• Title/Summary/Keyword: frequency-altered feedback

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Stuttering Reduction Rate during Sentence Reading: Choral Speech and Altered Auditory Feedback (문장읽기에서의 말더듬 감소율: 합독과 변조청각피드백)

  • Park, Jin;Park, Heeyoung
    • Phonetics and Speech Sciences
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    • v.4 no.4
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    • pp.109-115
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    • 2012
  • This paper mainly aims to investigate how differently choral speech and altered auditory feedback (i.e., delayed auditory feedback, frequency-altered feedback) enhance speech fluency during sentence reading. To do this, a stuttering reduction rate was used and measured how much stuttering in frequency was reduced during each of the fluency enhancing conditions (i.e, typical choral reading, DAF, FAF) relative to typical solo reading. The results showed that stuttering frequency was reduced in the three fluency enhancing conditions and the highest mean value in stuttering reduction rate was observed during typical choral reading. Some discussion was provided in relation to the stuttering reduction rate observed during typical choral reading and its further speculation.

Experimental verification of leverage-type stiffness-controllable tuned mass damper using direct output feedback LQR control with time-delay compensation

  • Chu, Shih-Yu;Yeh, Shih-Wei;Lu, Lyan-Ywan;Peng, Chih-Hua
    • Earthquakes and Structures
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    • v.12 no.4
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    • pp.425-436
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    • 2017
  • Vibration control using a tuned mass damper (TMD) is an effective technique that has been verified using analytical methods and experiments. It has been applied in mechanical, automotive, and structural applications. However, the damping of a TMD cannot be adjusted in real time. An excessive mass damper stroke may be introduced when the mass damper is subjected to a seismic excitation whose frequency content is within its operation range. The semi-active tuned mass damper (SATMD) has been proposed to solve this problem. The parameters of an SATMD can be adjusted in real time based on the measured structural responses and an appropriate control law. In this study, a stiffness-controllable TMD, called a leverage-type stiffness-controllable mass damper (LSCMD), is proposed and fabricated to verify its feasibility. The LSCMD contains a simple leverage mechanism and its stiffness can be altered by adjusting the pivot position. To determine the pivot position of the LSCMD in real time, a discrete-time direct output-feedback active control law that considers delay time is implemented. Moreover, an identification test for the transfer function of the pivot driving and control systems is proposed. The identification results demonstrate the target displacement can be achieved by the pivot displacement in 0-2 Hz range and the control delay time is about 0.1 s. A shaking-table test has been conducted to verify the theory and feasibility of the LSCMD. The comparisons of experimental and theoretical results of the LSCMD system show good consistency. It is shown that dynamic behavior of the LSCMD can be simulated correctly by the theoretical model and that the stiffness can be properly adjusted by the pivot position. Comparisons of experimental results of the LSCMD and passive TMD show the LSCMD with less demand on the mass damper stroke than that for the passive TMD.