• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.189-189
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• 2009

This work was focused on the dielectrophoretic force of fullerenes dispersed in liquid crystal host medium, which are investigated in the homogeneously aligned liquid crystal (NLC) cells driven by external electric field. A fullerene of 10 wt% was doped into the LC medium and its electric field induced motion was controlled by both in-plane and vertical electric field. When the electric field was applied, the fullerene start to move in direction of applied electric field. The dark, grey and white states in the proposed device can be obtained by suitable combination of the polarity of applied electric field. The w and l are the width and distance between the electrodes. The reflectance at different l was measured and was found to be increased with increasing l. The dynamical motions of fullerene particles in LC medium suggest that fullerene can be designed for electronic-paper like displays.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.289.1-289.1
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• 2016

Germanium (Ge) with higher carrier mobility and a lower crystallization temperature has been considered as the channel material of thin-film transistors for display applications. Various methods were studied for crystallizaion of poly-Ge from amorphous Ge at low temperature. Especially Metal induced crystalliazation (MIC) process was widely studied because low process cost. In this paper, we investigate copper diffusion process of different thick (70 nm, 350 nm) poly-Ge film obtained by MIC process at various temperatures (250, 300, and $350^{\circ}C$) through atomic force microscopy (AFM), Raman spectroscopy, and secondary ion mass spectroscopy (SIMS) measurement. Crystallization completeness and grain size was similar in all the conditions. Copper diffusion profile of 370 nm poly-Ge film show simirly results regardless of process temperature. However, copper diffusion profile of 70 nm poly-Ge film show different results by process temperature.

• Journal of the Korean Society for Heat Treatment
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• v.28 no.1
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• pp.7-16
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• 2015

The fabrication of high quality graphene using chemical vapor deposition (CVD) method for application in semiconductor, display and transparent electrodes is investigated. Temperature and pressure have major impact on the growth of graphene. Graphene doping was obtained by deposition of $MoO_3$ thin films using thermal evaporator. Bilayer graphene and the metal layer graphene were obtained. According to the behavior of graphene growth P-type doping was confirmed. Graphene obtained through experiments was analyzed using optical microscopy, Raman spectroscopy, UV-visible light spectrophotometer, 4-point probe sheet resistance meter and atomic force microscopy.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1173-1176
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• 2004

In a previous work we reported the bistable property by doping a chiral material in a splay cell. The bistable states are the splay state and the metastable 180$^{\circ}$twist state. The retention time of the metastable state can be changed by the variation of d/p (cell gap over pitch), cell gap, pretilt angle, azimuthal anchoring force, liquid crystal material, and so on. In this paper we will present uniform bend transition and twist retention time improvement in a multi-domain BCSN LC cell by using the multi cell gap method.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1125-1131
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• 2004

We have investigated the generation of pretilt angle for a nematic liquid crystal (NLC) alignment with rubbing alignment method on the two kinds of polyimide (PI) surfaces using thin plastic substrates. The NLC pretilt angles generated on thin plastic substrates are higher than that on the glass substrate. We study that AFM (atomic force microscope) image of rubbed PI surface with polymer film has formed the micro-groove. Also, EO characteristics of the TN-LCD with a rubbed PI surface based on polymer are almost the same as that of the TN-LCD with a rubbed PI surface based on glass.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.4
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• pp.790-800
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• 1998

This paper presents a haptic rendering algorithm in the case that the virtual environment elastically deforms in response to the force applied by a user with a virtual tool. Considering friction, elasticity, multiple contacts and dynamics of the virtual object, this algorithm lets the operator have the feel of interactions in the virtual environment as close as to the reality. Based on the proposed algorithm several experiments are conducted and its effectiveness is confirmed.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1469-1474
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• 2007

In recent years, research to machine large-surface micro-features has become important because of the light guide panel of a large-scale liquid crystal display and the bipolar plate of a high-capacity proton exchange membrane fuel cell. In this study, in order to realize the systematic design technology and performance improvements of an ultra-precision machine for machining the large-surface micro-features, a structural characteristic analysis was performed using its virtual prototype. The prototype consisted of gantry-type frame, hydrostatic feed mechanisms, linear motors, brushless DC servo motor, counterbalance mechanism, and so on. The loop stiffness was estimated from the relative displacement between the tool post and C-axis table, which was caused by a cutting force. Especially, the causes of structural stiffness deterioration were identified through the structural deformation analysis of sub-models.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1415-1418
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• 2007

Electronic and structural properties of the interfaces formed by pentacene deposited on a polymer-based dielectrics are investigated by electron spectroscopy, atomic force microscopy, and water contact angle measurement. There is strong influence of surface treatment of the polymer dielectrics on the energy level alignment and the surface topography upon the pentacene deposition.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.10a
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• pp.198-201
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• 2006

In this paper, we fabricated drag force type and pressure difference type gas flow sensor with dry etching technology which used Deep RIE(reactive ion etching) and etching stop technology which used SOI(silicon-on-insulator). we fabricated four kinds of sensor, which are cantilever, paddle type, diaphragm, and diaphragm with orifice type. Both cantilever and paddle type flow sensors have similar sensitivity as 0.03mV/V kPa. Sensitivity of the fabricated diaphragm and diaphragm with orifice type sensor were relatively high as about 3.5mV/V kPa, 1.5mV/V kPa respectively.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.10a
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• pp.150-153
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• 2006

Micro vibration isolation, typically originated from ground, is always a prime concern for the nano-measurement instruments such as Atomic Force Microscopes. A four mount active vibration isolation system is proposed in this paper. Modeling and control of such a four mount system as analyzed. Combined active-passive isolation principle is used for vibration isolation by mounting the instrument on a passively damped isolation system made of Elastomer along with the active stage in parallel that consists of very soft actuation system, the Voice Coil Motor. The active stage works in combination with the passive stage for working as a very low frequency vibration attenuator.