• 한국전자거래학회지
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• 제2권1호
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• pp.53-77
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• 1997

This paper presents an efficient methodology for information system development by adopting the concept of extended components which can achieve the improvement of development productivity, reductrion of development time periods, quality improvement of information systems, etc. when information development projects are carried out. First of all, for efficient development of information systems, development steps of current methodologies for information system analysis are subdivided into components in detail and outputs required at each step are defined. The components are extended by types and various application methods are proposed in each step of information system development. In addition, a method which uses advantages of current methods such as SDLC, prototyping, and RAD, is also proposed. In this research, a CASE tool named S-Designer is used for the development of extended components and their interface, and a system development method called DSDM for the deviation of detailed steps and corresponding outputs.

• 한국전기전자재료학회논문지
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• 제17권8호
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• pp.866-870
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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 polyimide surfaces using plastic substrates. It was found that monodomain alignment of NLC is obtained with rubbing alignment method on polyimide surfaces using thin plastic substrates. The NLC pretilt angles on thin plastic substrates generated higher than that on glass substrate. Also, EO characteristics of the TN-LCD with a rubbed PI surface based on polymer substrate are almost the same as that of the TN-LCD with a rubbed PI surface based on glass. However, the transmittances of the TN-LCD with a rubbed PI surface based on polymer is less than that with a rubbed PI surface based on g1ass.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.1007-1009
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• 2004

We investigated the electro-optical(EO) performances of the super twisted nematic liquid crystal display(STN-LCD) on the polyimide(PI) surface with polymer film using rubbing and photoalignment method. Monodomain alignment of the plastic STN-LCD can be observed. A faster response time for the photoaligned plastic STN-LCD on the polyimide(PI) surfaces can be achieved than rubbingaligned plastic STN-LCD.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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• pp.210-213
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• 2004

We synthesized photoalignment material of high thermal resistance with hydroxyl aromatic polyimide, and studied the liquid crystal (LC) aligning capabilities on the photopolymer layers. Also, electro-optical (EO) performances for the twisted-nematic (TN)-liquid crystal display (LCD) photoaligned with linearly polarized UV exposure were investigated. A good LC alignment with UV exposure on the photopolymer surface can be obtained. However, the low pretilt angles were obtained below $1^{\circ}$. The Voltage-transmittance (V-T) curve without backflow bounce in the photoaligned TN cell with UV exposure was observed. The response time of photoaligned TN cell was measured about 24 ms. Finally, The photoaligned TN cell has few hysteresis, and shows the residual DC voltage that is less.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.195-196
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• 2008

A ring resonator based band-pass filter enabling enhanced sideband suppression was proposed and demonstrated. It is composed of a single-ring based-pass section combined with a band-rejection section based on two different coupled rings. As for the achieved device performance, bandwidth was reduced from 98 MHz to 48 MHz by about 51% with no remarkable excessive insertion loss as expected. And the quality factor of the device was increased by about 105%.

• 전자공학회논문지D
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• 제34D권7호
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• pp.62-70
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• 1997

In this paper, the optical conditins of a reflective multi-color STN-LCD based on electrical control of birefringence is designed on the poincare sphere. First of all, the angles of polarizer and analyzer for the best color purity are decided in the configuration without a retardation film. A retardation film is introduced for a bright white in the range of the applied voltage. The sretardation and the angle of the retardation film are also decided on the poincare shpere. The test cell is farbricated and its measured spectral transmittance and the CIE chromaticity diagram agree well with simulations.

• 대한전자공학회논문지TC
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• 제49권2호
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• pp.50-55
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• 2012

이 논문에서는 스캔 기능을 갖는 패브리 패롯형 공진기 안테나에 대해서 다룬다. 제안하는 배열 안테나는 슈퍼스트레이트/PEC 복합체내에 마이크로스트립 급전 어레이를 이용하는 것으로 급전 위상에 따라서 빔 틸트 각도의 제어가 가능하다. 기존의 배열 안테나와 비교하여 안테나 어퍼쳐 크기의 증가로 높은 디렉티비티와 사이드 로브 억압비의 개선을 가져온다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 디스플레이 광소자분야
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• pp.81-83
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• 2003

We have investigated the generation of pretilt angle for a nematic liquid crystal (NLC) alignment with rubbing alignment method on polyimide surfaces using thin plastic substrates. It was found that monodomain alignment of LNC is obtained with rubbing alignment method on polyimide surfaces using thin plastic substrates. The generated NLC pretilt angles are about $3^{\circ}$ by the rubbing alignment method on thin plastic substrates, However, the pretilt angle measured at about $1.7^{\circ}$ lower on the glass substrate than by thin plastic substrate. It is considered that this alignment may be attributed to roughness of micro groove substrate. The tilt angle increases with increasing baking temperature for making polyimide layer using glass substrate. It was concluded that pretilt angle in the polyimide surface is attributable to the increasing of imide rato.

• 한국전기전자재료학회논문지
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• 제29권10호
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• pp.630-634
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• 2016

In this paper, we analyzed the power consumption and the accumulated energy in HTSC (high-TC superconducting elements) according to the resistance of HTSC element and the winding current of transformer type SFCL (superconducting fault current limiter) using double quench. For the analysis, two different inductances of the one secondary winding among two secondary windings comprising the transformer type SFCL were selected and the short-circuit tests were carried out. The consumed power and the accumulated energy in HTSC element connected into the secondary winding with larger inductance were analyzed to be larger compared to the one connected into the secondary winding with lower inductance.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2006년도 전력전자학술대회 논문집
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• pp.441-443
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• 2006

인버터 출력측에 변압기를 이용하지 않는 고효율의 3상 UPS는 크게 3부분의 전력변환 장치로 구성되어진다. 입력단 역률제어 및 고조파 전류억제를 위한 PWM 컨버터, 출력단 전압 제어를 위한 PWM 인버터, 그리고 출력단 변압기를 이용하지 않기 때문에 높아지는 직류단 전압을 낮은 배터리 전압으로 변환할 수 있는 양방향 컨버터이다. 본 논문에서는 이러한 무변압기형 UPS의 구성 및 실험결과에 대해 기술한다.