• 한국통계학회:학술대회논문집
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• 한국통계학회 2002년도 추계 학술발표회 논문집
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• pp.141-146
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• 2002

In this article we consider the problem of constructing confidence intervals for a linear regression model with nested error structure. A popular approach is the likelihood-based method employed by PROC MIXED of SAS. In this paper, we examine the ability of MIXED to produce confidence intervals that maintain the stated confidence coefficient. Our results suggest the intervals for the regression coefficients work well, but the intervals for the variance component associated with the primary level cannot be recommended. Accordingly, we propose alternative methods for constructing confidence intervals on the primary level variance component. Computer simulation is used to compare the proposed methods. A numerical example and SAS code are provided to demonstrate the methods.

• Communications for Statistical Applications and Methods
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• 제12권1호
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• pp.87-100
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• 2005

In order to construct confidence intervals on the sum of variance components in a simple regression model with unbalanced nested error structure, alternative confidence intervals using Graybill and Wang(1980) and generalized inference concept introduced by Tsui and Weerahandi(1989) are proposed. Computer simulation programmed by SAS/IML is performed to compare the simulated confidence coefficients and average interval lengths of the proposed confidence intervals. A numerical example is provided to demonstrate the confidence intervals and to show consistency between the example and simulation results.

• Communications for Statistical Applications and Methods
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• 제8권3호
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• pp.581-588
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• 2001

The $ED_{100p}$ is that value of the dose associated with 100p% response rate in the analysis of quantal response data. Brand, Pinnock, and Jackson (1973) studied the confidence bands of $ED_{100p}$ obtained by solving extremal values algebraically on the ellipsoid confidence region of the parameters in the simple logistic regression model. In this paper, we develope and illustrate a simpler method for obtaining confidence bands for $ED_{100p}$ based on the rectangular confidence region of parameters.

• 한국시스템다이내믹스연구
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• 제5권1호
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• pp.35-47
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• 2004

Analyzers adopt a variety of techniques in analyzing public policy. Based on the results of exploration, they explain problems and suggest prescriptions such as policy alternatives. By doing so, however, they have different degree of confidence in their own results according to what techniques they adopt. This study explores whether system dynamics apporach gives analyzers more confidence on their own simulation results than other approaches do. This study designed an experiment. Three research teams are organized. Each of them applies different analytic techniques on the same policy issue, i.e., introduction of transportation tax. It flnds that researchers using S,D. simulation technique are most confident on what they predict, while researchers adopting survey techniques show moderate degree of confidence on their results. Researchers using regression are least confident.

• Communications for Statistical Applications and Methods
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• 제18권5호
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• pp.615-623
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• 2011

이항비율에 대한 구간추정에 다양한 신뢰구간들이 사용된다. 그러나 대부분의 신뢰구간들은 모비율 p가 0이나 1에 근사할 때 포함확률이 신뢰수준(또는 명목수준, 1 - ${\alpha}$)을 크게 벗어난다. 이는 극단적인 관찰값의 영향 때문이다. Vollset (1993), Agresti와 Coull (1998), Newcombe (1998), Brown 등 (2001) 등은 극단값의 조정을 통해서 이러한 문제를 해결하는 방법들을 제시하였다. 본 연구에서는 극단값들이 이항비율에 대한 신뢰구간에 어느 정도 영향을 미치는지를 6개의 신뢰구간들에 대해서 수치적으로 비교해 보았다.

• Communications for Statistical Applications and Methods
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• 제18권1호
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• pp.103-110
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• 2011

Exponential distribution is widely adopted as a lifetime model. Many authors have considered the interval estimation of the parameters of two-parameter exponential distribution based on complete and censored samples. In this paper, we consider the interval estimation of the location and scale parameters and the joint confidence region of the parameters of two-parameter exponential distribution based on upper records. A simulation study is done for the performance of all proposed confidence intervals and regions. We also propose the predictive intervals of the future records. Finally, a numerical example is given to illustrate the proposed methods.

• 공학교육연구
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• 제14권6호
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• pp.16-23
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• 2011

As a basic study on an effective operation of EMIs (English Medium Instructions) gradually expanded by social needs, the research analyses the effects of English competence, motivation, achievement, and self-confidence on learners' satisfaction and cognition of effects of EMI. Sixty-seven students (55 male and 12 female students) of the department of Civil Engineering in University A participated in the research. First, the analysis results indicate that participants evaluated their own English competence and self-confidence below average but evaluated English motivation and achievement above average. Second, participants' satisfaction with EMI was above average but they cognized its effects below average. Third, English motivation and self-confidence influenced on learners' satisfaction and cognition of effects of EMI in a meaningful way. Especially, English self-confidence influenced relatively more on the two dependent variables. Based on those result, the implications were suggested.

• Communications for Statistical Applications and Methods
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• 제26권1호
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• pp.35-46
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• 2019

Multivariate Confidence Region (MCR) cannot be used to obtain the confidence region of the mean vector of multivariate data when the normality assumption is not satisfied; however, the Quantile Confidence Region (QCR) could be used with a Multivariate Quantile Vector in these cases. The coverage rate of the QCR is better than MCR; however, it has a disadvantage because the QCR has a wide shape when the probability density function follows a bimodal form. In this study, we propose a Quantile Confidence Region using the Highest density (QCRHD) method with the Highest Density Region (HDR). The coverage rate of QCRHD was superior to MCR, but is found to be similar to QCR. The QCRHD is constructed as one region similar to QCR when the distance of the mean vector is close. When the distance of the mean vector is far, the QCR has one wide region, but the QCRHD has two smaller regions. Based on these features, it is found that the QCRHD can overcome the disadvantages of the QCR, which may have a wide shape.

• Child Health Nursing Research
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• 제29권3호
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• pp.229-236
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• 2023

Purpose: The purpose of this study was to investigate perceptions of fatherhood among fathers of high-risk neonates and their confidence regarding neonatal care. Methods: A study was conducted of 100 fathers whose neonates had been admitted to a neonatal intensive care unit (NICU) for at least 48 hours. Perceptions of fatherhood, neonatal characteristics, and fathers' confidence regarding neonatal care were measured using a self-reported questionnaire. The survey took approximately 10 minutes to complete and was completed anonymously. The factors that affected fathers' confidence regarding neonatal care were analyzed using multiple regression. Results: The scores for positive and negative perceptions of fatherhood were relatively high at 4.27 and 3.42 out of 5 points, respectively. A positive perception of fatherhood was found to influence fathers' confidence regarding neonatal care. Conclusion: NICU nurses should encourage fathers to effectively perform their parenting roles by implementing educational programs and interventions to promote positive perceptions of fatherhood and fathers' confidence regarding neonatal care after discharge.

• 한국비블리아학회지
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• 제8권1호
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• pp.157-178
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• 1997

1. Only 6 libraries(23.1%) among 26 surveyed libraries have a person or part in charge of continuing education. It means that the method to select education program and education object is systemless. The 19 libraries (73.1%) encourage continuing education of librarian. 2. Compared with the group who didn't receive a formal education, the group who received have a high degree in the grade of confidence, self-satisfaction and ability for job in Internet education case. And the group that received a formal education have also a high degree in the grade of ability for job in OA education case. Confidence, self-satisfaction for job in the carreer is significantly different according to the formal education in Internet education case and OA education case. Confidence, self-satisfaction and ability for Sob in the scholarship are significantly different according to the formal education in internet and computer OA education case 3. Compared with the group that didn't receive periodical education the group that received periodical education have a high degree in the grade of confidence, self-satisfaction for Job in internet education case. Confidence, self-satisfaction and ability for job in the carreer are significantly different according to the periodical education in OA education case. Confidence, self-satisfaction and ability for businessin in the scholarship are significantly different according to the periodical education in internet and OA education case. 4. Compared with the group that didn't receive self-education the group that received self-education have a high degree in the grade of confidence, self-satisfaction and ability for job in internet and OA education case. Confidence, self-satisfaction and ability for Job in the carreer are significantly different according to the self education in internet and OA education case. Confidence, self-satisfaction and ability for Job in the scholarship are significantly different according to the self-education in internet and OA education case.