• Title/Summary/Keyword: noise energy

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Free Vibration and Dynamic Stability of the Axially Moving Continuum with Time-varying Length (축방향으로 이동하며 길이가 변하는 연속체의 자유 진동 및 동적 안정성)

  • 사재천;이민형;이승엽
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.4
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    • pp.272-279
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    • 2002

  • The time-dependent frequency and energy of free vibration of the spagetti problem, that is the axially moving continuum with time-varying length, are investigated. Exact expressions for the natural frequency and time-varying vibration energy are derived by dealing with traveling waves. The vibration period increases with increasing length, but the free vibration energy decreases. When the string undergoes retraction, the vibration energy increases with time. The free response of the time-varying string is represented by superposing two traveling waves.

  • https://doi.org/10.5050/KSNVN.2002.12.4.272 인용 PDF KSCI

Vibration-based Energy Harvester for Wireless Condition Monitoring System (무선 상태감시 시스템용 진동 기반 에너지 획득 장치)

  • Cho, Sung-Won;Son, Jong-Duk;Yang, Bo-Suk;Choi, Byeong-Keun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.4
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    • pp.393-399
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    • 2009

  • Historically, industrial condition monitoring has been performed by costly hard-wired sensors or infrequent checks by maintenance personnel equipped with hand held monitoring equipment. Self- powered wireless condition monitoring systems provides on-line monitoring of critical plant and machinery providing major operating cost benefits. A vibration energy harvester(VEH) is a device that converts kinetic energy occurred by machine vibration into useable electrical energy. Using VEHs to power wireless monitoring systems can yield significant benefits: increased reliability, lower life time costs and no battery disposal issues, etc. This paper proposes the novel prototype design and manufacturing of a VEH that can eliminate the effect by failed batteries.

  • https://doi.org/10.5050/KSNVN.2009.19.4.393 인용 PDF KSCI