Browsing Department of Mathematics by Issue Date
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Association between body height and chronic low back pain: a followup in the NordTrøndelag Health Study
(BMJ, 20150615)Objective: To study potential associations between body height and subsequent occurrence of chronic low back pain (LBP). Design: Prospective cohort study. Setting: The NorthTrøndelag Health Study (HUNT). Data ... 
Entropy solutions to the Compressible Euler Equations
(The author, 20150511)We consider the threedimensional Euler equations of gas dynamics on a bounded periodic domain and a bounded time interval. We prove that LaxFriedrichs scheme can be used to produce a sequence of solutions with ever ... 
Brøkforståing hjå elevar som startar i den vidaregåande skulen
(The University of Bergen, 20150430)Målet for denne oppgåva har vore å få større innsikt i kva brøkforståing elevar som startar i den vidaregåande skulen kan ha. To forskingsspørsmål har lagt til grunn for arbeidet mitt: 1.Kva forståing av og dugleikar ... 
Skipped spawning in Northeast Arctic haddock Melanogrammus aeglefinus
(InterResearch, 20150422)Large interannual fluctuations in the numbers of offspring joining a teleost population are common, yet factors affecting offspring production, a key driver of fish population size and demography, are often poorly understood. ... 
Inversion of CSEM Data for Subsurface Structure Identification and Numerical Assessment of the Upstream Mobility Scheme
(The University of Bergen, 20150327)Part I In this part of the thesis, two different methodologies for solving the inverse problem of mapping the subsurface electric conductivity distribution using controlled source electromagnetic (CSEM) data are presented. ... 
Identification of subsurface structures using electromagnetic data and shape priors
(Elsevier, 201503)We consider the inverse problem of identifying largescale subsurface structures using the controlled source electromagnetic method. To identify structures in the subsurface where the contrast in electric conductivity can ... 
On weak solutions and a covergent numerical scheme for the compressible NavierStrokes Equations
(SIAM Journal on Numerical Analysis, 20150226)In this paper, the threedimensional compressible NavierStokes equations are considered on a periodic domain. We propose a semidiscrete numerical scheme and derive a priori bounds that ensures that the resulting system ... 
Pseudo Htype algebras and subRiemannian cut locus
(The University of Bergen, 20150213) 
Assessment of Sequential and Simultaneous Ensemblebased History Matching Methods for Weakly Nonlinear Problems
(The University of Bergen, 20150213)The ensemble Kalman filter (EnKF) has, since its introduction in 1994, gained much attention as a tool for sequential data assimilation in many scientific areas. In recent years, the EnKF has been utilized for estimating ... 
Weak solutions and convergent numerical schemes of BrennerNavierStokes equations
(20150120)Lately, there has been some interest in modifications of the compressible NavierStokes equations to include diffusion of mass. In this paper, we investigate possible ways to add mass diffusion to the 1D NavierStokes ... 
On the extension giving the truncated Witt vectors
(The University of Bergen, 20150105)We explore the theory of cohomology of groups and the classification of group extensions with abelian kernel. We then look at the group extensions that underlie the truncated Witt vectors on the truncation set {1,p} where ... 
Dynamic Capillary Effects in the Simulation of Flow and Transport in Porous Media: A New Linearisation Method
(The University of Bergen, 20141225)In this thesis mathematical models with and without dynamic capillary effects are developed to model water flow and solute transport through a porous medium. The system of equations are discretised using the finite volume ... 
Numerical solutions of twophase flow with applications to CO2 sequestration and polymer flooding
(The University of Bergen, 20141219)This thesis addresses challenges related to mathematical and numerical modeling of flow in porous media. To address these challenges, two applications are considered: firstly, countercurrent twophase flow in a heterogeneous ... 
Inexact linear solvers for control volume discretizations in porous media
(Springer, 20141203)We discuss the construction ofmultilevel inexact linear solvers for control volume discretizations for porous media. The methodology forms a contrast to standard iterative solvers by utilizing an algebraic hierarchy ... 
Tensor Induction as Left Kan Extension
(The University of Bergen, 20141202) 
Methods and Tools for Analysis of Symmetric Cryptographic Primitives
(The University of Bergen, 20141201)The development of modern cryptography is associated with the emergence of computing machines. Since specialized equipment for protection of sensitive information was initially implemented only in hardware, stream ciphers ... 
Modeling of oil reservoirs with focus on microbial induced effects
(The University of Bergen, 20141101)As an abstract to this thesis, we review some literatures in EOR and discussed the processes, strength and weakness of Microbial Enhanced Oil Recovery techniques. A two phase flow model comprising water and oil via the ... 
Classical and Stochastic Slit Löwner Evolution
(The University of Bergen, 20141010) 
On the Formulation of Mass, Momentum and Energy Conservation in the KdV Equation
(Springer, 201410)The Kortewegde Vries (KdV) equation is widely recognized as a simple model for unidirectional weakly nonlinear dispersive waves on the surface of a shallow body of fluid. While solutions of the KdV equation describe the ... 
Investigating population genetic structure in a highly mobile marine organism: The minke whale Balaenoptera acutorostrata acutorostrata in the North East Atlantic
(PLoS, 20140930)Inferring the number of genetically distinct populations and their levels of connectivity is of key importance for the sustainable management and conservation of wildlife. This represents an extra challenge in the marine ...