Abstract. Reverse-time migration (RTM) of teleseismic converted and free-surface reflected phases has been successful in helping to constrain the structure of the crust and upper mantle, but its accuracy is to a large extent determined by the background velocity model used in the underlying wave propagation. To this end, we develop a technique for RTM based wave-equation reflection tomography i...

Hydrocarbon production modifies the stress conditions in the subsurface and changes the model parameters previously estimated from the prospect. The capability to remotely monitor the changes in the reservoir using seismic data has strategic importance since it allows us to infer fluid movement and evolution of stress conditions, which are key factors to enhance recovery and reduce uncertainty ...

Knowing how the solution to time-harmonic wave scattering problems depends on medium properties and boundary conditions is pivotal in wave-based inverse problems, e.g. for imaging. This paper devoted exposition of a computationally efficient method, called adjoint state that allows quantify influence media properties, directly through conditions, study acoustic, electromagnetic elastic waves. F...

Waveform inversion is a velocity model building technique based on full seismograms as the input and seismic wavefields as the information carrier. Conventional waveform inversion is implemented in the data-domain. Similar techniques can be formulated in the image domain, with seismic image as the input and seismic wavefields as the information carrier. The objective function for image-domain w...

Application of computational fluid dynamics to the optimization of aeroshell shapes usually entails high computational cost. Many converged solutions are required to generate gradients and optimize a shape with respect to very few design variables. The benefits of high-fidelity aerodynamic analysis can be reaped early in the design cycle with less computational cost if the traditional direct op...

This paper deals with mathematical issues relating to the computation of spectra of self adjoint operators on Hilbert spaces. We describe a general method for approximating the spectrum of an operator A using the eigenvalues of large finite dimensional truncations of A. The results of several papers are summarized which imply that the method is effective in most cases of interest. Special atten...

Polymer flooding is one of the most important technologies for enhanced oil recovery EOR . In this paper, an optimal control model of distributed parameter systems DPSs for polymer injection strategies is established, which involves the performance index as maximum of the profit, the governing equations as the fluid flow equations of polymer flooding, and some inequality constraints as polymer ...

This paper presents a continuous adjoint-based optimization theory for a general closed-loop transport hyperbolic model controlled via a periodic boundary control to minimize a multi-objective cost functional. The periodic boundary control is subject to a nonlinear differential equation constraint, thus resulting in a coupling between the hyperbolic equation and the ordinary differential equati...