Study on the attenuation of inelastic response spectra
To study the characteristics of inelastic response spectra,an attenuation relationship is established for inelastic response spectra involving earthquake magnitude,source-to-site distance,and site class based on 266 strong ground motion records which collected from 15 strong earthquakes in California of America.The effects of parameters such as magnitude,site class and ductility factor on inelastic response spectra are discussed.It is found that the inelastic response spectra increase with the increasing of magnitude and softening of site,but decrease with the increasing of ductility factor.The inelastic response spectra attenuate quickly with the increasing of distance.
We consider a classic scheduling problem for optimally allocating a resource to multiple competing users and place it in the framework of Stochastic Flow Models (SFMs). We derive Infinitesimal Perturbation Analysis (IPA) gradient estimators for the average holding cost with respect to resource allocation parameters. These estimators are easily obtained from a sample path of the system without any knowledge of the underlying stochastic process characteristics. Exploiting monotonicity properties of these IPA estimators, we prove the optimality of the well-known cμ-rule for an arbitrary finite number of queues and stochastic processes under non-idling policies and linear holding costs. Further, using the IPA derivative estimates obtained along with a gradient-based optimization algorithm, we find optimal solutions to similar problems with nonlinear holding costs extending current results in the literature.