• 천문학회보
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• 제41권1호
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• pp.59.2-59.2
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• 2016

보현산천문대가 준공되면서, 1.8 m 망원경이 연구자들에게 공개된지 20년이 되었다. 당시 보현산 천문대의 연구자들은 1.8 m 망원경을 도약망원경이라 부르면서, 우리나라 천문학의 비약적인 발전의 토대가 되기를 희망하였다. 보현산천문대 10주년 기념 담양 워크샵에서 BOES의 성과를 발표한 이후 10년 동안, 천문연구원 광학천문기술 그룹에서는 BOES 편광분광기와 IGRINS를 개발 완료하였으며, GMTNIRS의 개념설계와 GCLEF의 기본설계가 진행되었다. 여기에서는 그동안 개발된 고분산 천체분광기 프로젝트의 성과를 정리하고, 앞으로의 계획을 논의한다.

• 한국전기전자재료학회논문지
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• 제17권4호
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• pp.426-431
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• 2004

We have studied the pressure-dependent liquid crystal's dynamics in a twisted nematic (TN) liquid crystal panel with thin film transistor by applying an external pressure to it. When the external pressure is applied to the panel in a dark state, the disclination lines were generated as a light leakage whereas they did not appear in a simple test cell that has only pixel and common electrodes. It was because the disclination lines were Provoked by the electric field between pixel electrode and data/gate bus line for active matrix driving. Consequently, the external pressure resulted in dynamic instability of the liquid crystal so that the disclination lines at the data/gate bus line intruded into the active area.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1760-1762
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• 2000

본 논문은 기존의 $Si_{3}N_4$, SiN 물질 대신 Pt를 사용해 HF 용액속에서 다공질 실리콘과 전극을 동시에 형성하는 기술을 개발하였다. Pt를 실리콘 웨이퍼 위에 직접 증착한 후 습식 에칭과 Lift-off 공정을 사용하여 Pt를 패터닝하였다. 습식 에칭은 에칭용액의 온도를 일정하게 유지하는 것이 중요하며, 증착한 Pt 박막이 BOE 에칭에 견디고, Lift-off 공정이 가능하기 위해서는 기판온도를 l100$^{\circ}C$ 이하로 해야한다. Pt를 사용하면 기존의 mask에서 발생하는 가장자리 부분에서의 전류 집중이 방지되기 때문에 다공질 실리콘이 일정한 깊이로 형성되고, Al대신 오믹 전극으로 사용할 수 있다. 현재 Pt를 mask와 전극으로 이용한 P-I-N UV detector, 광 바이오센서, 습도센서 제작등에 응용 연구가 진행되고 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1730-1732
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• 2000

Powder Electroluminescent Device is the solid state device which has a low power consumption, large area emission with uniformity, easy manufacturing, simple structure, and flexible mechanically. In this paper, we made the information display with the powder electroluminescent device using back-light and designed the driving circuit.

• Elastomers and Composites
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• 제42권1호
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• pp.1-8
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• 2007

풀러렌 산화물 쪼개짐 반응은 $FeCl_3$를 첨가한 초음파 조건에서 4-nitroaniline, 3-nitroaniline, 4-isopropylaniline 등의 방향족 아민 화합물과 풀러렌 산화물을 반응시켜 일어났다. MALDI-TOF-MS와 UV-vis 스펙트라를 사용하여 풀러렌 산화물 쪼개짐 반응으로 생성된 화합물이 아민화 풀러렌 유도체임을 확인하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.483-484
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• 2005

The field sequential liquid crystal display (FSLCD) does not need a color filter so that it is suitable for high resolution display. However, FSLCD has a drawback which requires a fast response time of sub-5 ms. We have studied the FSLCD with electrically controlled birefringence (ECB) mode. The ECB mode exhibits fast response time, high transmittance, low operating voltage and adequate viewing angle with a help of optical compensation films. In this paper, we present electro-optic characteristics of the ECB mode using a discotic film.

• Steel and Composite Structures
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• 제39권3호
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• pp.229-241
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• 2021

This work focused on aluminum foam sandwich (AFS) with different foam core densities and different face-sheet thicknesses subjected to constant amplitude three-point bending cyclic loading to study its fatigue performance. The experiments were conducted out by a high frequency fatigue test machine named GPS-100. The experimental results showed that the fatigue life of AFS decreased with the increasing loading level and the structure was sensitive to cyclic loading, especially when the loading level was under 20%. S-N curves of nine groups of AFS specimens were obtained and the fatigue life of AFS followed three-parameter lognormal distribution well. AFS under low cyclic loading showed pronounced cyclic hardening and the static strength after fatigue test increased. For the same loading level, effects of foam core density and face-sheet thickness on the fatigue life of AFS structure were trade-off and for the same loading value, the fatigue life of AFS increased with aluminum foam core density or face-sheet thickness monotonously. Core shear was the main failure mode in the present study.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.278-278
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• 2009

A photovoltaic device consisting of arrays of radial p-n junction wires enables a decoupling of the requirements for light absorption and carrier extraction into orthogonal spatial directions. Each individual p-n junction wire in the cell is long in the direction of incident light, allowing for effective light absorption, but thin in orthogonal direction, allowing for effective carrier collection. To fabricate radial p-n junction solar cells, p or n-type vertical Si wire cores need to be produced. The majority of Si wires are produced by the vapor-liquid-solid (VLS) method. But contamination of the Si wires by metallic impurities such as Au, which is used for metal catalyst in the VLS technique, results in reduction of conversion efficiency of solar cells. To overcome impurity issue, top-down methods like noble metal catalytic etching is an excellent candidate. We used noble metal catalytic etching methods to make Si wire arrays. The used noble metal is two; Au and Pt. The method is noble metal deposition on photolithographycally defined Si surface by sputtering and then etching in various BOE and $H_2O_2$ solutions. The Si substrates were p-type ($10{\sim}20ohm{\cdot}cm$). The areas that noble metal was not deposited due to photo resist covering were not etched in noble metal catalytic etching. The Si wires of several tens of ${\mu}m$ in height were formed in uncovered areas by photo resist. The side surface of Si wires was very rough. When the distance of Si wires is longer than diameter of that Si nanowires are formed between Si wires. Theses Si nanowires can be removed by immersing the specimen in KOH solution. The optimum noble metal thickness exists for Si wires fabrication. The thicker or the thinner noble metal than the optimum thickness could not show well defined Si wire arrays. The solution composition observed in the highest etching rate was BOE(16.3ml)/$H_2O_2$(0.44M) in Au assisted chemical etching method. The morphology difference was compared between Au and Pt metal assisted chemical etching. The efficiencies of radial p-n junction solar Cells made of the Si wire arrays were also measured.

• 한국의사학회지
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• 제14권2호
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• pp.189-248
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• 2001

In this essay, following final conclusions have been drawn by analyzing medical ideology and research system of Yi cheon in Yi hak yip mun("醫學入門"). Firstly, even though the existing medical history researchers are not noting the system of Yi-cheon's medical ideology, this essay has proved the man as a doctor who succeeded the (main system) based on the content of Yi-hak-yip-mun("醫學入門") by Ju-Dan-Gae(朱丹溪). The outline of this proof is as follows. 1. Those doctors who had actively researched in Myung era(明代), were basically taking over the medical studies and result of Gum-Won era(金元代). However, depending on whose theory is to be followed, the followers are largely divided into two groups of Ju-Dan-Gae Academics(丹溪學派) and On-Boe Academics(溫補學派). In addition, both Ju-Dan-Gae Academics(丹溪學派) and On-Boe Academics(溫補學派) hold contradictory ideologies to that of the main medical system. In Yi-hak-yip-mun("醫學入門"), Yi-cheon(李?) ties The Text of Whang-Jae-Nae-Kyung("黃帝內經"), Jang-Jung-Kyung(張仲景), Yu-Ha-Gun(劉河間), Yi-Dong-Won(李東垣), Ju-Dan-Gae(朱丹溪) into one pedigree. With regard to the main system, he especially marks Ju-Dan-Gae(朱丹溪) for his efforts in gathering various medical theories into a large compilement. 2. When Yi-Cheon(李?) was writing Yi-Hak-Yip-Mun("醫學入門"), he made references to various medical publishings, among those book which he had utilized, books by Ju-Dan-Gae Academics(丹溪學派) had affected him more than anything else in terms of both quality and quantity. 3. Yi-Cheon(李?)'s "Congested Phlegm Theory(痰鬱論)" had succeeded "Congested Phlegm Theory(痰鬱論) of Ju-Dan-Gae Academics(丹溪學派). His Yi-Hak-Yip-Mun("醫學入門"), carries a more complete form of "Congested Phlegm Theroy(痰鬱論) which was made into a more systemic and widely applicable method which was by Ju-Dan-Gae Academics(丹溪學派). Secondly, Yi-Hak-Yip-Mun("醫學入門"), is a medical book which was written in the process of systemic reorganization of medical theories of various academic parties in Myung 명 era. Since this process was hearing its completion in the period of Yi-Cheon(李?), he chose specific ways of reshuffling, whilst seeking ways to efficiently utilizing existing medical information . He provided a standard to specific ways. He rearranged the existing medical theories based upon these standards. He also contributed to clinical medicine by providing description of symptoms focused upon the symptoms differentiated In Conclusion, Yi-Hak-Yip-Mun("醫學入門") holds systematic medical information which was developed by Ju-Dan-Gae Academics(丹溪學派). Also, Yi-Cheon(李?) uniformly classified the clinical experiences of existing Ju-Dan-Gae Academics(丹溪學派). He had contributed in the clinical use of Ju-Dan-Gae Academic(丹溪學派)'s clinical experience by providing main points from differentiation of symptoms.

• 센서학회지
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• 제22권4호
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• pp.244-248
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• 2013

The discovery of a two-dimensional electron gas (2DEG) in $LaAlO_3$ (LAO)/$SrTiO_3$ (STO) heterostructure has stimulated intense research activity. We suggest a new structure model based on $KNbO_3$ (KNO) material. The KNO thin films were grown on $TiO_2$-terminated STO substrates as a p-type structure ($NbO_2/KO/TiO_2$) to form a two-dimensional hole gas (2DHG). The STO thin films were grown on KNO/$TiO_2$-terminated STO substrates as an n-type structure to form a 2DEG. Oxygen pressure during the deposition of the KNO and STO thin films was changed so as to determine the effect of oxygen vacancies on 2DEGs. Our results showed conducting behavior in the n-type structure and insulating properties in the p-type structure. When both the KNO and STO thin films were deposited on a $TiO_2$-terminated STO substrate at a low oxygen pressure, the conductivity was found to be higher than that at higher oxygen pressures. Furthermore, the heterostructure formed at various oxygen pressures resulted in structures with different current values. An STO/KNO heterostructure was also grown on the STO substrate, without using the buffered oxide etchant (BOE) treatment, so as to confirm the effects of the polar catastrophe mechanism. An STO/KNO heterostructure grown on an STO substrate without BOE treatment did not exhibit conductivity. Therefore, we expect that the mechanics of 2DEGs in the STO/KNO heterostructures are governed by the oxygen vacancy mechanism and the polar catastrophe mechanism.