Now showing items 1-20 of 289

    • A robust linearization scheme for finite volume based discretizations for simulation of two-phase flow in porous media 

      Radu, Adrian Florin; Nordbotten, Jan Martin; Pop, Iuliu Sorin; Kumar, Kundan (Elsevier, 2015-12)
      In this work we consider a mathematical model for two-phase flow in porous media. The fluids are assumed immiscible and incompressible and the solid matrix non-deformable. The mathematical model for the two-phase flow is ...
      Journal article
    • A robust implicit scheme for two-phase flow in porous media 

      Kvashchuk, Anna (The University of Bergen, 2015-11-26)
      In this thesis we present a new implicit scheme for the numerical simulation of two-phase flow in porous media. Linear finite elements are considered for the spatial discretization. The scheme is based on the ...
      Master thesis
    • Heat Transfer Upscaling in Geothermal Reservoirs 

      Varzina, Anna (The University of Bergen, 2015-11-20)
      In this thesis we implement a numerical model of heat transfer in geothermal reservoirs. We use existing pressure and flow transport solvers as a starting point to investigate discretization techniques for a ...
      Master thesis
    • A Comparison of Anthropometric Measures for Assessing the Association between Body Size and Risk of Chronic Low Back Pain: TheHUNT Study 

      Heuch, Ingrid; Heuch, Ivar; Hagen, Knut; Zwart, John-Anker (PLOS, 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 ...
      Journal article
    • Analytical Methods for Upscaling of Fractured Geological Reservoirs 

      Sævik, Pål Næverlid (The University of Bergen, 2015-10-16)
      Numerical simulations have become an essential tool for planning well operations in the subsurface, whether the application is petroleum production, geothermal energy, groundwater utilization or waste disposal and leakage. ...
      Doctoral thesis
    • Algebra i første klasse 

      Lid, Elin Røkeberg (The University of Bergen, 2015-10-12)
      Oppgaven handler om algebra i første klasse. Hva er tidlig algebra og hvordan kan vi undervise på en slik måte at vi utvikler elevenes algebraiske tenkning? Tidlig algebra er ikke at vi underviser skolealgebra tidligere, ...
      Master thesis
    • Modeling of heat transfer in porous media in the context of geothermal energy extraction 

      Bringedal, Carina (The University of Bergen, 2015-10-02)
      This dissertation concerns mathematical modeling related to heat transfer in the subsurface relevant for geothermal energy extraction. Two applications are considered: First, natural convection in a homogeneous porous ...
      Doctoral thesis
    • Design of a monitoring program in a varying marine environment 

      Frøysa, Håvard Guldbrandsen (The University of Bergen, 2015-09-14)
      In this thesis we develop methods for optimal design of a monitoring program for offshore geological CO2 storage. The goal is to find the layout of fixed chemical sensors at the seafloor that maximizes the probability ...
      Master thesis
    • Ensemble Methods of Data Assimilation in Porous Media Flow for Non-Gaussian Prior Probability Density 

      Zhang, Yanhui (The University of Bergen, 2015-08-28)
      Ensemble-based data-assimilation methods have gained fast growth since the ensemble Kalman filter (EnKF) was introduced into the petroleum engineering. Many techniques have been developed to overcome the inherent disadvantages ...
      Doctoral thesis
    • Solution strategies for nonlinear conservation laws 

      Skogestad, Jan Ole (The University of Bergen, 2015-08-21)
      Nonlinear conservation laws form the basis for models for a wide range of physical phenomena. Finding an optimal strategy for solving these problems can be challenging, and a good strategy for one problem may fail spectacularly ...
      Doctoral thesis
    • The Whitham Equation as a model for surface water waves 

      Moldabayev, Daulet; Kalisch, Henrik; Dutykh, Denys (Elsevier, 2015-08)
      The Whitham equation was proposed as an alternate model equation for the simplified description of uni-directional wave motion at the surface of an inviscid fluid. As the Whitham equation incorporates the full linear ...
      Journal article
    • Non-standard shocks in the Buckley-Leverett equation 

      Kalisch, Henrik; Mitrovic, Darko; Nordbotten, Jan Martin (Elsevier, 2015-08)
      It is shown how delta shock waves which consist of Dirac delta distributions and classical shocks can be used to construct non-monotone solutions of the Buckley–Leverett equation. These solutions are interpreted using a ...
      Journal article
    • Numerical Modelling of Microbial Enhanced Oil Recovery with Focus on Dynamic Effects: An Iterative Approach 

      Skiftestad, Kai (Universitetet i Bergen (UiB), 2015-06-27)
      Recovering more of the available oil has been a main driver behind the extensive work done in the field of enhanced oil recovery (EOR) over the last decades. Microbial en- hanced oil recovery (MEOR) has been heavily ...
      Master thesis
    • Association between body height and chronic low back pain: a follow-up in the Nord-Trøndelag Health Study 

      Heuch, Ingrid; Heuch, Ivar; Hagen, Knut; Zwart, John-Anker (BMJ, 2015-06-15)
      Objective: To study potential associations between body height and subsequent occurrence of chronic low back pain (LBP). Design: Prospective cohort study. Setting: The North-Trøndelag Health Study (HUNT). Data ...
      Journal article
    • Mønstre og kvalitet. Analyse av samtaler i matematikkundervisning 

      Mjaavatn, Geir (The University of Bergen, 2015-06-03)
      Oppgaven diskuterer hvordan man kan analysere samtaler mellom lærer og elever i matematikkundervisning. Deretter diskuterer oppgaven hva som kjennetegner en kvalitativ god samtale.
      Master thesis
    • Logarithmic Hochschild homology 

      Piceghello, Stefano (The University of Bergen, 2015-06-01)
      The purpose of this thesis is to analyse the logarithmic Hochschild homology for pre-log rings and to provide some tools to compute it in certain cases. One of the main strategies that we will employ to describe the log ...
      Master thesis
    • Statistiske modelleringer i det europeiske gassmarkedet 

      Frontéri, Anette Ullestad (The University of Bergen, 2015-06-01)
      I denne oppgaven studerer vi naturgassmarkedet i Europa. Først ser vi på hvilke forhold som påvirker gassprisen. Deretter studerer vi statistisk teori om tidsrekker, volatilitet og copula. Til slutt blir det gjort ...
      Master thesis
    • Modellering og estimering av romlig avhengighet i forsikring 

      Sellereite, Nikolai (The University of Bergen, 2015-06-01)
      De seneste årene har det blitt publisert flere studier hvor bayesianske hierarkiske modeller, med gitte spatiale avhengighetsstrukturer, blir foreslått som potensielle verktøy i forsikringsselskapers arbeid rettet mot ...
      Master thesis
    • Detecting atmospheric rivers using persistent homology 

      Alfsvåg, Kristian Stusdal (The University of Bergen, 2015-06-01)
      This master's thesis is a first investigation on the problem of seeing whether it is possible to detect atmospheric rivers using persistent homology. Two different computations are done and a basic analysis is made. In ...
      Master thesis
    • Natural Convection in Layered Porous Media between Coaxial Cylinders 

      Selheim, Bianca (The University of Bergen, 2015-05-31)
      In this thesis a mathematical model is developed to describe the onset of natural convection in a two-layer porous medium located between two coaxial cylinders, motivated by natural convection processes in geothermal ...
      Master thesis