• The Pure and Applied Mathematics
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• v.3 no.1
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• pp.9-18
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• 1996

In this paper, we consider the existence of a solution to the elliptic nonlinear partial differential equation ${\Delta}u＋H({\chi})e^{u}$ = 0 (H $\neq$ 0) (1) on a compact manifold without boundary. This equation is related to the problem of a pointwise conformal deformation of metrics on two dimensional compact connected manifolds.(omitted)

• Journal for History of Mathematics
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• v.19 no.2
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• pp.25-46
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• 2006

We investigate the process of western mathematics into Chosun and its influences. Its initial and middle stages are examined by Choi Suk Jung(崔錫鼎, $1645\sim1715$)'s Gu Su Ryak(九數略), Hong Jung Ha(洪正夏, $1684\sim?$)'s Gu Il Jib(九一集) and Hwang Yun Suk(黃胤錫, $1719\sim1791$)'s I Su Shin Pyun(理藪新編), Hong Dae Yong(洪大容, $1731\sim1781$)'s Ju Hae Su Yong(籌解需用), respectively. Western mathematics was transmitted for the study of the Shi xian li(時憲曆) when it was introduced in Chosun. We also analyze Su Ri Jung On Bo Hae(數理精蘊補解, 1730?) whose author studied $Sh\grave{u}\;l\breve{i}\;j\bar{i}ng\;y\grave{u}n$ most thoroughly, in particular for astronomy, and finally Lee Sang Hyuk(李尙爀, $1810\sim?$), Nam Byung Gil(南秉吉, $1820\sim1869$) who studied together structurally western mathematics.

• Journal for History of Mathematics
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• v.25 no.3
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• pp.1-14
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• 2012

Since JiuZhang SuanShu(九章算術), the basic field of the traditional mathemtics in Eastern Asia is the field of rational numbers and hence irrational solutions of equations should be replaced by rational approximations. Thus approximate solutions of equations became a very important subject in theory of equations. We first investigate the history of approximate solutions in Chinese sources and then compare them with those in Chosun mathematics. The theory of approximate solutions in Chosun has been established in SanHakWonBon(算學原本) written by Park Yul(1621 - 1668) and JuSeoGwanGyun(籌書管見, 1718) by Cho Tae Gu(趙泰耉, 1660-1723). We show that unlike the Chinese counterpart, Park and Cho were concerned with errors of approximate solutions and tried to find better approximate solutions.

• The Mathematical Education
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• v.45 no.1 s.112
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• pp.35-60
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• 2006

In the seventh mathematics curriculum, the use of technological tools including calculator and computer are generally recommended through the seventh subjects related to mathematics emphasized, and especially in 'Applied Mathematics' subject, their use are more strongly emphasized and reflected. The total four kinds of textbooks of Applied Mathematics includes contents on their use. This study investigates what are contents on calculator use, how they are developed and constructed in Applied Mathematics Textbook. Furthermore, this study is focused on the analysis and comparison on those factors of four kinds of textbooks. Based on these results, this study ultimately hope to suggest how effectively calculator use be developed and constructed in textbook both in Applied Mathematics and the other mathematics subjects.

• The Pure and Applied Mathematics
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• v.12 no.2 s.28
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• pp.143-152
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• 2005

We present a new block cipher called DyC. It consists of four sets (procedures) having the different $2^2,\;2^2,\;2^4$, and $2^8$ one-to-one correspondence functions as the elements. The round key is used to determine exactly one composite function from the possible $2^{16}$ composite functions. DyC supports 8 $\times$ n bit key size, 16 $\times$ m bit block length, and n rounds. We have confirmed that DyC offers security against other well-known advanced cryptanalytic attacks including the slide attacks and interpolation attacks. In this paper, we show several properties of the key schedule of DyC by mathematical analysis.

• Journal for History of Mathematics
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• v.17 no.4
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• pp.1-16
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• 2004

Investigating theory of equations in Chosun Dynasty mathematics books Mooksa-jipsanbub, Guiljib(九一集), Chageunbangmonggu(借根方夢求), Sanhakjungeui (算學正義), and Iksan(翼算), we study the history of equation theory in Chosun Dynasty. We first deal with development of representation of polynomials and equations and then method how to solve them.

• Journal of the Korean School Mathematics Society
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• v.23 no.1
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• pp.25-44
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• 2020

This study investigated the representation and algorithms of western mathematics reflected on the algebra domains of Chosun-Sanhak in the 18th century. I also analyzed the co-occurrences and replacement phenomenon between western algorithms and traditional algorithms. For this purpose, I analyzed nine Chosun mathematics books in the 18th century, including Gusuryak and Gosasibijip. The results of this study are as follows. First, I identified the process of changing to a calculation by writing of western mathematics, from traditional four arithmetical operations using Sandae and the formalized explanation for the proportional concept and proportional expression. Second, I observed the gradual formalization of mathematical representation of the solution for a simultaneous linear equation. Lastly, I identified the change of the solution for square root from traditional Gaebangsul and Jeungseunggaebangbeop to a calculation by the writing of western mathematics.

• Honam Mathematical Journal
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• v.32 no.1
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• pp.85-89
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• 2010

In this paper, when N is a compact Riemannian manifold, we discuss the nonexistence of conformal deformations on space-times M = $({\alpha},{\infty}){\times}_fN$ with prescribed scalar curvature functions.

• Honam Mathematical Journal
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• v.28 no.2
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• pp.233-240
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• 2006

In this paper, we consider the problem of achieving a prescribed scalar curvature on warped product manifolds according to fiber manifolds with constant scalar curvature.

• Honam Mathematical Journal
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• v.30 no.4
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• pp.693-701
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• 2008

In this paper, when N is a compact Riemannian manifold of class (A), we consider the nonexistence of some warping functions on space-times M = $[a,{\infty}){\times}_fN$ with prescribed scalar curvatures.