• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.418-419
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• 2013

현재, 인듐 주석 산화물(indium tin oxide, ITO) 박막은 가시영역에서 전기적 특성 및 광학적 특성이 우수하기 때문에 평면 디스플레이(flat displays), 박막 트랜지스터(thin film transistors), 태양전지(solar cells) 등을 포함한 광소자에 투명전도성산화물(transparent conducting oxide, TCO) 전극으로 가장 일반적으로 사용되고 있다. 하지만, 이 물질은 밴드갭이 3.4 eV로 다소 작아 다양한 분야의 의료기기, 환경 보호에 응용 가능한 자외선 영역에서 상당히 많은 양의 광흡수가 발생하는 치명적인 문제점을 가지고 있다. 또한, 인듐(Indium)의 급속한 소비는 인듐의 매장량의 한계로 인해 가격을 상승시키는 주요한 원인으로 작용하고 있다. 한편, InGaN 기반의 자외선 발광다이오드 분야에서는 팔라듐(Pd) 기반의 반투명 전극과 은(Ag) 기반의 반사전극을 주로 사용하고 있지만, 낮은 투과도와 낮은 굴절률을 때문에 여전히 자외선 발광다이오드의 광추출 효율(extraction efficiency)에 문제점을 가지고 있다. 따라서 자외선 발광다이오드의 외부양자 효율(external quantum efficiency, EQE)을 높이기 위해 높은 투과도와 GaN와 유사한 굴절률을 가지는 p-형 오믹 전극을 개발해야 한다. 본 연구에서는 초박막의 ITO (16 nm)/Ag (7 nm)/ITO (16 nm) 다층 구조를 갖는 투명전도성 전극을 제작한 후, 열처리 온도에 따른 전기, 광학적 특성에 향상에 대해서 조사하였다. 사용된 산화물/금속/산화물 전극의 구조는 유기발광 다이오드(organic light emitting diode, OLED), 태양전지 등에 많이 사용되는 안정적인 투명 전극을 자외선 LED 소자에 처음 적용하여, ITO의 전체 사용량은 줄이고, ITO 사이에 금속을 삽임함으로써 금속에 의한 전기적 특성 향상과 플라즈몬 효과에 의한 투과도를 높일 수 있는 장점을 가지고 있다. 실험 결과로는, $400^{\circ}C$에서 열처리한 ITO/Ag/ITO 다층 구조는 365 nm에서 84%의 광학적 특성과 9.644 omh/sq의 전기적 특성을 확인하였다. 실험 결과로부터 좀 더 최적화를 수행하면, ITO/Ag/ITO 다층 구조는 자외선 발광다이오드의 투명전도성 전극으로 사용될 수 있을 것이라 기대된다.

• The Journal of the Korea Contents Association
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• v.12 no.4
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• pp.108-118
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• 2012

In Korean society entered into an aging society, seeing aging women's lives, the lives of older women through women's eyes means, in a sense, calling the older female audience as the subject. On International Women's Film Festival in Seoul (2006), and now in South Korea opened with the title (2002) through the respective movies understanding 'aging' and the way represented older women will be discussed. shows grandma Marta's a pleasant commotion drew with the villagers, family and friends until openig Lingerie Shop brought in her own sewing skills. challenges social prejudices regarding dementia and the brutality, and reflect the meaning of the 'the provision of care for the elderly' in a circle around bond of the mother-in-law and daughter-in-law There is difference of the producig region of made in Switzerland and made in Japan. Nevertheless, women's solidarity and alone 'late blooming flowers, cut back, even if the theme of encapsulate life through a person as a new subject to buy back more than once on the community have to be made is significant hope.

• The Journal of the Korea Contents Association
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• v.8 no.3
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• pp.117-126
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• 2008

Lacan's Identification theory has been applied to various cultural genres such as literature, film, media so on. Especially, Identification theory in Film Theory gives game researchers who try to apply identification theory to the game, a concrete base. This paper aims to explain the gamer's action through identification theory. Thus, we divide identification into the level of the gamer's point of view and that of the character in game text. While point-on-view of identification, the primary identification, in film has been explained that the audience identifies with camera's point-of view, in game one identifies with various point-of-views. There are two aspects of Identification of characters in game. First, gamers identify themselves with moving images on screen. Second, They identify with the roles given to themselves. The factors which allow them identification are suppression of false statement system, interpolation and process of selection, arrangement, a cursor, colours on screen.

• Geophysics and Geophysical Exploration
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• v.9 no.1
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• pp.93-101
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• 2006

In this study, we propose a joint inversion method, using genetic algorithms, to determine the shear-wave velocity structure of deep sedimentary layers from receiver functions and surface-wave phase velocity. Numerical experiments with synthetic data indicate that the proposed method can avoid the trade-off between shear-wave velocity and thickness that arises when inverting the receiver function only, and the uncertainty in deep structure from surface-wave phase velocity inversion alone. We apply the method to receiver functions obtained from earthquake records with epicentral distances of about 100 km, and Rayleigh-wave phase velocities obtained from a microtremor array survey in the Kanto Plain, Japan. The estimated subsurface structure is in good agreement with the previous results of seismic refraction surveys and deep borehole data.

• Journal of Hydrogen and New Energy
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• v.7 no.2
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• pp.121-128
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• 1996

A direct cooling equipment for hydrogen liquefaction has been developed and tested. A direct cooling equipment consists of a liquefaction vessel, a radiation shield, a cryostat and a GM refrigerator. The cool-down and warm-up characteristics of the liquefaction apparatus have been investigated in detail. It is found that the hydrogen starts to be liquefied in the liquefaction vessel after 45 minutes of cool-down. The cool-down and warm-up tests of helium gas are also performed. The cool-down and warm-up characteristics of helium gas are found to be very different from those of hydrogen gas, since helium is not liquefied under the present operating conditions. When the liquefaction vessel is evacuated, natural convection phenomena of charged gas in liquefaction vessel can be removed. It is seen that the cool-down time of liquefaction vessel is substantially increased in vacuum environment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.257-257
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• 2010

최근 저항 변화 메모리는 종래의 비휘발성 기억소자인 Flash memory보다 access time(writing)이 105배 이상 빠르고, DRAM과 같이 2~5 V 이하의 낮은 전압 특성 및 간단한 제조 공정 등으로 차세대 비휘발성 메모리 소자로 주목 받고 있지만, 여전히 소자의 Endurance 및 Retention 특성 등의 신뢰성 문제를 해결해야 할 과제로 안고 있다. 이러한 문제점들을 해결하기 위해 페로브스카이트계 산화물 또는 이원 산화물 등의 다양한 저항 변화 물질에 대한 연구가 진행되고 있다. 하지만, 현재 주로 연구되고 있는 금속 산화물계 물질들은 그 제조 공정상 산소에 의한 다수의 산소 디펙트 형성과 제작 시 쉽게 발생할 수 있는 표면 오염의 문제점을 안고 있다. 본 연구는 기존의 금속 산화물계 박막의 제조 공정에서 발생하는 문제점을 해결하기 위해 질화물계 박막을 저항변화 물질로 도입함으로써, 기존의 저항 변화 물질의 장점인 간단한 공정 및 저전압/고속 동작 특성을 동일하게 유지 할 뿐 아니라, 그 제조 공정상 발생하는 다수의 산소 디펙트와 표면 오염의 문제를 해결함으로써, 보다 고효율을 가지며 재현성이 우수한 메모리 소자를 구현 하고자 한다 [1, 2]. 본 연구를 위해 Pt/AlN/Pt 구조의 Metal/Insulator/Metal(MIM) 저항 변화 메모리를 제작 하였다. 최적의 저항 변화 특성 조건을 확인하기 위해 70~200nm까지 두께 구분과 N2 가스 분위기의 열처리 온도를 $200{\sim}600^{\circ}C$까지 진행 하였다. 본 소자의 저항 변화 특성 실험은 Keithley 4200-SCS을 이용하여 진행 하였다. 실험 결과, AlN의 최적의 두께 및 열처리 온도 조건은 130nm/$500^{\circ}C$였으며, 안정적인 unipolar 저항 변화 특성을 확인 활 수 있었다.

• Korean Journal of Social Welfare
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• v.65 no.2
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• pp.357-384
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• 2013

In this study I've analyzed the strategy and techniques of the welfare discourses of korean conservative newspapers based on the discourse theory. Emphasizing the political and social characteristics of the discourse, It is investigated the way that the conservative newspapers criticize against assertions for welfare increase and universal welfare and the way that produce social meaning on welfare. The study is focused on the discourse techniques like symmetrical contrasts, making new contexts, and formation of identity. The critical welfare discourses are structured according to symmetrical contrasts of welfare to the rationality, the morality, and the prospects for future. The elements of the discourses are reinforced by one another and were recontextualized to the new stories on welfare. The conservative newspapers had emphasized secession welfare from the politics, solving the problem of inefficiency of welfare administration. Regarding the technique of identification, the newspapers had treated people as owners and victims of welfare on the role of financing welfare expenditure. It is noteworthy the newspapers have began to call people separately according to generations and income class using finance.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.11
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• pp.2196-2202
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• 1992

The optimum size combination of heat exchangers in a Joule-Thomson(J-T) circuit for small cryogenic systems has been sought analytically, when the circuit is combined with a two-stage Gifford-McMahon(GM) cooler. Full thermodynamic cycle analysis was carried out to predict the performance of the combined refrigeration system. Relevant convective heat transfer coefficients, the computerized properties of helium, and the refrigeration capacity curve of a typical GM cooler have been used in the analysis. The result showed that, by changing the configuration(heat exchanger area ratio) of the system, the performance of the commonly-used GM/J-T refrigerators could be optimized. For the maximum refrigeration performance, the optimum mass flow rate of the refrigerant and the relative size between the heat exchangers have been obtained, when the cooling load was 0.1W at 3.995K with the total heat exchanger area being given.

• Journal of Science Education
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• v.42 no.1
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• pp.1-11
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• 2018

STEAM program as integrating Science, Technology, Engineering, Arts, and Mathematics became essential part of secondary education and software education will be a required subject in secondary schools. In this study, we propose the application of the Lego mindstorms robotics programs for the developments of both STEAM and software educational materials. Our program consisting of five hours of classes is made based on the problem solving strategies. According to students' impression obtained after our program had been applied, our program appears to provide students opportunities for conceiving creative thinking and problem solving strategies. It also shows positive results for the application to the software and science educations as well as other extracurricular such as after school programs or programs for gifted students.

• Korean journal of communication and information
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• v.84
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• pp.28-98
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• 2017

This work critically deals with the much unstable and fragmented states of young adults in contemporary Korean society. Nowadays, most of young adults in Korea have encountered much severe, uncertain, and 'hellish' socio-economic situations while their dreams of getting regular jobs are hard to achieve. This study aims to present a nuanced and detailed analysis of their sedimented feelings, variegated emotions, as well as embodied positions by utilizing in-depth interviews and critical explorations on their particular modes of survival.