• Journal of Educational Research in Mathematics
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• v.27 no.2
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• pp.249-267
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• 2017

The unit of multiplication in the mathematics textbook for third graders deals with two-digit number multiplied by one-digit number. Students tend to perform multiplication without necessarily understanding the principle behind the calculation. Against this background, we designed the unit in a way for students to explore the principle of multiplication with cuisenaire rods and array models. The results of this study showed that most students were able to represent the process of multiplication with both cuisenaire rods and array models and to connect such a process with multiplicative expressions. More importantly, the associative property of multiplication and the distributive property of multiplication over addition were meaningfully used in the process of writing expressions. To be sure, some students at first had difficulties in representing the process of multiplication but overcame such difficulties through the whole-class discussion. This study is expected to suggest implications for how to teach multiplication on the basis of the properties of the operation with appropriate instructional tools.

• Journal of the Korea Society of Computer and Information
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• v.5 no.4
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• pp.7-12
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• 2000

This paper is an attempt to design and implement a multimedia title for the lesson of' Creatu Environment' which appears in the textbook of the second semester for the fourth graders. The title make the most use do multimedia features so that students my be able to reach the best result of activities. The title adopts the Cocktail program developed by Hite-Media Co. It is designed to resolve that are associated with sequential and letter-centered simplicity. As a result, students can interact on the other and the amount of their lessons. The title can effectively combines visual and aural (i. e. information to bring in motivations and participations in learning activities. This title is believed to help students to solve many classroom questions and to try individual learning. Finally, it is hoped that the title helps students to understand the ultimate go subject. 'Environment does affect the life of plants'.

• Education of Primary School Mathematics
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• v.19 no.4
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• pp.277-289
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• 2016

Fraction is one of the concepts which are difficult to elementary school students. So, many researches about fraction were performed in mathematics education research. In special, fraction has so many subordinative concepts-proper fraction, improper fraction, mixed number. We have to concentrate on the conceptual understanding in teaching of fraction. In this case, a mixed number and improper fraction are concepts which can convert respectively. And there are methods that a mixed number and improper fraction can be converted. So, it's needed to analyze the converting methods in textbooks for getting the implication of teaching in this areas. In this study, I analyzed the Korean and foreign's textbooks. I certified the methods-using addition expression, using part-whole model in the textbooks. For the conceptual understanding, I suggested to use the fusion of the various part-whole fraction models and addition expression more than the algorithm in converting between a mixed number and improper fraction. It's reason that the use of models in converting between a mixed number and improper fraction is important for the relational understanding.

• Hwankyungkyoyuk
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• v.12 no.1
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• pp.189-204
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• 1999

Recently, the interest in artificial environment made by mankind as well as natural environment has been increased. This interest in the environment began to be reflected in the physical education, which environmental problems affect modern people's living quality as a crucial factor affecting directly or indirectly our life. Furthermore, since we entered the era of mass sports the physical education subject has dealt with destruction of natural environment by constructing golf courses, ski slopes, etc., destruction of ecosystem by water sports, mountaineering sports, aero sports, etc., and noise pollution near the sport facilities. Therefore, the purpose of this paper is to examine the means to reinforce environmental education in many ways in the physical education concerning environmental problems. For this purpose this paper analyzed the contents of the 7th curriculum for physical education which can be thought to be teaching materials for environmental education, and described the contents in detail. Also, this paper established the orientation and goals of environmental education in the physical education subject and examined some important teaching and learning methods. In addition, this paper suggested some considerations concerning environmental education and a textbook model for the development of physical education textbooks connecting with the 7th curriculum for physical education, which is to suggest a means to connect physical education with environmental education smoothly. The physical education has an attribute that its activities like swimming, climbing mountains, and camping are performed outdoor. The physical activities in the physical education are, of course, performed in the environment, so we had better implement the environmental education including such physical activities at the same time with physical education. Also, there should be efforts so that the education through environment, the education about environment, and the education in the environment can be implemented along with the physical education.

• Journal of Educational Research in Mathematics
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• v.14 no.4
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• pp.347-366
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• 2004

Recently, there have been many assessment researches in Korea. The aim of this study is to reflect on framework for mathematics assessment in RME which is based on Jan de Lange's assessment theory and to induce desirable directions for our mathematics assessment in nation-level and class-level. In order to attain these purposes, the present paper reflects the philosophy of RME, Jan de Lange's framework for mathematics assessment, assessment framework of the unit 'Side Seeing', one of Mathematics in Context textbook series, as an exemplar to which Jan de Lange's framework is applied. Based on these reflections, it is discussed that it needs to specify achievement standards presented in mathematics curriculum more particularly in order to have framework including mathematical abilities of level 2 and level 3 in Jan de Lange's framework appropriate to our situations, to apply the framework to nation-level and class-level consistently, and to enhance abilities of teachers and student teachers for mathematics assessment.

• Communications of Mathematical Education
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• v.35 no.4
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• pp.505-525
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• 2021

In this study, we investigated how multiplication by 2-digit numbers had been taught in elementary mathematics textbooks of Korea, Japan, Singapore, and USA. As a result of analysis, we found as follows. Korean textbooks do not teach the multiplication by 10 and the multiplication by power of 10, but Japanese, Singapore, and US textbooks explicitly teach related content. In the '×tens' teaching, Japanese and American textbooks teach formally the law of association of multiplication applied in the process of calculating the partial product of multiplication. The standard multiplication algorithm generally followed a standard method of recording partial product result according to the law of distribution, but the differences were confirmed in the multiplication model, the teaching method of the law of distribution, and the notation of the last digit '0'. Based upon these results, we suggested some proposals for improving the multiplication teaching.

• Journal of the Korean Society of Radiology
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• v.11 no.5
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• pp.371-377
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• 2017

General phantom for practical X-ray photography Practical phantom is an indispensable textbook for radiology, but it is difficult for existing commercially available phantom to be equipped with various kinds of phantom because it is an expensive import. Using 3D printing technology, I would like to make the general phantom for practical X-ray photography less expensive and easier. We would like to use a skeleton model that was produced based on CT image data using a 3D printer of FDM (Fused Deposition Modeling) method as a phantom for general X-ray imaging. 3D slicer 4.7.0 program is used to convert CT DICOM image data into STL file, convert it to G-code conversion process, output it to 3D printer, and create skeleton model. The phantom of the completed phantom was photographed by X - ray and CT, and compared with actual medical images and phantoms on the market, there was a detailed difference between actual medical images and bone density, but it could be utilized as a practical phantom. 3D phonemes that can be used for general X-ray practice can be manufactured at low cost by utilizing 3D printers which are low cost and distributed and free 3D slicer program for research. According to the future diversification and research of 3D printing technology, it will be possible to apply to various fields such as health education and medical service.

• Environmental and Resource Economics Review
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• v.24 no.1
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• pp.1-53
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• 2015

In environmental policy areas, a greater use of economic instruments (EIs) has recently been observed in many countries. However, EIs are heterogeneous policy tools. The textbook case of a Pigouvian tax is far from widely used, mainly due to the information requirements and other structural and institutional constraints. The successful implementation of EIs might heavily depend on pre-existing structural and institutional conditions. Moreover, these institutional conditions are particularly unfavorable in developing countries. Using a simple analytical general equilibrium model, this paper examines how these constraints affect the welfare gain from the introduction of environmental taxes in developing countries. First, this paper solves for the second-best optimal Pigouvian tax and output tax in the presence of a distortionary tax on market use of labor. The result confirms that an environmental output tax achieves a socially-efficient level of emissions in the least-cost manner only if the nature of the linkage between the tax base and the environmental damage is fixed. Second, incorporating structural and institutional constraints into the model through a set of parameter values from China and the US, this paper calculates the net welfare effects of either using the ideal Pigouvian tax or instead using an output tax. The numerical simulation results show that the net welfare gain from the use of an ideal Pigouvian tax could be more than six times larger than that of an output tax in developing countries. On the other hand, the welfare gain is only 50 percent in developed countries. This means that the potential welfare disadvantage from using output taxes instead emissions tax for environmental purposes could be much greater in the case of developing countries.

• Journal of The Korean Association For Science Education
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• v.28 no.6
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• pp.685-695
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• 2008

An analysis on the Inquiry unit of Science 10 textbooks was conducted in terms of nature of science (NOS). The subject of the analysis was instructional objectives, activities and sentences in the unit of ten Science 10 textbooks. Contents of the instructional objectives could be grouped into nature of science, nature of scientists, scientific methods, and Science-Technology-Society. The concrete nature of scientific knowledge (SK) and constructing scientific theory or model, however, were not found in the objectives. The total number of activities in the Inquiry unit was 38. Seventeen out of them were presented without any supplemental or introductory materials, and 21 activities were provided with information followed by questions, discussions or investigations. For the most activities, any clear statements about NOS elements and desired/informed views of NOS were not made. The sentences of the Inquiry units were mixed up with constructivist and inductive views on NOS. The definition of science tended to be described based on the inductive view. And the generation of SK tended to be described as discovering regularities in natural phenomena rather than constructing theories. For science teachers who want to teach NOS effectively, stating clear learning objectives and elements of NOS and presenting reading materials with relevant views on nature of science were necessary.

• 대한공업교육학회지
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• v.38 no.2
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• pp.89-113
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• 2013

The study started from the point that learners should be basically equipped to quickly respond to changes in demand for future human resources efficiently and effectively, and an attitude to take part in learning voluntarily should thus be cultivated. To this end, the author applied the TAI model based on a module as a class strategy to solve problems related to several classes occurred in specialized high schools. This application of the TAI model was also motivated by the necessity for designing an appropriate teaching-learning method that encourages improvement of self-learning capacity, consistent learning motivation, and willingness rather than external factors. Through this work, the author aims to heighten the interest of learners and improve endurance in learning. The study results are as follows. First, the learning unit was structuralized as a module and then learning stages were proceeded with so that capacity to adapt to learning would improve. The achievement standard (learning goal) was structuralized in a module type by analyzing and reorganizing the textbook considering the link between the actual practice field and a curriculum based on subject characteristics. Through the process of module type learning stages, the student's capacity to ascertain characteristics of units and to adapt to learning both improved. Second, through application of a TAI model based on a module, Self-Directed Learning capacity and capacity to adapt to a new field improved. By applying the module, Self-Directed Learning could be accomplished more effectively than in the existing passive learning environment. By grafting cooperative learning of the TAI model, students had greater interest and achievement in classes, self-confidence and community consciousness, and an opportunity to broaden their thinking. In particular, improvement of self-confidence is effective in cultivating the capacity required in industrial society to transcend the learning of simple functions and knowledge, as well as the capacity to adapt to new environments. Third, by solving tasks focused on fields related to industrial sites, not only actual survey capacity but also additional capacity to identify and solve tasks through various experiences improved. Furthermore, it was helpful for students to have interest and motivation about their own life and learning to cultivate the qualities and capacity to adapt to the working world where new knowledge and technology rapidly change. Fourth, by applying a standard-based assessment system for technical subjects introduced in 2012 to model design for learning plans, clearer and more objective assessment criteria were arranged, and individual learning through instruction at each achievement level could be accomplished. This improved achievement level of individual learners was helpful in reaching achievement goals at specific levels by overcoming the disadvantages of cooperative learning in each group.