• 제목/요약/키워드: Flexible Mode

검색결과 489건 처리시간 0.026초

Enhancement of Mass Transfer Using Piezoelectric Material in Fluid Flow System

  • Kim, Gi-Beum;Chong, Woo-Suk;Kwon, Tae-Kyu;Hong, Chul-Un;Kim, Nam-Gyun;Jheong, Gyeong-Rak
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2004년도 ICCAS
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    • pp.165-170
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    • 2004
  • The purpose of this work was to assess and quantify the beneficial effects of long-term gas exchange, at varying frequencies, for the development of a vibrating intravascular lung assistance device (VIVLAD), for patients suffering from acute respiratory distress syndrome (ARDS). The experimental design and procedure have been applied to the construction of a new device for assessing the effectiveness of membrane vibrations. An analytical solution has been developed for the hydrodynamics of flow through a bundle of sinusoidally vibrated hollow fibers, with the intention of gaining insight into how wall vibrations might enhance the performance of the VIVLAD. As a result, the maximum oxygen transfer rate was reached at the maximum amplitude and through the transfer of vibrations to the hollow fiber membranes. The device was excited by a frequency band of 7Hz at various water flow rates, as this frequency was the 2nd mode resonance frequency of the flexible beam. 675 hollow fiber membranes were also bundled, within the blood flow, into the device.

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선박용 디젤발전기의 진동 절연을 위한 설계 기준 (A Design Criterion for the Vibration of a Marine Diesel Generator Set)

  • 이돈출
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 춘계학술대회논문집
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    • pp.648-655
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    • 2005
  • The resilient mounts of a diesel engine installed onboard a ship should be designed for both static and dynamic loads. If possible, the resonance frequencies of the six rigid body modes of the installation and the flexible modes of the engine support structure should not lie within the engine operation range. In this paper a design criterion is proposed to evaluate an isolation system which involves the summation of dynamic forces transmitted through the resilient mounts and elastic potential energy index stored in the mounts. A case study is also presented in which a diesel engine generator, which had an elastic foundation and was mounted in a 5500 TEU container vessel, was studied both theoretically and experimentally. The theoretical analysis of the test model was performed by using a single mass 6 degree of freedom system. Actual measurements of mechanical vibration of the Engine and its foundation onboard were carried out, which showed the importance of including the flexibility of the engine support structure in the mode

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신 자기회로가 적용된 광픽업 액추에이터의 동특성 (Dynamic characteristics of optical pickup actuator with a newly designed electromagnetic circuit)

  • 박관우;김재은;정제현;이경택;고의석;민병훈
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2008년도 추계학술대회논문집
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    • pp.512-514
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    • 2008
  • In this paper, a new electromagnetic circuit is proposed for an optical pickup actuator with high sensitivity. Contrary to those of conventional actuators, the proposed circuit has two focusing coils which are diagonally placed at the front and rear of a moving part. The configuration which makes the effective length of the focusing coil longer and the moving part lighter, is helpful in increasing the sensitivity of the actuator. However, the asymmetry of the moving part by two focusing coils causes flexible node vibrations in quite low frequency range. This paper shows that the design modification of the moving part for the reconfiguration of mass moment of inertia can reduce the mode vibrations.

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위치결정 스테이지의 고속 정밀 위치결정을 위한 입력성형명령 생성 기법 (Command Generation Method for High-Speed and Precise Positioning of Positioning Stage)

  • 장준원;박상원;홍성욱
    • 한국정밀공학회지
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    • 제25권10호
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    • pp.122-129
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    • 2008
  • This paper deals with precise positioning of a high-speed positioning stage without inducing residual vibration by using an input shaping technique. Input shaping is well known to be a very effective tool for suppressing the residual vibration of flexible structures. However, the ordinary input shaping for positioning stages is designated mostly for velocity regulation, not for the residual vibration at the target position. The main difficulties in implementing input shaping along with precise positioning are the time delay caused by the servo system characteristics and the s-curve feature often employed in some motor controllers. This paper analyzes the dynamic responses of a single-mode-dominate stage system subjected to input shaping. A theoretical model is developed io investigate the nature of system. In order to overcome the difficulty, this paper proposes an improved input shaper based on modified command profile generation. The proposed method is proved effective through experiments and simulations.

초소형 광디스크 드라이브용 VCM타입 엑추에이터 개선 (Development of Rotary VCM type Actuator for Small Form Factor Optical Disk Drive)

  • 우정현;김사웅;송명규;이동주;박노철;박영필
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2006년도 추계학술대회논문집
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    • pp.474-478
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    • 2006
  • It is becoming more significant to develop a rotary voice coil motor(VCM) type's actuator for small form factor (SFF) optical disk drive(ODD), as portables are getting more and more popularized nowadays. The actuator which is applicable to small-sized ODD with a compact flash(CF) II card size was developed and fabricated. The experimental results showed that the finite element(FE) model is different from the fabricated model. And so flexible mode frequencies did not satisfy specifications of small-sized ODD, and tuning. Tuning procedures were required to improve dynamic characteristics of the fabricated actuator through finite difference method(FDM). At first, design variables were extracted through parameter study and the tuned FE model was improved by design of experiment(DOE). Consequently, It was confirmed that the improved model was applicable to SFF ODD.

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Wearable Personal Network Based on Fabric Serial Bus Using Electrically Conductive Yarn

  • Lee, Hyung-Sun;Park, Choong-Bum;Noh, Kyoung-Ju;SunWoo, John;Choi, Hoon;Cho, Il-Yeon
    • ETRI Journal
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    • 제32권5호
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    • pp.713-721
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    • 2010
  • E-textile technology has earned a great deal of interest in many fields; however, existing wearable network protocols are not optimized for use with conductive yarn. In this paper, some of the basic properties of conductive textiles and requirements on wearable personal area networks (PANs) are reviewed. Then, we present a wearable personal network (WPN), which is a four-layered wearable PAN using bus topology. We have designed the WPN to be a lightweight protocol to work with a variety of microcontrollers. The profile layer is provided to make the application development process easy. The data link layer exchanges frames in a master-slave manner in either the reliable or best-effort mode. The lower part of the data link layer and the physical layer of WPN are made of a fabric serial-bus interface which is capable of measuring bus signal properties and adapting to medium variation. After a formal verification of operation and performances of WPN, we implemented WPN communication modules (WCMs) on small flexible printed circuit boards. In order to demonstrate the behavior of our WPN on a textile, we designed a WPN tutorial shirt prototype using implemented WCMs and conductive yarn.

트랜스미디어 콘텐츠의 텍스트 및 이용 특징 (Characteristics of Transmedia Contents Textuality and Usage)

  • 전경란
    • 한국콘텐츠학회논문지
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    • 제10권9호
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    • pp.243-250
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    • 2010
  • 디지털기술은 콘텐츠의 제작과정을 매우 유연하게 하고, 그와 동시에 디지털화된 미디어는 동일 콘텐츠 혹은 동일 콘텐츠에서 변형, 수정, 가공된 콘텐츠가 자유롭게 호환될 수 있는 트랜스미디어 현상을 추동하고 있다. 트랜스미디어 콘텐츠는 다차원적인 속성을 지님으로써 각각의 콘텐츠 판본이 독자적인 세계를 구현하는 동시에 하나의 전체 콘텐츠 세계를 창조하는데 기여하게 된다. 이 과정에서 이용자들은 다양한 미디어 플랫폼에 기반한 여러 판본의 콘텐츠를 접하면서 콘텐츠 체험을 창조하고 심화할 수 있다. 트랜스 미디어 콘텐츠는 독자적인 미학과 존재의의를 구축하면서 콘텐츠의 텍스트적 특징, 제작원리, 소비행위 등 콘텐츠 전반에 걸쳐 변화를 가져오고 있다.

주행질량에 의한 불균일 단면보의 동적응답 (Dynamic Response of Non-uniform Beams under a Travelling Mass)

  • 김인우;이영신;이규섭;류봉조
    • 한국소음진동공학회논문집
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    • 제11권5호
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    • pp.140-147
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    • 2001
  • In this paper, the dynamic response of non-uniform beams subjected to a travelling mass is investigated. Dynamic behaviors of flexible beam structures under a moving mass have been a concern in the design of bridges, ceiling crain in industry, as well as gun barrel fields. Most of studies for moving mass problems have been related to the theoretical dynamic responses of a simple beam model with uniform cross-sections. In some experimental studies, only a few transverse inertia effects due to travelling mass have been studied so far. The intended aim of the present Paper is to investigate the dynamic response of non-uniform beams taking into account of inertia force. centrifugal force, Coriollis force and self weight due to travelling mass. Galerkin's mode summation method is applied for the discretized equations of motion. Numerical results for the dynamic response of non-uniform beams under a travelling mass are demonstrated for various magnitudes and velocities of the travelling mass. In order to verify propriety of numerical solutions, experiments were conducted. Experimental resu1ts have a good agreement wish theoretical Predictions.

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디지털 사이니지를 위한 장거리 고효율 전송 기법 (Long Distance High Efficiency Transmission Techniques for Digital Signage)

  • 이선의;차재상;장영민;김진영
    • 한국위성정보통신학회논문지
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    • 제10권1호
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    • pp.62-66
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    • 2015
  • 본 논문은 디지털 사이니지의 다양한 콘텐츠 유형과 활용범위에 대하여 소개하고 송수신 거리를 늘리기 위하여 기존의 통신 방식을 분석하였다. 디지털 사이니지를 장거리에서 구현하기 위하여 기존의 모듈레이션 기법들을 결합한 하이브리드 모듈레이션 기법을 제안하고 성능을 분석하였다. 그리고 실제 채널에서의 성능을 검증하기 위해 USRP 장비를 이용하여 심벌을 매핑하고 가시광 통신 송수신 모듈로 데이터를 송수신하는 실험을 수행하였다. 기존의 QAM 방식을 이용한 데이터 수신거리와 송수신 파워를 실험을 통하여 확인하였다. 제안된 하이브리드 모듈레이션 기법을 이용한 데이터 수신거리와 송수신 파워가 기존 QAM 방식보다 뛰어남을 보였다.

광표백 폴리머 광도파로를 이용한 디지탈 광스위치 (Polymeric digital optical switch based on photobleached waveguides)

  • 이상신;신상영
    • 한국광학회지
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    • 제7권4호
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    • pp.414-418
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    • 1996
  • 광표백 광도파로 자기정렬 전극을 이용하여 전기광학 폴리머 디지탈 광스위치를 제작하였다. 이 광스위치는 파장에 무관하게 동작하고 제작조건에 민감하지 않고 설계가 다양하다는 특성을 갖는다. 또한 광섬유와의 결합 손실이 작고 넓은 대역폭을 갖는 장점이 있다. 스위칭 성능을 향상시킬 목적으로 광표백 시간을 이용하여 광표백 광도파로의 도파모드 분포를 적절하게 조절함으로써 브랜치 영역에서의 모드 결합을 최적화 하였다. 또한 광과 인가 전계의 효과적인 겹침과 점진적으로 테이퍼된 전극을 형성하기 위해 자기정렬전극을 이용하였다. 측정된 누화는 1.32.mu.m와 1.55.mu.m에서 모두 -21dB 이하였고 각 출력포트의 소멸비도 모두 20dB 이상이었다.

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