Abstract. Strong ground motions of near-fault earthquakes are mostly generated by forward-directivity effects. Forward-directivity effects develop energetic pulses particularly in horizontal velocity history of fault-normal component. The narrow-band nature of the pulses results in revealing at least two peaks on the response spectra and also increasing seismic demand especially for mid-rise and high-rise buildings.Iranian seismic code (IS 2800-14) presents the coefficient N, for considering near-fault effects. It seems that the N is not efficient for designing in near-fault zone. The accurate near-fault demands can be determined by using nonlinear response history analyses. In the present paper, two 3-D reinforced concrete framed structures (RC buildings) are designed according to ACI 2014 and IS 2800-14. Then, the demands are estimated by employing linear response history analysis (LRHA) and also nonlinear response history analysis (NRHA) under an ensemble of 11 near-fault ground motions. The results reveal that the design spectrum of IS 2800-14 is incompatible with near-fault spectra and underestimates demands in the long periods range. Further, implementation of LRHA using response modification factor (R u ) and deflection amplification factor (C d ) leads to insufficient inter-story drift ratios. Finally, the 2 influence of enhancing ductility is studied by determining ductility reduction factors for near-fault records.
In this paper we are going to estimate domain of attraction of tumor-free equilibrium points in a perturbed cancer tumor model which is describing the tumor-immune system competition dynamics. The proposed method is based on solving an optimization problem for a chosen Lyapunov function that can be casted in terms of Linear Matrix Inequalities constraint and Taylor expansion of nonlinear terms. We will find a specific Lyapunov function in order to vanishing maximum perturbation of modeling error, aging or uncertainties which exist in this system. Using this method and appropriate Lyapunov function, we demonstrate there is an invariant polytope that for the set of perturbed initial conditions which belongs to such region, the convergence to the healthy state is guaranteed.
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