• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.3
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• pp.321-328
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• 2008

In this paper, a novel log-periodic cantor dipole antenna(LPCDA), which is composed of the cantor-dipole elements instead of the existing dipole elements, is proposed. The proposed antenna makes possible the antenna miniaturization by using the cantor-dipole elements. To investigate the reliability of the proposed antenna, LPCDA is designed and analyzed at $1{\sim}4GHz$ band and compared with LPDA(Log-Periodic Dipole Antenna) characteristics. It is shown that although the elements of LPCDA are 13.3% shorter than LPDA, the gain increases about 2dB and VSWR is less than 2 in at the upper band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.9
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• pp.1005-1012
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• 2010

In this paper, a novel log periodic cantor koch dipole antenna(LPCKDA), which is composed of the cantor Koch dipole elements instead of the Koch dipole elements, is proposed to reduce the size of the log periodic koch dipole antenna(LPKDA). To investigate the reliability of the proposed antenna, the LPCKDA is designed and analyzed at 0.5~1.5 GHz and compared with the LPKDA(Log Periodic Koch Dipole Antenna) characteristic. It is shown that although the proposed LPCKDA has a decreases of 5 % in the length of the dipole elements, radiation characteristics of LPCKDA are similar to radiation characteristics of the LPKDA.

• Journal for History of Mathematics
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• v.30 no.5
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• pp.289-304
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• 2017

The interdisciplinary study explores the discussion of actual infinity between Georg Cantor and Roman Catholic Church. Regarding the actual infinity, we first trace the theological background of Cantor by interpreting his correspondence and major works including ${\ddot{U}}ber$ die verschiedenen Standpunkte in bezug auf das aktuelle Unendliche(1885) and Mitteilungen zur Lehre vom Transfiniten (1887), and then investigate his argumentation for two points at issue: (1) pantheism and (2) inconsistency of the necessity with freedom of God. In terms of mathematics and theology, Cantor defined the actual infinity(aphorismenon) as characterized by (1) the transfinite infinity(Transfinitum) and (2) the absolute infinity(Absolutum). Transfinitum is conceptualized here in mathematical terms as a multipliable actual infinity, whereas Absolutum is not as a multipliable actual infinity. The results imply that Cantor's own concept of Transfinitum and Absolutum is adequate for Roman Catholic theology as well as mathematics including the reflection principle.

• Communications of Mathematical Education
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• v.15
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• pp.1-7
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• 2003

수학사 및 수리철학에 관한 연구는 교사양성 대학에서 더욱 강조되어야 할 부분임에도 불구하고 그에 관한 연구가 미진하다. 자연대의 수학과는 수학 그 자체가 중요하겠지만, 교사양성 대학에서는 수학 내용자체 뿐만 아니라, 수학의 역사적인 측면과 수학에 관한 인식론적인 측면이 함께 요구되어 진다. 절대적인 것으로 인식되어 온 수학에 대한 잘못된 선입견은 수학교육에도 심각한 악영향을 끼칠 수 있다. 그러나 괴델의 불완전성 정리 등으로 인해 수학에서의 논리체계는 더 이상 절대적이지 않다는 것을 알 수 있다. 본 연구에서는 숱한 오류들의 극복을 통해 발전해 온 수학사적인 측면과 그로 인하여 수학에 관한 인식론적 변화를 수학에서의 큰 사건들을 중심으로 살펴보고자 한다. 구체적으로 유클리드 기하에서 비유클리드 기하의 발견, 칸토어의 무한한 역설의 발생, 역설을 극복하기 위한 수학기토론의 탄생, 괴델의 불완전성 정리로 이어지는 과정들을 살펴보고, 그로 인해 도출되어지는 수학교육적 시사점을 논의해 보며, 이르르 바탕으로 교사양성 대학에서의 수학사 및 수리철학 강좌의 운영 방안을 제시한다.

• Journal for History of Mathematics
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• v.23 no.3
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• pp.57-73
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• 2010

Transcendental numbers are important in the history of mathematics because their study provided that circle squaring, one of the geometric problems of antiquity that had baffled mathematicians for more than 2000 years was insoluble. Liouville established in 1844 that transcendental numbers exist. In 1874, Cantor published his first proof of the existence of transcendentals in article [10]. Louville's theorem basically can be used to prove the existence of Transcendental number as well as produce a class of transcendental numbers. The number e was proved to be transcendental by Hermite in 1873, and $\pi$ by Lindemann in 1882. In 1934, Gelfond published a complete solution to the entire seventh problem of Hilbert. Within six weeks, Schneider found another independent solution. In 1966, A. Baker established the generalization of the Gelfond-Schneider theorem. He proved that any non-vanishing linear combination of logarithms of algebraic numbers with algebraic coefficients is transcendental. This study aims to examine the concept and development of transcendental numbers and to present students with its open problems promoting a research on it any further.

• Korean Journal of Logic
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• v.15 no.1
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• pp.155-190
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• 2012

As far as Hilbert's Program is concerned, there seems to be important differences in the development of Wittgenstein's thoughts. Wittgenstein's main claims on this theme in his middle period writings, such as Wittgenstein and the Vienna Circle, Philosophical Remarks and Philosophical Grammar seem to be different from the later writings such as Wittgenstein's Lectures on the Foundations of Mathematics (Cambridge 1939) and Remarks on the Foundations of Mathematics. To show that differences, I will first briefly survey Hilbert's program and his philosophy of mathematics, that is to say, formalism. Next, I will illuminate in what respects Wittgenstein was influenced by and criticized Hilbert's formalism. Surprisingly enough, Wittgenstein claims in his middle period that there is neither metamathematics nor proof of consistency. But later, he withdraws his such radical claims. Furthermore, we cannot find out any evidences, I think, that he maintained his formerly claims. I will illuminate why Wittgenstein does not raise such claims any more.

• Journal for History of Mathematics
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• v.25 no.2
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• pp.23-34
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• 2012

The International Congress of Mathematicians (ICM) will next be held in Seoul, Korea from August 13th to 21st 2014. The ICM, currently hosted by the International Mathematical Union, has a history spanning a period of one hundred years and is traditionally held every four years. Felix Klein has often been credited with formulating the concept of the ICM, however George Cantor not only initially propagated the idea of forming a mathematical society in Germany, but also proposed organizing an international mathematical union. This study has endeavored to investigate the early period of development of the ICM. Specifically, this paper has studied the development of early 20th century mathematics through changes in the formulaic language of the ICM, the number of participants, the number of presentations, the nationality of plenary speakers, and the changes in sessions.