## Search

Now showing items 1-100 of 691

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

The sparseness promoted by the total variation norm is utilized to achieve superresolution amplitude-variation-with-offset (AVO) inversion. The total variation norm promotes solutions that have constant values within ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

New methods for time-to-event prediction are proposed by extending the Cox proportional hazards model with neural networks. Building on methodology from nested case-control studies, we propose a loss function that scales ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

We describe a method for geophysical inversion of seismic amplitude data, we argue that this type of inversion is a natural extension of the processing flow. The methodology is related to digital image-video restoration ...

(Research report / Forskningsrapport, 2019)

Based on a study of isolated restrained columns, and two-column panel frames, the often complicated mechanics of moment formations in the members are studdied using elastic second-order theory for the purpose of establishing ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

We use a white noise approach to study the problem of optimal insider control of a stochastic delay equation driven by a Brownian motion B and a Poisson random measure N. In particular, we use Hida-Malliavin calculus and ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

Clicking data, which exists in abundance and contains objective user preference information, is widely used to produce personalized recommendations in web-based applications. Current popular recommendation algorithms, ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

The notion of a generalized scale emerged in recent joint work with Afsar–Brownlowe–Larsen on equilibrium states on C*-algebras of right Least Common Multiple (LCM) monoids, where it features as the key datum for the ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

We present a Bayesian model for multi-resolution component separation for cosmic microwave background (CMB) applications based on Wiener filtering and/or computation of constrained realizations, extending a previously ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

In [IMA J. Numer. Anal., 29 (2009), pp. 24--42], Nielsen, Tveito, and Hackbusch study the operator generated by using the inverse of the Laplacian as the preconditioner for second order elliptic PDEs $-\nabla \cdot (k(x) ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

Appendages of seeds, fruits and other diaspores (dispersal units) are essential for their wind dispersal, as they act as wings and enable them to fly. Whirling fruits generate an auto-gyrating motion from their sepals, a ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

Water wave attenuation by grease ice is a key mechanism for the polar regions, as waves in ice influence many phenomena such as ice drift, ice breaking and ice formation. However, the models presented so far in the literature ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

Multiphase flow simulations were run in OpenFOAM utilizing InterFoam, a volume of fluid type solver. A concentric annulus geometry was constructed and periodic boundary conditions were applied to alleviate the requirement ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

Current theories suggest that waste solutes are cleared from the brain via cerebrospinal fluid (CSF) flow, driven by pressure pulsations of possibly both cardiac and respiratory origin. In this study, we explored the ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

Coupled multiphysics problems often give rise to interface conditions naturally formulated in fractional Sobolev spaces. Here, both positive and negative fractionality are common. When designing efficient solvers for ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

The category of finite Milnor-Witt correspondences, introduced by Calmès and Fasel, provides a new type of correspondences closer to the motivic homotopy theoretic framework than Suslin-Voevodsky's finite correspondences. ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

An inherent problem with microfluidic filters is the tendency to clog, especially when applied to cells due to their geometrical complexity, deformability, and tendency to adhere to surfaces. In this work, we handle live ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

Deep Reinforcement Learning (DRL) has recently been proposed as a methodology to discover complex active flow control strategies [Rabault et al., “Artificial neural networks trained through deep reinforcement learning ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

The posterior predictive p value (ppp) was invented as a Bayesian counterpart to classical p values. The methodology can be applied to discrepancy measures involving both data and parameters and can, hence, be targeted to ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

We develop cointegration for multivariate continuous-time stochastic processes, both in finite and infinite dimension. Our definition and analysis are based on factor processes and operators mapping to the space of prices ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

In this paper, we present and analyze a new mixed finite element formulation of a general family of quasi-static multiple-network poroelasticity (MPET) equations. The MPET equations describe flow and deformation in an ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

A central problem in traffic management is that of scheduling the movements of vehicles so as to minimize the cost of the schedule. It arises in important applications such as train timetabling, rescheduling, delay and ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

We prove that the integral Hodge conjecture holds for 1-cycles on irreducible holomorphic symplectic varieties of K3[n]-type and of generalized Kummer type. As an application, we give a new proof of the integral Hodge ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

In an article from 1865, Arthur Cayley claims that given a plane algebraic curve there exists an associated 2-Hessian curve that intersects it in its sextactic points. In this paper we fix an error in Cayley's calculations ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

For spaces of constant, linear, and quadratic splines of maximal smoothness on the Powell–Sabin 12-split of a triangle, the so-called S-bases were recently introduced. These are simplex spline bases with B-spline-like ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

Life expectancies at birth are routinely computed from period life tables. When mortality is falling, such period life expectancies will typically underestimate real life expectancies, that is, life expectancies for birth ...

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2019)

We show that two approaches to equivariant deformation of C[Formula: see text]-algebras by actions of negatively curved Kählerian Lie groups, one based on oscillatory integrals and the other on quantizations maps defined ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2019)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

We compare three different models of two phase flow in a porous medium; the standard Darcy/Buckley–Leverett model, the Brinkman model and the Helmholtz model. These three models are all singular perturbations of the inviscid ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

We provide a rather simple proof of a homogenization result for the bidomain model of cardiac electrophysiology. Departing from a microscopic cellular model, we apply the theory of two-scale convergence to derive the ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

We introduce and analyze the full [Formula: see text] and the reduced [Formula: see text] Nica–Toeplitz algebra associated to an ideal [Formula: see text] in a right-tensor [Formula: see text]-precategory [Formula: see ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

We analyze a model equation arising in option pricing. This model equation takes the form of a nonlinear, nonlocal diffusion equation. We prove the well posedness of the Cauchy problem for this equation. Furthermore, we ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

We propose novel modifications to an anomaly detection methodology based on multivariate signal reconstruction followed by residuals analysis. The reconstructions are made using Auto Associative Kernel Regression (AAKR), ...

(Chapter / Bokkapittel / AcceptedVersion; Peer reviewed, 2019)

Tchebycheffian splines are smooth piecewise functions where the different pieces are drawn from extended Tchebycheff spaces. They are a natural generalization of polynomial splines and can be represented in terms of an ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

This article is concerned with inference in parametric copula setups, where both the marginals and the copula have parametric forms. For such models, two-stage maximum likelihood estimation, often referred to as inference ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

We give a description of cyclic cohomology and its pairing with K-groups for 2-cocycle deformation of algebras graded over discrete groups. The proof relies on a realization of monodromy for the Gauss–Manin connection on ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

We develop a method to give presentations of quantized function algebras of complex reductive groups. In particular, we give presentations of quantized function algebras of automorphism groups of finite dimensional simple ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

In this paper, we extend the focused information criterion (FIC) to copula models. Copulas are often used for applications where the joint tail behavior of the variables is of particular interest, and selecting a copula ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

Objective. Mechanistic modeling of neurons is an essential component of computational neuroscience that enables scientists to simulate, explain, and explore neural activity. The conventional approach to simulation of ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

The bidomain system of degenerate reaction–diffusion equations is a well-established spatial model of electrical activity in cardiac tissue, with “reaction” linked to the cellular action potential and “diffusion” representing ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

We investigate a class of scalar conservation laws on manifolds driven by multiplicative Gaussian (Itô) noise. The Cauchy problem defined on a Riemanian manifold is shown to be well-posed. We prove existence of generalized ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

In 1994, Nessyahu, Tadmor and Tassa studied convergence rates of monotone finite volume approximations of conservation laws. For compactly supported, Lip+-bounded initial data they showed a first-order convergence rate in ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

Wind dispersal of seeds is an essential mechanism for plants to proliferate and to invade new territories. In this paper we present a methodology used in our recent work [Rabault, Fauli, and Carlson, Phys. Rev. Lett. 122, ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

We prove a version of the classical ‘generic smoothness’ theorem with smooth varieties replaced by non-commutative resolutions of singular varieties. This in particular implies a non-commutative version of the Bertini theorem.

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

The fast Fourier transform (FFT) is an algorithm that efficiently computes the discrete Fourier transform. Since the dawn of our digital society, the FFT has permeated to the heart of everyday life applications involving ...

Unsupervised anomaly detection based on clustering methods and sensor data on a marine diesel engine

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

Sensor data from marine engine systems can be used to detect changes in performance in near real time which may be indicative of an impending failure. Thus sensor-based condition monitoring can be important for the reliability ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

Kuznetsov has conjectured that Pfaffian varieties should admit noncommutative crepant resolutions which satisfy his Homological Projective Duality. We prove half the cases of this conjecture by interpreting and proving a ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

Each extended Cartan-Eilenberg system (H,∂) gives rise to two exact couples and one spectral sequence. We show that the canonical colim-lim interchange morphism associated to H is a surjection, and that its kernel is ...

(Doctoral thesis / Doktoravhandling, 2019)

Teknikker og konsepter som er knyttet til kombinatorikk blir ofte brukt innenalgebraisk geometri. Et eksempel på dette er toriske degenerasjoner, som kanbrukes til å besvare visse klassifiseringsspørsmål. I denne avhandlingen ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

In this paper, we introduce a sublinear conditional expectation with respect to a family of possibly nondominated probability measures on a progressively enlarged filtration. In this way, we extend the classic reduced-form ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

In this paper, we provide a priori error estimates in standard Sobolev (semi-)norms for approximation in spline spaces of maximal smoothness on arbitrary grids. The error estimates are expressed in terms of a power of the ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

A conceptual variable is any variable defined by a person or by a group of persons. Such variables may be inaccessible, meaning that they cannot be measured with arbitrary accuracy on the physical system under consideration ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

Let L⊂\R×J1(M) be a spin, exact Lagrangian cobordism in the symplectization of the 1-jet space of a smooth manifold M. Assume that L has cylindrical Legendrian ends Λ±⊂J1(M). It is well known that the Legendrian contact ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

(Chapter / Bokkapittel / PublishedVersion; Peer reviewed, 2019)

Environmental contours are widely used as a basis for e.g., ship design, especially in early design phases. The traditional approach to such contours is based on the well-known Rosenblatt transformation. In the present ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

Instabilities arise in a number of flow configurations. One such manifestation is the development of interfacial waves in multiphase flows, such as those observed in the falling liquid film problem. Controlling the development ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

We consider a banking network represented by a system of stochastic differential equations coupled by their drift. We assume a core-periphery structure, where banks in the core hold a bubbly asset. Investments are modeled ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

In this paper we present a new method for the construction of strong solutions of SDE’s with merely integrable drift coefficients driven by a multidimensional fractional Brownian motion with Hurst parameter H<1/2. Furthermore, ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

Kinetic simulation results are presented to study the response of multi-Needle Langmuir Probes of the type used on many satellites. Simulations of isolated probes are used to parametrize the current collected as a function ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

Given a Stein manifold with the density property, we show that under a suitable topological condition it is possible to prescribe derivatives at a finite number of points to automorphisms depending holomorphically on a ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

Risk measure is a fundamental concept in finance and in the insurance industry. It is used to adjust life insurance rates. In this article, we will study dynamic risk measures by means of backward stochastic Volterra ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

The utility of flow simulations relies on the robustness of computational fluid dynamics (CFD) solvers and reproducibility of results. The aim of this study was to validate the Oasis CFD solver against in vitro experimental ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

Stratified gas–liquid flow is a flow regime typically encountered in multiphase pipelines. The understanding and modeling of this regime is of engineering importance especially for the oil and gas industry. In this work, ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

We consider a model for flow of liquid and gas in a pipe. We assume that the gas is ideal and that the liquid is incompressible. Under this assumption the resulting system of equations, expressing conservation of mass and ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

The collected current by spherical and cylindrical Langmuir probes immersed in an unmagnetized and collisionless non-Maxwellian plasma at rest are theoretically studied, and analytical expressions for the currents of ...

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2019)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

An elastic sheet that deforms near a solid substrate in a viscous fluid is a situation relevant to various dynamical processes in biology, geophysics, and engineering. Here, we study the relaxation dynamics of an elastic ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

Our purpose of this paper is to study stochastic control problems for systems driven by mean-field stochastic differential equations with elephant memory, in the sense that the system (like the elephants) never forgets its ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

Excitable biological cells, such as cardiac muscle cells, can exhibit complex patterns of oscillations such as spiking and bursting. Moreover, it is well known that an enhancement in calcium currents may yield certain kind ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

Given a free unitary quantum group G = Au(F), with F not a unitary 2-by-2 matrix, we show that the Martin boundary of the dual of G with respect to any G-Gˆ-invariant, irreducible, finite range quantum random walk coincides ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

In this paper we study the Ostrovsky–Hunter equation for the case where the flux function f(x, u) may depend on the spatial variable with certain smoothness. Our main results are that if the flux function is smooth enough ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

Principal component analysis (PCA) is often used in anomaly detection and statistical process control tasks. For bivariate normal data, we prove that the minor projection (the least varying projection) of the PCA‐rotated ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

We study the algebraic combinatorics of monomial degenerations of Plücker forms which is governed by matching fields in the sense of Sturmfels and Zelevinsky. We provide a necessary condition for a matching field to yield ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

This paper is devoted to the multivariate estimation of a vector of Poisson means. A novel loss function that penalises bad estimates of each of the parameters and also the sum (or equivalently the mean) of the parameters ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

Atlantic cod (Gadus morhua) is an ecologically important species with a wide‐spread distribution in the North Atlantic Ocean, yet little is known about the diversity of its intestinal microbiome in its natural habitat. No ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

We study vehicular traffic on a road with multiple lanes and dense, unidirectional traffic following the traditional Lighthill--Whitham--Richards model where the velocity in each lane depends only on the density in the ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

We prove a necessary and sufficient condition in terms of the barycenters of a collection of polytopes for existence of coupled Kähler–Einstein metrics on toric Fano manifolds. This confirms the toric case of a coupled ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

This work introduces a general concept of center for graphs, built on the model of the characteristic set ([12], [14]) of trees. We define it as the set of cycles in a specific directed graph associated with the original ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

We perform an experimental analysis of two-phase stratified wavy pipe flow, with the aim to detect and quantify the effect of small scale wave breaking. Particle image velocimetry is employed to analyze the velocity fields ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

We present the first application of an Artificial Neural Network trained through a Deep Reinforcement Learning agent to perform active flow control. It is shown that, in a 2D simulation of the Kármán vortex street at ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

Internal solitary waves (ISWs) propagating in a stably stratified two‐layer fluid in which the upper boundary condition changes from open water to ice are studied for grease, level, and nilas ice. The ISW‐induced current ...

(Doctoral thesis / Doktoravhandling, 2019)

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

Data integration, i.e. the use of different sources of information for data analysis, is becoming one of the most important topics in modern statistics. Especially in, but not limited to, biomedical applications, a relevant ...

(Doctoral thesis / Doktoravhandling, 2019)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2019)

We consider Tchebycheffian spline spaces over planar T-meshes and we study their dimension. We show that the structure of extended Tchebycheff spaces allows us to fully generalize the dimension upper bounds known in the ...