• Economic and Environmental Geology
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• v.40 no.2 s.183
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• pp.153-170
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• 2007

Loading time and loading environment of the Dokdo seamounts were studied from flexure model and VGP(Virtual Geomagnetic Pole) determined by gravity and magnetic data. In spite of their similarity in size. a large difference about 50 mGal between gravity anomaly peaks of Dokdo and the Isabu Tablemount suggests different compensation degrees. Flexural modeling results show that the flexural rigidity(effective elastic thickness) of lithosphere for Dokdo is stronger(thicker) than that for the Isabu Tablemount. Also, it implies that the age of lithosphere at the time of loading of the Isabu Tablemount may be younger than that of Dokdo. Magnetic anomalies occur complicated over the Dokdo seamounts. Paleomagnetism was studied from VGP estimated by the least square and the seminorm magnetization methods with 1500 m upward continued magnetic anomalies. Age dating of Dokdo from previous study, flexural modeling, VGP, and geomagnetic polarity time scale suggest that after the cease of spreading in the Ulleung Basin, the Isabu Tablemount was formed first in normal polarity interval and followed by Dokdo. Also, they indicate that the fist large eruption of Dokdo was in normal polarity interval and the second large eruption in reversed polarity interval. The Simheungtaek Tablemount was formed in normal polarity interval between the formations of the Isabu Tablemount and Dokdo. These loading times for the Dokdo seamounts show a good coherence with the compressive stress period after the end of the opening of the East Sea. The Dokdo seamounts probably was caused by volcanism associated with the compressive stress.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.3
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• pp.307-315
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• 2016

The aim of this research is analyzing the fundamental properties and autogenous shrinkage reducing performance of 70 and 100MPa grade high performance concrete including emusified refined cooking oil(ERCO) under the mock-up conditions. As a results of experiment, the mixture contained 0.5% of ERCO showed slightly decreased slump flow while the slump was increased and segregation resistance performance was improved as 2.5 of EIS. For air content, all mixtures satisfied target air content with increased unit weight and delayed setting time with ERCO addition. In the case of compressive strength, when ERCO was added 0.5%, the result of approximately 5 to 10% of increased compressive strength was observed. For the autogenous shrinkage, ERCO contributed on 20-30% of shrinkage reducing performance comparing to Plain mixture without ERCO. It is considered that capillary pore filling action of soap particles occurred by the reaction of ERCO in cement paste between fatty aicd and calcium hydroxide contributed the shrinkage reducing performance. Based on these mock-up test results, application of the high performance concrete mixture with ERCO on CFT actual structure was decided.

• Journal of the Korean Magnetics Society
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• v.5 no.4
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• pp.275-280
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• 1995

The sites for $Fe^{+3}$ are partly substituted by $Co^{+2}$ and $Ti^{+4}$ cations to control coercivity of Ba-ferrite particles for use in high density magnetic recording. The substituted $Co^{+2}$ cation has very much different effects on magnetic properties and particle characteristics from that $Ti^{+4}$ cation has. The decrease in the coercivity with the $Co^{+2}$ substitution is attributed to the formation of excessive spinel-block(S-block) in pure Ba-ferrite crystal, while saturation magnetization is increased and the distributions of coercivity and particle size become broad. The substitution with the $Ti^{+4}$ decreases the sauration magnetization, but has less effect on a change in coercivity than the $Co^{+2}$. The $Ti^{+4}$ acts as a nucleation agent in amorphous phase of formulated compound, and consequently particle size and aspect ratio are decreased. Furthermore, the enhancement of substitution of the $Co^{+2}$ for the $Fe^{+3}$ sites in rhombohedral-block(R-block) by the $Ti^{+4}$ retards the nucleation of spinel phase of Ba-ferrite, which results in uniform magnetic properties of Ba-ferrite particles. It is suggested that the contents of the cations to be substituted for the $Fe^{+3}$ sites are optimized on the bases of magnetic properties and particle characteristics rather than on the base of electrical charge balance.

• Journal of Science Education
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• v.33 no.2
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• pp.173-183
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• 2009

We aimed to examine difference between the brain activation pattern based upon hypothesis-generating and hypothesis-understanding among the pre-service teachers not majoring in biology, the pre-service teachers majoring in biology and the biologists using fMRI. We have designed two sets of task paradigm on the biological phenomena: hypothesis-generating and hypothesis-understanding and thirty six healthy participants (twelve participants per group) performed the tasks. The result was showed that 1) there were significant differences of brain activation patterns in hypothesis-generating on the biological phenomena among three groups, 2) the left middle frontal gyrus in the part of DLPFC region was play an important roles of hypothesis-generating and make a significant differences among three groups. The superior ability of biologists were based upon the activation of middle frontal gyrus which has secondary integration of abstract information, and 3) there were no significant differences of brain activation patterns in hypothesis-understanding on the biological phenomena among three groups. These findings provided that scientist might be skillful in generating a new scientific knowledge.

• Journal of Korean Philosophical Society
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• v.145
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• pp.195-215
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• 2018

Plato said that our cosmos was created from the union of nous and $anank{\bar{e}}$ in Timaeus. In addition to this, 'the third kind', namely $ch{\bar{o}}ra$, exists already with genesis before the birth of the cosmos. Plato explains this $ch{\bar{o}}ra$ with several metaphors. That is, 'receptacle', 'mother', 'gold', 'space', 'place' etc. From Aristotle to contemporary scholars, generally three types of interpretations are presented. First, $ch{\bar{o}}ra$ is a kind of a 'void.' Secondly, $ch{\bar{o}}ra$ is Aristotle's $prot{\bar{e}}$ $hyl{\bar{e}}$. Thirdly, $ch{\bar{o}}ra$ has two aspects of space and matter. I will accept the third opinion. Plato's $ch{\bar{o}}ra$ has both a spatial aspect and material aspect. $Ch{\bar{o}}ra$ is a place that accommodates all sensible things in itself. On the other hand, $ch{\bar{o}}ra$ seems to be a mother who nourishes sensible things like a child. In this, Plato lacks a logical consistency. The research of $ch{\bar{o}}ra$ can not deviate from the limits of $eik{\bar{o}}s$ logos.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.241-241
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• 2003

실리카 나노 분말의 제조공정과 얻어진 나노분말의 자기조립 현상에 대하여 연구하였다. 나노분말은 TEOS(Tetraethylorthosilicate)를 이용하여 Stober process로 단분산 콜로이드 SiO2를 제조하였다. 다양한 응용을 위해서 좁은 입도분포를 가지면서도 다양한 크기를 가지는 분말을 제조하고자 TEOS, NH4OH, 에탄올, 증류수 등의 절대량과 몰비를 변화시키면서 나노분말을 제조하였다. 실험조건에 대한 입도분포와 평균 입자크기의 변화는 핵생성 이론으로 설명될 수 있었다. 얻어진 나노분말을 이용하여 dipcoating과 electron plating방법으로 단층 혹은 여러층의 박막을 형성하였다. 자기배열에 기초한 두 가지 증착방법에서 박막층에 미치는 변수들의 영향을 주로 electorn plating 방법에 대하여 고찰하였다.

• Journal of the Korean Ceramic Society
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• v.33 no.3
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• pp.327-331
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• 1996

$\delta$-FeOOH was prepared by rapid oxidation method of Fe(OH)2 using H2O2. The effects of reaction temperature and mole ratio ([OH-]/[Fe2+])의 몰비를 제조 변수로 하여 최종 생성된 $\delta$-FeOOH의 입자크기 입자형태, 자기특성을 조사하였다. Fe(OH)2 의 반응온도 및 [OH-]/[Fe2+] 비가 $\delta$-FeOOH의 입자크기 및 형상에 많은 영향을 미침을 알수 있었으며 입자 크기는 이 두인자에 비례하여 증가하였다 Fe(OH)2 의 반응온도가 4$0^{\circ}C$ [OH-]/[Fe2+]=5 Fe(OH)2 숙성 시간 2시간에서 제조된 $\delta$-FeOOH를 TEM, VSM으로 입자의 크기 및 자기특성을 조사한결과 평균 입경이 630$\AA$ 정도이고 입도 분포가 양호하였으며 포화자화 및 보자력은 각각 20.8emu/g 210 Oe였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.516-516
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• 2012

약한 자기장 (~20 G)이 인가된 유도 결합 플라즈마 장치는 고효율, 높은 균일도의 플라즈마를 생성할 수 있다. 그러므로 이 장치에 대한 변수 제어뿐만 아니라, 전자 싸이클로트론 공명(Electron cyclotron resonance) 현상에 의한 방전 특성에 대한 연구는 매우 중요하다. 그에 연관된 여러 연구가 있었지만, 대부분의 연구는 평판형 유도 결합 플라즈마에서 진행되었다. 그에 따라서, 본 연구는 솔레노이드 형태의 유도 결합 플라즈마 장치에서 플라즈마 변수에 대한 약한 자기장의 영향을 살펴보았다. 실험에 사용된 인가주파수는 13.56 MHz에서 27.12 MHz였으며, 다양한 압력과 전력에서 실험이 진행되었다. 이러한 솔레노이드 형태의 유도 결합 플라즈마에서의 플라즈마 변수는 국부적인 특성을 보였으며, 평판형 유도 결합 플라즈마와 비교/분석을 진행하였다.

• Journal of the Korean Magnetics Society
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• v.7 no.4
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• pp.212-216
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• 1997

A pulsed field magnetometer with maximum applied field of 130 kOe has been constructed. The pulsed field generated by a 18 kJ capacitor bank system combined with a pulse coil was damped oscillation with the period of 10.12 ms. Magnetic hysteresis loop was measured by induction method during 10.12 ms of a pulse duration from the first positive to the second positive peak. The difference from DC magnetic properties due to the eddy current effect was inferred below 3% for the NdFeB magnet with the diameter below 5 mm.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.724-726
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• 2020

본 논문에서는 GAN 과 자기 지도 학습(self-supervised learning)을 통해 입력 얼굴 영상의 공간 해상도를 4 배 증가시키는 기법을 제안한다. 제안하는 기법은 변형된 StarGAN v2 구조의 생성자와 구분자를 사용하여 저해상도의 입력 영상만을 가지고 학습 과정을 거쳐 고해상도 영상을 복원하도록 자기 지도 학습을 수행한다. 제안하는 기법은 복원된 영상과 고해상도 영상 간의 손실을 줄이는 지도 학습이 가지고 있는 단점을 극복하고 입력 영상만을 가지고 영상 내부에 존재하는 특징을 학습하여 얼굴 영상에 대한 고해상도 영상을 복원한다. 제안하는 기법과 Bicubic 보간법과의 비교를 통해 우수성을 검증한다.