• Journal of Korean Institute of Industrial Engineers
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• v.17 no.1
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• pp.75-82
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• 1991

This research is concerned with Machine-Part Group Formation(MPGF) methodology for Flexible Manufacturing Systems(FMS). The purpose of the research is to develop a new heuristic algorithm for effectively solving MPGF problem. The new algorithm is proposed and evaluated by 100 machine-part incidence matrices generated. The performance measures are (1) grouping ability of mutually exclusive block-diagonal form. (2) number of unit group and exceptional elements, and (3) grouping time. The new heuristic algorithm has the following characteristics to effectively conduct MPGF : (a) The mathematical model is presented for rapid forming the proper number of unit groups and grouping mutually exclusive block-diagonal form, (b) The simple and effective mathematical analysis method of Rank Order Clustering(ROC) algorithm is applied to minimize intra-group journeys in each group and exceptional elements in the whole group. The results are compared with those from Expert System(ES) algorithm and ROC algorithm. The results show that the new algorithm always gives the group of mutually exclusive block-diagonal form and better results(85%) than ES algorithm and ROC algorithm.

• Journal of The Korean Association For Science Education
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• v.18 no.1
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• pp.61-70
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• 1998

This study investigated the effects of grouping (group composition) in cooperative learning strategy upon students' achievement, the attitude toward science instruction, the perception of learning environment, and the self-esteem. Three different groups were used in this study. For the two treatment groups with cooperative learning strategies, High-Medium-Low ability grouping (HML) and High-Low I Medium-Medium ability grouping (HL/MM) were used. For the control group, traditional instruction was used. Before the instructions, the short-version Group Assessment of Logical Thinking, the test of attitudes toward science instruction, the perception questionnaire of learning environment, and the questionnaire of self-esteem were administered, and their scores were used as covariates. Mid-term examination score was used as a blocking variable. After the instructions, a researcher-made achievement test consisting of three subtests (knowledge, understanding, and application), the test of attitude toward science instruction, the perception questionnaire of learning environment, and the questionnaire of self-esteem were administered. The ANCOVA results revealed that there were significant interactions between the instruction and the level of prior achievement although there were no significant differences in all subtest scores of the achievement test. The high-level students in the HL/MM cooperative group performed better than those in the control group and the HML cooperative group. The low-level students in the HL/MM cooperative group also performed better in the subtest of knowledge than those in the other groups. However, the medium-level students in the HML cooperative group scored better than those in the control group and the HL/MM cooperative group. Significant main effect was also found in the perception of learning environment but not in the attitude toward science instruction and self-esteem. The cooperative groups, regardless of grouping, exhibited more positive perception than the control group.

• Journal of The Korean Association For Science Education
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• v.24 no.6
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• pp.1063-1069
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• 2004

This study investigated the effects of grouping method in solving chemistry problems using Think-Aloud Paired Problem Solving (TAPPS). Three classes (125 students) of a co-ed high school in Seoul were randomly assigned to the control, the homogeneous TAPPS, and the heterogeneous TAPPS groups. Prior to the instructions, a test of awareness of metacognition was administered. In the treatment groups, students were grouped into either homogeneous or heterogeneous group on the basis of their pre-achievement levels, and worked in pairs on chemistry problems about chemical equation and stoichiometry. Students' analytical skill, problem solving ability, and awareness of metacognition were examined after the instructions. One-way ANCOVA results indicated that the scores of the homogeneous TAPPS group in the analytical skill test were significantly higher than those of the heterogeneous TAPPS group. However, there were no significant differences among the three groups in the problem solving ability and the awareness of metacognition.

• Journal of Educational Research in Mathematics
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• v.8 no.1
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• pp.199-216
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• 1998

One of the main features of the 7th revised national curriculum is the implementation of a 'Differentiated Curriculum'. Differentiated Curriculum is often interpreted as meaning the same as 'tracking' or 'ability grouping' in western countries. In the 7th revised curriculum, mathematics is organized and implemented by 'Level-Based Differentiated Curriculum'. To develop mathematics textbooks and teaching-and-learning materials for Differentiated Curriculum, the ideas of 'Enriched and Supplemental Differentiated Curriculum'need to be applied, that is, to provide advanced contents for fast learners, and plain contents for slow learners. Level Based Differentiated Curriculum could be implemented by ability grouping either between classes or within classes. According to these two exemplary models, the implementation models for supplemental course and enriched course are determined. The contents for supplemental course are comprised of minimal essential elements selected from the standard course at a decreased level of complexity and abstraction. The contents of enriched courses are focused on various applications of mathematical knowledge in the real world. Special remedy course will be offered to extremely underachieved students, The principles of developing teaching-and-learning material for special remedy course were obtained from the histo-genetic principle, progressive mathematizing principle, and constructivism.

• Journal of the Korean School Mathematics Society
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• v.14 no.3
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• pp.339-354
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• 2011

The purpose of this paper is to find out the effective teaching method and improvement for managing the special lecture of basic mathematics which is grouped by the level of low achievement students who are matriculants. From the result, we want to know how the lecture with teaching method of differentiated learning affect on the students, especially who have under achievement, to be interested and confidential in mathematics.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.62-63
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• 2015

In this paper, to prevent overspending of the CM Fee, Agent CM for the normal work-oriented, Willing to separate order model being used in the construction, using a multi-national grouping Go to offer the right company, a number of groups according to the appropriate CM Fee setting is aimed to suggest a reasonable basis. This paper does not use the domestic point of order characteristic of the model, and using a different theory of affinity grouping projection method is presented. The main disadvantage of the domestic order model because it is a contractual relationship, the contractual relationship as unified as possible by the most reasonable way of construction and construction capabilities and commercialization agreement upon the ability of companies also expect to be very helpful. The grouping by using the multi-order construction of the separation problem of the increase and thus the management object construction type administration was to solve the problem.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.8
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• pp.739-746
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• 2011

Recently, recommender systems have been widely applied in E-commerce websites to help their customers find the items what they want. A recommender system should be able to provide users with useful information regarding their interests. The ability to immediately respond to the changes in user's preference is a valuable asset of recommender systems. This paper proposes a novel recommender system which aims to effectively adapt and respond to the immediate changes in user's preference. The proposed system combines IEC (Interactive Evolutionary Computation) with a content-based filtering method and also employs data grouping in order to improve time efficiency. Experiments show that the proposed system makes acceptable recommendations while ensuring quality and speed. From a comparative experimental study with an existing recommender system which uses the content-based filtering, it is revealed that the proposed system produces more reliable recommendations and adaptively responds to the changes in any given condition. It denotes that the proposed approach can be an alternative to resolve limitations (e.g., over-specialization and sparse problems) of the existing methods.

• Journal of Labour Economics
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• v.33 no.1
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• pp.1-30
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• 2010

Using the College Scholastic Ability Test of year 1995, the paper investigates effects of classroom peers on a student's test scores. It exploits exogenous assignment of students across different classrooms within a school under the leveling policy in 1990s. The empirical results reveal strong impacts of peers on individual students. Negative effects of low-performing peers exceed positive effects of high-performing peers. Such a structure of peer interactions has important implications for ability grouping vs. mixing debates in Korea.

• Journal of The Korean Association For Science Education
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• v.19 no.3
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• pp.400-408
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• 1999

This study investigated the effect of the grouping method in cooperative learning applied to chemistry concept learning. Two grouping methods used were the HML (High-Medium-Low) and the HL/MM (High-Low/Medium-Medium) ability grouping. Three classes (N = 136) at a high school in Seoul were randomly assigned to the control and the treatment groups. Before instruction. the test of attitude toward science instruction, the perception questionnaire of learning environment consisting of three subtests (participation, conflict, and competition), and the questionnaire of self-esteem were administered, and a mid-term examination score was obtained. These scores were used as covariates. After instruction, the three tests administered before instruction and the conceptions test were administered. Two-way ANCOVA results revealed that there was a significant interaction between the treatment and the level of previous achievement. The low-level students in the HL/MM cooperative group performed better than those in the other groups. The cooperative groups, regardless of the grouping methods, exhibited more positive perception than the control group at participation subtest of the perception questionnaire of learning environment.

• The Mathematical Education
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• v.44 no.2 s.109
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• pp.169-178
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• 2005

We briefly survey the previous researches on mathematics curriculum of Korean. Without discussing deeply on each issue, we do on some issues. At the end of this article we suggest some direction and process for future revision of mathematics curriculum.