Browsing Department of Mathematics by Title
Now showing items 116-135 of 1106
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Comparing Structure and Dynamics of Transition Graphs by the Symmetric Difference Metric Over an Edge-Filtration
(Journal article; Peer reviewed, 2024)Transition graphs or transition diagrams, describing the rates and probabilities with which a system changes between discrete states, are common throughout the sciences. In many cases, parameterisations of transition graphs ... -
A Comparison of Anthropometric Measures for Assessing the Association between Body Size and Risk of Chronic Low Back Pain: TheHUNT Study
(Peer reviewed; Journal article, 2015-10-27)Background: Previous work indicates that overweight and obese individuals carry an increased risk of experiencing chronic low back pain (LBP). It is not known, however, how the association with body size depends on the ... -
Comparison of distance measures in Multimodal registration of medical images
(Master thesis, 2011-06-14)In this thesis I have worked with medical image registration, in particular registration of multimodal images. I have tested the image registration software package FAIR developed by Jan Modersitzki, with particular focus ... -
Comparison of Iterative Solvers for Non-Symmetric Linear Systems in Porous Media Problems
(Master thesis, 2014-09-02)We investigate the performance of the IDR(s)-algorithms when solving nonsymmetric systems in porous media problems. We derive a mathematical model for the flow in porous media, and discretized this with the method known ... -
A comparison of Monte Carlo sampling methods for metabolic network models
(Journal article; Peer reviewed, 2020)Reaction rates (fluxes) in a metabolic network can be analyzed using constraint-based modeling which imposes a steady state assumption on the system. In a deterministic formulation of the problem the steady state assumption ... -
A Comparison of Two Numerical Models for Flow in Fractured Porous Media and the Impact of Fracture Intersection Cell Removal
(Master thesis, 2016-11-21)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, 2006-04-07) -
Computational issues in parameter estimation for hidden Markov models with template model builder
(Journal article; Peer reviewed, 2023)A popular way to estimate the parameters of a hidden Markov model (HMM) is direct numerical maximization (DNM) of the (log-)likelihood function. The advantages of employing the TMB [Kristensen K, Nielsen A, Berg C, et al. ... -
Computer-aided proofs and algorithms in analysis
(Doctoral thesis, 2013-06-14)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 continuous-time 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, 2021-09-09)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 Mixed-Dimensional Partial Differential Equations
(Doctoral thesis, 2018-06-01)Mixed-dimensional partial differential equations (PDEs) are coupled equations defined on connected manifolds of different dimensionalities. Two main examples of mixed-dimensional PDEs are considered in this dissertation, ... -
Conforming, non-conforming and non-matching 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 close-kin 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. Close-kin 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 one-point one-time 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 ... -
Construction of Equilibria in Strategic Stackelberg Games in Multi-Period Supply Chain Contracts
(Journal article; Peer reviewed, 2022-10-27)Almost every supplier faces uncertain and time-varying demand. E-commerce and online shopping have given suppliers unprecedented access to data on customers’ behavior, which sheds light on demand uncertainty. The main ... -
A continous Dependence Result for nonlinear degenerate parabolic Equations with spatially dependent flux Function.
(Department of Applied Mathematics report; 146, Research report, 2000-06) -
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 ...