• Journal of Information Display
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• 제6권1호
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• pp.1-7
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• 2005

We propose new fabrication methods of a pixel-isolated liquid crystal (LC) structure for flexible display applications. In the LC structure fabricated through the proposed method, the patterned interpixel walls for sustaining the cell thickness are supported by the solidified polymer layer through anisotropic phase separation of LC/polymer composite, causing the alignment of the LC molecules to have very good mechanical stability against external pressure. In addition, we show that such pixel-isolating walls can be made by the stamping method which can be applied to fabricate large size plastic LCDs by roll-to-roll processing.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.283-287
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• 2003

Novel design techniques of half switching method, double layer structure, and multidomain structure for transflective liquid crystal display modes are introduced. Design examples of these techniques which perform excellent display characteristics are described.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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• pp.153-156
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• 2004

We have studied electro-optic characteristics of transflective liquid crystal display (LCD) using in-plane switching mode. Unlike previous transflective LCD using a dual gap structure and multi driving circuit, this transflective LCD has a single gap structure and a single driving circuit. In the voltage on state, the electric field is applied horizontally to the LC directors, and then homogeneously aligned LC directors at initial state is rotated to with the electric field. But the twist angle of the LC directors in reflective area is lower than transmissive area. As a result, it is possible to design the transflective LCD with a single gap and a single driving circuit. The transflective display associated with this LC cell exhibits a wide viewing angle in both reflective and transmissive areas.

• 대한기계학회논문집B
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• 제27권4호
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• pp.440-446
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• 2003

Steady-state structure and acoustic pressure responses of GH$_2$-LOx diffusion flames in stagnation-point flow configuration have been studied numerically with a detailed chemistry to investigate the acoustic instabilities. The Rayleigh criterion is adopted to judge the instability of the GH$_2$-LOx flames from amplification and attenuation responses at various acoustic pressure oscillation conditions for near-equilibrium to near-extinction regimes. Steady state flame structure showed that the chain branching zone is embedded in surrounding two recombination zones. The acoustic responses of GH$_2$-LOx flame showed that the responses in near-extinction regime always have amplification effect regardless of realistic acoustic frequency. That is, GH$_2$-LOx flame near-extinction is much sensitive to pressure perturbation because of the strong effect of a finite-chemistry.

• International Journal of Precision Engineering and Manufacturing
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• 제9권3호
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• pp.13-17
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• 2008

This paper deals with the directional mobility of droplets on structured surfaces. Structured surfaces were micro-patterned with rectangular lines and spaces of varying pitch and height in the sub-millimeter range. The material used was polydimethylsiloxane, which is hydrophobic and wettable by oil. First, we studied the effect of the structural design on the sliding angle of pure water or oil through experiments. For pure water droplets, we found that a wider pitch enhanced the directionality. On the other hand, oil droplets spread along the groove because of their low surface tension and strong capillary force. The directionality of the sliding angle of oil droplets was larger than that of pure water, especially when the groove was narrower and deeper. Second, we poured a large amount of liquid on the structure and evaluated the removal rate on the tilted surface. We found that a parallel structure enhanced the liquid mobility for both pure water and oil.

• 동력기계공학회지
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• 제9권4호
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• pp.214-219
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• 2005

The effects of change in injection pressure on spray structure in high temperature and pressure field have been investigated. The analysis of liquid and vapor phases of injected fuel is important for emissions control of diesel engines. Therefore, this work examines the evaporating spray structure using a constant volume vessel. The injection pressure is selected as the experimental parameter, is changed from 72MPa to 112MPa by using a common rail injection system(ECD-U2). The images of liquid and vapor phase in the evaporating free diesel spray are simultaneously taken by exciplex fluorescence method. As a result, it can be confirmed that the distribution of vapor concentration is more uniform in the case of the high injection than in that of the low injection pressure.

• 한국구조물진단유지관리공학회 논문집
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• 제7권1호
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• pp.289-296
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• 2003

The evaluation on performance of gel type penetrative water-repellent for durability progress of concrete structure has carried out in this study. And liquid type waterproof agents have been estimated with same method. Also normal concrete that was not applied water-repellent and waterproof agents have been estimated. As results, the penetrative depth of gel type water-repellent were deeper than that of liquid type waterproof agents and those were superior to these in physical and durable performance.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.403-406
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• 2005

We optimized a patterned-vertical-alignment (PVA) transflective liquid-crystal (LC) cell for small pixel application. To achieve the high resolution display performance in the mobile communication equipments such as mobile phones, personal data assistants, and tablet personal computers, we optimized the parameters of liquid crystal and the electrode structure. Both the transmittance and the reflectance are maximized at the same time.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권12호
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• pp.558-560
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• 2005

The carbon film was deposited by the electrolysis of methanol solution. Carbon films have been grown on silicon substrates using the method of chemical process. From investigations of the Raman spectroscopy and the FTIR spectroscopy, the carbon film deposited by the electrolysis was identified the hydrogenated carbon film with the porous structure. The carbon film deposited by elctrolysis of methanol was identified as the hydrogenated carbon film with porous structure. Deposition parameters for the growth of the carbon films were current density, methanol liquid temperature. We electrical resistance and surface morphology of carbon films formed various conditions specified by deposition parameters. It was clarified that the high electrical resistance carbon films with smooth surface morphology are grown when a distance between the electrodes is relatively wider. We found that the electrical resistance in the films independent of both current density and methanol liquid temperature. The temperature dependence of the electrical resistance in the low resistance carbon films is different from one obtained in graphite..

• 대한화학회지
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• 제8권4호
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• pp.183-187
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• 1964

액체에 관한 hole theory 를 사용하여 여러가지 액체들의 표면장력과 표면 각층의 excess molar sulface entropy 들을 계산하였다. 표면 첫째층의 것은 이상적인 분자가 표면을 형성할 때의 값 Rln2보다 다소 큰 값을 보여주며 액체 내부에 들어감에 따라 점점 줄어들어 저온에서는 셋째층부터 거의 없어진다. 그리고 알곤, 질소, 메탄, 벤젠 및 할로겐들의 표면장력을 계산하여 측정치와 비교하였다.