• English
    • Norsk
  • English 
    • English
    • Norsk
  • Administration
Search 
  •   Home
  • Det matematisk-naturvitenskapelige fakultet
  • Matematisk institutt
  • Matematisk institutt
  • Search
  •   Home
  • Det matematisk-naturvitenskapelige fakultet
  • Matematisk institutt
  • Matematisk institutt
  • Search
JavaScript is disabled for your browser. Some features of this site may not work without it.

Search

Show Advanced FiltersHide Advanced Filters

Filters

Use filters to refine the search results.

Now showing items 101-200 of 2702

  • Sort Options:
  • Relevance
  • Title Asc
  • Title Desc
  • Issue Date Asc
  • Issue Date Desc
  • Results Per Page:
  • 5
  • 10
  • 20
  • 40
  • 60
  • 80
  • 100
Analysis and approximation of mixed-dimensional pdes on 3d-1d domains coupled with lagrange multipliers 
Kuchta, Miroslav; Laurino, Federica; Mardal, Kent-Andre; Zunino, Paolo (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Coupled partial differential equations (PDEs) defined on domains with different dimensionality are usually called mixed-dimensional PDEs. We address mixed-dimensional PDEs on three-dimensional (3D) and one-dimensional (1D) ...
Infinite Dimensional Pathwise Volterra Processes Driven by Gaussian Noise -- Probabilistic Properties and Applications 
Harang, Fabian Andsem; Benth, Fred Espen (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
We investigate the probabilistic and analytic properties of Volterra processes constructed as pathwise integrals of deterministic kernels with respect to the Hölder continuous trajectories of Hilbert-valued Gaussian ...
Multiplicative Tate Spectral Sequences 
Hedenlund, Alice Petronella (Doctoral thesis / Doktoravhandling, 2021)
Many important results in mathematics deal with the question of figuring out what objects are ‘the same’. One way of rigorously dealing with this is through the notion of isomorphic objects. However, it is sometimes better ...
Extreme Wave Statistics of Surface Gravity Waves over Bathymetry 
Lawrence, Christopher (Doctoral thesis / Doktoravhandling, 2021)
Rogue waves are unexpected and unusually larger waves than their surrounding and can be dangerous to ship and offshore structures. In normally distributed wave fields also known as Gaussian sea, rogue waves actually exist, ...
Two-phase co-current flow simulations using periodic boundary conditions in horizontal, 4, 10 and 90° inclined eccentric annulus, flow prediction using a modified interFoam solver and comparison with experimental results 
Friedemann, Christopher; Mortensen, Mikael; Nossen, Jan (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Two-phase oil and gas flow were simulated in an entirely eccentric annulus and compared with experimental data at horizontal, 4, 10, and 90° inclination. The gas-phase was sulphur hexafluoride and the liquid phase a mixture ...
Real-time fault detection in PV systems under MPPT using PMU and high-frequency multi-sensor data through online PCA-KDE-based multivariate KL divergence 
Bakdi, Azzeddine; Bounoua, Wahiba; Guichi, Amar; Mekhilef, Saad (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
This paper considers data-based real-time adaptive Fault Detection (FD) in Grid-connected PV (GPV) systems under Power Point Tracking (PPT) modes during large variations. Faults under PPT modes remain undetected for longer ...
Fault detection and diagnosis of nonlinear dynamical processes through correlation dimension and fractal analysis based dynamic kernel PCA 
Bounoua, Wahiba; Bakdi, Azzeddine (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
A novel Dynamic Kernel PCA (DKPCA) method is developed for process monitoring in nonlinear dynamical systems. Classical DKPCA approaches still exhibit vague linearity assumptions to determine the number of principal ...
Asymptotic, Convergent, and Exact Truncating Series Solutions of the Linear Shallow Water Equations for Channels with Power Law Geometry 
Pedersen, Geir Kleivstul (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
The present study was originally motivated by some intriguing exact solutions for waves propagating in nonuniform media. In particular, for special depth profiles reflected waves did not appear and ray theory became exact. ...
Film coating by directional droplet spreading on fibers 
Chan, Tak Shing; Lee, Carmen L.; Pedersen, Christian (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Plants and insects use slender conical structures to transport and collect small droplets, which are propelled along the conical structures due to capillary action. These droplets can deposit a fluid film during their ...
The deconvolution as a method to deal with gaps in ocean wave measurements 
Støle-Hentschel, Susanne; Nieto Borge, Jose Carlos; Trulsen, Karsten (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
This work introduces the deconvolution as a technique to reconstruct missing information in data. While the method was originally developed for ocean waves, it will be useful in a wider range of applications where gaps in ...
On a rough perturbation of the Navier–Stokes system and its vorticity formulation 
Nilssen, Torstein; Hofmanova, Martina; Leahy, James-Michael (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
We introduce a rough perturbation of the Navier–Stokes system and justify its physical relevance from balance of momentum and conservation of circulation in the inviscid limit. We present a framework for a well-posedness ...
C*-algebras of right LCM one-relator monoids and Artin-Tits monoids of finite type 
Li, Xin; Omland, Tron; Spielberg, Jack (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Abstract We study C*-algebras generated by left regular representations of right LCM one-relator monoids and Artin–Tits monoids of finite type. We obtain structural results concerning nuclearity, ideal structure and pure ...
Correlators of Polynomial Processes 
Benth, Fred Espen; Lavagnini, Silvia (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
In the setting of one-dimensional polynomial jump-diffusion dynamics, we provide an explicit formula for computing correlators, namely, cross-moments of the process at different time points along its path. The formula ...
Modelling publication bias and p-hacking 
Moss, Jonas; De Bin, Riccardo (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Publication bias and p-hacking are two well-known phenomena that strongly affect the scientific literature and cause severe problems in meta-analyses. Due to these phenomena, the assumptions of meta-analyses are seriously ...
Simulations of two-phase gas-liquid flow in concentric and eccentric annuli at 0 to 90 degrees inclination using the volume of fluid method 
Friedemann, Christopher (Doctoral thesis / Doktoravhandling, 2021)
In this thesis, two-phase flow in an annular pipe geometry is studied using an open-source software known as OpenFOAM. The data collected through the simulations in this thesis are compared to experimental data collected ...
Statistical properties of wave kinematics in long-crested irregular waves propagating over non-uniform bathymetry 
Lawrence, Christopher; Trulsen, Karsten; Gramstad, Odin (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
Experimental and numerical evidence have shown that nonuniform bathymetry may alter significantly the statistical properties of surface elevation in irregular wave fields. The probability of “rogue” waves is increased near ...
A mean counting function for Dirichlet series and compact composition operators 
Brevig, Ole Fredrik; Perfekt, Karl-Mikael (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
We introduce a mean counting function for Dirichlet series, which plays the same role in the function theory of Hardy spaces of Dirichlet series as the Nevanlinna counting function does in the classical theory. The existence ...
Direction and magnitude of cerebrospinal fluid flow vary substantially across central nervous system diseases 
Eide, Per K; Valnes, Lars M; Lindstrøm, Erika K; Mardal, Kent-Andre; Ringstad, Geir (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Background Several central nervous system diseases are associated with disturbed cerebrospinal fluid (CSF) flow patterns and have typically been characterized in vivo by phase-contrast magnetic resonance ...
Rational Quartic Spectrahedra 
Helsø, Martin; Ranestad, Kristian (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
Rational quartic spectrahedra in 3-space are semialgebraic convex subsets in R3 of semidefinite, real symmetric (4×4)-matrices, whose boundary admits a rational parameterization. The Zariski closure in CP3 of the boundary ...
Maternal Anxiety and Infants Birthweight and Length of Gestation. A sibling design 
Bekkhus, Mona; Lee, Yunsung; Brandlistuen, Ragnhild E.; Samuelsen, Sven O.; Magnus, Per (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Background The overall aim of this study is to examine the effect of prenatal maternal anxiety on birthweight and gestational age, controlling for shared family confounding using a sibling comparison design. ...
Two coniveau filtrations 
Ottem, John Christian; Benoist, Olivier (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
A cohomology class of a smooth complex variety of dimension n has coniveau at least c if it vanishes in the complement of a closed subvariety of codimension at least c, and it has strong coniveau at least c if it comes by ...
A two diffusion stochastic model for the spread of the new corona virus SARS-CoV-2 
Dordevic, Jasmina (Journal article / Tidsskriftartikkel / SubmittedVersion, 2021)
We propose a refined version of the stochastic SEIR model for epidemic of the new corona virus SARS-Cov-2, causing the COVID-19 disease, taking into account the spread of the virus due to the regular infected individuals ...
Analysis of the risk premium in the forward market for salmon 
Benth, Fred Espen; Eikeset, Anne Maria; Levin, Simon A.; Ren, Wanjuan (Journal article / Tidsskriftartikkel / SubmittedVersion, 2021)
We analyse forward prices observed at the Fishpool market, and propose a two-factor continuous-time stochastic process for modelling the time dynamics. The data analysis reveals that the two factors can be assumed to be a ...
Regularity of Local Times Associated with Volterra–Lévy Processes and Path-Wise Regularization of Stochastic Differential Equations 
Harang, Fabian Andsem; Ling, Chengcheng (Journal article / Tidsskriftartikkel / PublishedVersion, 2021)
We investigate the space-time regularity of the local time associated with Volterra–Lévy processes, including Volterra processes driven by α-stable processes for α∈(0,2]. We show that the spatial regularity of the local ...
Applying deep reinforcement learning to active flow control in weakly turbulent conditions 
Ren, Feng; Rabault, Jean; Tang, Hui (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Machine learning has recently become a promising technique in fluid mechanics, especially for active flow control (AFC) applications. A recent work [Rabault et al., J. Fluid Mech. 865, 281–302 (2019)] has demonstrated the ...
On complex dynamics in a Purkinje and a ventricular cardiac cell model 
Erhardt, André Henrik; Solem, Susanne (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Cardiac muscle cells can exhibit complex patterns including irregular behaviour such as chaos or (chaotic) early afterdepolarisations (EADs), which can lead to sudden cardiac death. Suitable mathematical models and their ...
A compact vocabulary of paratope-epitope interactions enables predictability of antibody-antigen binding 
Akbar, Rahmad; Robert, Philippe Paul Auguste; Pavlović, Milena; Jeliazkov, Jeliazko R.; Snapkov, Igor; Slabodkin, Andrei; Weber, Cédric R.; Scheffer, Lonneke; Miho, Enkelejda; Haff, Ingrid Hobæk; Haug, Dag Trygve Truslew; Lund-Johansen, Fridtjof; Safonova, Yana; Sandve, Geir Kjetil Ferkingstad; Greiff, Victor (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Antibody-antigen binding relies on the specific interaction of amino acids at the paratope-epitope interface. The predictability of antibody-antigen binding is a prerequisite for de novo antibody and (neo-)epitope design. ...
Combined blockade of complement C5 and TLR co-receptor CD14 synergistically inhibits pig-to-human corneal xenograft induced innate inflammatory responses 
Islam, Rakibul; Islam, Mohammad Mirazul; Nilsson, Per H.; Mohlin, Camilla; Hagen, Kjersti Thorvaldsen; Paschalis, Eleftherios I.; Woods, Russell L.; Bhowmick, Sabuj Chandra; Dohlman, Claes H.; Espevik, Terje; Chodosh, James; Gonzalez-Andrades, Miguel; Mollnes, Tom Eirik (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Inadequate supplies of donor corneas have evoked an escalating interest in corneal xenotransplantation. However, innate immune responses contribute significantly to the mechanism of xenograft rejection. We hypothesized ...
Importance Measures in Repairable Multistate Systems With Aging 
Huseby, Arne Bang; Halle, Madeleine (Chapter / Bokkapittel / PublishedVersion; Peer reviewed, 2021)
Within the field of reliability multistate systems represent a natural extension of the classical binary approach. For an extensive introduction to this topic, see Natvig (2011b). Repairable multistate systems quickly ...
On subrecursive representation of irrational numbers: Contractors and Baire sequences 
Kristiansen, Lars (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
We study the computational complexity of three representations of irrational numbers: standard Baire sequences, dual Baire sequences and contractors. Our main results: Irrationals whose standard Baire sequences are of low ...
Can breast cancer be stopped? Modifiable risk factors of breast cancer among women with a prior benign or premalignant lesion 
Lilleborge, Marie; Falk, Ragnhild Sørum; Sørlie, Therese; Ursin, Giske; Hofvind, Solveig (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Physical inactivity, high postmenopausal body mass index, alcohol consumption and use of menopausal hormone therapy are established risk factors for breast cancer. Less is known about whether these factors influence the ...
Stochastic Modelling in Energy Markets - From the Spot Price to Derivative Contracts 
Lavagnini, Silvia (Doctoral thesis / Doktoravhandling, 2021)
The production of renewable energy is growing world-wide, and -- as a result -- power production is becoming increasingly dependent on weather factors such as temperature, wind and precipitation. All of these factors are ...
skweak: Weak Supervision Made Easy for NLP 
Lison, Pierre; Barnes, Jeremy; Hubin, Aliaksandr (Chapter / Bokkapittel / PublishedVersion; Peer reviewed, 2021)
We present skweak, a versatile, Python-based software toolkit enabling NLP developers to apply weak supervision to a wide range of NLP tasks. Weak supervision is an emerging machine learning paradigm based on a simple idea: ...
Accurate discretization of poroelasticity without Darcy stability -- Stokes–Biot stability revisited 
Mardal, Kent-Andre; Rognes, Marie E.; Thompson, Travis (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Abstract In this manuscript we focus on the question: what is the correct notion of Stokes–Biot stability? Stokes–Biot stable discretizations have been introduced, independently by several authors, as a means of discretizing ...
On functorial (co)localization of algebras and modules over operads 
Østvær, Paul Arne; Röndigs, Oliver; Spitzweck, Markus; Gutierrez, Javier J (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Motivated by calculations of motivic homotopy groups, we give widely attained conditions under which operadic algebras and modules thereof are preserved under (co)localization functors.
Elastohydrodynamic and capillary thin film flows at small scales 
Pedersen, Christian (Doctoral thesis / Doktoravhandling, 2021)
Thin viscous films are ubiquitous in Nature and biology and they are indispensable in industrial applications through lubrication and coating. In order to utilize the potential of thin viscous films on the micro and nano ...
The reliability of wind power in the Longyearbyen area 
Grochowicz, Aleksander; Heineken, Daniel; Wennberg, Sondre (Research report / Forskningsrapport, 2021)
Within this decade the current energy system in Longyearbyen has to be revolutionised. Right now, it relies entirely on fossil fuels, but in the future it is envisioned to be a front-runner of renewable systems in the ...
Influence of Submarine Landslide Failure and Flow on Tsunami Genesis 
Zengaffinen-Morris, Thomas (Doctoral thesis / Doktoravhandling, 2021)
Submarine mass movements are important sources for tsunamis with potential destructive consequences at coastlines. A famous example from historical records is, for instance, the 1929 Grand Banks tsunami in Canada. This ...
Max-and-Smooth: A Two-Step Approach for Approximate Bayesian Inference in Latent Gaussian Models 
Hrafnkelsson, Birgir; Siegert, Stefan; Huser, Raphaël; Bakka, Haakon C.; Jóhannesson, Árni (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
With modern high-dimensional data, complex statistical models are necessary, requiring computationally feasible inference schemes. We introduce Max-and-Smooth, an approximate Bayesian inference scheme for a flexible class ...
On the time-dependent electrolyte Seebeck effect 
Sehnem, André Luiz; Janssen, Mathijs Adriaan (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
Single-ion Soret coefficients αi characterize the tendency of ions in an electrolyte solution to move in a thermal gradient. When these coefficients differ between cations and anions, an electric field can be generated. ...
Locating the Frequency of Turnover in Thin-Film Diffusion Impedance 
Janssen, Mathijs Adriaan (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
The impedance of diffusion is an important tool to investigate a wide variety of systems, including electrochemical devices such as Li-ion batteries, porous electrodes, and solar cells. The classical impedance model for ...
Transmission Line Circuit and Equation for an Electrolyte-Filled Pore of Finite Length 
Janssen, Mathijs Adriaan (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
I discuss the strong link between the transmission line (TL) equation and the TL circuit model for the charging of an electrolyte-filled pore of finite length. In particular, I show how Robin and Neumann boundary conditions ...
Tailored graphical lasso for data integration in gene network reconstruction 
Lingjærde, Camilla; Lien, Tonje G.; Borgan, Ørnulf; Bergholtz, Helga; Glad, Ingrid K. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Background Identifying gene interactions is a topic of great importance in genomics, and approaches based on network models provide a powerful tool for studying these. Assuming a Gaussian graphical model, ...
Generalized Gauge Actions on k-graph C∗-Algebras: KMS States and Hausdorff Structure 
Farsi, Carla; Gillaspy, Elizabeth; Larsen, Nadia S.; Packer, Judith A. (Journal article / Tidsskriftartikkel / SubmittedVersion, 2021)
Long wave generation and coastal amplification due to propagating atmospheric pressure disturbances 
Dogan, Gozde Guney; Pelinovsky, Efim; Zaytsev, Andrey; Metin, Ayse Duha; Ozyurt Tarakcioglu, Gulizar; Yalciner, Ahmet Cevdet; Yalciner, Bora; Didenkulova, Irina (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Abstract Meteotsunamis are long waves generated by displacement of a water body due to atmospheric pressure disturbances that have similar spatial and temporal characteristics to landslide tsunamis. NAMI DANCE that solves ...
Betwixt Turing and Kleene 
Normann, Dag; Sanders, Sam (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
Turing’s famous ‘machine’ model constitutes the first intuitively convincing framework for computing with real numbers. Kleene’s computation schemes S1–S9 extend Turing’s approach and provide a framework for computing with ...
From Frequency Domain to Time Transient Methods for Halide Perovskite Solar Cells: The Connections of IMPS, IMVS, TPC, and TPV 
Bisquert, Juan; Janssen, Mathijs Adriaan (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
The correlation of different methods of measurement can become an important tool to identify the dominant physical elements that govern the electronic and ionic dynamics in perovskite solar cells. The diverse phenomena ...
Decline in body condition in the Antarctic minke whale (Balaenoptera bonaerensis) in the Southern Ocean during the 1990s 
Cunen, Celine; Walløe, Lars; Konishi, Kenji; Hjort, Nils Lid (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Abstract Changes in the body condition of Antarctic minke whales ( Balaenoptera bonaerensis ) have been investigated in a number of studies, but remain contested. Here we provide a new analysis of body condition measurements, ...
Unsupervised deep learning with higher-order total-variation regularization for multidimensional seismic data reconstruction 
Greiner, Thomas Larsen; Lie, Jan-Erik; Kolbjørnsen, Odd; Kjelsrud Evensen, Andreas; Harris Nilsen, Espen; Zhao, Hao; Demyanov, Vasily; Gelius, Leiv Jacob (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
In 3D marine seismic acquisition, the seismic wavefield is not sampled uniformly in the spatial directions. This leads to a seismic wavefield consisting of irregularly and sparsely populated traces with large gaps between ...
The partly parametric and partly nonparametric additive risk model 
Hjort, Nils Lid; Stoltenberg, Emil Aas (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Aalen’s linear hazard rate regression model is a useful and increasingly popular alternative to Cox’ multiplicative hazard rate model. It postulates that an individual has hazard rate function h(s)=z1α1(s)+⋯+zrαr(s) in ...
Strong Solutions of Stochastic Differential Equations with Generalized Drift and Multidimensional Fractional Brownian Initial Noise 
Banos, David; Ortiz-Latorre, Salvador; Pilipenko, Andrey (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
In this paper, we prove the existence of strong solutions to an stochastic differential equation with a generalized drift driven by a multidimensional fractional Brownian motion for small Hurst parameters H<12. Here, the ...
Real-time prediction of propulsion motor overheating using machine learning 
Hellton, Kristoffer Herland; Tveten, Martin; Stakkeland, Morten; Engebretsen, Solveig; Haug, Ola; Aldrin, Magne Tommy (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
Thermal protection in marine electrical propulsion motors is commonly implemented by installing temperature sensors on the windings of the motor. An alarm is issued once the temperature reaches the alarm limit, while the ...
Reversible heat production during electric double layer buildup depends sensitively on the electrolyte and its reservoir 
Glatzel, Fabian; Janssen, Mathijs Adriaan; Härtel, Andreas (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
Several modern technologies for energy storage and conversion are based on the screening of electric charge on the surface of porous electrodes by ions in an adjacent electrolyte. This so-called electric double layer (EDL) ...
Well conditioned frames for high order finite element methods 
Hu, Kaibo; Winther, Ragnar (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
The purpose of this paper is to discuss representations of high order C0 finite element spaces on simplicial meshes in any dimension. When computing with high order piecewise polynomials the conditioning of the basis is ...
Metatimes, random measures and cylindrical random variables 
Benth, Fred Espen; Simonsen, Iben Cathrine (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Metatimes constitute an extension of time-change to general measurable spaces, defined as mappings between two σ-algebras. Equipping the image σ-algebra of a metatime with a measure and defining the composition measure ...
Lefschetz section theorems for tropical hypersurfaces 
Shaw, Kris; Renaudineau, Arthur; Arnal, Charles (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
We establish variants of the Lefschetz section theorem for the integral tropical homology groups of tropical hypersurfaces of tropical toric varieties. It follows from these theorems that the integral tropical homology ...
Idempotent Fourier multipliers acting contractively on Hp spaces 
Brevig, Ole Fredrik; Ortega-Cerdà, Joaquim; Seip, Kristian (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
We describe the idempotent Fourier multipliers that act contractively on Hp spaces of the d-dimensional torus Td for d≥1 and 1≤p≤∞. When p is not an even integer, such multipliers are just restrictions of contractive ...
Body mass index and subfertility: multivariable regression and Mendelian randomization analyses in the Norwegian Mother, Father and Child Cohort Study 
Hernaez Camba, Alvaro; Rogne, Tormod; Skåra, Karoline Hansen; Håberg, Siri Eldevik; Page, Christian Magnus; Fraser, Abigail; Burgess, Stephen; Lawlor, Deborah A.; Magnus, Maria Christine (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Abstract STUDY QUESTION What is the association between BMI and subfertility? SUMMARY ANSWER We observed a J-shaped relationship between BMI and ...
Co-evolutionary Signals Identify Burkholderia pseudomallei Survival Strategies in a Hostile Environment 
Chewapreecha, Claire; Pensar, Johan; Chattagul, Supaksorn; Pesonen, Maiju; Sangphukieo, Apiwat; Boonklang, Phumrapee; Potisap, Chotima; Koosakulnirand, Sirikamon; Feil, Edward J.; Dunachie, Susanna; Chantratita, Narisara; Limmathurotsaku, Direk; Peacock, Sharon J.; Day, Nick P.J.; Parkhill, Julian; Thomson, Nicholas R.; Sermswan, Rasana W.; Corander, Jukka (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Abstract The soil bacterium Burkholderia pseudomallei is the causative agent of melioidosis and a significant cause of human morbidity and mortality in many tropical and subtropical countries. The species notoriously ...
Begonia - a two-photon imaging analysis pipeline for astrocytic Ca2+ signals 
Bjørnstad, Daniel Marelius; Åbjørsbråten, Knut Sindre; Hennestad, Eivind; Cunen, Celine; Hermansen, Gudmund Horn; Bojarskaite, Laura; Pettersen, Klas Henning; Vervaeke, Koen Gerard Alois; Enger, Rune (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Imaging the intact brain of awake behaving mice without the dampening effects of anesthesia, has revealed an exceedingly rich repertoire of astrocytic Ca 2+ signals. Analyzing and interpreting such complex signals pose ...
A (Dual) Network Model for Heat Transfer in Porous Media 
Koch, Timo; Weishaupt, Kilian; Müller, Johannes; Weigand, Bernhard; Helmig, Rainer (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Abstract We present a dual network model to simulate coupled single-phase flow and energy transport in porous media including conditions under which local thermal equilibrium cannot be assumed. The models target applications ...
A novel effective nonlinear state observer based robust nonlinear sliding mode controller for a 6 kW Proton Exchange Membrane Fuel Cell voltage regulation 
Dali, Ali; Abdelmalek, Samir; Bakdi, Azzeddine; Bettayeb, Maamar (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
This paper presents an effective strategy for controlling an Interleaved DC/DC Boost Converter (IBC) that is employed for reducing the current fluctuations in a 6 kW Proton Exchange Membrane Fuel Cell (PEMFC). The proposed ...
The Hunter-Saxton equation with noise 
Holden, Helge; Karlsen, Kenneth Hvistendahl; Pang, Ho Cheung (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
In this paper we develop an existence theory for the Cauchy problem to the stochastic Hunter–Saxton equation (1.1), and prove several properties of the blow-up of its solutions. An important part of the paper is the ...
Applications to A^1 -enumerative geometry of the A^1 -degree 
Pauli, Sabrina; Wickelgren, Kirsten (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
These are lecture notes from the conference Arithmetic Topology at the Pacific Institute of Mathematical Sciences on applications of Morel’s A1-degree to questions in enumerative geometry. Additionally, we give a new dynamic ...
Balancing efficiency and homogeneity of biomaterial transport in networks 
Liese, Susanne; Mahadevan, Lakshminarayana; Carlson, Andreas (Journal article / Tidsskriftartikkel / AcceptedVersion, 2021)
Transport of biomaterial in tubular networks is ubiquitous in nature, where examples include the endoplasmic reticulum, leaf venation or vessel networks in vertebrates. Flow feedback by adjustment of the local tube radius ...
Accuracy of deep learning in calibrating HJM forward curves 
Benth, Fred Espen; Detering, Nils; Lavagnini, Silvia (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
We price European-style options written on forward contracts in a commodity market, which we model with an infinite-dimensional Heath–Jarrow–Morton (HJM) approach. For this purpose, we introduce a new class of state-dependent ...
Dynamic probabilistic forecasting with uncertainty 
Benth, Fred Espen; Kutrolli, Gleda; Stefani, Silvana (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
In this paper, we introduce a dynamical model for the time evolution of probability density functions incorporating uncertainty in the parameters. The uncertainty follows stochastic processes, thereby defining a new class ...
High-dimensional structure learning of sparse vector autoregressive models using fractional marginal pseudo-likelihood 
Suotsalo, Kimmo; Xu, Yingying; Corander, Jukka; Pensar, Johan (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Abstract Learning vector autoregressive models from multivariate time series is conventionally approached through least squares or maximum likelihood estimation. These methods typically assume a fully connected model which ...
Wave dispersion and dissipation in landfast ice: Comparison of observations against models 
Voermans, Joey; Liu, Qingxiang; Marchenko, Aleksey; Rabault, Jean; Filchuk, Kirill; Ryzhov, Ivan; Heil, Petra; Waseda, Takuji; Nose, Takehiko; Kodaira, Tsubasa; Li, Jingkai; Babanin, Alexander V. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Abstract. Observations of wave dissipation and dispersion in sea ice are a necessity for the development and validation of wave–ice interaction models. As the composition of the ice layer can be extremely complex, most ...
A fully implicit coupled pore-network/free-flow model for the pore-scale simulation of drying processes 
Weishaupt, Kilian; Koch, Timo; Helmig, Rainer (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
We present a fully coupled pore-network/free-flow model providing pore-scale insight into drying processes. We solve the Navier–Stokes equations with component transport in the free-flow region, coupled to a dynamic ...
Laboratory investigations of the bending rheology of floating saline ice and physical mechanisms of wave damping in the HSVA hamburg ship model basin ice tank 
Marchenko, Aleksey; Haase, Andrea; Jensen, Atle; Lishman, Ben; Rabault, Jean; Evers, Karl-Ulrich; Shortt, Mark; Thiel, Torsten (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
An experimental investigation of flexural-gravity waves was performed in the Hamburg Ship Model Basin HSVA ice tank. Physical characteristics of the water-ice system were measured in several locations of the tank with a ...
Bringing optical fluid motion analysis to the field: A methodology using an open source ROV as a camera system and rising bubbles as tracers 
Løken, Trygve Kvåle; Ellevold, Thea Josefine; Ramirez de La Torre, Reyna Guadalupe; Rabault, Jean; Jensen, Atle (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
Detailed water kinematics are important for understanding atmosphere–ice–ocean energy transfer processes in the Arctic. There are few in situ observations of 2D velocity fields in the marginal ice zone. Particle tracking ...
Best low-rank approximations and Kolmogorov n-widths 
Floater, Michael S.; Manni, Carla; Sande, Espen; Speleers, Hendrik (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
We relate the problem of best low-rank approximation in the spectral norm for a matrix $A$ to Kolmogorov $n$-widths and corresponding optimal spaces. We characterize all the optimal spaces for the image of the Euclidean ...
Individualized VDJ recombination predisposes the available Ig sequence space 
Slabodkin, Andrei; Chernigovskaia, Maria; Mikocziova, Ivana; Akbar, Rahmad; Scheffer, Lonneke; Pavlović, Milena; Bashour, Habib; Snapkov, Igor; Mehta, Brij Bhushan; Weber, Cédric R.; Gutierrez-Marcos, Jose; Sollid, Ludvig Magne; Haff, Ingrid Hobæk; Sandve, Geir Kjetil Ferkingstad; Robert, Philippe Paul Auguste; Greiff, Victor (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
The process of recombination between variable (V), diversity (D), and joining (J) immunoglobulin (Ig) gene segments determines an individual's naive Ig repertoire and, consequently, (auto)antigen recognition. VDJ recombination ...
On the Unification of Schemes and Software for Wavelets on the Interval 
Antun, Vegard; Ryan, Øyvind (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Abstract We revisit the construction of wavelets on the interval with various degrees of polynomial exactness, and explain how existing schemes for orthogonal- and Spline wavelets can be extended to compactly supported ...
Multi-task learning for virtual flow metering 
Sandnes, Anders Thoresen; Grimstad, Bjarne Andre; Kolbjørnsen, Odd (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Virtual flow metering (VFM) is a cost-effective and non-intrusive technology for inferring multiphase flow rates in petroleum assets. Inferences about flow rates are fundamental to decision support systems that operators ...
Second-order accurate TVD numerical methods for nonlocal nonlinear conservation laws 
Fjordholm, Ulrik Skre; Ruf, Adrian Montgomery (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
We present a second-order accurate numerical method for a class of nonlocal nonlinear conservation laws called the “nonlocal pair-interaction model,” which was recently introduced by Du, Huang, and LeFloch [SIAM J. Numer. ...
Bayesian neural networks for virtual flow metering: An empirical study 
Grimstad, Bjarne Andre; Hotvedt, Mathilde; Sandnes, Anders Thoresen; Kolbjørnsen, Odd; Imsland, Lars Struen (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Recent works have presented promising results from the application of machine learning (ML) to the modeling of flow rates in oil and gas wells. Encouraging results and advantageous properties of ML models, such as ...
On best constants in L2 approximation 
Bressan, Andrea; Floater, Michael S.; Sande, Espen (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
In this paper we provide explicit upper and lower bounds on certain L2n-widths, i.e., best constants in L2 approximation. We further describe a numerical method to compute these n-widths approximately and prove that this ...
Data-driven state of health modelling—A review of state of the art and reflections on applications for maritime battery systems 
Vanem, Erik; Bertinelli Salucci, Clara; Bakdi, Azzeddine; Alnes, Øystein Åsheim (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Battery systems are becoming an increasingly attractive alternative for powering ocean going ships, and the number of fully electric or hybrid ships relying on battery power for propulsion and manoeuvring is growing. In ...
Convex cones in mapping spaces between matrix algebras 
Girard, Mark; Kye, Seung-Hyeok; Størmer, Erling (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
We introduce the notion of one-sided mapping cones of positive linear maps between matrix algebras. These are convex cones of maps that are invariant under compositions by completely positive maps from either the left or ...
PRICING ASIAN OPTIONS with CORRELATORS 
Lavagnini, Silvia (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
We derive a series expansion by Hermite polynomials for the price of an arithmetic Asian option. This requires the computation of moments and correlators of the underlying asset price which for a polynomial jump–diffusion ...
Parameter robust preconditioning by congruence for multiple-network poroelasticity 
Piersanti, Eleonora; Lee, Jeonghun; Thompson, Travis; Mardal, Kent-Andre; Rognes, Marie (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
The mechanical behavior of a poroelastic medium permeated by multiple interacting fluid networks can be described by a system of time-dependent partial differential equations known as the multiple-network poroelasticity ...
Nanobubble-induced flow of immersed glassy polymer films 
Pedersen, Christian; Ren, Shuai; Wang, Yuliang; Carlson, Andreas; Salez, Thomas (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
We study the free-surface deformation dynamics of an immersed glassy thin polymer film supported on a substrate, induced by an air nanobubble at the free surface. We combine analytical and numerical treatments of the glassy ...
Universal self-similar attractor in the bending-driven levelling of thin viscous films 
Pedersen, Christian; Salez, Thomas; Carlson, Andreas (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
We study theoretically and numerically the bending-driven levelling of thin viscous films within the lubrication approximation. We derive Green’s function of the linearized thin-film equation and further show that it ...
Self-Exciting Multifractional Processes 
Harang, Fabian Andsem; Lagunas, Marc; Ortiz-Latorre, Salvador (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
We propose a new multifractional stochastic process which allows for self-exciting behavior, similar to what can be seen for example in earthquakes and other self-organizing phenomena. The process can be seen as an extension ...
On Assessing Trustworthy AI in Healthcare: Machine Learning as a Supportive Tool to Recognize Cardiac Arrest in Emergency Calls 
Zicari, RV; Brusseau, James; Blomberg, Stig Nikolaj Fasmer; Christensen, Helle Collatz; Coffee, Megan; Ganapini, Marianna B; Gerke, Sara; Gilbert, Thomas Krendl; Hickman, Eleanore; Antun, Vegard; Tørresen, Jim; Volland, Holger; Kararigas, Georgios (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Artificial Intelligence (AI) has the potential to greatly improve the delivery of healthcare and other services that advance population health and wellbeing. However, the use of AI in healthcare also brings potential risks ...
Multilevel Monte Carlo finite volume methods for random conservation laws with discontinuous flux. 
Risebro, Nils Henrik; Badwaik, Jayeesh; Klingenberg, Christian; Ruf, Adrian Montgomery (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
We consider conservation laws with discontinuous flux where the initial datum, the flux function, and the discontinuous spatial dependency coefficient are subject to randomness. We establish a notion of random adapted ...
On causal and non-causal cointegrated vector autoregressive time series 
Swensen, Anders Rygh (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Previous-30 treatments of multivariate non-causal time series have assumed stationarity. In this article, we consider integrated processes in a non-causal setting. We generalize the Johansen–Granger representation for ...
Variation in chemical composition of MSWI fly ash and dry scrubber residues 
Nedkvitne, Eirik Nøst; Borgan, Ørnulf; Eriksen, Dag Øistein; Rui, Haakon Marius Vatten (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Our society generates extensive amounts of municipal solid waste (MSW), which are mainly incinerated for volume reduction and energy recovery. Though, MSW incineration generates hazardous air pollution control (APC) residues ...
Volterra Equations Driven by Rough Signals 
Harang, Fabian Andsem; Tindel, Samy (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
This article is devoted to the extension of the theory of rough paths in the context of Volterra equations with possibly singular kernels. We begin to describe a class of two parameter functions defined on the simplex ...
DATA-DRIVEN DIAGNOSTICS AND PROGNOSTICS FOR MODELLING THE STATE OF HEALTH OF MARITIME BATTERY SYSTEMS – A REVIEW 
Vanem, Erik; Alnes, Øystein Åsheim; Lam, James (Chapter / Bokkapittel / PublishedVersion; Peer reviewed, 2021)
Battery systems are becoming an increasingly attractive alternative for powering ocean going ships, and the number of fully electric or hybrid ships relying on battery power for propulsion and maneuvering is growing. In ...
A review on deep reinforcement learning for fluid mechanics 
Garnier, Paul; Viquerat, Jonathan; Rabault, Jean; Larcher, Aurelien; Kuhnle, Alexander; Hachem, Elie (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
Deep reinforcement learning (DRL) has recently been adopted in a wide range of physics and engineering domains for its ability to solve decision-making problems that were previously out of reach due to a combination of ...
A Local-in-Time Theory for Singular SDEs with Applications to Fluid Models with Transport Noise 
Alonso-Orán, Diego; Rohde, Christian; Tang, Hao (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Abstract We establish a local theory, i.e., existence, uniqueness and blow-up criterion, for a general family of singular SDEs in Hilbert spaces. The key requirement relies on an approximation property that allows us to ...
A new robust control scheme: Application for MPP tracking of a PMSG-based variable-speed wind turbine 
Dali, Ali; Abdelmalek, Samir; Bakdi, Azzeddine; Bettayeb, Maamar (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2021)
This paper proposes a novel Improved Maximum Power Point Tracking (IMPPT) algorithm to extract the maximum available power from a direct-drive Permanent-Magnet Synchronous Generator (PMSG) based standalone Small-scale ...
The compressible granular collapse in a fluid as a continuum: validity of a Navier-Stokes model with, μ(J), ϕ(J)-rheology 
Rauter, Matthias (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
The incompressible μ(I)-rheology has been used to study subaerial granular flows with remarkable success. For subaquatic granular flows, drag between grains and the pore fluid is substantially higher and the physical ...
On a class of stochastic partial differential equations with multiple invariant measures 
Farkas, Bálint; Friesen, Martin; Rüdiger, Barbara; Schroers, Dennis (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
In this work we investigate the long-time behavior for Markov processes obtained as the unique mild solution to stochastic partial differential equations in a Hilbert space. We analyze the existence and characterization ...
Sensitivity and identification quantification by a relative latent model complexity perturbation in Bayesian meta-analysis 
Roos, Malgorzata; Hunanyan, Sona; Bakka, Haakon C.; Rue, Håvard (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
In recent years, Bayesianmeta-analysis expressed by a normal–normal hierarchical model (NNHM) has been widely used for combining evidence from multiple studies. Data provided for the NNHM are frequently based on a small ...
AIS-based near-collision database generation and analysis of real collision avoidance manoeuvres 
Vestre, Arnstein; Bakdi, Azzeddine; Vanem, Erik; Engelhardtsen, Øystein (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
Economic and technological development has increased the amount, density and complexity of maritime traffic, which has resulted in new challenges. One challenge is conforming to the distinct evasion manoeuvres required by ...
Combining information across diverse sources: The II-CC-FF paradigm 
Cunen, Celine; Hjort, Nils Lid (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
We introduce and develop a general paradigm for combining information across diverse data sources. In broad terms, suppose 𝜑 is a parameter of interest, built up via components 𝜓1,…,𝜓𝑘 from data sources 1, … , k. The ...
  • «
  • 1
  • 2
  • 3
  • 4
  • 5
  • . . .
  • 28
  • »
 
Responsible for this website 
University of Oslo Library


Contact Us 
duo-hjelp@ub.uio.no


Privacy policy
 

 

For students / employeesSubmit master thesisAccess to restricted material

Browse

All of DUOCommunities & CollectionsBy Issue DateAuthorsTitlesThis CollectionBy Issue DateAuthorsTitles

For library staff

Login

Discover

Date Issued2020 - 2022 (384)2010 - 2019 (692)2000 - 2009 (455)1990 - 1999 (463)1980 - 1989 (258)1970 - 1979 (349)1960 - 1969 (100)1937 - 1939 (1)Document TypeForskningsrapport (1677)Tidsskriftartikkel (870)Doktoravhandling (91)Bokkapittel (38)Serietittel (7)Bok (3)Konferansebidrag (1)... View MoreAuthorØksendal, Bernt (187)Benth, Fred Espen (98)Hjort, Nils Lid (78)Natvig, Bent (72)Karlsen, Kenneth H. (51)... View MorePeer ReviewedPeer reviewed (833)
RSS Feeds
feedRSS 2.0
 
Responsible for this website 
University of Oslo Library


Contact Us 
duo-hjelp@ub.uio.no


Privacy policy