Blar i Institutt for matematiske fag på forfatter "Fjeldstad, Torstein Mæland"
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A Bayesian model for lithology/fluid class prediction using a Markov mesh prior fitted from a training image
Tjelmeland, Håkon; Luo, Xin; Fjeldstad, Torstein Mæland (Journal article; Peer reviewed, 2019)We consider a Bayesian model for inversion of observed amplitude variation with offset data into lithology/fluid classes, and study in particular how the choice of prior distribution for the lithology/fluid classes influences ... -
Bayesian Inversion and Inference of Categorical Markov Models with Likelihood Functions Including Dependence and Convolution
Fjeldstad, Torstein Mæland (Master thesis, 2015)A convolutional two-level Markov model is studied in this thesis. The bottom level contains a latent Markov chain, and given the variables, the middle contains a latent Gaussian random field. We observe the second level ... -
Bayesian Inversion of Convolved Hidden Markov Models With Applications in Reservoir Prediction
Fjeldstad, Torstein Mæland; Omre, Henning (Peer reviewed; Journal article, 2019)The efficient assessment of convolved hidden Markov models is discussed. The bottom layer is defined as an unobservable categorical first-order Markov chain, whereas the middle layer is assumed to be a Gaussian spatial ... -
Spatial Gaussian Mixture Models Applied to Bayesian Seismic Inversion
Fjeldstad, Torstein Mæland (Doctoral theses at NTNU;2020:181, Doctoral thesis, 2020)Summary Stochastic reservoir characterization of a subsurface is the process of creating a quantitative model of the subsurface based on various geophysical measurements to predict the occurrence of hydrocarbons such as ...