Browsing Department of Mathematics by Issue Date

Now showing items 41-60 of 938

    • Stromule Geometry Allows Optimal Spatial Regulation of Organelle Interactions in the Quasi-2D Cytoplasm 

      Johnston, Iain George; Schattat, Martin; Hause, Gerd; Niemeyer, Frederik; Reynvoet, Frisine; Prautsch, Jennifer; Erickson, Jennifer Lee (Journal article; Peer reviewed, 2023)
      In plant cells, plastids form elongated extensions called stromules, the regulation and purposes of which remain unclear. Here, we quantitatively explore how different stromule structures serve to enhance the ability of a ...

    • Crustal Conditions Favoring Convective Downward Migration of Fractures in Deep Hydrothermal Systems 

      Halldorsdottir, Sæunn; Berre, Inga; Keilegavlen, Eirik; Axelsson, Gudni (Journal article; Peer reviewed, 2023)
      Cooling magma plutons and intrusions are the heat sources for hydrothermal systems in volcanic settings. To explain system longevity and observed heat transfer at rates higher than those explained by pure conduction, the ...

    • Collective mitochondrial dynamics resolve conflicting cellular tensions: From plants to general principles 

      Johnston, Iain George; Chustecki, Joanna M. (Journal article; Peer reviewed, 2023)
      Mitochondria play diverse and essential roles in eukaryotic cells, and plants are no exception. Plant mitochondria have several differences from their metazoan and fungal cousins: they often exist in a fragmented state, ...

    • Screening for Circulating Inflammatory Proteins Does Not Reveal Plasma Biomarkers of Constant Tinnitus 

      Cederroth, Christopher R.; Hong, Mun-Gwan; Freydin, Maxim B.; Edvall, Niklas K.; Trpchevska, Natalia; Jarach, Carlotta; Schlee, Winfried; Schwenk, Jochen M.; Lopez-Escamez, Jose-Antonio; Gallus, Silvano; Canlon, Barbara; Bulla, Jan; Williams, Frances M. K. (Journal article; Peer reviewed, 2023)
      Background and Objective Tinnitus would benefit from an objective biomarker. The goal of this study is to identify plasma biomarkers of constant and chronic tinnitus among selected circulating inflammatory proteins. ...

    • Computational issues in parameter estimation for hidden Markov models with template model builder 

      Bacri, Timothee Raphael Ferdinand; Berentsen, Geir Drage; Bulla, Jan; Støve, Bård (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. ...

    • Effective Preconditioners for Mixed-Dimensional Scalar Elliptic Problems 

      Hu, Xiaozhe; Keilegavlen, Eirik; Nordbotten, Jan Martin (Journal article; Peer reviewed, 2023)
      Discretization of flow in fractured porous media commonly lead to large systems of linear equations that require dedicated solvers. In this work, we develop an efficient linear solver and its practical implementation for ...

    • Simulation of Reactive Transport in Fractured Porous Media 

      Banshoya, Shin Irgens; Berre, Inga; Keilegavlen, Eirik (Journal article; Peer reviewed, 2023)
      Numerical simulations of reactive transport in fractured porous media require the solution of coupled physical and chemical processes that depend on the fractures. Such coupled processes are described by a system of nonlinear ...

    • PoroTwin: A Digital Twin for a FluidFlower Rig 

      Keilegavlen, Eirik; Fonn, Eivind; Johannessen, Kjetil Andre; Eikehaug, Kristoffer; Both, Jakub Wiktor; Fernø, Martin; Kvamsdal, Trond; Rasheed, Adil; Nordbotten, Jan Martin (Journal article; Peer reviewed, 2023)
      We present a framework for integrated experiments and simulations of tracer transport in heterogeneous porous media using digital twin technology. The physical asset in our setup is a meter-scale FluidFlower rig. The digital ...

    • A posteriori error estimation and adaptivity for multiple-network poroelasticity 

      Ødegaard, Emilie Eliseussen; Rognes, Marie Elisabeth; Thompson, Travis B. (Journal article; Peer reviewed, 2023)
      The multiple-network poroelasticity (MPET) equations describe deformation and pressures in an elastic medium permeated by interacting fluid networks. In this paper, we (i) place these equations in the theoretical context ...

    • Decay of solitary waves of fractional Korteweg-de Vries type equations 

      Eychenne, Arnaud; Valet, Frederic Fernand Jacques (Journal article; Peer reviewed, 2023)
      We study the solitary waves of fractional Korteweg-de Vries type equations, that are related to the 1- dimensional semi-linear fractional equations: |D|αu + u − f (u) = 0, with α ∈ (0, 2), a prescribed coefficient p∗(α), ...

    • Decay estimates of Green's matrices for discrete-time linear periodic systems 

      Malyshev, Alexander; Sadkane, M. (Journal article; Peer reviewed, 2023)
      We study periodic Lyapunov matrix equations for a general discrete-time linear periodic system Bpxp−Apxp−1=fp, where the matrix coefficients Bp and Ap can be singular. The block coefficients of the inverse operator of the ...

    • The dissolution of a miscible drop rising or falling in another liquid at low Reynolds number 

      Nordbotten, Jan Martin; Mossige, Joachim (Journal article; Peer reviewed, 2023)
      “A basic and basically unsolved problem in fluid dynamics is to determine the evolution of rising bubbles and falling drops of one miscible liquid in another” [D. D. Joseph and Y. Y. Renardy, Fundamentals of Two-Fluid ...

    • An isenthalpic formulation for simulating geothermal systems with phase changes 

      Duran Triana, Omar Yesid; Lipovac, Veljko; Keilegavlen, Eirik; Radu, Adrian Florin; Berre, Inga (Chapter; Peer reviewed, 2023)
      We propose a unified isenthalpic formulation for the equilibrium problem of compositional multiphase mixtures. To solve the equilibrium problem numerically, we used an interior point method with line search and present an ...

    • The weight spectrum of two families of Reed-Muller codes 

      Carlet, Claude Michael; Solé, Patrick (Journal article; Peer reviewed, 2023)
      We determine the weight spectra of the Reed-Muller codes RM (m− 3, m) for m ≥ 6 and RM (m − 4, m) for m ≥ 8. The technique used is induction on m, using that the sum of two weights in RM (r −1, m−1) is a weight in RM (r, ...

    • Limited Link of Common Blood Parameters with Tinnitus 

      Bulla, Jan; Brueggemann, Petra; Wrzosek, Małgorzata; Klasing, Sven; Boecking, Benjamin; Basso, Laura; Nyamaa, Amarjargal; Psatha, Stamatina; Rose, Matthias; Mazurek, Birgit (Journal article; Peer reviewed, 2023)
      Background: Tinnitus severity is generally assessed by psychometric and audiological instruments. However, no objective measure exists to evaluate the subjective discomfort and suffering caused by this hearing phenomenon. ...

    • Quantifying prior model complexity for subsurface reservoir models 

      Mioratina, Nomenjanahary Tanteliniaina; Oliver, Dean (Journal article; Peer reviewed, 2023)
      In Bayesian approaches to history matching for subsurface inference, the prior model specifies the uncertain model parameters and the joint probability of those parameters before incorporating production-related data. A ...

    • Symmetric waves are traveling waves of some shallow water scalar equations 

      Hussien Elkhorbatly, Bashar (Journal article; Peer reviewed, 2023)
      Following a straightforward proof for symmetric solutions to be traveling waves by Pei (Exponential decay and symmetry of solitary waves to Degasperis-Procesi equation. Journal of Differential Equations. 2020;269(10):7730-7749), ...

    • The aromatic bicomplex for the description of divergence-free aromatic forms and volume-preserving integrators 

      Laurent, Adrien Ange Andre; Mclachlan, Robert I.; Munthe-Kaas, Hans Zanna; Verdier, Olivier Philippe Paul (Journal article; Peer reviewed, 2023)
      Aromatic B-series were introduced as an extension of standard Butcher-series for the study of volume-preserving integrators. It was proven with their help that the only volume-preserving B-series method is the exact flow ...

    • Menopausal hormone therapy, oral contraceptives and risk of chronic low back pain: the HUNT Study 

      Heuch, Ingrid; Heuch, Ivar; Hagen, Knut; Storheim, Kjersti; Zwart, John Anker Henrik (Journal article; Peer reviewed, 2023)
      Background There are indications that use of menopausal hormone therapy (MHT) and oral contraceptives (OC) increases the risk of low back pain (LBP), with higher oestrogen levels involved in the underlying mechanisms. The ...

    • The FluidFlower Validation Benchmark Study for the Storage of CO2 

      Flemisch, Bernd; Nordbotten, Jan Martin; Fernø, Martin; Juanes, Ruben; Both, Jakub Wiktor; Class, Holger; Delshad, Mojdeh; Doster, Florian; Ennis-King, Jonathan; Franc, Jacques; Geiger, Sebastian; Gläser, Dennis; Green, Christopher; Gunning, James; Hajibeygi, Hadi; Jackson, Samuel J.; Jammoul, Mohamad; Karra, Satish; Li, Jiawei; Matthäi, Stephan K.; Miller, Terry; Shao, Qi; Spurin, Catherine; Stauffer, Philip; Tchelepi, Hamdi; Tian, Xiaoming; Viswanathan, Hari; Voskov, Denis; Wang, Yuhang; Wapperom, Michiel; Wheeler, Mary F.; Wilkins, Andrew; Youssef, AbdAllah A.; Zhang, Ziliang (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 ...