Browsing Department of Mathematics by Title
Now showing items 258-277 of 978
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A Fast Continuous Max-Flow Approach to Non-Convex Multilabeling Problems
(Working paper, 2011)This work addresses a class of multilabeling problems over a spatially continuous image domain, where the data fidelity term can be any bounded function, not necessarily convex. Two total variation based regularization ... -
Fast Image Segmentation Using Variational Optimization Methods With Edge Detector
(Master thesis, 2014-06-02)In this work, we apply techniques in variational optimization to image segmentation. We study three different segmentation models: one is based on the active contour method, the second is based on a piecewise constant level ... -
A fast Level Set Method for Reservoir Simulation
(Department of Applied Mathematics report, Research report, 1999-05) -
Fast robust optimization using bias correction applied to the mean model
(Peer reviewed; Journal article, 2021)Ensemble methods are remarkably powerful for quantifying geological uncertainty. However, the use of the ensemble of reservoir models for robust optimization (RO) can be computationally demanding. The straightforward ... -
Feasibility of simplified integral equation modeling of low-frequency marine CSEM with a resistive target
(Peer reviewed; Journal article, 2009)We have assessed the accuracy of a simplified integral equation (SIE) modeling approach for marine controlledsource electromagnetics (CSEM) with low applied frequencies and a resistive target. The most computationally ... -
Field-case simulation of CO2-plume migration using vertical-equilibrium models
(Peer reviewed; Journal article, 2011)When injected in deep saline aquifers, CO2 moves radially away from the injection well and progressively higher in the formation because of buoyancy forces. Analyzes have shown that after the injection period, CO2 will ... -
Field-scale impacts of long-term wettability alteration in geological CO2 storage
(Journal article; Peer reviewed, 2022)Constitutive functions that govern macroscale capillary pressure and relative permeability are central in constraining both storage efficiency and sealing properties of storage systems. Constitutive functions for porous ... -
A finite mixture analysis of structural breaks in the G-7 gross domestic product series
(Journal article; Peer reviewed, 2023)In this paper we apply a clustering procedure to detect trend changes in macroeconomic data, focusing on the GDP time series for the G-7 countries. A finite mixture of regression models is considered to show different ... -
Finite volume discretization for poroelastic media with fractures modeled by contact mechanics
(Peer reviewed; Journal article, 2020)A fractured poroelastic body is considered where the opening of the fractures is governed by a nonpenetration law, whereas slip is described by a Coulomb‐type friction law. This physical model results in a nonlinear ... -
Finite volume hydromechanical simulation in porous media
(Peer reviewed; Journal article, 2014-05-27)Cell-centered finite volume methods are prevailing in numerical simulation of flow in porous media. However, due to the lack of cell-centered finite volume methods for mechanics, coupled flow and deformation is usually ... -
Finite volume methods for elasticity with weak symmetry
(Peer reviewed; Journal article, 2017-11)We introduce a new cell‐centered finite volume discretization for elasticity with weakly enforced symmetry of the stress tensor. The method is motivated by the need for robust discretization methods for deformation and ... -
Finite-Element Modelling of Buoyancy-Driven Flow in Natural Geothermal Systems
(Master thesis, 2010-05-27)Finite element modelling of buoyancy driven flow in geothermal systems is presented in this thesis. The main focus is on the development of a numerical modelling tool. The program developed is tested for classical benchmarks ... -
A Finite-Volume-Based Module for Unsaturated Poroelasticity
(Chapter, 2021)In this chapter, we present fv-unsat, a multipoint finite-volume–based solver for unsaturated flow in deformable and nondeformable porous media. The latter is described using the mixed form of Richards’ equation, whereas ... -
Fish louse and treatment options: A mathematical approach
(Master thesis, 2018-09-04) -
The Fixed-Stress splitting scheme for Biot's equations as a modified Richardson iteration: Implications for optimal convergence
(Journal article; Peer reviewed, 2021)The fixed-stress splitting scheme is a popular method for iteratively solving the Biot equations. The method successively solves the flow and mechanics subproblems while adding a stabilizing term to the flow equation, which ... -
Flexible and rigorous numerical modelling of multiphysics processes in fractured porous media using PorePy
(Journal article; Peer reviewed, 2024)Multiphysics processes in fractured porous media is a research field of importance for several subsurface applications and has received considerable attention over the last decade. The dynamics are characterized by strong ... -
Flow in Fractured Porous Media: A Review of Conceptual Models and Discretization Approaches
(Peer reviewed; Journal article, 2019)The last decade has seen a strong increase of research into flows in fractured porous media, mainly related to subsurface processes but also in materials science and biological applications, as connected fractures can ... -
The Flow of Quasiconformal Mappings on S³ with Contact structure and a Family of Surfaces on the Heisenberg Group
(Master thesis, 2011-05-31) -
Flow Properties of Fully Nonlinear Model Equations for Surface Waves
(Doctoral thesis, 2017-11-03)The focus of this thesis is wave motion in shallow water. In particular, we investigate some properties of flows underneath long waves in shallow water and present the results in two parts. The first part contains a ... -
The FluidFlower Validation Benchmark Study for the Storage of CO2
(Journal article; Peer reviewed, 2023)Successful deployment of geological carbon storage (GCS) requires an extensive use of reservoir simulators for screening, ranking and optimization of storage sites. However, the time scales of GCS are such that no sufficient ...