• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전력기술부문
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• pp.95-97
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• 2007

Transformer inrush current can cause the voltage drop by source impedance. The accurate modeling and analysis for inrush current is first step to limit the inrush current and improve the power qualify. This paper presents the modeling of transformer inrush current by EMTP-RV using Jeju power system, Korea. The method to model the hysteresis curve of transformer in EMTP-RV is discussed. Simulations demonstrate the verification of modeling of inrush current by comparing the data recorded in field with simulation values and analyzing the harmonics of inrush current.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전력기술부문
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• pp.139-141
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• 2007

차단기, 단로기와 간은 개폐기는 투입 동작이 이루어질 때, 접점 간의 내전안과 양단간의 전안차 사이의 관계에 의하여 pre-strike 현상이 발생한다. 따라서, 개폐기가 투입되는 동안 발생하는 과도철상을 파악하기 위해서는 개폐기의 pre-strike 친상을 모델링하는 것이 중요하다. 본 논문에서는 개폐기의 pre-strike 현상을 EMTP로 모델링하고 이를 모델 계통에 적용하여 구현된 pre-strike 모델이 타당함을 보였다.

• 한국정밀공학회지
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• 제24권11호
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• pp.101-107
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• 2007

Jettability analysis using one-dimensional(1D) lumped parameter model has been investigated to design the industrial inkjet head with proper drop velocity and drop volume. By simplifying the inkjet head system into an equivalent electrical circuit, lumped model has been developed. Performance of the lumped model is verified by the comparison between measured results of droplet velocity and ejection volume and predicted value. Also, the jetting performance of an inkjet head is characterized by varying the design parameter and driving condition. As a result, simulation results shows good agreement with the experimentally measured value. The developed lumped model enables to easily understand the effect of dimension change and predict the jetting performance.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.357-361
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• 2007

Transverse Linear Motor(TFLM) has been using in many areas of manufacture such as LCD, PDP construction and etc. However, the areas of TFLM application become wider, it needs a modification for new application. Above all, the conventional position estimation method is expensive in proportional to the length of the motor. Therefore, we need new position estimation algorithm using hall effect sensor.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.34-37
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• 2006

Accoarding as a specimen for reinforced concrete bridge deck was designed by each researcher's opinions, its size and shape was variable. Therefore, it makes difficult to comparison with other experiments. In the result of researching papers for design method of reinforced concrete bridge deck specimens, there is hardly found. The target of this study is introduction of the design method of a reinforced concrete bridge deck specimen. The most important point for the specimen design is materialization of the curvature of the real bridge deck. The result of this study appears that the specimens thickness effects highly to fit for the real reinforced concrete bridge deck's curvature.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(2)
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• pp.257-260
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• 2000

In this paper, a Gm-C filter for low voltage and low power applications using a fully-differential transconductor is presented. The designed transconductor using the series composite transistors and the low voltage composite transistors has wide input range at low supply voltage. A negative resistor load (NRL) technology for high DC gain of the transconductor is employed with a common mode feedback (CMFB). As a design example, the third-order Elliptic lowpass filter is designed. The designed filter is simulated and examined by HSPICE using 0.25${\mu}{\textrm}{m}$ CMOS n-well parameters. The simulation results show 105MHz cutoff frequency and 2.4㎽ power dissipation with a 2.5V supply voltage.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.829-834
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• 2000

This paper is primarily directed toward analyzing the transient response characteristics in hydraulic pipe lines. The exact solution to the transient response characteristics was obtained by using the complicated transfer function derived by Iberall. The discrepancy with the exact and approximate is small, so the approximate solution is adopted to the theoretical one. An equation was derived which describes the pressure times relationship Hat occurs at the end of volume terminated transmission line following a sudden pressure change at its inputs. As a result, It is found that the density has relationship about the Wave Propagation is very useful in analyzing the transient response characteristics of hydraulic pipe lines. The velocity of Pressure wave Propagation decreases as the density of fluid increased.

• 한국재난정보학회:학술대회논문집
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• 한국재난정보학회 2016년 정기학술대회
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• pp.122-125
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• 2016

최근 전 세계적인 기후변화로 인한 풍수해 증가 추세와 금년 잦은 지진발생으로 인해 재난에 대한 관심이 증가하였다. 그러나 대부분의 재난대비는 도시지역에 기초하고 있기 때문에 농촌마을의 재난대비책을 마련하는 것 이 필요하다. 이에 본 연구에서는 농촌지역의 공간구조분석을 통하여 농촌지역 특성을 도출하였고, 농촌지역 특성에 따른 자연재해현황을 조사하여 공간구문론 분석을 통한 농촌마을 재난대비 공간정비 가이드라인을 개발하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1283-1285
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• 1994

A three-layered piezoelectric ceramic transducer is fabricated with three piezoelectric ceramic disk transducers and two sheets of thin insulator. Its equvalent circuit is derived from the Mason's model of a thickness-driven piezoelectric transducer. We applied the electric input near its fundamental resonant frequency to the center transducer and connect the output voltages across the left and right transducers in series to the resistor load. Then we investigate the load characteristics at resonant frequencies under various resistor loads and the frequency characteristics near the resonant frequency under no load. Moreover, symbolic expressions for input impedances, voltage ratios, resonant frequencies, and bandwidths have been derived. The values calculated from those symbolic expressions are shown to agree well with the measurement values.

• Elastomers and Composites
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• 제27권4호
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• pp.267-274
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• 1992

Polydimethylsiloxane(PDMS)-containing polyurethane coating materials were synthesized because PDMS-based elastomers have unique properties including an extremely low glass transition temperature, good thermal and oxidative stability, and good dielectric properties. In this experiment a vinyl copolymer which consisted of vinyl chloride, vinyl acetate, vinyl alcohol, and maleic acid was used, and Coronate L was used as a polyisocyanate. PDMS-containing polyurethane was synthesized from polydimethylsiloxane, MDI, and 1,4-butanediol. Films were casted by reaction of viny copolymer, Coronate L, and PDMS-containing polyurethane. Thickness of tile films were $150-170{\mu}m$ and the films were characterized by IR, DSC, and Instron.