Blar i Bergen Open Research Archive på forfatter "Eikrem, Kjersti Solberg"

Viser treff 1-5 av 5

    • 3-D induction log modelling with integral equation method and domain decomposition pre-conditioning 

      Saputera, Durra Handri; Jakobsen, Morten; van Dongen, Koen W. A.; Jahani, Nazanin; Eikrem, Kjersti Solberg; Alyaev, Sergey (Journal article; Peer reviewed, 2024)
      The deployment of electromagnetic (EM) induction tools while drilling is one of the standard routines for assisting the geosteering decision-making process. The conductivity distribution obtained through the inversion of ...

    • Homotopy method for seismic modeling in strongly scattering acoustic media with density variation 

      Xiang, Kui; Jakobsen, Morten; Eikrem, Kjersti Solberg; Nævdal, Geir (Journal article; Peer reviewed, 2020)
      The wave equation for acoustic media with variable density and velocity can be transformed into an integral equation of the Lippmann-Schwinger type; but for a 4-dimensional state vector involving the gradient of the pressure ...

    • Homotopy scattering series for seismic forward modelling with variable density and velocity 

      Xiang, Kui; Eikrem, Kjersti Solberg; Jakobsen, Morten; Nævdal, Geir (Journal article; Peer reviewed, 2021)
      We have derived a convergent scattering series solution for the frequency-domain wave equation in acoustic media with variable density and velocity. The convergent scattering series solution is based on the homotopy analysis ...

    • A matrix-free variant of the distorted Born iterative method for seismic full-waveform inversion 

      Xiang, Kui; Jakobsen, Morten; Eikrem, Kjersti Solberg; Nævdal, Geir (Journal article; Peer reviewed, 2023)
      The distorted Born iterative method reduces a nonlinear inverse scattering problem to a sequence of (ill-posed) linear inverse scattering problems that can be solved using a regularized least-squares formulation. This ...

    • Non-Gaussian Ensemble Optimization 

      Nilsen, Mathias Methlie; Stordal, Andreas Størksen; Raanes, Patrick Nima; Lorentzen, Rolf Johan; Eikrem, Kjersti Solberg (Journal article; Peer reviewed, 2024)
      Ensemble-based optimization (EnOpt), commonly used in reservoir management, can be seen as a special case of a natural evolution algorithm. Stein’s lemma gives a new interpretation of EnOpt. This interpretation enables us ...