• Journal of the Korean Society of Costume
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• v.63 no.8
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• pp.171-187
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• 2013

This is a study on the military costumes of Hunryeondogam, which was the center of Five Military Camps in the mid and the late Joseon dynasty. I confirmed the characteristics and system of military costumes of Hunryeondogam by document research and positive research. The military organization of Hunryeondogam was comprised of the high-ranking military officers such as Hunryeondaejang, Junggun, Cheonchong, Byeoljang and Gukbyeoljang, the mid and low ranking military officers such as Pachong, Chogwa and soldiers. And the military costume of Hunryeondogam included Gapju, Yoongbok and Goonbok for military officers and all kinds of military uniforms for soldiers. Imjin war and ritualized military ceremonies in the era of peace had influence on the military costume. Officers, for example, were wearing Dangap and soldiers were wearing Cheolgap or Pigap that depended on the branch of the army. Politically, kings in the mid and the late Joseon had organized military organizations to strengthen their royal authority. I think that the policy can be effectively seen by observing the military costume system. The qualitative differences in cloth materials and the presence or absence of patterns of Goonbok, the qualitative differences in the decoration of Jeonrip and the presence or absence of Yodae were able to distinguish the identity and the rank. An assumption can be made that these things could have been affected by social causes, such as frequent trips of the King and stable society. This cause could be influence on substitute Yoongbok with Goonbok that from the low ranking military officers to the high ranking military officers of Hunryeondogam. The societal changes in the mid and the late Joseon dynasty are reflected on the military costumes system of Hunryeondogam.

• School Mathematics
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• v.18 no.4
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• pp.839-856
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• 2016

In 2009 revision and 2015 revision mathematics national curriculum, 'proof' was moved to high school from middle school in consideration of the cognitive development level of students, and 'proof by contradiction' was stated in the "success criteria of learning contents" of the first year high school subject while it had been not officially introduced in $7^{th}$ and 2007 revision national curriculum. Proof by contradiction is known that it induces a cognitive conflict due to the unique nature of rather assuming the opposite of the statement for proving it. In this article, based on the logical, mathematical and historical analysis of Proof by contradiction, we looked about the introductions and the applications of the current textbooks which had been revised recently, and searched for improvement measures from the viewpoint of discovery, explanation, and consilience. We suggested introducing Proof by contradiction after describing the discovery process earlier, separately but organically describing parts necessary to assume the opposite and parts not necessary, disclosing the relationships with proof by contrapositive, and using the viewpoint of consilience.

• Journal of The Korean Association of Information Education
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• v.26 no.5
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• pp.307-315
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• 2022

The purpose of this study was to design a training program for pre-service elementary teachers, incorporating the concepts of extended reality technologies. This program contained the basic skills necessary for them to utilize in their future classrooms. To accomplish this, 12 undergraduate students of various majors enrolled in one of Korea's national universities of education were selected as research subjects. For a total of 6 times over 6 weeks, they participated in a training program learning the basic concepts of virtual, augmented, and mixed reality, as well as creating their own education software to use in simulated classes. To improve the quality of future research efforts, this study found it would be beneficial to: 1) expand the relevant support equipment, 2) provide students with preliminary, background knowledge of text-based programming, 3) introduce short-term, more intensive training, and 4) improve the survey methods for this research.