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A New Structure of Triode-type CNT-FEAs for Enhanced Electron Emission and Beam Focusing

  • Jun, Pil-Goo;Kwak, Byung-Hwak;Noh, Hyung-Wook;Lee, Soo-Myun;Uh, Hyung-Soo;Park, Sang-Sik;Ko, Sung-Woo;Cho, Euo-Sik;Lee, Jong-Duk
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.456-458
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    • 2004
  • We proposed a novel triode-type carbon nanotube field emitter arrays in which extracted gate is surrounded by CNT emitters. We carried out 3-dimensional numerical calculations of electrostatic potential for the proposed CNT-FEAs using the finite element method and compared the results with those obtained from the structure of conventional CNT-FEAs. It was found that the proposed structure could reduce the turn-on voltage for electron emission and improve beam focusing.

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FORM 신뢰성 기반 항타강관말뚝 저항계수 산정 (FORM Reliability-based Resistance Factors for Driven Steel Pipe Piles)

  • 박재현;허정원;이주형;정문경;곽기석
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 추계 학술발표회
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    • pp.779-783
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    • 2008
  • LRFD Resistance factors for static bearing capacity of driven steel pipe piles were calibrated in the freamework of reliability theory. Reliability analysis was performed by the First Order Reliability Method (FORM) using resistance bias factor statistics.The target reliability indices are selected as 2.0 and 2.33 for group pile case and 2.5 for single pile case, based on the reliability level of the current design practice and considering redundancy of pile group, acceptable risk level, construction quality control, and significance of individual structure.

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Trajectory control of direct drive robot using two-degrees-of-freedom compensator

  • Shin, Jeong-Ho;Fujiune, Kenji;Suzuki, Tatsuya;Okuma, Shigeru;Yamada, Koji
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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    • pp.422-427
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    • 1994
  • In this paper, we propose a new design approach of a two-degrees-of-freedom compensator which assures the robust stability. First of all, we clarify the internal structure of the generalized two-degrees-of-freedom compensator. By adopting this structure, we can make a bridge between the generalized controller and the disturbance observer based controller, Secondly, based on the clarified structure we derive a robust stability condition, and propose a design algorithm of free parameter taking the condition into account. The proposed design algorithm is easy to implement and, as a result, we obtain lower order free parameter then that of the conventional design algorithm.. Thirdly, we show by adopting an appropriate coprime factorization that the clarified structure can also be regarded as an extended version of the conventional PID compensator. Finally, we apply the proposed algorithm to a three-degrees-of freedom direct drive robot, and show some experimental results to verify the effectiveness of the proposed algorithm.

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Vibration measurement and vulnerability analysis of a power plant cooling system

  • Anil, Ozgur;Akbas, Sami Oguzhan;Kantar, Erkan;Gel, A. Cem
    • Smart Structures and Systems
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    • 제11권2호
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    • pp.199-215
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    • 2013
  • During the service life of a structure, design complications and unexpected events may induce unforeseen vibrations. These vibrations can be generated by malfunctioning machinery or machines that are modified or placed without considering the original structural design because of a change in the intended use of the structure. Significant vibrations occurred at a natural gas plant cooling structure during its operation due to cavitation effect within the hydraulic system. This study presents findings obtained from the in-situ vibration measurements and following finite-element analyses of the cooling structure. Comments are made on the updated performance level and damage state of the structure using the results of these measurements and corresponding numerical analyses. An attempt was also made to assess the applicability of traditional displacement-based vulnerability estimation methods in the health monitoring of structures under vibrations with a character different from those due to seismic excitations.

광기록을 위한 Te-based Antireflection구조의 열적, 광학적 특성 (The Thermal and Optical Properties of Te-based Antireflection structure for Optical Recording)

  • 이성준;이현용;정홍배;이영종
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 하계학술대회 논문집 B
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    • pp.1256-1258
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    • 1993
  • Optical data storage offer high density storage and archival storage capability. In this study, we selected the ablation mechanism-one of an irreversible recording system-using the antireflection trilayer(ART) structure. Optical recording medium is a $(Te_{86}Se_{14})_{50}Bi_{50}$ thin films. Actually, ART structure is fabricated and compared to monolayer structure. ART structure leads to the reduction of recording power as well as an increase in the effciency compared to the monolayer structure.

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Transflective IPS LCD with Multi-Domain Structures

  • Park, Kyoung-Ho;Ko, Young-Jo;Kim, Jung-Hyoung;Kim, Jae-Chang;Yoon, Tae-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.895-898
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    • 2004
  • We propose configurations for a transflective in-plane switching (IPS) cell using muti-domain structures. Usually, the cell configurations for a transflective liquid crystal(LC) cell have a complicated structure, because retardation change of transmissive part and reflective part are not same. The transflective LC cell should have two configurations for each part, such as a multi-cell gap structure. With the ion-beam alignment and the horizontal switching LC cell, a simple structure for a transflective LC cell is proposed. The configuration only adopts one cell gap structure, which may help the enhancement of a yield. Their original optical properties in conventional transmissive and reflective type IPS liquid crystal dispaly(LCD) are kept, it shows the wide-viewing angle and the good wavelength dispersion characteristics.

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퍼지 신경망 제어기의 구조 및 매개 변수 최적화 (The Structure and Parameter Optimization of the Fuzzy-Neuro Controller)

  • 장욱;권오국;주영훈;윤태성;박진배
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 B
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    • pp.739-742
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    • 1997
  • This paper proposes the structure and parameter optimization technique of fuzzy neural networks using genetic algorithm. Fuzzy neural network has advantages of both the fuzzy inference system and neural network. The determination of the optimal parameters and structure of the fuzzy neural networks, however, requires special efforts. To solve these problems, we propose a new learning method for optimization of fuzzy neural networks using genetic algorithm. It can optimize the structure and parameters of the entire fuzzy neural network globally. Numerical example is provided to show the advantages of the proposed method.

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AC-PDP의 새로운 셀구조와 그 전기 광학적 특성에 관한 연구 (The study on the electrical and optical characteristics of a new structure for color AC plasma display)

  • 박재문;김영기;이재영;신중홍;조정수;박정후
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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    • pp.128-130
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    • 2000
  • A new type ac plasma display panels(PDPs) cells are designed and tested electrically and optically. One cells have the structure of sin discharge path shape and small electrode area. The other cells have the non-symmetric structure with a same electrode area. They show a higher luminous efficienccy and a lower power consumption about 30% improvement than the conventional standard ac PDP cells.

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새로운 전극구조를 가진 AC-PDP의 전기 광학적 특성에 관한 연구(II) (The study on the electrical and optical characteristics of a new structure for color ac plasma displays(II))

  • 이우근;이재영;김영대;이기범;조정수;박정후
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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    • pp.1093-1095
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    • 1999
  • A new type ac plasma display panels(PDPs) cells are designed and tested electrically and optically. One cells have the structure of sin discharge path shape and small electrode area. The other cells have the non-symmetric structure with a same electrode area. They show a higher luminous efficiency and a lower power consumption about 25% improvement than the conventional standard ac PDP cells.

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새로운 전극구조를 가진 ac-PDP의 전기 광학적 특성에 관한 연구 (II) (The study on the electrical and optical characteristics of a new structure for color ac plasma displays)

  • 고지성;이우근;이재영;박재문;조정수;박정후
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 E
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    • pp.2230-2232
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    • 1999
  • A new type ac plasma display panel(PDP) cells are designed and tested electrically and optically. One cell has the structure of sin discharge path shape and small electrode area. The other cells have the non-symmetric structure with a same electrode area. They show a higher luminous efficienccy and a lower power consumption about 25% improvement than the conventional standard ac PDP cells.

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