• Communications for Statistical Applications and Methods
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• 제19권5호
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• pp.721-729
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• 2012

Various methods control the influence of a covariate on a response variable. These methods are analysis of covariance(ANCOVA), RANK ANCOVA, ANOVA of (covariate-adjusted) residuals, and Kruskal-Wallis tests on residuals. Covariate-adjusted residuals are obtained from the overall regression line fit to the entire data set that ignore the treatment levels or factors. It is demonstrated that the methods on covariate-adjusted residuals are only appropriate when the regression lines are parallel and covariate means are equal for all treatments. In this paper, we proposed the new nonparametric method on the ANCOVA model, as applying joint placement in a one-way layout on residuals as described in Chung and Kim (2007). A Monte Carlo simulation study is adapted to compare the power of the proposed procedure with those of the previous procedure.

• 응용통계연구
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• 제27권2호
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• pp.227-237
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• 2014

우리는 회귀분석에서 설명변수들 중 일부가 질적 변수인 경우 지시변수를 사용한다. 또한 공분산분석모형에서는 관심인자의 효과에 대한 유의성 검정시 연속변수인 공변수로 주어지는 방해인자를 미리 회귀분석으로 제거한다. 지시변수 사용 회귀모형이나 공분산분석모형을 위한 확증적 자료분석 전에 탐색적 자료분석의 한 수단으로서 자료깊이에 근거한 DD-plot을 이용하면 집단 간의 차이를 쉽게 알아볼 수 있다. 이 방법은 오차항의 통계모형을 가정하지 않으므로 유용한 탐색적 방법이 될 수 있다. 몇 가지 사례들을 통하여 DD-plot이 지시변수 사용 회귀모형이나 공분산분석모형을 위한 그래픽 탐색적 자료분석방법으로서 유용함을 보였다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권6호
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• pp.765-772
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• 2017

Objective: This study examines the genetic factors influencing the phenotypes (four economic traits:oleic acid [C18:1], monounsaturated fatty acids, carcass weight, and marbling score) of Hanwoo. Methods: To enhance the accuracy of the genetic analysis, the study proposes a new statistical model that excludes environmental factors. A statistically adjusted, analysis of covariance model of environmental and genetic factors was developed, and estimated environmental effects (covariate effects of age and effects of calving farms) were excluded from the model. Results: The accuracy was compared before and after adjustment. The accuracy of the best single nucleotide polymorphism (SNP) in C18:1 increased from 60.16% to 74.26%, and that of the two-factor interaction increased from 58.69% to 87.19%. Also, superior SNPs and SNP interactions were identified using the multifactor dimensionality reduction method in Table 1 to 4. Finally, high- and low-risk genotypes were compared based on their mean scores for each trait. Conclusion: The proposed method significantly improved the analysis accuracy and identified superior gene-gene interactions and genotypes for each of the four economic traits of Hanwoo.

• Journal of applied mathematics & informatics
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• 제32권3_4호
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• pp.343-357
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• 2014

In many non-life insurance applications past data are given in a form known as the run-off triangle. Smoothing such data using parametric crisp regression models has long served as the basis of estimating future claim amounts and the reserves set aside to protect the insurer from future losses. In this article a fuzzy counterpart of the Hoerl curve, a well-known claim reserving regression model, is proposed to analyze the past claim data and to determine the reserves. The fuzzy Hoerl curve is more flexible and general than the one considered in the previous fuzzy literature in that it includes a categorical variable with multiple explanatory variables, which requires the development of the fuzzy analysis of covariance, or fuzzy ANCOVA. Using an actual insurance run-off claim data we show that the suggested fuzzy Hoerl curve based on the fuzzy ANCOVA gives reasonable claim reserves without stringent assumptions needed for the traditional regression approach in claim reserving.

• 응용통계연구
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• 제30권3호
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• pp.427-439
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• 2017

공변량(covariate)이 존재하는 경우, 각 처리군 간 효과의 차이를 검정하기 위한 대표적인 비모수적 방법에는 Quade (1967)가 제안한 검정법이 있다. 또한 반응변수에 대해 공변량으로 단순선형회귀분석을 실시하여 얻은 잔차에 대해 일원배치분산분석과 Kruskal Wallis가 제안한 방법을 적용하는 방법, 그리고 Hwang과 Kim (2012)이 제안한 비모수적 도구인 위치(placement)를 이용한 방법이 있다. 본 논문에서는 공분산분석 모형에서 Hwang과 Kim (2012)이 제안한 방법을 확장하여 공분산분석에서의 새로운 방법을 제안하였다. 또한 모의실험(Monte Carlo simulation study)을 통하여 기존의 검정법들과 제안한 방법의 검정력을 비교하였다.

• Communications for Statistical Applications and Methods
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• 제24권3호
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• pp.241-254
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• 2017

Drawing a sample can be costly or time consuming in some studies. However, it may be possible to rank the sampling units according to some baseline auxiliary covariates, which are easily obtainable, and/or cost efficient. Ranked set sampling (RSS) is a method to achieve this goal. In this paper, we propose a modified approach of the RSS method to allocate units into an experimental study that compares L groups. Computer simulation estimates the empirical nominal values and the empirical power values for the test procedure of comparing L different groups using modified RSS based on the regression approach in analysis of covariance (ANCOVA) models. A comparison to simple random sampling (SRS) is made to demonstrate efficiency. The results indicate that the required sample sizes for a given precision are smaller under RSS than under SRS. The modified RSS protocol was applied to an experimental study. The experimental study was designed to obtain a better understanding of the pathways by which positive experiences (i.e., goal completion) contribute to higher levels of happiness, well-being, and life satisfaction. The use of the RSS method resulted in a cost reduction associated with smaller sample size without losing the precision of the analysis.

• 한국콘텐츠학회논문지
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• 제14권8호
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• pp.505-516
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• 2014

본 연구는 국제영재교육에서 창의사고필터링모형(Creative Thinking Filtering Model : CTFM)교육프로그램 적용이 창의성의 인지적 영역(유창성, 융통성, 독창성)과 정의적 영역(독자성, 호기심, 다양성, 민감성, 유모감각, 개별성)에 어떠한 영향을 미치는 지를 규명하는데 있다. 자료처리를 위한 통계방법으로 공분산분석 (Analysis of Covariance : ANCOVA)를 실시하였으며, 그 결과는 다음과 같다. 첫째, CTFM을 적용한 집단이 통제집단보다 인지적 영역과 정의적 영역이 높은 것으로 나타났다. 구체적으로 인지적 영역에서는 유창성, 융통성, 독창성 3요인 모두에서, 정의적 영역에서는 민감성을 제외한 독자성, 호기심, 개별성, 다양성, 민감성, 유모감각의 5요인에서 CTFM을 적용한 학생들이 높은 것으로 나타났다. 둘째, CTFM을 적용하기 전과 적용한 후에 인지적 영역의 창의성을 분석한 결과, 인지적 영역의 3요인인 유창성, 융통성, 독창성 모두 향상되었으며, 특히 유창성이 가장 많이 향상된 것으로 나타났다. 셋째, CTFM을 적용하기 전과 적용한 후에 정의적 영역의 창의성을 분석한 결과, 정의적 영역의 6요인 중 독자성, 다양성, 유모감각, 개별성의 4요인이 향상되었으며, 특히 독자성이 가장 많이 향상된 것으로 나타났다.

• 한국초등과학교육학회지:초등과학교육
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• 제23권4호
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• pp.273-278
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• 2004

According to Piaget, children aged 11 are in the middle of concrete operation period and formal operation period. So, it is necessary to adopt the Learning Cycle Model (LCM) which helps students improve their cognitive development. After determining the test for the Science Concept of Matter (SCOM), the experimental group showed higher average than the comparative group in the post-test. In the sound understanding, the experimental group showed higher ratio than the comparative group. And in the ratio of imperfect, wrong understanding and no response, the experimental group was lower than the comparative group. On the questions that were needed the complicated inquiry, many students of both groups still couldn't find the fundamental cause. In forming the scientific conceptualization, there was a meaningful difference (p < .001) after post-test Analysis of Covariance (ANCOVA) with pre-test result. After determining the test for the Test Inquiry Science Process (TISP), the experimental group showed higher average than the comparative group in the post-test. In the category of basic inquiry process which is needed in concrete operation, there was a meaningful difference (p < .05). In the category of unified inquiry process which is needed in formal operation, they showed no meaningful difference (p > .05). Therefore, applying the LCM to the chapter of 'Solution and Dissolving' is more effective on improving the scientific conceptualization and on helping the concrete operation abilities than the teacher centered learning.

• 한국보육지원학회지
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• 제16권5호
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• pp.27-45
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• 2020

Objective: The purpose of this study is to develop a music making program that utilizes the characteristics of the picture books medium through the ADDIE model so that teachers can easily apply it to children, and to determine whether it affects children's musical aptitude and music creativity. Methods: The Participants of the study were 42 five-year-old children attending a daycare in Seoul, of which 20 were in the experimental group and 22 in the comparative group. The experimental group participated in a music production program using picture books, and during the same period, the comparison group participated in music activities suggested by the Nuri Course. Using the SPSS 22.0 program, average, standard deviation, independent sampling t-test, and ANCOVA(Analysis of Covariance) were calculated. Results: The music making program using picture books improved children's rhythm and tone which are the sub-items of music aptitude. The music making program enhanced children's music flexibility, music creativity, music logic which are the sub-items of music creativity. Conclusion/Implications: The music making program presented systemic teaching-learning method with which teachers explained the modeling and practiced from simple activities to various activities repeatedly in order to make teachers approach music making more easily. It is recommendable to make the music making program by using I-pad and computers.

• Nutritional Sciences
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• 제6권2호
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• pp.118-126
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• 2003

To prevent food-borne diseases and ensure food safety, foodservice operators have been implementing the HACCP system in their facilities. Employees' knowledge of food safety can be improved through training and, as a result, their food safety behavior can be positively changed. A nonequivalent pretest and posttest control group model was designed to investigate the effectiveness of HACCP-based training on hospital foodservice employees' food safety knowledge and behavior, and to determine relationships between food safety knowledge and food safety behavior. The subjects used in this study were 84 hospital foodservice employees, assigned either to the intervention group (n=44) or the control group (n=40). Data were analyzed using the Statistical Package for the Social Sciences (SPSS). Descriptive statistics were computed, while the Student's t-test and ANCOVA (Analysis of Covariance) were used to investigate significant differences between groups, and the Pearson correlation was used to determine significant correlations. There were significant gains in both food safety knowledge and behavior, after the HACCP-based training. However, no significant correlation was found between food safety knowledge and food safety behavior. Based on this study we conclude that HACCP-based training is effective in improving both the food safety knowledge and food safety behavior of hospital foodservice employees.