• 응용통계연구
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• 제11권2호
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• pp.389-401
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• 1998

본 논문에서는 멀티미디어를 활용한 회귀분석 학습시스템 CybeRClass(Cyber Regression Class)를 소개하고자 한다. CybeRClass는 음성정보와 애니메이션 등을 활용하여 회귀분석에 대한 학습을 시켜주는 시스템이다. 이 시스템은 군집분석이나 판별분석 등의 다변량분석 학습이 가능하도록 설계되었다. 멀티미디어 기술을 위한 도구로는 Multimedia ToolBook을 사용하였으며, 통계계산과 통계그라픽을 위해서는 객체지향 통계 언어인 Xlisp-Stat을 사용하였다.

• 지역사회간호학회지
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• 제30권4호
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• pp.449-459
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• 2019

Purpose: The aim of this study is to explore different types of self-rated health trajectories among one-person households in Korea. Methods: We used five time-point data derived from Korea Health Panel (2011~2015). A latent growth curve modeling was used to assess the overall feature of self-rated health trajectory in one-person households, and a latent class growth modeling was used to determine the number and shape of trajectories. We then applied multinomial logistic regression on each class to explore the predicting variables. Results: We found that the overall slope of self-rated health in one-person households decreases. In addition, latent class analysis demonstrated three classes: 1) High-Decreasing class (i.e., high intercept, significantly decreasing slope), 2) Moderate-Decreasing class (i.e., average intercept, significantly decreasing slope), and 3) Low-Stable class (i.e., low intercept, flat and nonsignificant slope). The multinomial logistic regression analysis showed that the predictors of each class were different. Especially, one-person households with poor health condition early were at greater risk of being Low-Stable class compared with High-Decreasing class group. Conclusion: The findings of this study demonstrate that more attentions to one-person households are needed to promote their health status. Policymakers may develop different health and welfare programs depending on different characteristics of one-person household trajectory groups in Korea.

• Journal of the Korean Data and Information Science Society
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• 제18권2호
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• pp.515-524
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• 2007

This paper deals with local linear estimation of fuzzy regression models based on Diamond(1998) as a new class of non-linear fuzzy regression. The purpose of this paper is to introduce a use of smoothing in testing for lack of fit of parametric fuzzy regression models.

• Communications for Statistical Applications and Methods
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• 제14권2호
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• pp.377-388
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• 2007

As one of multi-class classification methods, ECOC (Error Correcting Output Coding) method is known to have low classification error rate. This paper aims at suggesting effective multi-class classification method (1) by comparing various encoding methods and decoding methods in ECOC method and (2) by comparing ECOC method and direct classification method. Both SVM (Support Vector Machine) and logistic regression model were used as binary classifiers in comparison.

• Journal of the Korean Data and Information Science Society
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• 제21권3호
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• pp.513-521
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• 2010

대부분의 대학들은 교수업적평가를 위해 강의평가제도를 실시하고 있다. 그러나 강의평가의 결과는 강좌규모, 강의형태, 개설학년, 이수구분, 평균평점 등과 같은 개설강좌의 특성에 많은 영향을 받게 된다. 따라서 이러한 각 강좌특성들이 강의평가 결과에 영향을 미치는 효과를 제거하지 않는다면, 담당교수가 강의평가 결과에 대한 공정성과 객관성을 신뢰할 수 없게 만들 정도로 심각한 편의를 갖게 된다. 따라서 강의평가의 공정성을 위해 강좌특성에 따른 편의를 제거하기 위한 사후조정된 점수가 요구된다. 따라서 본 연구에서는 단계적 변수선택법에 의한 회귀분석을 이용하여 강의평가 결과에 대한 균등화 방법을 이용하여 사후조정된 점수를 계산하는 방법을 제안한다. 그리고 제안된 방법은 기존의 방법과 비교를 하였다.

• Educational Technology International
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• 제15권2호
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• pp.71-88
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• 2014

A variety of studies to predict students' performance have been conducted since educational data such as web-log files traced from Learning Management System (LMS) are increasingly used to analyze students' learning behaviors. However, it is still challenging to predict students' learning achievement in blended learning environment where online and offline learning are combined. In higher education, diverse cases of blended learning can be formed from simple use of LMS for administrative purposes to full usages of functions in LMS for online distance learning class. As a result, a generalized model to predict students' academic success does not fulfill diverse cases of blended learning. This study compares two blended learning classes with each prediction model. The first blended class which involves online discussion-based learning revealed a linear regression model, which explained 70% of the variance in total score through six variables including total log-in time, log-in frequencies, log-in regularities, visits on boards, visits on repositories, and the number of postings. However, the second case, a lecture-based class providing regular basis online lecture notes in Moodle show weaker results from the same linear regression model mainly due to non-linearity of variables. To investigate the non-linear relations between online activities and total score, RF (Random Forest) was utilized. The results indicate that there are different set of important variables for the two distinctive types of blended learning cases. Results suggest that the prediction models and data-mining technique should be based on the considerations of diverse pedagogical characteristics of blended learning classes.

• Journal of the Korean Data and Information Science Society
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• 제23권6호
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• pp.1137-1144
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• 2012

요즘 대부분의 대학들이 국제화를 목표로 재학생들의 어학능력 및 국제적 경쟁력 강화와 함께 영어강의의 중요성이 증대되고 있다. 본 연구에서는 강의평가점수를 이용해서 과목특성 변수들과 개인특성 변수들 별로 영어강의와 한국어강의의 효과성을 비교하였다. 또한 로지스틱회귀분석과 의사결정나무분석을 이용하여 어떤 요인들이 영어강의가 한국어강의에 비해서 효과적인지를 주효과와 상호작용효과 측면에서 분석하였다. 분석결과에 따르면 영어강의의 효과성에 영향을 미치는 변수로는 학년, 계열, 강좌규모, 평균평점, 계열, 전형방법 등으로 나타났다. 또한 영어강의 효과성이 특히 높은 그룹은 1학년이면서 인문계열인 경우, 그리고 1학년이면서 자연 및 예체능계열이고 평균평점이 높은 그룹이 높게 나타났다. 그리고 영어강의의 효과성 비율이 특히 낮은 그룹은 2-3학년 학생이면서 강좌규모가 크고 인문계열인 경우로 나타났다.

• Communications for Statistical Applications and Methods
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• 제27권1호
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• pp.129-140
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• 2020

In this paper, we introduce an efficient algorithm for the non-convex penalized multinomial logistic regression that can be uniformly applied to a class of non-convex penalties. The class includes most non-convex penalties such as the smoothly clipped absolute deviation, minimax concave and bridge penalties. The algorithm is developed based on the concave-convex procedure and modified local quadratic approximation algorithm. However, usual quadratic approximation may slow down computational speed since the dimension of the Hessian matrix depends on the number of categories of the output variable. For this issue, we use a uniform bound of the Hessian matrix in the quadratic approximation. The algorithm is available from the R package ncpen developed by the authors. Numerical studies via simulations and real data sets are provided for illustration.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제26권3호
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• pp.127-146
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• 2023

Statistical thinking has a broad definition but focuses on the context of regression modelling in the present study. To foster students' statistical thinking within the context, teaching should no longer be seen as transfer of knowledge from teacher to students but as a process of engaging with learning activities in which they develop ownership of knowledge. This study aims at collaborative learning contexts; students were divided into small groups in order to increase opportunities for peer collaboration. Each group of students was asked to do a regression project after class. Through doing the project, they learnt to organize and connect previously accrued piecemeal statistical knowledge in an integrated manner. They could also clarify misunderstandings and solve problems through verbal exchanges among themselves. They gave a clear and lucid account of the model they had built and showed collaborative interactions when presenting their projects in front of class. A survey was conducted to solicit their feedback on how peer collaboration would facilitate learning of statistics. Almost all students found their interaction with their peers productive; they focused on the development of statistical thinking with concerted effort.

• 보건의료산업학회지
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• 제11권1호
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• pp.131-142
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• 2017

Objectives : This study aimed to examine to relevance of socioeconomic class recognition and subjective health status of injured workers. Methods : We used data collected over 3years by the Panel Study of Worker's Compensation Insurance(PSWCI; 2015). Data was analyzed using the chi-square test and logistic regression using SPSS ver. 22.0 to verify the relevance between the socioeconomic class recognition and general characteristics of injured workers. Results : First, the income groups of first class, second class and third class were analyzed as being of lower socioeconomic class status, and the income group four class and five class was analyzed as being the middle-ower the socioeconomic class status. Second, the better the subjective health status, higher the perception of socioeconomic class status, as analyzed by Model 1 using only the parameters of socioeconomic status recognition and Model 2 and Model 3 using income class and general characteristics. Conclusions : Health and industrial accident policies are needed to improve awareness of socioeconomic class status of injured workers.