Stochastic process acceleration model

The acceleration is modeled as stochastic process defined as filtered white noise. With respect to Equation 8,... 

In order to illustrate the application of the procedure for failure probability sensitivity estimation, the following example is considered. It involves a two-story reinforced cmicrete (RC) frame which includes nmilinear hysteretic devices (NLDs). Figure 1 illustrates the elevation of the model. The frame is excited by a horizontal ground acceleration of 15 [s] duration, which is modeled as a stochastic process. The failure event... 

In general the method of confidence intervals (Zacks, 1971, Ch. 10) may be suggested for approaching a problem of this kind. As it follows from the nature of the stochastic model, an increase in input load of phosphorus does not necessarily lead to an acceleration of the eutrophication process. The same input load, however, may lead to a major increase in algae biomass (as was probably the case in 1982). 

To simulate the slow-pressure phenomena, a stochastic mixing and reorientation model can be used. It describes the dissipation and the observed tendency of the Reynolds stresses to become isotropic. The stochastic mixing model is similar to that used for the scalar dissipation, whereas the reorientation process is described in analogy with collisions between Maxwellian molecules, i.e., conserving both momentum and energy. Pope [1985] developed an alternative model for the conditional acceleration term, based on the generalized Langevin model. 

The following sections are devoted to the review of the most relevant models of ground motion acceleration processes aimed to satisfy the code requirements. Namely, the stationary, quasi-stationary, and fully nonstationary as well as spatially variable stochastic spectrum-compatible ground motion will be discussed. 

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