• 소성∙가공
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• 제9권2호
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• pp.103-111
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• 2000

It is necessary to improve mechanical and optical properties in the optical disk substrates as the information storage density using short wavelength laser are being developed. The birefringence distribution is regarded as one of the most important optical properties for optical disk. In the present study, the birefringence distrubution is calculated using the Leonov model for viscoelastic constitutive equations and Cross/WLF model for viscosity approximation. The effects of processing conditions upon the development of birefringence discosity approximation. The effects of processing conditions upon the development of birefringence distribution in the optical disk were examined theoretically. It was found that the values of the birefringence distributions were very sensitive to the mold wall temperature history which minimizes the birefringence distribution. The analytical results showed the possibility of improving mechanical and optical properties in the optical disk substrates by active control of the mold wall temperature history.

• 한국가구학회지
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• 제28권3호
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• pp.135-144
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• 2017

The development of human civilization has been accompanied by a corresponding development of storage facilities. In particular, the storage of residential spaces not only performs the storage management function for personal property but also is considered an important prerequisite for a comfortable life. While examining the history of the transformation of built-in furniture, this study emphasizes the social and cultural implications of Korean residences. Therefore, We attempt to uncover the Korean characteristics that can be discovered in the transformation of storage furniture according to the changes that occurred in Korean residential forms following the modern era and to question the problematic issues of the built-in furniture in Korea.

• 한국수학사학회지
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• 제27권6호
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• pp.387-394
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• 2014

Since ancient civilization, solving equations has become one of the most important subjects in mathematics and mathematics education. The extractions of square roots and cube roots were first dealt in Jiuzhang Suanshu in the setting of subdivisions. Extending these, Shisuo Kaifangfa and Zengcheng Kaifangfa were introduced in the 11th century and the subsequent development became one of the most important contributions to mathematics in the East Asian mathematics. The translation of coordinate axes plays an important role in school mathematics. Connecting the translation and Kaifangfa, we find strong didactical implications for improving students' understanding the history of Kaifangfa together with the translation itself although the latter is irrelevant to the former's historical development.

• 한국수학사학회지
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• 제17권1호
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• pp.43-52
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• 2004

In this paper we investigate the origin of the variational calculus with respect to the extremal principle. We also study the role the extremal principle has played in the development of the calculus of variations. We deal with Dido's isoperimetric problem, Maupertius's least action principle, brachistochrone problem, geodesics, Johann Bernoulli's principle of virtual work, Plateau's minimal surface and Dirichlet principle.

• 한국수학사학회지
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• 제15권3호
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• pp.35-48
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• 2002

In this paper, we explore development of mathematical knowledge, especially calculus, non-Euclidean geometry, Euler's theorem, and the comparison of the number of elements in two infinite sets. And we analyze kinds of errors and the roles for errors with respect to increasing knowledge in mathematics.

• 한국수학사학회지
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• 제12권1호
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• pp.21-31
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• 1999

This paper deals with the development of universal algebras. We first investigate how the abstract algebra has emerged as a common generalization of arithmetic and algebra of logic, which was finalized by A. N. Whitehead in his "A treatise on universal algebra with applications." And we investigate also the process of formalizing universal algebras by G. Birkhoff. Birkhoff.

• 한국수학사학회지
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• 제12권1호
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• pp.82-87
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• 1999

The Internet has developed the computer and communications world. The Internet has tons of millions of sites. To find the specific information, we use a search engine. All search engines are operated by keyword against a database, but many different factors affect the result of search by engines. In this paper, we investigate the development of the Internet and try to find the differences among the most popular search engines.

• Journal of the Korean Data and Information Science Society
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• 제18권2호
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• pp.375-384
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• 2007

As teachings that use the ICT are more popular, many studies on the dynamic geometry environment(DGE) are under way. An important factor emphasized in the studies is to practical use learning activities of learners. In this study, we first define the learning history data in DGE. Second we develop a prototype of the DGE that is able to collect and analyze the learning history data automatically. The environment enables not only to grasp leaning history but also to create and manage new learning objects.

• 한국의사학회지
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• 제29권2호
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• pp.71-81
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• 2016

This paper discusses the research of preventive medicine in terms of philosophy and history, publication and people, branch research, applied research, Gi-gong, conduction exercise and so on. Currently, fields of philosophy, history, physical education and Korean Medicine are actively participating in the research on preventive medicine. From the philosophical view, theoretical aspects of preventive medicine are closely examined. From the historical view, the historical context is of focus. From the physical education viewpoint, Gi-gong, gymnastics and physical education philosophy are studied. In the field of Korean medicine where practicality is most important, plans to apply preventive medicine to life are creating new possibilities for research on preventive medicine. In this time where social interest on health is at peak, combined research of basic theory and application will have positive effects on the development of preventive medicine.

• 한국의사학회지
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• 제17권2호
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• pp.45-62
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• 2004

In this paper, we will take a look at the perception of gynecological diseases in the JinYuanSiDaJia (金元四大家-the four great schools of Jin Yuan), including the academic schools LiuWanSu(劉完素), ZhangCongZheng(張從正), LiGao, and ZhuZhenheng(朱震亨) during JinYuan Dynasty(金元時代). We also examined the medical history of gynecology up until the MingQingDynasty(明淸時代) when the dialectical system on gynecological diseases was relatively complete.