• Title/Summary/Keyword: wave response

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Field measurements of natural periods of vibration and structural damping of wind-excited tall residential buildings

  • Campbell, S.;Kwok, K.C.S.;Hitchcock, P.A.;Tse, K.T.;Leung, H.Y.
    • Wind and Structures
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    • v.10 no.5
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    • pp.401-420
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    • 2007
  • Field measurements of the wind-induced response of two residential reinforced concrete buildings, among the tallest in the world, have been performed during two typhoons. Natural periods and damping values have been determined and compared with other field measurements and empirical predictors. Suitable and common empirical predictors of natural period and structural damping have been obtained that describe the trend of tall, reinforced concrete buildings whose structural vibrations have been measured in the collection of studies in Hong Kong compiled by the authors. This data is especially important as the amount of information known about the dynamic parameters of buildings of these heights is limited. Effects of the variation of the natural period and damping values on the alongwind response of a tall building for serviceability-level wind conditions have been profiled using the gust response factor approach. When using this approach on these two buildings, the often overestimated natural periods and structural damping values suggested by empirical predictors tended to offset each other. Gust response factors calculated using the natural periods and structural damping values measured in the field were smaller than if calculated using design-stage values.

Non-Response Imputation for Panel Data (패널자료의 무응답 대체법)

  • Pak, Gi-Deok;Shin, Key-Il
    • Communications for Statistical Applications and Methods
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    • v.17 no.6
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    • pp.899-907
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    • 2010
  • Several non-response imputation methods are suggested, however, mainly cross-sectional imputations are studied and applied to this analysis. A simple and common imputation method for panel data is the cross-wave regression imputation or carry-over imputation as a special case of cross-wave regression imputation. This study suggests a multiple imputation method combined time series analysis and cross-sectional multiple imputation method. We compare this method and the cross-wave regression imputation method using MSE, MAE, and Bias. The 2008 monthly labor survey data is used for this study.

Effects of Dynamic Soil Behaviour on Wave-Induced Seabed Response

  • Cha, D.H;Jeng, D.S;Rahman, M.S.;Sekiguchi, H.;Zen, K.;Yamazaki, H.
    • Journal of Ocean Engineering and Technology
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    • v.16 no.5
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    • pp.21-33
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    • 2002
  • In this paper, an analytical solution for the wave-induced seabed response in a porous seabed is derived. Unlike previous investigations with quasi-static soil behaviour, dynamic soil behaviour is considered in the new solution. The basic one-dimensional framework proposed by Zienkiewicz et al (1980) is extended to two-dimensional cases. Based on the analytical solution derived, the effects of dynamic soil behaviour on the wave-induced seabed response are examined. The boundary of quasi-static soil behaviour and dynamic soil behaviour is clarified, and formulated for engineering practice.

Response analysis of 5 vitals relation to meridian by Stimulus of sound wave based on 5 tones. (5음기준 음파자극에 따른 5장관련 경락의 반응분석)

  • 김용진;정동명;이봉구;손인철
    • Proceedings of the IEEK Conference
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    • 2000.06e
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    • pp.99-102
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    • 2000
  • This study analyze of reflection wave to Acoustic stimulation on acupoints and contrast parts for objectification of the meridian substance. In order to verify meridian pathway and channel theory of bio-energy in body. It was analyzed response characteristic of reflection waves after acoustic stimulation by sound wave of 5 specific tones. The response characteristics of reflection are measured by the average current magnitude of meridian. The current variation ratio are Live Meridian(gung) 33.2%, Heart Meridian(sang) 30.7%, Kidney Meridian (gak) 33.1%, Spleen Meridian(chi) 33.9%, Lung Meridian (wo) 30.7% compare with contrast parts (non-acupoint and meridian). Therefore meridian is distinguished to non-meridian and 5 vital meridians have relationship with sound wave of 5 specific tones.

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Theoretical analysis of transient wave propagation in the band gap of phononic system

  • Lin, Yi-Hsien;Ma, Chien-Ching
    • Interaction and multiscale mechanics
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    • v.6 no.1
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    • pp.15-29
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    • 2013
  • Phononic system composed of periodical elastic structures exhibit band gap phenomenon, and all elastic wave cannot propagate within the band gap. In this article, we consider one-dimensional binary materials which are periodically arranged as a 20-layered medium instead of infinite layered system for phononic system. The layered medium with finite dimension is subjected to a uniformly distributed sinusoidal loading at the upper surface, and the bottom surface is assumed to be traction free. The transient wave propagation in the 20-layered medium is analyzed by Laplace transform technique. The analytical solutions are presented in the transform domain and the numerical Laplace inversion (Durbin's formula) is performed to obtain the transient response in time domain. The numerical results show that when a sinusoidal loading with a specific frequency within band gap is applied, stress response will be significantly decayed if the receiver is away from the source. However, when a sinusoidal force with frequency is out of band gap, the attenuation of the stress response is not obvious as that in the band gap.

Application of the Weak-Scatterer Hypothesis to the Wave-Body Interaction Problems

  • Kim, Yong-hwan;Sclavounos, Paul-D.
    • Journal of Ship and Ocean Technology
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    • v.4 no.2
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    • pp.1-12
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    • 2000
  • The present study concentrates on the weak-scatterer hypothesis for the nonlinear wave-body interaction problems. In this method, the free surface boundary conditions are linearized on the incoming wave profile and the exact body motion is applied. The considered problems are the diffraction problem near a circular cylinder and the ship response in oblique waves. The numerical method of solution is a Rankine panel method. The Rankine panel method of this study adopts the higher-order B spline basis function for the approximation of physical variables. A modified Euler scheme is applied for the time stepping, which has neutral stability. The computational result shows some nonlinear behaviors of disturbance waves and wave forces. Moreover, the ship response shows very close results to experimental data.

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Effects of Dynamic Soil Behaviour on Wave-Induced Seabed Response

  • Cha, D.H.;Jeng, D.S.;Rahman, M.S.;Sekiguchi, H.;Zen, K.;Yamazaki, H.
    • International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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    • v.5 no.1
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    • pp.1-13
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    • 2002
  • In this paper, an analytical solution for the wave-induced seabed response in a porous seabed is derived. Unlike previous investigations with quasi-static soil behaviour, dynamic soil behaviour is considered in the new solution. The basic one-dimensional framework proposed by Zienkiewicz et al (1980) is extended to two-dimensional cases. Based on the analytical solution derived, the effects of dynamic soil behaviour on the wave-induced seabed response are examined. The boundary of quasi-static soil behaviour and dynamic soil behaviour is clarified, and formulated for engineering practice.

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Influence of shear preload on wave propagation in small-scale plates with nanofibers

  • Farajpour, M.R.;Shahidi, A.R.;Farajpour, A.
    • Structural Engineering and Mechanics
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    • v.70 no.4
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    • pp.407-420
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    • 2019
  • In the present work, an attempt is made to explore the effects of shear in-plane preload on the wave propagation response of small-scale plates containing nanofibers. The small-scale system is assumed to be embedded in an elastic matrix. The nonlocal elasticity is utilized in order to develop a size-dependent model of plates. The proposed plate model is able to describe both nanofiber effects and the influences of being at small-scales on the wave propagation response. The size-dependent differential equations are derived for motions along all directions. The size-dependent coupled equations are solved analytically to obtain the phase and group velocities of the small-scale plate under a shear in-plane preload. The effects of this shear preload in conjunction with nanofiber and size effects as well as the influences of the elastic matrix on the wave propagation response are analyzed in detail.

Study on seismic performance of steel frame with archaized-style under pseudo-dynamic loading

  • Liu, Zuqiang;Zhou, Chaofeng;Xue, Jianyang
    • Earthquakes and Structures
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    • v.17 no.1
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    • pp.39-48
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    • 2019
  • This paper presents an experimental study on a 1/2 scale steel frame with archaized-style under the pseudo-dynamic loading. Four seismic waves, including El Centro wave, Taft wave, Lanzhou wave and Wenchuan wave, were input during the test. The hysteresis characteristic, energy dissipation acceleration response, displacement response, strength, stiffness and strain were analyzed. Based on the experiment, the elastoplastic dynamic time-history analysis was carried out with the software ABAQUS. The stress distribution and failure mode were obtained. The results indicate that the steel frame with archaized-style was in elastic stage when the peak acceleration of input wave was no more than 400 gal. Under Wenchuan wave with peak acceleration of 620 gal, the steel frame enters into the elastoplastic stage, the maximum inter-story drift was 1/203 and the bearing capacity still tended to increase. During the loading process, Dou-Gong yielded first and played the role of the first seismic fortification line, and then beam ends and column bottom ends yielded in turn. The steel frame with archaized-style has good seismic performance and meets the seismic design requirement of Chinese code.

Response State of EEG Wave Type on Visual Cortex According to Color Vision Target (색각 시표에 따른 시피질 뇌파의 반응 상태)

  • Kim, Douk Hoon
    • Journal of Korean Ophthalmic Optics Society
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    • v.5 no.2
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    • pp.5-9
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    • 2000
  • The visual evoked potential was electrophysiological method for the identify of the EEG response on visual cortex. This test was objective test method on the eye function. This study was used the visual evoked potential for the objective color test. The subjects was a normal color function in Korean adults. The test condition was performed on the differens distance and illumination. According to convergence condition of color vision target. On the appearance of EEG wave of visual stimulation on visual cortex. The most EEG wave style was delta wave, and the next amount wave form was beta wave and theta wave, and the least EEG wave form was alpha wave. The histogram of amplitude of EEG wave form was almost non-Gaussian shape, and the phase diagram of amplitude was almost all linear shape. On the kinds of color vision target, the frequency of EEG wave style appeared a similar results.

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