• Journal of the Korean Magnetics Society
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• v.5 no.1
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• pp.27-33
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• 1995

The microwave absorbing characteristics and complex permeability of $Ni_{2-x}Zn_{x}Y$ - rubber composites with variation of composition and particle size were investigated. With a ferrite particle with a diameter of about $1\mu\textrm{m}$, only spin rotational resonance was observed. This behavior probably due to the particle being sufficiently small to approach single domain characteristics so that only spin rotations can occur. The first matching frequency, found in $Ni_{2-x}Zn_{x}Y$ - rubber composites, which was higher than that of spin rotational resonance, increased with spin rotational resonance frequency. It is also found that the second matching frequency is independent of spin rotational resonance frequency. Based on these findings, it could be concluded that the microwave absorbing characteristics were caused by only one type of resonance, the spin rotational resonance.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.3
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• pp.235-240
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• 2007

Recently, energy saving buildings are interested in many parts and many types of thermal insulating materials have been developed. The temperature and brightness of inside and outside building are influenced by weather change and sun's brightness and location. The location of building considering the natural daylight is an important parameter to build a building. To modeling the natural daylight, we used 342 electric bulbs which mean artificial daylight. All these bulbs are installed on dome shape frame. Especially it is focused on the luminosity control of each bulb in this paper. The luminosity of bulbs is controlled by phase control using several PIC microprocessors and triacs.

• Korean Journal of Materials Research
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• v.8 no.5
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• pp.464-469
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• 1998

HF 세정후 자연 산화막의 존재가 급속 열처리 장비를 이용, 아르곤 분위기에서 열처리할 때 티타늄 실리사이드 형성을 관찰하였다. 고분해능 단면 투과 전자 현미경 관찰 결과 기판 온도가 상온일 때 자연산화막(native oxide)이 존재함을 확인하였으며 기판 온도가 40$0^{\circ}C$일 때는 실리콘 기판과 티타늄 박막의 계면 부위에서 자연산화막, 티타늄 및 실리콘이 혼합된 비정질층이 존재함을 확인하였다. 티타늄을 증착하는 동안 기판 온도를 40$0^{\circ}C$로 유지했을 때는 C54~$TiSi_2$상이 형성되는데 요구되는 급속 열처리(Rapid Thermal Annealing : RTA)온도가 기판 온도를 상오느로 유지 했을 때보다 $100^{\circ}C$정도 감소함을 확인하였다. 이 같은 결과는 산소불순물을 함유한 비정질 층이 핵생성 자리를 제공하여 이 상의 형성이 촉진된다는 사실을 말한다. 기판온도 $400^{\circ}C$에서 형성된 티타늄 실리사이드막의 경우 비저항 $\mu$$\Omega$cm임을 확인하였다.

• Journal of the Korean Magnetics Society
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• v.17 no.6
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• pp.253-258
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• 2007

In this study, an analysis of natural convection of magnetic fluids in a closed-semicircular pipe was performed by the numerical methods. For the numerical method GSMAC method of Siliomis is used. From the results of numerical methods it is verified that the natural convection of the magnetic fluid, I investigated the nature convection phenomenon of the magnetic fluid with numerical analysis and was going to study the thermodynamic characteristic of the magnetic fluid. Because the effect of magnetic field control natural convection, we needed to find effective method to eliminate heat in the cure of heat transfer.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.183-184
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• 2000

종합적인 오존대책을 구축하기 위해서는 광화학 옥시단트의 생성물리ㆍ화학과정 및 생물기원(자연발생원) 탄화수소의 영향을 고려한 3차원 광화학반응 모델의 구축이 가장 절실하다. 특히, 광화학 옥시단트는 국지적인 순환(해륙풍)및 혼합층에 의해 지배되기 때문에 지형을 고려한 3차원 기상장 수치모델(도시규모)과 광화학을 포함한 농도장(광화학반응 모델) 모델에 의한 대상지역의 시간적, 공간적인 오존농도 분포를 재현할 수 있는 모델 개발이 필요하다. (중략)

• Communications of Mathematical Education
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• v.25 no.2
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• pp.341-360
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• 2011

This paper deals with contents that Sang-Seol Lee contributed to the natural science in the 19th century Korea. Prof. Sung-Rae Park, the science historian, called Sang-Seol Lee Father of the Modern Mathematics education of Korea. Sang-Seol Lee wrote a manuscript Botany with a brush in late 19th century. Botany was transcribed from Science Primers: Botany (written by J. D. Hooker), which is translated into Chinese by Joseph Edkins in 1886. The existence of Sang-Seol Lee's book Botany was not known to Korean scientists before. In this paper, we study the contents of Botany and its original text. Also we analyze people's level of understanding Western sciences, especially botany at that time. In addition, we study authors of 16 Primers jar Western Knowledge. We study the contribution of mathematician Sang-Seol Lee to science education in the 19th century Korea.

• Journal for History of Mathematics
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• v.18 no.2
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• pp.31-42
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• 2005

Renaissance is revival of the ancient Greek and Roman cultures. So, in Renaissance period, the artists began to study Euclidean geometry and then their mind was a spirit of experience and observation. These spirits is namely modernism. In other words, Renaissance was a dawn of modern times. In this paper, we notice modern spirits and ones social backgrounds. Differential and integral calculus was created by these modern spirits. And in art field, 'painter of light', 'artist of moment' appeared. Because in the 17th and 18th centuries, the intelligentsia researched for motions, speeds and lights.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10b
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• pp.520-522
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• 2001

본 논문에서는 동작 표본을 이용하여 내재하는 동작 특성을 추정하고, 이를 동작 변환에 적용하는 새로운 동작 변환 알고리즘을 제안한다. 기존의 역 운동학에 기반한 동작 변환 알고리즘은 우선 앤드 이펙터 (end effector)의 궤적 차이를 줄이도록 한 후, 자세 공간에서 동작간의 거리를 최소화하는 방향으로 자세를 변환시켰다. 그러나 동작간의 거리에 대한 정의가 명확하지 않고, 이렇게 생성된 동작이 동작 주체가 취할 수 있는 자세라는 보장이 없기 때문에 실존 가능성이 낮은 부자연스러운 동작이 생성될 수 있다. 본 논문에서 제안하는 방법은 역 운동학 기반의 실존 가능성이 높은 자연스러운 동작 생성을 위해 동작 주체의 동작 표본을 고려한 확률분포를 이용한다. 제시된 알고리즘을 통한 동작 변환은 실존 가능성이 높은 자연스러운 동작을 생성할 수 있다.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.4
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• pp.232-241
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• 2020

Purpose: This study investigated the complications and patterns of implants that confronted with the extruded natural teeth. Materials and Methods: Among patients who received implant treatment between 2006 and 2018 at Chosun University Dental Hospital, only implants that had a maintenance period of at least 5 years and that both implants and confronting natural teeth could be measured and compared on a radiograph were selected. They were divided into two groups. Group 1, experimental group consisted of Implants confronting the extruded natural posterior teeth (n = 167: maxilla (Group 1max) = 92, mandible (Group 1man) = 75) and Group 2, control group consisted of Implants confronting the normal natural posterior teeth (n = 656: maxilla (Group 2max) = 272, mandible (Group 2man) = 384). Results: The incidence of complications between Group 1 and Group 2 was statistically significant. In particular, there was a statistically significant difference between the frequency of marginal bone loss and the amount of marginal bone loss. Conclusion: The extruded natural tooth may cause more frequent complications including bone resorption in the opposing implant.

• 한국프랑스학논집
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• v.108
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• pp.69-113
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• 2019

S'il est évident que la publication de la Deffence marquait le triomphe du français sur le latin dans le domaine littéraire, elle annonçait également une nouvelle idée sur l'imagination à laquelle Du Bellay préfère le mot d'invention(inventio). Aux yeux de Du Bellay, l'art n'est que la part la plus superficielle du travail poétique. L'essentiel de la poésie, sa "sève" ou son "énergie" réside dans son contenu intellectuel. Pour inventer, c'est-à-dire trouver cet energeia des choses, si l'on reprend le terme d'Aristote, et ce qui constitue l'objet de l'imitation et de la représentation, le poète doit faire opérer l'imagination naturelle par laquelle peut se découvrir ce qui est caché dans la nature ou ce que la Nature a caché dans les choses imitées. Cette invention ou cette imagination naturelle exige au poète de se munir non seulement de la finesse et de la sagacité intellectuelles mais de l'art naturel qui se différencie de l'art porté sur "la nue écorce", parce qu'il peut transposer le naturel des choses en langue poétique et fictive. Cela peut témoigner aussi de l'inspiration authentique du poète. Cette idée sur le dynamisme créatif de l'imagination naturelle permet au poète de saisir la force vitale immanente aux choses qu'il imite. Du Bellay refuse ainsi de considérer les forces productrices du texte comme objectives, extérieures au poète. Considérée jusqu'ici comme comme une manifestation de la Pléiade pour la langue française, la Deffence nous propose une des idées primordiales sur l'imagination qui découvre "la vive Energie" qui caractérise le naturel. Cette notion d'imagination naturelle contibue à assurer l'individualité et la créativité aux poètes, puisqu'ils auront la liberté de saisir le naturel invisible en se donnant la propre manière.