• Journal of Educational Research in Mathematics
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• v.16 no.4
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• pp.345-366
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• 2006

In this study, we investigated the methods of using the Cabri3D program for education of problem solving in school mathematics. Cabri3D is the program that can represent 3-dimensional figures and explore these in dynamic method. By using this program, we can see mathematical relations in space or mathematical properties in 3-dimensional figures vidually. We conducted classroom activity exploring Cabri3D with 15 pre-service leachers in 2006. In this process, we collected practical examples that can assist four stages of problem solving. Through the analysis of these examples, we concluded that Cabri3D is useful instrument to enhance problem solving ability and suggested it's educational usage as follows. In the stage of understanding the problem, it can be used to serve visual understanding and intuitive belief on the meaning of the problem, mathematical relations or properties in 3-dimensional figures. In the stage of devising a plan, it can be used to extend students's 2-dimensional thinking to 3-dimensional thinking by analogy. In the stage of carrying out the plan, it can be used to help the process to lead deductive thinking. In the stage of looking back at the work, it can be used to assist the process applying present work's result or method to another problem, checking the work, new problem posing.

• Journal of Educational Research in Mathematics
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• v.25 no.2
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• pp.241-261
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• 2015

"SMART" is a word to condense a new kind of educational system recently proposed by the Korean government. It signifies an intelligent adaptive learning system to innovate the educational environment, the contents, methodology and assessment. Developing a digital textbook was one of the main strategic goals to drive forward "smart" education. The Korean government expected to finish the development of digital textbooks of science, mathematics, social studies and English by 2013 and to have a field experiment for them in 2014. However, the case of mathematics was postponed for an indefinite period because its draft version was no different from a traditional textbook in its functional aspect. This situation might come from the non-existence of a good authoring tool and an inexperienced sense by developers of the opportunities available with digital textbooks. This paper introduces the main features for developing a digital mathematics textbook for the 12th grade students, which was developed in the environment of Cabri LM as an authoring tool. This paper also looks upon the results of a whole lesson using the textbook in managing the classroom interaction with students.

• Journal of the Korean School Mathematics Society
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• v.6 no.2
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• pp.39-53
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• 2003

We study the dynamic geometry software suitable for the Internet Environment. First, we look into the necessity of dynamic geometry software and compare the functions and the features of commercial softwares, GSP, Cabri and Cinderella. Secondly, we introduce the process of development and the structure of the new software DRC(Digital Ruler and Compass) designed by authors and discuss the learning program with DRC and Internet, and view the upgrade of the software in the future.

• Korean Journal of Crystallography
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• v.1 no.2
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• pp.66-75
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• 1990

The Pd-Te system has been investigated by differential thermal analysis, X-ray diffration, electron probe microanalysis and reflected light microscopy. New phase relations in 0-50at% Te portion of the binary system are proposed. Eight binary phases exist in the system:Pd17Te4, Pd20Te7.PdsTe3, P477e3, P497e4, P637e2, PeTe and PaTe2. Of these, P677e3 is a newly reported phase. P4177e4 is cubic, space group Fd3c, with a=12.678(5)A. The X-ray powder data of PdsTe3, indexed on an orthorhombic cell, give a= 12.843(3), b=15.126(3), c: 11.304(2)A and those of PdTTe.1, indexed on a monoclinic cell, give a=7.444(1), b= 13.918(2) , c=8.873(2)A. p =92.46(2). Some physical and optical properties of synthetic phases in the system are also reported.

• Nuclear Engineering and Technology
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• v.47 no.3
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• pp.240-252
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• 2015

In the original licensing application for the prototype fast-breeder reactor, MONJU, the event progression during an unprotected loss of flow (ULOF), which is one of the technically inconceivable events postulated beyond design basis, was evaluated. Through this evaluation, it was confirmed that radiological consequences could be suitably limited even if mechanical energy was released. Following the Fukushima-Daiichi accident, a new nuclear safety regulation has become effective in Japan. The conformity of MONJU to this new regulation should hence be investigated. The objectives of the present study are to conduct a preliminary evaluation of ULOF for MONJU, reflecting the knowledge obtained after the original licensing application through CABRI experiments and EAGLE projects, and to gain the prospect of in-vessel retention for the conformity of MONJU to the new regulation. The preliminary evaluation in the present study showed that no significant mechanical energy release would take place, and that thermal failure of the reactor vessel could be avoided by the stable cooling of disrupted-core materials. This result suggests that the prospect of in-vessel retention against ULOF, which lies within the bounds of the original licensing evaluation and conforms to the new nuclear safety regulation, will be gained.