• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.34-34
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• 2009

The electrical characteristics of tunnel barrier engineered charge trap flash (TBE-CTF) memory with $SiO_2/Si_3N_4/SiO_2/Si$ engineered tunnel barrier, $HfO_2$ charge trap layer and $Al_2O_3$ blocking oxide layer (MAHONOS) were investigated. The energy bad diagram was designed by using the quantum-mechanical tunnel model (QM) and then the CTF memory devices were fabricated. As a result, the best thickness combination of MAHONOS is confirmed. Moreover, not enhanced P/E speed (Program: about $10^6$ times) (Erase: about $10^4$ times) but also enhanced retention and endurance characteristics are represented.

• 한국전기전자재료학회논문지
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• 제28권7호
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• pp.473-479
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• 2015

Hybrid supercapacitors with high power density and long cycle life are widely used for emergency power source of LED emergency luminaires. In this paper, we designed and fabricated a hybrid capacitor cell and a module for the LED emergency luminaires. Using hybrid supercapacitor cells (1,000 F, 2.8 V), we designed a module in a 10-year warranty considering aging and ESR. Considering the ESR and efficiency has been designed to module with 1,000 F 5.6 V design results in 2 series and 2 parallel combination. Module was used to confirm that the operation 77.5 minutes at room temperature, discharge LED emergency luminaires with 2 W. As a LED emergency luminaires of emergency power supply that we can support more than 10 years of life was confirmed the applicability of hybrid supercapacitor.

• 한국세라믹학회지
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• 제19권4호
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• pp.300-308
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• 1982

A new perovskite type compound, (Pb1a-χKy□χ-y) (Zr0.33Ti0.67)O3-χ+y/2 was proposed and synthesized by "Wet-Dry Combination Technique". This defect ferroelectric material was characterized by partial substitutions of K+ for Pb+2 in Pb(Zr0.33Ti0.67)O3. This material was mono-phasic perovskite compound at 800℃ for 1hr., but ZrO2 was more or less isolated from the (Pb1a-χKy□χ-y) (Zr0.33Ti0.67)O3-χ+y/2. As a result, snitering temperature, sintered density, curie temperature, and dielectric constant of test pieces decreased and a-axis was nearly constant, while c-axis gradually decreased with the value x in the region of tetragonal phase of PZT. It was also recognized that the defect structure caused by adding K+ was found in both A-site cation and O-site anion vacancies in the defect PZT.

• 한국세라믹학회지
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• 제26권5호
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• pp.682-690
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• 1989

Fine mullite powder was prepared by colloidal sol-gel route. Boehmite as a starting material of Al2O3 and silica sol or fumed silica as a starting material of SiO2 were used. $\alpha$-Al2O3, TiO2 and ZrO2 were used as seeding materials. The combination of boehmite and silica was found to be the stoichiometric mullite powder. Techniques for drying used were spray drying, freeze drying, reduced pressure evaporation and drying in a oven. The gelled powder was heated at 130$0^{\circ}C$ for 100min and was attrition-milled for 1~3hrs. The mullite powder obtained was composed of submicrometer, uniform and spherical particles with a narrow size distribution. The mullite powder was characterized by BET, SEM, XRD and IR spectroscopy.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 추계 학술논문 발표대회
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• pp.213-214
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• 2012

This study is about the assessment of utilization possibility as a material for cementation of ground which is necessary for the reinforcement of soft ground by making environment-friendly inorganic composite utilizing inorganic recycled resources, and it was verified that it showed higher uniaxial compressive strength than the existing cementitious ground solidifier when it was applied as a combination material for soft ground such as dredge reclaimed land, and since an inorganic composite utilizing recycled resources such as high calcium fly ash and blast furnace slag etc. does never use cement, it is considered that it would be safe in the issue of a hexavalent chromium that was recognized as a problem of a cementitious solidifier.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.124-128
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• 2004

By the use of a similar numerical method as that in the previous paper, the forming limit strain by coaling method of clad sheet metals is investigated, in which the FEM is applied and J2G(J$_2$-Gotoh's corner theory) is utilized as the plasticity constitutive equation. Declined Multilayer Metals Materials are stretched in a plane-strain state, with various work-hardening exponent n-values and thicknesses of each layer. Processes of shear-band formation in such composite sheets are clearly illustrated. It is concluded that, in the bonded state, the higher limiting strain of one layer is reduced due to the lower limiting strain of the other layer and vice versa, and does not necessarily obey the rule of linear combination of the limiting strain of each layer weighted according thickness.

• 한국정밀공학회지
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• 제18권6호
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• pp.166-173
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• 2001

Composite materials consists of two or more different material layers. The usefulness of clad metal rods forms the possibilities of combination of properties of different metals. Copper clad aluminum composite materials are being used for economic and structural purpose. In this study, composite billet consists of commercially pure copper and aluminum(A6061) and experimental conditions consist of the combinations of clad thickness, extrusion ratio, and semi-cone angle of die. In order to investigate the influence of these parameters on the hot direct extrudability of the copper clad aluminum composite material rods, the experimental study have been performed with various extrusion temperatures, extrusion ratios, semi-cone angles of die, and composition rate of Cu:Al.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2001년도 The Pacific Aisan Confrence On Intelligent Systems 2001
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• pp.224-229
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• 2001

When a semiconductor package is assembled, various materials such as die attach adhesive, lead frame, EMC (Epoxy Molding Compound), and gold wire are used. For better preconditioning performance, the combination between the packaging materials by studying the compatibility of their properties as well as superior packaging material selection is important. But it is not an easy task to find proper packaging material sets, since a variety of factors like package design, substrate design, substrate size, substrate treatment, die size, die thickness, die passivation, and customer requirements should be considered. This research applies case-based reasoning(CBR) technique to solve this problem, utilizing prior cases that have been experienced. Our particular interests lie in building decision support model to aid the selection of proper die attach adhesive. The preliminary results show that this approach is promising.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 및 기술 세미나 논문집 디스플레이 광소자
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• pp.59-60
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• 2008

In this paper, we have investigated the sintering of the organometallic silver electronic ink. We have changed the sintering temperature from 100 to $300^{\circ}C$ in the various atmospheres. The sheet resistance was abruptly changed at the temperature range between 115 and $120^{\circ}C$, due to the f of the crystalline silver resulting from the dissociation of Ag complex, which phenomenon has been confirmed by X-ray diffraction. The grain sizes of Ag films were about 50nm and 70nm at the sintering temperatures of 115 and $150^{\circ}C$, respectively.