Amplification Factor

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Ahmed Maarouf - One of the best experts on this subject based on the ideXlab platform.

  • Deflection Amplification Factor for Seismic Design Provisions
    Journal of Structural Engineering-asce, 1994
    Co-Authors: Chia-ming Uang, Ahmed Maarouf
    Abstract:

    Seismic design provisions estimate the maximum roof and story drifts occurring in major earthquakes by amplifying the drifts computed from elastic analysis at the prescribed design seismic force level with a deflection Amplification Factor (DAF). A comparison of several seismic design provisions indicated that the deflection Amplification Factor in both the UBC and NEHRP Recommended Provisions, being equal to 3Rw/8 and Cd, respectively, is very low and could lead to unconservative drift estimations. An analytical study of the seismic responses of four instrumented buildings confirmed that drifts developed in major earthquakes are much higher than those predicted by the UBC or NEHRP approach. It is recommended that the deflection Amplification Factor be increased to at least the seismic force reduction Factor (Rw in UBC and R in NEHRP) for estimating maximum drifts. The effects of the ratio between building period and earthquake predominant period, types of yield mechanisms, and structural overstrength on ...

  • Displacement Amplification Factor for Seismic Design Provisions
    Structural Engineering in Natural Hazards Mitigation, 1993
    Co-Authors: Chia-ming Uang, Ahmed Maarouf
    Abstract:

    To estimate the maximum roof and story drifts occurring during severe earthquakes, the UBC and NEHRP use 3R w /8 and C d respectively as the displacement Amplification Factor (DAF) to amplify elastic design drifts. A comparison of several seismic design codes shows that both the UBC and NEHRP's DAF are very low. A study conducted on seismic response of four instrumented buildings indicates that maximum drifts developed in severe earthquakes are much higher than those predicted by UBC and NEHRP. Recommended DAF values for building frames are presented.

K. Chung - One of the best experts on this subject based on the ideXlab platform.

  • Tube diameter effect on deflagration-to-detonation transition of propane–oxygen mixtures
    Shock Waves, 2006
    Co-Authors: J. Li, K. Chung
    Abstract:

    An experimental study was conducted to study the tube diameter effect on deflagration- to-detonation run-up distance. The tube diameter effect is associated with the Amplification Factor, flame acceleration and heat loss. A simplified correlation of the run-up distance and tube diameter is proposed for the fuel-lean, stoichiometric and slight fuel-rich mixtures. The Amplification Factor, which is evaluated from the initial conditions of the propane–oxygen mixtures, might also be used to get a quick estimation of the run-up distance in tubes of larger diameter.

  • tube diameter effect on deflagration to detonation transition of propane oxygen mixtures
    Shock Waves, 2006
    Co-Authors: J. Li, K. Chung
    Abstract:

    An experimental study was conducted to study the tube diameter effect on deflagration- to-detonation run-up distance. The tube diameter effect is associated with the Amplification Factor, flame acceleration and heat loss. A simplified correlation of the run-up distance and tube diameter is proposed for the fuel-lean, stoichiometric and slight fuel-rich mixtures. The Amplification Factor, which is evaluated from the initial conditions of the propane–oxygen mixtures, might also be used to get a quick estimation of the run-up distance in tubes of larger diameter.

David J. Love - One of the best experts on this subject based on the ideXlab platform.

  • On the Optimal Delay Amplification Factor of Multi-Hop Relay Channels
    2019 IEEE International Symposium on Information Theory (ISIT), 2019
    Co-Authors: Dennis Ogbe, Chih-chun Wang, David J. Love
    Abstract:

    The abstract model of the multi-hop relay channel is fundamental to a vast variety of modern communication systems. This fact, coupled with the demand for ultra-reliable-low-latency communication (URLLC), motivates a new investigation of relay channels from a delay-vs-throughput perspective. This work seeks to analyze this tradeoff in the regime of asymptotically large, yet still finite delay. A new metric called the Delay Amplification Factor (DAF) is introduced, which allows analytic comparison of the asymptotic delay across different relay solutions, e.g. decode-&-forward (DF), compress-&-forward, etc. The optimal DAF (over all possible existing/future designs) is then characterized for two special settings, one with fixed-length coding and one with variable-length coding and 1-bit stop feedback. The results show that under some general conditions, the optimal end-to-end delay over an L-hop line network is asymptotically comparable to the delay over the single bottleneck hop, and it does not grow linearly with respect to L. The linearly growing delay penalty commonly encountered in DF and other schemes is thus an artifact rather than a fundamental limit of multi-hop relay communication.

Haiying Yu - One of the best experts on this subject based on the ideXlab platform.

  • Study on real-time correction of site Amplification Factor
    Natural Hazards and Earth System Sciences, 2019
    Co-Authors: Qiang Ma, Jingfa Zhang, Haiying Yu
    Abstract:

    Abstract. The site Amplification Factor was usually considered to be scalar values, such as Amplification of peak ground acceleration or peak ground velocity, or increments of seismic intensity in the earthquake early warning (EEW) system or seismic-intensity repaid report system. This paper focuses on evaluating an infinite impulse recursive filter method that could produce frequency-dependent site Amplification and compare the performance of the scalar-value method with the infinite impulse recursive filter method. A large number of strong motion data of IBRH10 and IBRH19 of the Kiban Kyoshin network (KiK-net) triggered in more than 1000 earthquakes from 2004 to 2012 were selected carefully and used to obtain the relative site Amplification ratio; we model the relative site Amplification Factor with a casual filter. Then we make a simulation from the borehole to the surface and also simulate from the front-detection station to the far-field station. Compared to different simulation cases, it can easily be found that this method could produce different Amplification Factors for different earthquakes and could reflect the frequency-dependent nature of site Amplification. Through these simulations between two stations, we can find that the frequency-dependent correction for site Amplification shows better performance than the Amplification Factor relative to velocity (ARV) method and station correction method. It also shows better performance than the average level and the highest level of the Japan Meteorological Agency (JMA) earthquake early warning system in ground motion prediction. Some cases in which simulation did not work very well were also found; possible reasons and problems were analyzed and addressed. This method pays attention to the amplitude and ignores the phase characteristics; this problem may be improved by the seismic-interferometry method. Frequency-dependent correction for site Amplification in the time domain highly improves the accuracy of predicting ground motion in real time.

  • Study on Site Amplification Factor Correction for Earthquake Early Warning System
    Natural Hazards and Earth System Sciences, 2019
    Co-Authors: Qiang Ma, Jingfa Zhang, Haiying Yu
    Abstract:

    Abstract. The site Amplification Factor was usually considered as scalar values, such as Amplification of peak ground acceleration or peak ground velocity, increments of seismic intensity in the conventional earthquake early warning system. This paper focus on evaluation of infinite impulse recursive filter method that could produce frequency-dependent site Amplification and compare the performance of the scalar value method with the infinite impulse recursive filter method. Firstly, the strong motion data of IBRH10 and IBRH19 of Kiban Kyoshin network (Kik-net)from 2004 to 2012 were processed and selected carefully. The relative spectral ratio of IBRH10 surface acceleration to IBRH10 borehole acceleration, the relative spectral ratio of IBRH19 surface acceleration to IBRH19 borehole acceleration, the relative spectral ratio the IBRH10 surface and borehole acceleration to the IBRH19 surface and borehole acceleration were calculated using the traditional spectral ratio method. Secondly, the relative spectral ratio were modelled using the infinite impulse recursive filter method. The simulated IBRH19 surface acceleration and Fourier spectrum were obtained by filtering the IBRH19 borehole data. The seismic intensity residual were calculated for both the observation and simulation data, it shows that 98.6 % of these seismic intensity residuals are less than 0.5, 100 % of these seismic intensity residuals are less than 1. Similarly, the simulated IBRH10 Surface acceleration and Fourier spectrum were obtained by filtering the IBRH19 surface acceleration time series. The seismic intensity residual were calculated for both the observation data and the simulation data. The statistical data shows that 69.7 % of these seismic intensity residuals are less than 0.5, 98.1 % of these seismic intensity residuals are less than 1. Through these comparisons, we can find that these simulations show better performance than the ARV method and station correction method. It also shows good performance than the average level and the highest level of all the 11 years Japan Meteorological Agency (JMA) earthquake early warning system. Thirdly, compare different simulation cases, it can be easily found that this method could produce different Amplification Factor for different earthquakes. It could produce the frequency-depend site Amplification Factor. It highly improve the situation that the scalar value site Amplification methods which could not produce different Amplification Factor for different earthquakes. This method pays attention to the amplitude and ignore the phase characteristic, this problem may be improved by the seismic interferometry method. This paper makes deep evaluation of the infinite impulse recursive filter method. Although there are some problems needed to consider carefully and solve, it shows good potential to be used in the future earthquake early warning systems for more accuracy modelling the site Amplification Factor.

Chia-ming Uang - One of the best experts on this subject based on the ideXlab platform.

  • Deflection Amplification Factor for Seismic Design Provisions
    Journal of Structural Engineering-asce, 1994
    Co-Authors: Chia-ming Uang, Ahmed Maarouf
    Abstract:

    Seismic design provisions estimate the maximum roof and story drifts occurring in major earthquakes by amplifying the drifts computed from elastic analysis at the prescribed design seismic force level with a deflection Amplification Factor (DAF). A comparison of several seismic design provisions indicated that the deflection Amplification Factor in both the UBC and NEHRP Recommended Provisions, being equal to 3Rw/8 and Cd, respectively, is very low and could lead to unconservative drift estimations. An analytical study of the seismic responses of four instrumented buildings confirmed that drifts developed in major earthquakes are much higher than those predicted by the UBC or NEHRP approach. It is recommended that the deflection Amplification Factor be increased to at least the seismic force reduction Factor (Rw in UBC and R in NEHRP) for estimating maximum drifts. The effects of the ratio between building period and earthquake predominant period, types of yield mechanisms, and structural overstrength on ...

  • Displacement Amplification Factor for Seismic Design Provisions
    Structural Engineering in Natural Hazards Mitigation, 1993
    Co-Authors: Chia-ming Uang, Ahmed Maarouf
    Abstract:

    To estimate the maximum roof and story drifts occurring during severe earthquakes, the UBC and NEHRP use 3R w /8 and C d respectively as the displacement Amplification Factor (DAF) to amplify elastic design drifts. A comparison of several seismic design codes shows that both the UBC and NEHRP's DAF are very low. A study conducted on seismic response of four instrumented buildings indicates that maximum drifts developed in severe earthquakes are much higher than those predicted by UBC and NEHRP. Recommended DAF values for building frames are presented.