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seismic-activity
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Anomalous fluctuations of vertical velocity of Earth and their possible implications for earthquakes
, Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 82, Issue 3 , September , 2010 ; 15393755 (ISSN) ; Ghasemi, F ; Matsumoto, T ; Gómez, J ; Sahimi, M ; Peinke, J ; Pacheco, A. F ; Rahimi Tabar, M. R ; Sharif University of Technology
2010
Abstract
High-quality measurements of seismic activities around the world provide a wealth of data and information that are relevant to understanding of when earthquakes may occur. If viewed as complex stochastic time series, such data may be analyzed by methods that provide deeper insights into their nature, hence leading to better understanding of the data and their possible implications for earthquakes. In this paper, we provide further evidence for our recent proposal for the existence of a transition in the shape of the probability density function (PDF) of the successive detrended increments of the stochastic fluctuations of Earth's vertical velocity Vz, collected by broadband stations before...
Retrofit of Ressalat jacket platform (Persian Gulf) using friction damper device
, Article Journal of Zhejiang University: Science A ; Volume 12, Issue 9 , 2011 , Pages 680-691 ; 1673565X (ISSN) ; Tabeshpour, M. R ; Golafshani, A. A ; Mualla, I ; Sharif University of Technology
Abstract
A friction damper device (FDD) is used for vibration control of an existing steel jacket platform under seismic excitation. First, the damping is presented for vibration mitigation of structures located in seismically active zones. A new method for quick design of friction or yielding damping devices is presented. The effectiveness of the damping system employing such FDDs in a jacket platform is evaluated numerically. The influence of key parameters of the damping system on the vibration suppression of the offshore structure is studied in detail. To examine the vibration control effectiveness of the FDD for the jacket platform, performance of the controlled structure under the seismic...