Browsing Department of Mathematics by Title
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A Comparison of Two Numerical Models for Flow in Fractured Porous Media and the Impact of Fracture Intersection Cell Removal
(Master thesis, 20161121)The simulation of flow and transport in fractured porous media is crucial to improve understanding and viability of geothermal energy. It is also challenging, due to complex geometries and large scale differences. In this ... 
Compositional reservoir simulation with emphasis on the IMPSAT formulation
(Doctoral thesis, 20060407) 
Computeraided proofs and algorithms in analysis
(Doctoral thesis; Peer reviewed, 20130614)The computational power has increased dramatically since the appearance of the first computers, making them a vital tool in the analysis of dynamical systems. We present further applications of those two basic ideas, namely ... 
Computing the distance to continuoustime instability of quadratic matrix polynomials
(Journal article; Peer reviewed, 2020)A bisection method is used to compute lower and upper bounds on the distance from a quadratic matrix polynomial to the set of quadratic matrix polynomials having an eigenvalue on the imaginary axis. Each bisection step ... 
Conditioning reservoir models on vast data sets
(Doctoral thesis, 20210909)History matching is a valuable process to obtain better models and a more reliable forecast in oil reservoir applications. In such processes, one conditions the simulation models on the observed data from the field. One ... 
Conforming Discretizations of MixedDimensional Partial Differential Equations
(Doctoral thesis, 20180601)Mixeddimensional partial differential equations (PDEs) are coupled equations defined on connected manifolds of different dimensionalities. Two main examples of mixeddimensional PDEs are considered in this dissertation, ... 
Conforming, nonconforming and nonmatching discretization couplings in discrete fracture network simulations
(Peer reviewed; Journal article, 2019)Simulations of fluid flow in naturally fractured rocks have implications for several subsurface applications, including energy storage and extraction, and waste disposal. We are interested in flow in discrete fracture ... 
Consideration of measurement errors for the Norwegian common minke whale (Balaenoptera acutorostrata acutorostrata) surveys
(Journal article; Peer reviewed, 2021)A discrete measurement error model for radial distance and angle to detected objects in line transect surveys is considered. This approach directly quantifies the effect of measurement error on the estimated effective strip ... 
Considering sampling bias in closekin mark–recapture abundance estimates of Atlantic salmon
(Journal article; Peer reviewed, 2021)Genetic methods for the estimation of population size can be powerful alternatives to conventional methods. Closekin mark–recapture (CKMR) is based on the principles of conventional mark–recapture, but instead of being ... 
Consistency issues in pdf methods
(Peer reviewed; Journal article, 2015)Concentrations of chemical species transported in random environments need to be statistically characterized by probability density functions (PDF). Solutions to evolution equations for the onepoint onetime PDF are usually ... 
Consistent MPFA Discretization for Flow in the Presence of Gravity
(Peer reviewed; Journal article, 2019)A standard practice used in the industry to discretizing the gravity term in the two‐phase Darcy flow equations is to apply an upwind strategy. In this paper, we show that this can give a persistent unphysical flux field ... 
A continous Dependence Result for nonlinear degenerate parabolic Equations with spatially dependent flux Function.
(Department of Applied Mathematics report; 146, Research report, 200006) 
Continuity of Formal Power Series Products in Nonlinear Control Theory
(Journal article; Peer reviewed, 2022)Formal power series products appear in nonlinear control theory when systems modeled by Chen–Fliess series are interconnected to form new systems. In fields like adaptive control and learning systems, the coefficients of ... 
Continuous dependence estimates for viscosity solutions of fully nonlinear degenerate elliptic equations.
(Department of Applied Mathematics report, Research report, 200108) 
A Continuous MaxFlow Approach to Minimal Partitions with Label Cost Prior
(Chapter; Peer reviewed, 2011)This paper investigates a convex relaxation approach for minimum description length (MDL) based image partitioning or labeling, which proposes an energy functional regularized by the spatial smoothness prior joint with a ... 
Continuous MaxFlow for Image Segmentation with Shape Priors
(Master thesis, 20140602)In this thesis we propose a stable method for image segmentation with shape priors. The original ChanVese intensity based segmentation model with regularisation term is extended to include shape prior information. We study ... 
Continuous Updating of a Coupled ReservoirSeismic Model Using an Ensemble Kalman Filter Technique
(Doctoral thesis, 20070329)This work presents the development of a method based on the ensemble Kalman filter (EnKF) for continuous reservoir model updating with respect to the combination of production data, 3D seismic data and timelapse seismic ... 
Controllability on InfiniteDimensional Manifolds: A ChowRashevsky Theorem
(Peer reviewed; Journal article, 20140429)One of the fundamental problems in control theory is that of controllability, the question of whether one can drive the system from one point to another with a given class of controls. A classical result in geometric control ... 
Convective mixing in geological carbon storage
(Doctoral thesis, 20111125)The industrial era has seen an exponential growth in the atmospheric concentration of carbon dioxide (CO2), resulting mainly from the burning of fossil fuels. This can cause changes in the climate that have severe impacts ... 
Convergence of a CellCentered Finite Volume Discretization for Linear Elasticity
(Peer reviewed; Journal article, 20151119)We show convergence of a cellcentered finite volume discretization for linear elasticity. The discretization, termed the MPSA method, was recently proposed in the context of geological applications, where cellcentered ...