• Journal of Gifted/Talented Education
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• v.24 no.3
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• pp.339-358
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• 2014

On the subjects of elementary 3-rd grade three child prodigies who learned primary concept of division, this study explored how they could compose schema and transformed schema through recognition of precise concepts and linking with the contents of division of fraction. That is to say, this study examined in depth what schema and transformed schema as primary concept of division they composed to get relational understanding of division of fraction, and how they used the schema and transformed schema composed by themselves to approach problem solving as well as how they transformed the schema in their concept composition and problem solving competence. As a result, it was found that learning of primary concept of division played a key role of composing schema and transformed schema needed for coping with division of fraction, and that at this time, composition of the transformed schema and transformed schema derived from the recognition of primary concept of division could play the inevitable role of problem solving for division of fraction.

• Nuclear Engineering and Technology
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• v.38 no.1
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• pp.33-44
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• 2006

This paper presents a review of small-to-medium-sized, pressurized-water-cooled nuclear power reactors whose major primary coolant systems are integrated into a reactor pressure vessel, the concepts categorized as Integrated Primary System Nuclear Reactors (IPSRs). Typical examples of these proposals of interest in this review are CAREM, SMART, IRIS and IMR, all of which are being aimed at the near term deployment. Emphasis is placed on thermal hydraulic aspects. A brief characterization of the IPSR concepts is made and comparisons of plant key parameters are shown. Discussions will follow for the core cooling under rated power conditions and natural circulation heat removal on the basis of the design data available in the public domain.

• Journal of Elementary Mathematics Education in Korea
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• v.20 no.1
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• pp.105-129
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• 2016

The elements of mathematical processes include mathematical reasoning, mathematical problem-solving, and mathematical communications. Proportion reasoning is a kind of mathematical reasoning which is closely related to the ratio and percent concepts. Proportion reasoning is the essence of primary mathematics, and a basic mathematical concept required for the following more-complicated concepts. Therefore, the study aims to analyze the proportion reasoning ability of sixth graders of primary school who have already learned the ratio and percent concepts. To allow teachers to quickly recognize and help students who have difficulty solving a proportion reasoning problem, this study analyzed the characteristics and patterns of proportion reasoning of sixth graders of primary school. The purpose of this study is to provide implications for learning and teaching of future proportion reasoning of higher levels. In order to solve these study tasks, proportion reasoning problems were developed, and a total of 22 sixth graders of primary school were asked to solve these questions for a total of twice, once before and after they learned the ratio and percent concepts included in the 2009 revised mathematical curricula. Students' strategies and levels of proportional reasoning were analyzed by setting up the four different sections and classifying and analyzing the patterns of correct and wrong answers to the questions of each section. The results are followings; First, the 6th graders of primary school were able to utilize various proportion reasoning strategies depending on the conditions and patterns of mathematical assignments given to them. Second, most of the sixth graders of primary school remained at three levels of multiplicative reasoning. The most frequently adopted strategies by these sixth graders were the fraction strategy, the between-comparison strategy, and the within-comparison strategy. Third, the sixth graders of primary school often showed difficulty doing relative comparison. Fourth, the sixth graders of primary school placed the greatest concentration on the numbers given in the mathematical questions.

• The Mathematical Education
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• v.47 no.2
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• pp.197-219
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• 2008

Unlike ordinary situations, deifinitions play a very important role in mathematics education in schools. Mathematical concepts have been mainly acquired by given definitions. However, according to didactical intentions, mathematics education in schools has employed mathematical concepts and definitions with less strict forms than those in pure mathematics. This research mainly discusses definitions used in geometry (promising) course in primary schools to cope with possibilities of creating misconception due to this didactical transformation. After analyzing problems with potential misconceptions, a survey was conducted $\underline{with}$ 80 primary school teachers in Jeju to investigate their recognitions in meaning of mathematical concepts in geometry and attitudes toward teaching. Most of the respondents answered they taught their students while they knew well about mathematical definitions in geometry but the respondents sometimes confused mathematical concepts of polygons and circles. Also, they were aware of problems in current mathematics textbooks which have explained figures in small topics (classes). Here, several suggestions are proposed as follows from analyzing teachers' recognitions and researches in mathematical viewpoints of definitions (promising) in geometric figures which have been adopted by current mathematics textbooks in primary schools from the seventh educational curriculum. First, when primary school students in their detailed operational stage studying figures, they tend to experience $\underline{a}$ collision between concept images acquired from activities to find out promising and concept images formed through promising. Therefore, a teaching method is required to lessen possibility of misconceptions. That is, there should be a communication method between defining conceptual definitions and Images. Second, we need to consider how geometric figures and their elements in primary school textbooks are connected with fundamental terminologies laying the foundation for geometrical definitions and more logical approaches should be adopted. Third, the consistency with studying geometric figures should be considered. Fourth, sorting activities about problems in coined words related to figures and way and time of their introductions should be emphasized. In primary schools mathematics curriculum, geometry has played a crucial role in increasing mathematical ways of thoughts. Hence, being introduced by parts from viewpoints of relational understanding should be emphasized more in textbooks and teachers should teach students after restructuring this. Mathematics teachers should help their students not only learn conceptual definitions of geometric figures in their courses well but also advance to rigid mathematical definitions. Therefore, that's why mathematics teachers should know meanings of concepts clearly and accurately.

• Journal of The Korean Association For Science Education
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• v.32 no.6
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• pp.1050-1062
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• 2012

Concepts of science have been developed by occupying 'ecological niche' within conceptual ecology. The ecological niche is determined from the mutual effect between intellectual environmental of the learner and new concept, which few studies have been conducted. This study examined how the ecological niche of the concept of photosynthesis in $7^{th}$ grade is changed by instruction. The ecological niche was analyzed using 2 methods: (1) the change in the diversity of concepts, and (2) the change in the proximity of concepts based on the frequency and the relativeness score of the concepts. The concept of photosynthesis was analyzed in the 4 domains in the place of photosynthesis, products of photosynthesis, reactants of photosynthesis, and environmental factors. The results of this study are as follows: (1) reduced diversity of concepts, (2) increased frequency and relativeness score of the scientific concepts, and (3) increased proximity of the scientific concepts by instruction. With these results, the mutual effects of the concepts within the conceptual ecology have become active by class to differentiate the relationships between the concepts, which accordingly displayed their changes in status.

• Education of Primary School Mathematics
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• v.7 no.1
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• pp.43-56
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• 2003

In late 19C, German mathematician Felix Klein declaired "Erlangen program" to reform mathematics education in Germany. The main ideas of "Erlangen program" contain the importance of instructing the concepts of functions and groups in school mathematics. After one century from that time, the importance of concepts of groups revived by Bourbaki in the sense of the algebraic structure which is the most important structure among three structures of mathematics - algebraic structure. ordered structure and topological structure. Since then, many mathematicians and mathematics educators devoted to work with the concepts of group for school mathematics. This movement landed on Korea in 21C, and now, the concepts of groups appeared in element mathematics text as plane rigid motion. In this paper, we state the rigid motions centered the symmetry - an important notion in group theory, then summarize the results obtained from some classroom activities. After that, we discuss the responses of children to concepts of groups.of groups.

• Korean Journal of Health Education and Promotion
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• v.7 no.1
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• pp.10-26
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• 1990

In Korean education, the health contents are scattered in various course subjects throughtout the primary and junior high school curriculum. So it is very difficult to provide systematic health education. The purpose of this study was to provide a guide for health education using health topic areas and major concepts that represent the scope of material that should be covered in health instruction. The steps used in selecting these health topic areas and major concepts were as follows: 1. A review of the literature related to health and health education was done to develop the rationale underlying this study. 2. Health topic areas basic to the growth and development characteristics of children, to human needs and to societal needs for healthful living were indentified. 3. The major concepts for each health topic area based on health sciences and children's growth and development levels were selected. 4. The major concepts selected were organized in sequence to guide health education from grade one to grade nine. The results of this study were as follows: 1. The identification of eleven health topic areas essential for health education. These include: personal habits and health healthy growth and development nutrition and health prevention of disease and disorders drugs and health mental health family life and health sex education accident prevention consumer health community health 2. The identification of the major concepts(generalizations) for each health topic area: 33 major concepts were identified as a guide in determining the health content of health education programs. These are 1) body cleaniness, 2) health of the sensory organs, 3) dental health, 4) exercise and rest, 5) growth and development, 6) body structure and function, 7) developmental tasks, 8) balanced nutrition, 9) eating habits, 10) food preparation and food storage, 11) sources of disease and disorders, 12) disease preventive behavior, 13) care during illness, 14) drug use and misuse, 15) drug addiction, 16) emotional responses, 17) human relationship, 18) self concept, 19) social adjustment, 20) health habits of the family, 21) interdependence of family members, 22) origin of life, 23) characteristics of man and woman, 24) sexual instinct, 25) safety behavior, 26) emergency measures, 27) criteria for selection of health products, 28) proper use of health information, 29) utilization of health and medical services, 30) environmental conservation, 31) environmental pollution, 32) population control, 33) function of public health services. 3. The organization of the concepts(generalizations) in sequence and for continuity in health instruction at the primary and junior high school level.

• Journal of applied mathematics & informatics
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• v.16 no.1_2
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• pp.585-593
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• 2004

In this paper we shall discuss the minimal, maximal and primary subautomata. Also the concepts of the totally reachable state and source will be introduced. It is an interesting part that mX＊ is minimal iff the source S(m) is maximal. We shall point out that the characterization of primary subautomaton comes from the properties associated with the sources S(m)'s.

• Journal of The Korean Association For Science Education
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• v.33 no.3
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• pp.650-663
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• 2013

Multidimensional scaling can be used to identify relationships among concepts, revealing the structure of the cognitive framework by measuring distances within perceptual maps. The current study sought to examine the relationships among concepts related to photosynthesis in 2,844 $3^{rd}-11^{th}$ grade science students. The questionnaire included items on 'location,' 'products,' 'reactants,' and 'environmental factors', presenting images related to each theme. Students provided responses corresponding to particular topics, and reported the extent to which the concept was related to the topic on a scale from 1 to 30. The survey results were as follows: first, students were not able to clearly distinguish between or understand the four main topics. Second, students organized their cognitive structures by closely associating related concepts after learning. Third, the presented concepts revealed a mixture of scientific and non-scientific concepts, suggesting that students needed to clearly distinguish the preconceptions through which they organized concepts, so that they are suitable for cognitive structures based on learning. Furthermore, non-scientific concepts within perceptions were consistently maintained throughout learning, affecting the proximity of scientific concepts.

• Korean Journal of Child Studies
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• v.25 no.6
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• pp.371-383
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• 2004

In this study, 197 4- to 6- year-old Korean children wereindividually tested with Concepts about Print(CAP Clay, 2000), the Picture Vocabulary Test(Kim, Jang, Lim & Bak, 1996), Korean-Wechsler Preschool and Primary Scale of Intelligence : Verbal Test (K-WPPSI), and the Basic Academy Skills Assessment : Reading(Kim, 2000). Data were analyzed by Pearson-correlation, analysis of variance, and factor analysis. There were significant differences of CAP mean scores by age. Within the subcategories of CAP, Book Orientation Concepts and Print-convention were acquired earlier than other subcategories, followed by Print-direction, Print-order and Advanced Print Concepts in that order. The scores of CAP were positively correlated with the Picture Vocabulary Test, the K-WPPSI verbal test and the reading test.