was repeated weekly during a 3 week period. At the end of this period post-test data were collected by mail. Data were analyzed with a random permutation test using SAS program. Result: 1) Scores on self-efficacy after the Self-Efficacy Information Resources Program were significantly higher than before the program (p=0.06). 2) Scores on self-care after the Program were significantly higher (subjective self-care, p=0.0005; objective self-care, p= 0.0002) than before the program. Conclusion: The Program was found to be an effective nursing intervention for increasing self-efficacy and self-care. When nurses who care for CAD patients plan to increase their patients' self care ability, they should always consider the concept of self-efficacy.