• Journal for History of Mathematics
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• v.19 no.4
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• pp.13-30
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• 2006

The purpose of this study is to investigate the meaning and roles of rhymes in oriental mathematics. To do this, we consider the rhymes in traditional chinese, korean, indian, arabian mathematical books and the mathematical knowledge which they implicate. And we discuss the reasons for which they were often used and the roles which they played. In addition, we suggest how to use them in teaching mathematics.

• Proceedings of the Korean Society for Information Management Conference
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• 2001.08a
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• pp.23-28
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• 2001

유니코드는 현재 또는 과거에 존재했던 다양한 언어의 문자를 처리하기 위한 국제 표준코드이며 2바이트로 형성될 수 있는 65,000여 개의 영역에 전세계문자들을 차례대로 배열, 각 문자에 일련의 코드값을 지정하였다. 우리나라는 ISO 10646-1:1993의 유니코드 체계를 그대로 수용하여 1995년 KS C 5700-1995 표준규격으로 채택하였다. 이러한 유니코드의 경우 한글과 한자의 정렬문제, 옛한글이나 구결문자의 표현에 있어 제약이 있다. 이에 본고에서는 유니코드의 기본적인 개념, 그리고 한글 유니코드와 그 문제점에 대해 고찰하였다.

• Composites Research
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• v.35 no.2
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• pp.93-97
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• 2022

The application of infrared heating in the hot press forming of the thermoplastic composites is conducive to productivity with high-speed heating. However, high energy, high forming temperature, and high-speed heating derived from infrared heating can cause material degradation and deteriorate properties such as re-melting performance. Therefore, this study was conducted to optimize the process conditions of the hot press forming suitable for carbon fiber reinforced polyetherketoneketone(CF/PEKK) composites that are actively researched and developed as high-performance aviation materials. Specifically, the degradation mechanisms and properties that may occur in infrared high-speed heating were evaluated through morphological and thermal characteristics analysis and mechanical performance tests. The degradation mechanism was analyzed through morphological investigation of the crystal structure of PEKK. As a result, the size of the spherulite decreased as the degradation progressed, and finally, the spherulite disappeared. In thermal characteristics, the melting temperature, crystallization temperature and heat of crystallization tend to decrease as degradation progresses, and the crystal structure disappeared under long-term exposure at 460℃. In addition, the low bonding strength was observed on the degraded surface, and the bonding surfaces of PEKK did not melt intermittently. In conclusion, it was confirmed that the CF/PEKK composite material degraded at 420℃ in the infrared high-speed heating. Furthermore, the spherulite experienced morphological changes and the re-melting properties of thermoplastic materials were degraded.

• KOMUNHWA
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• no.66
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• pp.37-56
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• 2005

이 연구는 강화경판 『高麗大藏經』에 入藏된 『合部金光明經』과 13세기 중엽에 간행된 것으로 추정되는 口訣本 『合部金光明經』의 조성에 참여한 刻成人에 대해 살펴본 것이다. 국가적·범종파적 사업으로 전개된 각성사업에 『합부금광명경』이 조성되고 있는데도 불구하고, 구결본 『합부금광명경』 조성에 참여한 이들은 각성사업과 어떤 관련성을 갖고 있는지 검토해 보았다. 이에 『고려대장경』에 입장된 『합부금광명경』과 구결본 『합부금광명경』을 상호 비교해 본 결과 경전의 내용과 板式, 그 구성 체계가 相異한 본이었다. 그리고 彫成에 참여한 각성인을 조사해 본 결과 『고려대장경』에는 ‘부령’이었고, 구결본은 ‘存植’, ‘立成’, ‘正安’, ‘孝兼’ 등이었다. ‘存植’, ‘正安’, ‘孝兼’은 고종 24년부터 16년간 전개된 각성사업에 참여한 각성인들과 동일 인물이었다. 특히 ‘孝兼’은 자신을 비구라고 밝힌 점으로 볼 때 당시 활동하던 刻字僧으로 파악된다. ‘存植’과 ‘正安’은 고종 33년에 간행된 『禪門三家拈頌集』과 13세기 중엽에 간행된 『圓覺類解』, 『弘贊法華傳』의 조성에도 참여하고 있는 것으로 보아 전문 刻手로 보여진다. 그래서 각성사업에 참여한 각성인들은 각자의 여건에 따라 활동하고 있음을 알 수 있다. 『合部金光明經』은 『妙法蓮華經』·『仁王經』과 함께 호국삼부경 중의 하나로서 고려시기에 수시로 간행되고 있었다. 『금광명경』은 국가를 보호하고 내우외환을 소멸시키기 위해 왕실을 비롯한 관료층들이 깊이 존신하고 권장하려 하였던 불교 경전이었다. 특히 대외관계상의 위기상황에는 『금광명경』을 바탕으로 하는 功德天道場이라는 호국적 성격의 법회를 개최되고 있었다. 따라서 『합부금광명경』의 간행 배경에는 『고려대장경』이 국왕을 정점으로 반외세력인 몽고군을 격퇴시키고, 또 최씨무인정권으로부터 왕권을 회복시키고자 시대적 분위기가 적극 반영되어 있다. 구결본 『합부금광명경』의 간행은 민족적·국가적 사업이었던 각성사업에 적극 동참하면서 현실을 직시하고 고려 불교의 창조적 발전은 물론 외세의 침략으로부터 조국을 지키고자 하는 호국의식을 바탕에 두고 있었다. 〔주제어〕『高麗大藏經』, 『合部金光明經』, 刻成人, 최씨무인정권, 護國經

• Journal for History of Mathematics
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• v.19 no.3
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• pp.95-112
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• 2006

The purpose of this paper is to investigate a classic mathematician and inventor Archimedes' work ${\ll}$On the Sphere and Cylinder${\gg}$. The propositions of this book which deals with three dimensional geometry are reviewed. Through the review this study tries to find out how Archimedes mastered spherical figures and how classical mathematics ideas are related to the modern concept of integration. The results of this study seems to help people understand deeply modern mathematics and to be good resources to develop new mathematical ideas.

• Journal of Korean Library and Information Science Society
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• v.27
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• pp.485-572
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• 1997

The purpose of this study is to investigate the textual and physical bibliography of these books that were printed from Koryo to Chosun Dynasty and written by the Kukyul system. This study is concerned with the Kukyul written in the transformed Chinese characters which representing their sino-Korean sound values only. The Kukyul is the Korean function word inserted to a written Chinese sentence for an easier understanding of the meaning by the Koreans. Until the present, most of these studies on the Kukyul are mainly concerned with the Korean linguistic characters. But this mentions to present the basic bibliographical information in order to presume the written period of the Kukyul system. 2The analysis of each book is made in the respect of: 1) historical aspect of the book 2) physical form and publishing date 3) transcription period of the Kukyul 4) the category of presenting Kukyul 5) historical change of transcribing Kukyul system The results of the study are as follows : First, the Kukyul system was divided into Sokdok and Sundok Kukyul according to the translation and recording format. Second, the Sokdok Kukyul is a kind of writing system for translated Chinese into Korean. Third, the Sundok Kukyul was frequently used Buddhist publications from later Koryo Dynasty to Middle Chosun period. Fourth, through the analysis of physical bibliography for that books, we rearrange the chronological oder of Sokdok Kukyul system as Hwaum-kyung, Hwaum-kyungSo, Kumkwngmyu ngkyung, Kuyeukinwang-kyung, Yukasajiron. Fifth, the characters of Sundok Kukyul systems were gradually decreased from eighty numbers to fifty numbers. This change is caused by the unification trends of sound value in morphological aspect.

• Korean Journal of Optics and Photonics
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• v.18 no.1
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• pp.37-43
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• 2007

We developed the equipment to measure the MTF(modulation transfer function) of an optical system for automatically inspecting the surface condition of an LCD substrate. We have made an object generator with USAF(United States Air Force) targets of three bar patterns and an integrating sphere, and an image analyzer with a 2 dimensional CCD(charge coupled device) and a relay lens. The MTF of the lens under test was obtained by correcting the measured CTF(contrast transfer function) which is the ratio of the contrast in the image of the USAF target to the contrast in the object. We have measured an optical system of F/13.65 (2.6x), the MTF are 30.6 % tangential plane and 26.1 % sagittal plane at 62.5 1p/mm.

• Korean Journal of Optics and Photonics
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• v.17 no.5
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• pp.447-454
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• 2006

We obtained analytic solutions of boundary conditions to the stable region of Z-fold $Cr^{4+}$ : YAG laser cavity when the conditions are with and without thermal tensing effect. Also we investigated the influence of the thermal tensing effect on the stability of cavity, beam waist, and astigmatic compensation using aberration transformation matrices. The thermal tensing effect almost has no influence on the stable region of the cavity when the crystal is located in the middle of two concave mirrors and when the distances from the concave mirror to the reflecting mirror and the output coupler are the same. The beam waist, however, is affected more in a tangential plane than in a sagittal plane, and so it is difficult to have astigmatic compensation when the thermal tensing effect exists. This result means that the thermal tensing effect should be considered even for the Kerr-lens mode-locking.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.55-60
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• 2002

In this paper, we investigate the MTF in image plane using the shifted magnitude, the shifted direction, and the astigmatism as the real amplitude distribution of incident beam in an optical system is shifted. The shifted magnitudes of incident beam are 0.0, 0.25, 0.5 and 0.75 and the shifted directions of incident beam are 0 and ${\pi}/2$. We also consider the optical system having the astigmatism which are $0.0{\lambda}$, $0.25{\lambda}$, $0.5{\lambda}$, and $0.75{\lambda}$. As the shifted magnitude of the real amplitude distribution of incident beam increases, the MTFs of sagittal and tangential direction in an optical system having an aberration free decrease, but that in an optical system having the astigmatism which is $0.75{\lambda}$ and the shifted direction of incident beam which is ${\pi}/2$ increases. We know from these results that the shift of the real amplitude distribution of the incident beam in an optical system compensates the effect of astigmatism as the shifted direction of that in an optical system is ${\pi}/2$, and Stiles-Crawford effect having the shifted real amplitude distribution of incident beam in pupil area is minimized the effect of astigmatism for eye.

• The Journal of Korean Philosophical History
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• no.39
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• pp.143-168
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• 2013

The purpose of this paper is to study the succession and method of five-masters of southern school in transmitting the internal alchemy in Taoism which is established by Zhang Bo-duan. In history, the internal alchemy is divided into a few schools but all of them are under the umbrella of Zhang Bo-duan's alchemy. The five master's method has been consistent from Zhang Bo-duan to Seok Tae to Seol Do Gwang based on three reasons. First, they lived long while practicing the method. Second, they learned the method from their direct master secretly. Third, they kept practicing the individual method while staying in the secular world rather than in a religious body. I limit three of them Zhang Bo-Dan, Seok Tae, Seol Do Gwang as figures who practiced the pure internal alchemy. Thus I argue that the method stayed only for 200 years, arising from the late Dang Dynasty and disappearing in 1911, when Seol Do-Gwang was dead. This method can be instructed only to the appropriate figure, and the specific steps of method are taught through the oral instruction so that this method cannot be wide spread. Based on the fact that the time of practicing method is quite long and it needs intensive and constant efforts, it is difficult for a mundane person to practice and cope with the training. Jin Nam and Baek Ok Seom are believed that they belonged to the school of Shin So. Baek Ok Seom is regarded as a figure that made efforts to unite the school of Wei and the internal alchemy. However, he made lots of fabrication and discrepancy. Thus I state that Jin Nam and Baek Ok Seom need to be out in the succession and method of five masters of southern school in Taoism. Their changed method in quality needs to be organized in a new genealogy.