• 제목/요약/키워드: Equivalent noise

검색결과 616건 처리시간 0.027초

인공위성 태양전지판 전개 시스템 동적 모델링 (Dynamic Modeling of Satellite with Deployable Solar Arrays)

  • Seok Heo;Moon K. Kwak;Kim, Hong-B;Sang M. Moon;Sung H. Woo;Lee, Sang S.
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문초록집
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    • pp.373.2-373
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    • 2002
  • This research is concerned with dynamic modeling of satellite with deployable solar arrays equipped with strain energy hinges (SEH). It is found from experiments that the SEH has nonlinear dynamic characteristics and complex buckling behavior, which is difficult to explain theoretically In this paper, we use an equivalent one dimensional nonlinear torsional spring for the SEH. Lagrangian equations of motion are used for the derivations.

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점탄성 재료의 제진특성 모델링 (Modeling for Vibration Characteristics of Viscoelastic Material)

  • 이택희;박상규;김중배;이상조
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 춘계학술대회논문집
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    • pp.1146-1149
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    • 2001
  • In this study, modeling methods for viscoelastic material are reviewed to investigate the vibration characteristics. Frequency response functions are obtained by employing experimental modal analysis and compared with the modeling results from a commercial software NASTRAN. Properties of equivalent model of the beam with damping material are also calculated by using the RKU equation.

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케스코드 증폭기와 인덕터 피킹기술을 이용한 광통신용 광 수신기의 설계 (Optical Receiver Design For Optical Communication Using Cascoded Amplifier with Inductor Peaking Technique)

  • 박정식;이강승;정윤하
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1999년도 하계종합학술대회 논문집
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    • pp.305-308
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    • 1999
  • In this paper, a transimpedance optical receiver based on PIN/P-HEMT with cascoded input stage and inductor peaking technique was designed for several giga bits optical communication. Analysis of the receiver shows that cascoded input stage with inductor peaking increase bandwidth without sacrificing low frequence gain. The receiver achieved a low noise characteristic and maximally flat frequence response. It is shown that the 3-dB bandwidth of the designed receiver is 8.3 ㎓ and input equivalent noise current is as low as 16pA/√Hz to 10㎓.

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조인트 등가빔을 이용한 저진동 차체 모델링 및 해석기법 (Modeling and Vibration Analysis of Vehicle Structures Using Equivalent Beam Stiffness for Joint)

  • 임홍재;김윤영;이상범;송명의
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1995년도 춘계학술대회논문집; 전남대학교, 19 May 1995
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    • pp.40-44
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    • 1995
  • 본 논문에서는 결합부의 강성도를 나타내기 위해 그동안 사용되어 오던 기존의 스프링 모델을 사용하는 대신 등가빔 조인트 모델을 차체의 유한요소모델에 적용하여 보았으며 차체의 기본 진동 모드 해석을 통해 그 타당성을 검증하여 보았다. 특히 본 연구를 통해 차체 설계시 특정 결합부 강성도를 효율적으로 결정할 수 있는 방법의 개발이 가능해졌으며 그 방법의 개발을 위해 현재 계속 연구가 진행되고 있음을 밝힌다.

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CRT 모아레 현상의 억제를 위한 진동 해석 및 설계 (Vibration Analysis and Design of CRT for Reduction of Moire Phenomena)

  • 이규헌;유홍희
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 추계학술대회논문집 I
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    • pp.413-418
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    • 2001
  • The moire phenomena, which are induced by mask vibration due to the excitation of speakers, degrades the color purity of CRT. So it is important to eliminate this phenomena to obtain a good CRT design. In this study we analyze the mask vibration by experiment as well as finite element method. To obtain the finite element solutions efficiently, an equivalent model was employed. The experimental and analysis results show reasonable agreements. An enhanced design configuration of mask welding points are suggested through this study.

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충격식 피로시험기 개발 (Development of Impact Fatigue Test Machine)

  • 남용윤;신병천;홍석균;이성우
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 춘계학술대회논문집
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    • pp.1154-1160
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    • 2000
  • This paper reports the development of a special impact fatigue test machine for high pressure vessels. The targeted vessels are subjected to shock pressures equivalent of explosions. This severe loading condition brings many difficulties to the design of test machine. Unfortunately, there are very rare such test machine in the world, and more worse, the machine is not opened and sold.

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트랜스포머에 의한 수중 음향 트랜스듀서의 송수신 특성의 변화 (Changes in Transmitting-Receiving Characteristics of Underwater Acoustic Transducer by Transformer)

  • 조치영;이정민
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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    • pp.493-499
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    • 1997
  • In this study, the changes in transmitting and receiving characteristics, especially resonance frequencies, of the underwater acoustic planar array transducer by the transformers used in the analog weighting circuit are investigated. Electrical equivalent circuit analysis shows that an ideal transformer does not change the resonance frequency of the transmitting mode, but the resonance frequency which gives the maximum receiving sensitivity can be designed by adjusting the magnitude of reactance of transformer.

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정량구조물의 차음성능 향상방안 : ″Honeycomb 구조의 적용사례″ (Evaluation of the Sound Transmission Loss of a Light Weight Honeycomb Structure)

  • 김운경;김정태;김석현
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2002년도 춘계학술대회 논문집
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    • pp.446-451
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    • 2002
  • Honeycomb structures have advantages in weight reduction with stiffness increment. As far as noise is concerned, however a light aluminum structure, instead of a steel frame, should have an equivalent mass density in order to maintain sound insulation performance. In this paper, an evaluation of a material effect on noise has been examined.

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HDD용 압전형 마이크로엑츄에이터의 동특성 규명 (Dynamic Characterizations of a Piezoelectric Microactuator in Hard Disk Drive)

  • 김철순;김규용
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 추계학술대회논문집
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    • pp.232-236
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    • 2000
  • To provide model parameters for servo control system design, dynamic characteristics of a piezoelectric microactuator for hard disk drive(HDD) were investigated. At first frequency response characteristics was measured and a second order model was proposed. Here the amplitude dependent dynamic characteristics such as low frequency gain and damping ratio were studied. In addition, the load current and equivalent impedance of the piezoelectric actuator were measured by varying excitation voltage and frequency. At last, the super-harmonic resonance of the piezoelectric actuator was discussed.

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열린 균열이 있는 보의 효율적 모델링 방법 (An Efficient Modeling Method for Open Cracked Beam Structures)

  • Kim, M. D.;Park, S. W.;S. W. Hong;Lee, C. W.
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문초록집
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    • pp.372.2-372
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    • 2002
  • This paper presents an efficient modeling method fur open cracked beam structures. An equivalent bending spring model is introduced to represent the structural weakening effect in the presence of open cracks. The proposed method adopts the exact dynamic element method (EDEM) to avoid the difficulty and numerical errors in association with re-meshing the structure. The proposed method is rigorously compared with a commercial finite element code. (omitted)

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