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A hybrid 8-node hexahedral element for static and free vibration analysis

  • Darilmaz, Kutlu
    • Structural Engineering and Mechanics
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    • 제21권5호
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    • pp.571-590
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    • 2005
  • An 8 node assumed stress hexahedral element with rotational degrees of freedom is proposed for static and free vibration analyses. The element formulation is based directly on an 8-node element. This direct formulation requires fewer computations than a similar element that is derived from an internal 20-node element in which the midside degrees of freedom are eliminated by expressing them in terms of displacements and rotations at corner nodes. The formulation is based on Hellinger-Reissner variational principle. Numerical examples are presented to show the validity and efficiency of the present element for static and free vibration analysis.

상악 매복 견치의 교정학적 고찰

  • 서정훈
    • 대한치과의사협회지
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    • 제25권1호통권212호
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    • pp.59-70
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    • 1987
  • Orthodontists, in evaluating maxillary impactd canines, must take into consideration the etiology of the problem. First, the possible etiologic factors must be eliminated. Thus some cases can be treated with orthodontic treatment alone without surgical trauma following window opening etc. Now, two cases are reported, which were treated without surgical intervention. Sometimes, impacted canine can be included in a plan for tooth removal due to its severe impaction and displacement. In such case, first premolar can be substituted for canine. One case which was treated by substituting maxillary first premolar for maxillary impacted canine is reported.

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고속 동기 릴럭턴스 전동기 비간섭 벡터제어 (Decupling Vector Control for High Speed Synchronous Reluctance Motor)

  • 김민태;백동기;최재동;성세진;전칠환
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1999년도 전력전자학술대회 논문집
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    • pp.155-158
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    • 1999
  • In the high speed range for Vector control of Synchronous Reluctance Motor, the effect of iron loss and the cross-coupling of dq axis currents is dependent on the increase of the operating frequency can not be negligible. In this paper, we propose a decupling Vector control of dq axis current that the effect of iron loss is eliminated, and confirm that through simulation results.

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능동 클램프 회로를 적용한 단상 ZCS 공진형 역률개선 컨버터 (An Integrated Single-Stage Zero Current Switched Quasi-Resonant Power Factor Correction Converter with Active Clamp Circuit)

  • 이준영;문건우;고관본;윤명중
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1999년도 전력전자학술대회 논문집
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    • pp.626-630
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    • 1999
  • A new integrated single-stage zero current switched(ZCS) quasi-resonant converter (QRC) for the power factor correction(PFC) converter is introduced in this paper. The power factor correction can be achieved by the discontinuous conduction mode(DCM) operation of an input current. The proposed converter has the characteristics of the good power factor, low line current harmonics, and tight output regulation. Furthermore, the ringing effect due to the output capacitance of the main switch can be eliminated by use of active clamp circuit.

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IGBT를 이용한 단산 PWM정류기 병렬운전 (The Parallel Operation of Single Phase PWM Rectifier using IGBT)

  • 이현원;장성영;김연준;이광주;김남해
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1999년도 전력전자학술대회 논문집
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    • pp.122-125
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    • 1999
  • The AC-to-DC single-phase PWM rectifier for traction applications using high power semiconductor, IGCT is made and tested. Parallel operation of two PWM converter is adopted for increasing capacity of converters. For reducing harmonics, the harmonic content is eliminated by the phase shift between two converters switching phase. The output voltage control is achieved by interns calculation without detecting the input current. The part of PLL used for controlling power factor is simply implemented by software.

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Data identified Time Extension Driving Method

  • Lin, L.;Liang, B.J.;Huang, C.M.;Chiang, S.P.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.1247-1250
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    • 2006
  • A new liquid crystal display (LCD) Data identified Time Extension (DiTEX) driving scheme with a high charged voltage is proposed. The different charged voltage owing to the differential charging time and various initial pixel-potential can be eliminated or diminished under this method. It is compatible with a 2-row inversion and can be realized into the commercial dual-sided gate circuits.

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System Interface for SoG in LTPS TFT Process

  • Min, Kyung-Youl;Yoo, Chang-Sik
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.1791-1794
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    • 2006
  • For system-on-glass (SoG) with low-temperature poly-silicon (LTPS) thin film transistor (TFT), a new system interface architecture and timing controller are developed. With the newly developed system interface architecture, line memory can be eliminated which would take large area of SoG display panel. The system interface and timing controller are targeted for the application for 6-bit gray scale, 60-frames/s qVGA format.

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정전형 MEMS 검출기의 새로운 Offset 보상 방법 (New Offset-compensation Technique for Capacitive MEMS-Sensor)

  • 민동기;전종업
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 C
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    • pp.1896-1898
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    • 2001
  • An offset problem caused by the static parasitic capacitors is analyzed and then some techniques to reduce their effect on the capacitive position sensor are presented. Also new offset compensation technique is proposed that by adjusting the magnitudes of the modulating signals independently, the charge imbalance between electrodes caused by the parasitic capacitors is eliminated without sensor gain variation. Simulation results are given to validate the proposed compensation technique.

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제어 자유도를 한 차원 증가시킨 순시무효전력 보상이론 (Instantaneous Reactive Power Compensation Theory Increasing The Control Freedom One Degree Higher)

  • 김효성
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 F
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    • pp.2481-2483
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    • 1999
  • This paper proposed the p-q-r coordinate system where the instantaneous active power p, and the two instantaneous reactive powers $q_{q}$, $q_{r}$ were defined. The three power components are linearly independent, so the compensation for the two instantaneous reactive powers leads to control the two components of the current space vector. With the theory, the neutral current of a three-phase four-wire system can be eliminated by only compensating the instantaneous reactive power using no energy storage element.

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A Study on the Optimal Model Following Sliding Mode Control

  • Kim, Min-Chan;Park, Seung-Kyu
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.38.4-38
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    • 2001
  • In this paper, a novel model following sliding mode control is proposed by using a novel sliding mode with virtual state. This sliding surface has nominal dynamics of an original system and makes it possible that the Sliding Mode Control(SMC) technique is combined with the optimal controller. Its design is based on the argument system whose dynamics have one higher order than that of the original system. The reaching phase is eliminated by using an initial virtual state that makes the initial sliding function equal to zero.

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