• School Mathematics
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• v.7 no.2
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• pp.139-168
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• 2005

The purpose of this study is to investigate children's informal knowledge of the fractional multiplication and to develop a teaching material connecting the informal and the formal knowledge. Six lessons of the pre-teaching material are developed based on literature reviews and administered to the 7 students of the 4th grade in an elementary school. It is shown in these teaching experiments that children's informal knowledge of the fractional multiplication are the direct modeling of using diagram, mathematical thought by informal language, and the representation with operational expression. Further, teaching and learning methods of formalizing children's informal knowledge are obtained as follows. First, the informal knowledge of the repeated sum of the same numbers might be used in (fractional number)$\times$((natural number) and the repeated sum could be expressed simply as in the multiplication of the natural numbers. Second, the semantic meaning of multiplication operator should be understood in (natural number)$\times$((fractional number). Third, the repartitioned units by multiplier have to be recognized as a new units in (unit fractional number)$\times$((unit fractional number). Fourth, the partitioned units should be reconceptualized and the case of disjoint between the denominator in multiplier and the numerator in multiplicand have to be formalized first in (proper fractional number)$\times$(proper fractional number). The above teaching and learning methods are melted in the teaching meterial which is made with corrections and revisions of the pre-teaching meterial.

• Journal of Service Research and Studies
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• v.10 no.3
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• pp.55-66
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• 2020

This study was attempted to demonstrate the service performance of non-face-to-face real-time video lecture service conducted in the coronavirus crisis in early 2020. Lecture service is divided into service production and service delivery from a service system perspective, and its role of lecture service system and the relationship between lecture service benefits and service satisfaction perceived by learners is demonstrated. In order to demonstrate this structural impact relationship, the result of analysis through a questionnaire survey on a total of 268 undergraduate students at G University, showed that the role and level of the non-face-to-face real-time video lecture service system affects the service convenience and service satisfaction. In the additional analysis, the learning orientation learners group perceived the service system level or role in the lecture service and the service benefit itself higher than the relationship orientation learners group. In the past, when a face-to-face class was conducted, learners group who attended a lot of extra curriculum activities perceived the benefits of coronavirus prevention lower than those of a group that did not. In this way, it is necessary to supplement the lecture service system by identifying the role expectation in the lecture service for the high relationship orientation group and the preferring extra curriculum activity group after detail research.

• Journal of Korean Society of Disaster and Security
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• v.15 no.4
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• pp.87-98
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• 2022

In recent years, frequent localized heavy rainfalls, which have a lot of rainfall in a short period of time, have been increasingly causing flooding damages. To prevent damage caused by localized heavy rainfalls, Hydrological Quantitative Precipitation Forecast (HQPF) was developed using the Local ENsemble prediction System (LENS) provided by the Korea Meteorological Administration (KMA) and Machine Learning and Probability Matching (PM) techniques using Digital forecast data. HQPF is produced as information on the impact of heavy rainfall to prepare for flooding damage caused by localized heavy rainfalls, but there is a tendency to overestimate the low rainfall intensity. In this study, we improved HQPF by expanding the period of machine learning data, analyzing ensemble techniques, and changing the process of Probability Matching (PM) techniques to improve predictive accuracy and over-predictive propensity of HQPF. In order to evaluate the predictive performance of the improved HQPF, we performed the predictive performance verification on heavy rainfall cases caused by the Changma front from August 27, 2021 to September 3, 2021. We found that the improved HQPF showed a significantly improved prediction accuracy for rainfall below 10 mm, as well as the over-prediction tendency, such as predicting the likelihood of occurrence and rainfall area similar to observation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.2
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• pp.237-243
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• 2010

This study was investigated the effect of antioxidative vitamin supplementation ($\beta$-carotene 175 mg, vitamin C 200 mg, vitamin E 33.5 mg) for 12 weeks on antioxidant status and autistic related behaviors in autistic children. The antioxidative vitamin-supplemented children had significantly lower concentrations of toxic mineral, such as cadmium (Cd), mercury (Hg) and lead (Pb) in hair, while they had higher concentration of antioxidant minerals (Se, Zn, Fe) in hair. Antioxidant vitamin supplementation for 12 weeks reduced free radical while it increased the hair levels of serotonin compared to the beginning of the study. Additionally, antioxidative vitamin supplementation resulted in significant improvement in social age. These results indicate that the consumption of antioxidative vitamin supplementation for 12 weeks in autistic children may increase plasma antioxidant mineral concentration, resulting in reduced toxic mineral and free radical and improved autistic behavior.

• The Korean Journal of Applied Statistics
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• v.34 no.3
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• pp.309-327
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• 2021

Dynamic treatment regimes (DTRs) are decision-making rules designed to provide personalized treatment to individuals in multi-stage randomized trials. Unlike classical methods, in which all individuals are prescribed the same type of treatment, DTRs prescribe patient-tailored treatments which take into account individual characteristics that may change over time. The Q-learning method, one of regression-based algorithms to figure out optimal treatment rules, becomes more popular as it can be easily implemented. However, the performance of the Q-learning algorithm heavily relies on the correct specification of the Q-function for response, especially in observational studies. In this article, we examine a number of double-robust weighted least-squares estimating methods for Q-learning in high-dimensional settings, where treatment models for propensity score and penalization for sparse estimation are also investigated. We further consider flexible ensemble machine learning methods for the treatment model to achieve double-robustness, so that optimal decision rule can be correctly estimated as long as at least one of the outcome model or treatment model is correct. Extensive simulation studies show that the proposed methods work well with practical sample sizes. The practical utility of the proposed methods is proven with real data example.

• Journal of The Korean Association of Information Education
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• v.12 no.1
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• pp.9-22
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• 2008

The purpose of this research is to develop a prototype of the support system in order for team building associated with web-based project learning having applied Kolb's learning style. To accomplish this purpose, the following research tasks were performed. First, core idea in order to embody the system's value, key activities, tools that will support pertinent activities and the strategy so as to develop guidelines, etc. were devised and prepared. Second, a system was designed on the basis of structural model of teaching design, then after, interface was developed. The core factors in this system are inspection of learning style, organizing a team and team building. Above all, it is required to make learners know about learning environments, of which they are in favor, and also its distinctive features through inspection of learning style, and then focusing on learning style, a team should be organized insomuch as to accommodate a variety of learning styles as much as possible. For the purpose of team building, after learning style of each constituent member of the team has been made known, then the roles will be divided among the constituent members of the team so as to suit their individual characteristics referring to each of their learning styles that have been exposed. To verify the value of this system developed and efficiency thereof, a focus group interview was conducted. The focus group consisted of professionals, all from related fields. After the interview, the points required to make further improvements were elicited and taken care of by follow-up actions as needed. And having reflected such improvements made, the final system was developed. With this newly developed system, learners can get the results of inspection of learning style so quickly by performing inspection any time any where, and based on the results from such inspection, a team comprising dissimilar constituents who exhibit a variety of different propensities will be automatically organized. Thus, this system may be used not only for web-based project learning having unspecified persons elected as constituents, but in the offline space also.

• Journal of the Korean Chemical Society
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• v.58 no.5
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• pp.463-477
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• 2014

The purpose of this study is to investigate the teaching-learning effects in the experimental classes for the 'Redox' unit of science textbook of 11th grade using self-regulated learning strategy. Simultaneously, the effects of teaching-learning through the student's characteristics of the scientific high school were also included. The experimental and the controlled groups were selected by the teaching-learning method established on self-regulated learning strategy and regular laboratory activity based on the teacher' instruction, respectively. The questionaries of the scientific inquiry and scientific attitude were examined by the student. For their achievement, the total score which was obtained from the formative evaluation and performance assessment was utilized. After the laboratory activity for the unit grounded on the self-regulated learning strategy, the mean values of the scientific inquiry, scientific attitude, and achievement by the experimental group were higher than those of the controlled group. There was significant difference between the two groups in the post-test. By the results of the post-test for the experimental group, there has been somewhat relationship between the self-regulated learning strategy and the scientific inquiry, the scientific attitude, and the scientific achievement.

• The Journal of Korean Academic Society of Nursing Education
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• v.19 no.3
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• pp.413-422
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• 2013

Purpose: This study was designed to explore the influencing factors on communication skill of nursing students and to investigate the relationship between learning style, critical thinking disposition and communication skill, Methods: The study sample was composed of 559 nursing students. Data was collected from 1st to 30th, May 2012 used a questionnaire which included Kolb's learning style inventory, critical thinking disposition inventory, communication skill inventory. The SPSS 18.0 Window program was used for descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient, and stepwise multiple regression. Results: Learning styles of subjects were diverging 39.5%, accommodating 32.6%, assimilating 22.7%, and converging 5.2%. The total mean score of critical thinking disposition and communication skill was 3.58 and 3.39 respectively. The score of Critical thinking disposition(t=3.06, p=.002) and Communication skill(t=3.25, p=.002) significantly differed between clinical practice satisfaction. Communication skill was the most significant predictor and accounted for 41.3% of the variance in critical thinking disposition in nursing students. Conclusion: It is important for students to use all four learning styles rather than to rely on one style. There should be more emphasis placed on the development of positive critical thinking disposition and communication skill of nursing students.

• Journal of the Korea Convergence Society
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• v.11 no.10
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• pp.181-186
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• 2020

In this study, an attempt was made to investigate the clinical reasoning of nursing students and to identify the factors that influence it. This study was held to grasp the learning ability related to core nursing competency for 297 3^rd and 4^rd grade nursing students. Results indicated that there was a significant difference when comparing clinical competence by grade(p=0.001). Also variables effecting clinical reasoning competence were Problem solving ability, Clinical Decision making ability, Clinical practice performance, and grade of nursing students were found to be significant (p,.001). Outcome of this study can be used as the basis for the development of various curriculums to enhance the clinical reasoning competence, in the future, research for this education development is expected to be needed.

• Journal of the Korean Society of Earth Science Education
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• v.12 no.3
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• pp.239-251
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• 2019

The study aims to run a 'Process-based Evaluation' and find out its effectiveness in science classes for prospective elementary school teachers. The Process-based Evaluation performed in this study was performed during unit classes and scored when significance was recognized in the student's learning behavior. The conclusions based on the results of the study are as follows. First, students scored an average of 3.6 points on whether the process-oriented assessment conducted during class was appropriate as an assessment. Second, on the basis of the assessment presented by the students, the main positive content is "assessing the process, not the outcome", "contributing positively to class participation" and "promoting accident activities". Third, the negative contents of the assessment grounds presented by the students include 'lack of objectivity in evaluation methods and results', 'the individual tendencies of students are involved in evaluation results' and 'poor learning effects of the textbook knowledge'.