• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.8
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• pp.6-11
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• 2009

The electro-optical characteristics of the Liquid Crystal on Silicon (hereinafter "LCOS") micro-display on vertically alignment (VA) mode were studied with 3-dimensional LC code. 5 different cell gaps, such as 1.4 ${\mu}m$, 1.8 ${\mu}m$, 2.1 ${\mu}m$, 2.4 ${\mu}m$ and 2.8 ${\mu}m$, were selected. The reflectance-voltage (R-V) characteristics, distribution of reflected light, reflectance, optical fill factor and contrast ratio were calculated and investigated depending on various cell gaps. Due to the surface anchoring effect, higher cell gap showed higher reflectance. However, considering the optical fill factor and contrast ratio, middle-height 2.1 ${\mu}m$ showed the best electro-optical characteristic. 0.7 inch Full-HD LCOS panels having same geometry and material property were fabricated. The reflected light intensity and contrast ratio were measured and the measured results were well-matched to the calculated results.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.4
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• pp.239-245
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• 2013

The data retention characteristics depending on neighbor cell's threshold voltage (Vt) in a multilevel NAND flash memory is studied. It is found that a Vt shift (${\Delta}Vt$) of the noted cell during a thermal retention test is increased as the number of erase-state (lowest Vt state) cells surrounding the noted cell increases. It is because a charge loss from a floating gate is originated from not only intrinsic mechanism but also lateral electric field between the neighboring cells. From the electric field simulation, we can find that the electric field is increased and it results in the increased charge loss as the device is scaled down.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2116-2118
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• 2000

In the technique of Q-switching, very fast electronically controlled optical shutters can be made by using the electro-optic effect in crystals or liquids. The driver for the Pockels cell must be a high-speed, high-voltage switch which also must deliver a sizeable current. Common switching techniques include the use of vacuum tubes, cold cathode tubes, thyratrons, SCRs, and avalanche transistors. Semiconductor devices such as SCRs, avalanche transistors, and MOSFETs have been successfully employed to drive Pockels cell Q-switch. In this study, a simple driver for the Pockels cell Q-switch was developed by using SCRs, pulse transformer and TTL ICs. The Pockels cell Q-switch which was operated by this driver was employed in pulsed Nd:YAG laser system to investigate the operating characteristics of this Q-switch. And we have investigated the output characteristics of this Q-switch as a function of the Q-switch delay time to Xe flashlamp current on.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1870-1872
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• 1999

Performance of 20-cell stack for direct methanol fuel cell (DMFC) was tested at constant temperature. Electrode evaluation used to the stack was tested by the performance of a single cell. A new composite electrode prepared from active carbon cloth and high porous active carbon was developed for hydrophilic layer of the cell. Characteristics of a single cell using the composite electrode showed the current density of $500mA/cm^2$ at the cell voltage of 0.4V at $120^{\circ}C$. For the operating of 20 days. the cell voltage at constant cell current densty of $100mA/cm^2$ was slightly reduced from 0.62V to 0.53V with the cell voltage decay rate of 14.5%. Power of 20-cell stack at 5.3V, $100^{\circ}C$ was about 180W.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1078_1079
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• 2009

본 논문에서는 태양열 온수급탕에 관한 모티너링 연구를 해석하고 이론을 바탕으로 실 시스템을 적용 운용시 시스템의 운전특성을 비교 분석하였다. 장기 적인 일사량 측정 데이터 수집을 통하여 그래프화, 모티터링 시스템에 관한 연구를 살펴보았다.

• IE interfaces
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• v.5 no.2
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• pp.87-100
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• 1992

This paper presents FMC prototypes developed to propagate manufacuting automation for small and medium sized enterprises in Korea. The system consists of two cells used to machine oil pump drive gears, turing cell and hobbing cell. Characteristics and processes of the fears are anaylzed for the cell design. The system configuration and functions of individual component machines are described. Furthermore, the developed system is compared with the current manual system in terms of manpower and cost reduction and productivity increase.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.515-516
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• 2008

We studied about new module technology to solve warpage problems that produce bending of cell in the LCD (Liquid crystal display). Characteristics of cell gap and glass bending of applying heat Panel's PAD part and cell at various temperature was investigated. When applies heat and compresses PAD party only in case of compressing COG(Chip on Glass), uniformity of cell gap that happen by glass bending by temperature of these compressing COG in the PAD party is decreased.

• Journal of environmental and Sanitary engineering
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• v.12 no.1
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• pp.77-83
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• 1997

An experimental research was conducted in order to study the treatment of waste reuse system using the membrane. Cell tester which supplied by Amicon was used to compare the fluxes of various membranes. Specially investigated items in the experiment were carried out by using 5 species of microfiltration membranes as to various MLSS concentrations. From the results, it is recognized from the cell test that 0.2 $\mu $m pore-sized membrane have the most effective performance at 2000mg/L of MLSS, and physical properties of membranes such as strength, deflection, elongation, structure of pore are more important than chemical properties in microfiltration membrane.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.273-276
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• 2004

The adhesion of hydrocarbon degrading bacteria(HDB) differing in surface hydrophobicity was investigated. Cell wall hydrophobicity was modified chemically and physiologically. Modified adhesion deficient mutant of HDB was selected in a soil column assay. Physiologically and chemical modification increased cell surface hydrophobicity. Cell surface characteristics including BATH and FTIR were measured. Physiological modification using ampicillin was not stable, but chemical modification was stable. Hydrocarbon degrading efficiency was measured of TPH modified and unmodifed HDB.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.213-214
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• 2008

최근 태양광 발전을 전력계통에 연계하는 연구가 많이 진행되고 있다. 태양광 발전 시스템은 조사량과 온도의 변화와 같은 환경요인에 의해 출력 특성이 달라지므로 이에 대한 연구와 계통에 미치는 영향 분석이 필요하다. 본 논문에서는 EMTP/MODELS를 사용하여 태양전지 내부 손실, 조사강도, 온도 조건을 고려한 Solar Cell의 특성을 구현하고 분석하였다. 또한 실제 Solar Cell 데이터와 비교하여 타당성을 검증하였다.