• Journal of Educational Research in Mathematics
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• v.13 no.3
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• pp.247-265
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• 2003

The purpose of this study is to analyze the essence of ratio concept from educational viewpoint. For this purpose, it was tried to examine contents and organizations of the recent teaching of ratio concept in elementary school text of Korea from ‘Syllabus Period’ to ‘the 7th Curriculum Period’ In these text most ratio problems were numerically and algorithmically approached. So the Wiskobas programme was introduced, in which the focal point was not on mathematics as a closed system but on the activity, on the process of mathematization and the subject ‘ratio’ was assigned an important place. There are some educational implications of this study which needs to be mentioned. First, the programme for developing proportional reasoning should be introduced early Many students have a substantial amount of prior knowledge of proportional reasoning. Second, conventional symbol and algorithmic method should be introduced after students have had the opportunity to go through many experiences in intuitive and conceptual way. Third, context problems and real-life situations should be required both to constitute and to apply ratio concept. While working on contort problems the students can develop proportional reasoning and understanding. Fourth, In order to assist student's learning process of ratio concept, visual models have to recommend to use.

• Journal of Educational Research in Mathematics
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• v.16 no.2
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• pp.157-177
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• 2006

The concepts of ratio and proportion do not develop in isolation. Rather, they are part of the individual's multiplicative conceptual field, which includes other concepts such as multiplication, division, and rational numbers. The current study attempted to clarify the beginning of this development process. One fourth student, Kyungsu, was encourage to schematize his trial-and-error-based method, which was effective in solving so-called missing-value tasks. This study describes several advancements Kyungsu made during the teaching experiment and analyzes the challenges Kyungsu faced in attempting to schematize his method. Finally, the mathematical knowledge Kyungsu needed to further develop his ratio and proportion concepts is identified. The findings provide additional support for the view that the development of ratio and proportion concepts is embedded within the development of the multiplicative conceptual field.

• Journal of The Korean Association For Science Education
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• v.32 no.10
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• pp.1524-1536
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• 2012

Science attitudes affect the quality of learning, and they are considered as one of the major concerns in science education. It is necessary to analyze the proximity between concepts with science attitudes. Accordingly, this study was designed to analyze the proximity of the concept related to photosynthesis as it changed after class according to the levels of science attitudes. A survey on the concept of photosynthesis and science attitudes before and after class was conducted on 270 7th-grade students. The concept of photosynthesis was composed of 'the place of photosynthesis,' 'products of photosynthesis,' 'reactants of photosynthesis,' and 'environmental factors.' The proximity of the concept of photosynthesis was analyzed through the utilization of multidimensional scaling (MDS). The research results were as follows: (1) Students changed the proximity between concepts by acquiring concrete concepts through class. (2) The upper group in science attitudes tends to be closer to the proximity between scientific concepts through class, compared to the intermediate and lower groups. (3) In all students with entire levels of science attitudes, non-scientific concepts continued to exist even after class, and the non-scientific concepts were deemed to interfere with the proximity between scientific concepts related to photosynthesis. (4) Students turned out to be aware of the concepts related to each other in four areas associated with photosynthesis. That is, it can be said that students are closely aware of the place where photosynthesis can occur and the materials needed as well as materials generated as a result of photosynthesis and the materials needed in terms of concepts related to photosynthesis.

• Journal of the Korean earth science society
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• v.24 no.3
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• pp.160-171
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• 2003

This study was designed to analyze the types of concepts about earth science related to seasonal changes, so as to develop a generative learning model focused on dissolving cognitive conflicts between the aforementioned concepts through debates and using said debates to find out how effectively the model works. There are 100 types of earth science concepts concering seasonal changes, 66 of which are unscientific in nature, including misconceptions. Through a second field trial and a research and development (R&D) process, a test on these concepts was developed, consisting of 14 items. For the experimental group, a four-phase generative learning strategy that reflects the types of earth science concepts and cognitive conflicts between such concepts was developed through pre-analysis and discussion, respectively. On the other hand, a traditional teaching and teaming strategy was used for the control group. A meaningful statistic gap found between the two groups through a covariance analysis, the significance level of which was 0.05. This result may be interpreted to mean that the generative teaming strategy is a possible alternative for correcting misconceptions about scientific concepts of seasonal changes.

• Proceedings of the Korean Society for Information Management Conference
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• 1994.12a
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• pp.105-108
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• 1994

시소러스는 다양한 형식과 순서로 표시되며. 인쇄매체인 경우와 화면인 경우에 따라 형식이 달라지게 된다. 온라인시소러스에서는 여러 가지 표시방법을 제공할 수 있으며 즉시 관련색인과 연관시켜 참조할 수 있으나 인쇄시소러스는 시간과 공간의 제약이 있으므로 표시방법을 달리 고려하여야 한다. 특히 인쇄시소러스는 어떤 개념을 찾았을 때 그 개념과 관련된 모든 정보를 한꺼번에 볼 수 있어야 한다. 관련부분을 다시 참조하는 것은 온라인시소러스에 비해 매우 어렵기 때문이다. 본 연구에서는 이와 같은 관점에서 인쇄시소러스의 각 표시방법에 대한 장단점을 고찰하고 보다 바람직한 표시형식을 제안하고자 한다.

• Journal of the Korean School Mathematics Society
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• v.13 no.3
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• pp.483-498
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• 2010

The purpose of this paper is to investigate the dispositions of university students' understanding and reasoning about rational number concept. For this, we surveyed for the subject groups of prospective math teachers(33), engineering major students(35), American engineering and science major students(28). The questionnaire consists of four problems related to understanding of rational number concept and three problems related to rational number operation reasoning. We asked multi-answers for the front four problem and the order of favorite algorithms for the back three problems. As a result, we found that university students don't understand exactly the facets of rational number and prefer the mechanic approaches rather than conceptual one. Furthermore, they reasoned illogically in many situations related to fraction, ratio, proportion, rational number and don't recognize exactly the connection between them, and confuse about rational number concept.

• Journal of the Korean earth science society
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• v.25 no.8
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• pp.684-696
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• 2004

Using six preservice teachers as subjects, this was purpose to research about concepts in understanding carbon cycle, which of concepts were related to the conception of the system, and finally whether or not the systems thinking was sufficiently around carbon cycle. To achieve this study purpose , an instrument related to carbon cycle was developed and administered to the six teachers. The study found that a total of 42 conceptions within the system were concepts related to carbon cycle. The consisted of 15 conceptions in atmosphere, 11 in atmosphere 9 in hydrosphere, and 7 in lithosphere. In aspect of applying the system thinking, 4 subjects who couldn't compose the feedback loop in their causal map failed to apply this type of thinking. The other two who applied systems thinking had 2 and 1 feedback loop each, in their causal maps. But, one of the feedback loop from the subject who made two was based on unscientific reasoning. As a result, the subjects had lower understanding of concepts related to carbon cycle in lithosphere than in atmosphere, atmosphere, and hydrosphere. Futhermore, the subjects' application of the earth systems thinking on carbon was at a low standard.

• Proceedings of the Korean Statistical Society Conference
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• 2004.11a
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• pp.149-154
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• 2004

이 논문에서는 표본조사에서 자주 사용되는 표본의 대표성, 비편향성, 그리고 효율성에 개넘에 대하여 고찰하였다. 표본의 대표성은 조사단위의 포함확률로 표현되며 조사모집단의 포함범위와 연관이 있는 반면, 비편향성과 효율성은 표집설계와 추정량에 관련된 개념이다. 비편향성과 효율성은 표본의 대표성을 전제로 하며 가중치 부여로 나타난다

• School Mathematics
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• v.11 no.1
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• pp.93-110
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• 2009

This paper provides an analysis of a survey on high school students' understanding of definite integral. The purposes of this survey were to identify high school students' private concept definitiones and concept images on definite integral. Definitions and images, as well as the relation between them of the definite integral concept, were examined in 108 high school students. A questionnaire was designed to explore the cognitive schemes for the definite integral concept that evoked by the students. The students' individual answers were collected through written environment. Four types of the private concept definitiones and concept images were identified in the analysis.

• Journal of Elementary Mathematics Education in Korea
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• v.12 no.1
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• pp.59-78
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• 2008

The purpose of this study was to research and analyze students' informal knowledge before they learned formal knowledge about fraction concepts and to see how to apply this informal knowledge to teach fraction concepts. According to this purpose, research questions were follows. 1) What is the students' informal knowledge about dividing into equal parts, the equivalent fraction, and comparing size of fractions among important and primary concepts of fraction? 2) What are the contents to can lead bad concepts among students' informal knowledge? 3) How will students' informal knowledge be used when teachers give lessons in fraction concepts? To perform this study, I asked interview questions that constructed a form of drawing expression, a form of story telling, and a form of activity with figure. The interview questions included questions related to dividing into equal parts, the equivalent fraction, and comparing size of fractions. The conclusions are as follows: First, when students before they learned formal knowledge about fraction concepts solve the problem, they use the informal knowledge. And a form of informal knowledge is vary various. Second, among students' informal knowledge related to important and primary concepts of fraction, there are contents to lead bad concepts. Third, it is necessary to use students' various informal knowledge to instruct fraction concepts so that students can understand clearly about fraction concepts.