S U M M A R YPassive seismic interferometry is a new promising methodology for seismic exploration. Interferometry allows information about the subsurface structure to be extracted from ambient seismic noise. In this study, we apply the cross-correlation technique to approximately 25 hr of recordings of ambient seismic noise at the Ketzin experimental CO 2 storage site, Germany. Common source gathers were generated from the ambient noise for all available receivers along two seismic lines by cross-correlation of noise records. This methodology isolates the interstation Green's functions that can be directly compared to active source gathers. We show that the retrieved response includes surface waves, refracted waves and reflected waves. We use the dispersive behaviour of the retrieved surface waves to infer geological properties in the shallow subsurface and perform passive seismic imaging of the subsurface structure by processing the retrieved reflected waves.

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Optimization of the control strategy plays an important role in improving the performance of electric vehicles. In order to improve the braking stability and recover the braking energy, a multi-objective genetic algorithm is applied to optimize the key parameters in the control strategy of electric vehicle electro-hydraulic composite braking system. Various limitations are considered in the optimization process, and the optimization results are verified by a software simulation platform of electric vehicle regenerative braking system in typical brake conditions. The results show that optimization objectives achieved a good astringency, and the optimized control strategy can increase the brake energy recovery effectively under the condition of ensuring the braking stability.

implemented layer by layer (Robinson, 1979;Bano, 1996). These phase inverse Q-filter algorithms can be used to eliminate the phase distortion caused by velocity dispersion and are stable without conditions (Robinson, 1979 and1982;Bickel and Natarajan, 1985) but the amplitude effect due to energy attenuation was neglected. Moreover, the amplitude compensation operator is an exponential function of frequency and traveltime. As a result, for deeper layers, the inverse Q-filter amplifies the noise level causing instability in the seismic band and undesirable artifacts in the solution (Wang, 2002;Zhang, 2006). Wang (2002) proposed a gain-limited inverse Q-filter amplitude compensation operator. This algorithm controls the inverse Q-filter noise from different depths by choosing a Q-dependent time-variant frequency threshold. However, using empirical formulas, it is difficult to approach the true time-variant threshold frequency.In this paper, we present a stable wavefield continuation approach to inverse Q-filtering assuming the subsurface media to be a layered-earth Q model. For each individual