• 제목/요약/키워드: Electrical engineering

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Properties of CdS:In Thin Films according to Substrate Temperature

  • Park, G.C;Lee, J.;Chang, H.D.;Jeong, W.J.;Park, J.Y.;Kim, Y.J.;Yang, H.H.;Yoon, J.H.;Park, H.R.;Lee, K.S.;Gu, H.B.
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.857-860
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    • 2004
  • Cubic CdS thin film with the strongest XRD peak (111) at diffraction angle $(\theta)$ of 26.5 was well made at substrate temperature of $150^{\circ}C$. At that time, lattice constant a of the thin film was $5.79{\AA}$, grain size of that was more over ${\mu}m$ and it's resistivity was over $10^3{\Omega}cm$. And the peak of diffraction intensityat miller index (111) of CdS:In thin film with dopant In of 1 atom% was shown higher about 20 % than undoped CdS thin film. Also, CdS:In thin film had in part hexagonal structure among cubic structure as secondary phase. Lattice constant of a and grain size of secondary phase of the film with dopant In of 1 atom% was $5.81{\AA}$ and around $1{\mu}m$ respectively The lowest resistivity of $5.1{\times}10^{-3}{\Omega}cm$ was appeared on dopant In of 1.5 atom%. Optical band gap of undoped CdS thin film was 2.43 eV and CdS:In thin film with dopant In of 0.5 atom% had the largest band gap 2.49 eV.

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Liquid Crystal Aligning Capabilities Treated on Organic Overcoat Thin Films by Ion Beam Irradiation Method

  • Han, Jeong-Min;Kim, Byoung-Yong;Kim, Jong-Yeon;Kim, Young-Hwan;Han, Jin-Woo;Hwang, Jeoung-Yeon;Lee, Sang-Keuk;Kang, Dong-Hun;Ok, Chul-Ho;Seo, Dae-Shik
    • 한국전기전자재료학회논문지
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    • 제20권3호
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    • pp.245-249
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    • 2007
  • The liquid crystal display (LCD) applications treated on the organic overcoat thin film surfaces by ion beam irradiation was successfully studied. The good LC aligning capabilities treated on the organic overcoat thin film surfaces with ion beam exposure of $60^{\circ}$ for 2 min above ion beam energy of 1200 eV can be achieved. But, the alignment of defect of NLC on the organic overcoat surface at low energy of 600 eV was measured. The pretilt angle of NLC on the organic overcoat thin film surface with ion beam exposure of $60^{\circ}$ for 2 min at energy of 1800 eV was measured about 1 degree. Finally, the good thermal stability of LC alignment on the organic overcoat thin film surface with ion beam exposure of $60^{\circ}$ for 2 min until annealing temperature of $200^{\circ}C$ can be measured.

염료감응형 태양전지용 $TiO_2$ 광전극에 Graphene을 이용한 전기화학적 특성 (Electrochemical properties of Graphene based $TiO_2$ photoelectrode for dye-sensitized solar cells)

  • 왕교;조흥관;김은미;박경희;구할본;박복기
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 추계학술대회 논문집
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    • pp.134-134
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    • 2009
  • We studied electrochemical properties of $TiO_2$ photoelectrode based graphene for dye-sensitized solar cells(DSSC). Gaphene has good electric conductivity and it is very good transparent when this is coated on monolayer. we prepared photoelectrode by squeeze methode and researched photoelectrical properties of $TiO_2$ electrode base gaphene. DSSC based on graphene was obtained conversion efficiency of 5.4% under irradiation of AM 1.5(100 $mWcm^2$).

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Controllable Pretilt Angles for Liquid Crystal Molecules using a Rubbing Treated Mixture Layer

  • Kim, Dae-Hyun;Park, Hong-Gyu;Kim, Young-Hwan;Kim, Byoung-Yong;Ok, Chul-Ho;Seo, Dae-Shik
    • Transactions on Electrical and Electronic Materials
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    • 제10권4호
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    • pp.140-142
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    • 2009
  • We have investigated the continuous pretilt angle generation for liquid crystals using a rubbing treated mixture layer consisting of homogeneous and homeotropic polyimides. Various pretilt angles in the range from $0^{\circ}$ to $60^{\circ}$ were achieved as a function of the concentration of homeotropic PI. The transmittance characteristics used to measure the pretilt angle showed that the pretilt angles were measured with a high reliability. We observed uniform liquid crystal alignment on the rubbing treated mixture layer.

Electron Transport Properties of Zn(phen)q Compared with Alq3 in OLED

  • Kim, Byoung-Sang;Kim, Dong-Eun;Choi, Gyu-Chae;Park, Jun-Woo;Lee, Burm-Jong;Kwon, Young-Soo
    • Journal of Electrical Engineering and Technology
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    • 제4권3호
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    • pp.418-422
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    • 2009
  • We synthesized new electroluminescence materials [(1,10-phenanthroline)(8-hydroxyquinoline)] Zn(phen)q and investigated their electron transport properties. We used Zn(phen)q and $Alq_3$ for the conductive materials and measured their electron transport properties as a function of the organic layer thickness. The difference between Zn(phen)q and $Alq_3$ as electron transporting materials suggests that the electrical properties depends on the carrier injection.

움직임을 고려한 전기기기의 유한요소 기법에 관한 연구 (A study on Moving Surface Method to consider a motion of electrical machine with Finite Element Method)

  • 배재남;임승빈;김기찬;정대성;이성구;이주
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.16-18
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    • 2006
  • 유한요소법을 사용한 전기기기의 해석에서는 움직임을 고려한 해석이 필수적이다. 본 논문에서는 전기기기의 유한요소 해석시 움직임을 고려하기 위한 방안으로써 Moving Suface기법을 소개하고 이 기법의 적용방법 및 장단점에 관하여 논하였다. 또한 이 기법을 검증하기 위하여 Moving Surface기법을 적용한 유한요소해석 프로그램을 개발하고, 개발한 프로그램을 사용하여 실제 모델을 해석해 그 결과치를 실험치와 비교함으로써 타당성을 입증하였다.

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Measurement and Comparison of Iron Loss in Bonded- and Embossed-Type Segmented Stator Cores for IPMSM

  • Jeong, Kwangyoung;Zhang, Dianhai;Kwon, Jaehoon;Ren, Ziyan;Koh, Chang-Seop
    • Journal of Electrical Engineering and Technology
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    • 제9권6호
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    • pp.2013-2018
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    • 2014
  • According to the manufacturing process of the laminated stator core for an inserted permanent magnet synchronous motor (IPMSM), the iron loss may be different. It is because the mechanical stress imposed to electrical steel sheet is strongly dependent on the manufacturing process. This paper proposes a new iron loss measurement algorithm which utilizes the induced voltage of a search coil and exciting current. The method is effective even when the distribution of magnetic flux density is not uniform along the magnetic flux path as well as uniform. The developed iron loss measurement system is applied to bonded- and embossed-type segmented stator cores of an IPMSM, and the iron losses are quantitatively compared.

ac-PDP의 상판 Bus 전극 위치 변화에 따른 addressing 속도 및 발광효율에 관한 연구 (A Study on the Addressing speed and Luminous Efficiency as Positions of Bus Electrodes in ac PDP)

  • 김윤기;이성현;문영섭;김규섭;조정수;박정후
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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    • pp.112-116
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    • 2000
  • In this paper, we investigated the relationship between the position of bus electrode and address time, luminance and luminous efficiency in ac PDP of 50in. XGA resolution. When the bus electrode was placed in which was about $140{\mu}m$ apart from discharge gap, the luminous efficiency was the highest and address time was the least. Whereas, when the bus electrode was placed in the edge of ITO, the luminance was the highest.

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교류 전기장 배열 기법에 의해 제작된 ZnO 나노선 기반의 자외선 광다이오드 (ZnO NW-based ultraviolet photodiodes fabricated by dielectrophoresis technique)

  • 김광은;강정민;이명원;윤창준;전영인;김상식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.259-259
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    • 2010
  • 교류 전기장에 의해 배열된 ZnO 나노선 기반의 광다이오드를 제작하고 자외선 광특성을 조사하였다. ZnO 나노선은 dielectrophoresis (DEP) force와 토크 (T)에 의하여 두 전극사이에 배열되며, silicon (Si)나노선과 접합을 하여 p-n 접합을 형성한다. 형성된 p-n 접합은 정류작용을 하는 다이오드 특성을 보이며, 자외선 입사시 전류 점멸비 (on/off ratio) $10^1{\sim}10^2$을 보이는 광다이오드(photodiode)로서 동작한다.

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