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Now showing items 1-100 of 2341

(Doctoral thesis / Doktoravhandling, 2020)

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)

Background
Infusion testing is a common procedure to determine whether shunting will be beneficial in patients with normal pressure hydrocephalus. The method has a well-developed theoretical foundation and ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)

Background
The standard lasso penalty and its extensions are commonly used to develop a regularized regression model while selecting candidate predictor variables on a time-to-event outcome in high-dimensional ...

(Doctoral thesis / Doktoravhandling, 2020)

Dementia is a growing concern for the health-care in the world and most treatment strategies are not successful. Dementia is associated with accumulation of metabolic waste in the form of protein fragments. Recent breakthroughs ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)

We classify rational, irreducible quartic symmetroids in projective 3-space. They are either singular along a line or a smooth conic section, or they have a triple point or a tacnode.

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)

Background
Graph-based reference genomes have become popular as they allow read mapping and follow-up analyses in settings where the exact haplotypes underlying a high-throughput sequencing experiment are ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)

Time integration of Fourier pseudospectral DNS is usually performed using the classical fourth‐order accurate Runge‐Kutta method or other second‐ or third‐order methods, with a fixed step size. We investigate the use of ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)

(Doctoral thesis / Doktoravhandling, 2020)

In the last decades the analytical value of data has really become apparent and the amount of data collected has vastly increased. This enables us to approach problems in more data driven manners. In the thesis, I have ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)

This paper is concerned with properties of permutation matrices and alternating sign matrices (ASMs). An ASM is a square (0,±1)-matrix such that, ignoring 0’s, the 1’s and −1’s in each row and column alternate, beginning ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)

Present first-order based design code formulations for slender columns in frames with sway, employ sway magnification factors (for global second-order effects) also as moment magnifiers for the individual columns of the ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)

We define Chern–Schwartz–MacPherson (CSM) cycles of an arbitrary matroid. These are balanced weighted fans supported on the skeleta of the corresponding Bergman fan. In the case that the matroid arises from a complex ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)

We report laboratory experiments of long-crested irregular water surface waves propagating over a shoal. For a sufficiently shallow shoal we find that the surface elevation can have a local maximum of skewness and kurtosis ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)

In this paper we aim at modeling stochastic transition rates of state processes in life insurance by using generalized Cox processes. A feature of a our non-Gaussian model is that it can be used to capture ‘regime switching’ ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)

Principal component analysis (PCA) is a common tool in the literature and widely used for process monitoring and fault detection. Traditional PCA is associated with the two well-known control charts, the Hotelling’s T2 and ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)

The continuous growth in maritime traffic and recent developments towards autonomous navigation have directed increasing attention to navigational safety in which new tools are required to identify real-time risk and complex ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)

In this paper, we consider the Keller–Segel chemotaxis system with additional cross-diffusion term in the second equation. This system is consisting of a fully nonlinear reaction–diffusion equations with additional ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)

Spot option prices, forwards and options on forwards relevant for the commodity markets are computed when the underlying process S is modelled as an exponential of a process ξ with memory as, e.g., a Volterra equation ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)

Environmental contours are used in structural reliability analysis of marine and coastal structures as an approximate means to locate the boundary of the distribution of environmental variables, and hence sets of environmental ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)

An old question of Mori asks whether in dimension at least three, any smooth specialization of a hypersurface of prime degree is again a hypersurface. A positive answer to this question is only known in degrees two and ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)

We study the logical and computational properties of basic theorems of uncountable mathematics, in particular Pincherle's theorem, published in 1882. This theorem states that a locally bounded function is bounded on certain ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)

Successful trading in electricity markets relies on the market actor's ability to accurately forecast the electricity price. The fundamental electricity price models use market information, provided by various price drivers, ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)

Numerical simulations of granular flows with Navier–Stokes type models emerged in the last decade, challenging the well established depth-averaged models. The structure of these equations allows for extension to general ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)

We argue that the very effective cover of hermitian K-theory in the sense of motivic homotopy theory is a convenient algebro-geometric generalization of the connective real topological K-theory spectrum. This means the ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)

Kemeny's constant κ(G) of a connected undirected graph G can be interpreted as the expected transit time between two randomly chosen vertices for the Markov chain associated with G. In certain cases, inserting a new edge ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2020)

We derive bounds for the constants in Poincaré–Friedrichs inequalities with respect to mesh-dependent norms for complexes of discrete distributional differential forms. A key tool is a generalized flux reconstruction which ...

(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 / 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)

The purpose of this paper is to study the following topics and the relation between them: (i) Optimal singular control of mean-field stochastic differential equations with memory; (ii) reflected advanced mean-field backward ...

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

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

We compute the 1-line of stable homotopy groups of motivic spheres over fields of characteristic not two in terms of hermitian and Milnor K-groups. This is achieved by solving questions about convergence and differentials ...

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2019)

We study optimal control of stochastic Volterra integral equations (SVIE) with jumps by using Hida-Malliavin calculus.
We give conditions under which there exist unique solutions of such equations.
Then we prove both a ...

(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)

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)

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 / 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 / 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)

(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 / 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)

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)

(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)

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)

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)

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)

(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)

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

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

(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 / 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), ...

(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 / 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 / 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 / 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)

In parametric copula setups, where both the margins and copula have parametric forms, two-stage maximum likelihood estimation, often referred to as inference functions for margins, is used as an attractive alternative to ...

(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 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 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 / SubmittedVersion, 2019)

(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 / 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 ...

(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 / 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 / AcceptedVersion; Peer reviewed, 2019)

Let G be an undirected simple graph. The signless Laplacian spread of G is defined as the maximum distance of pairs of its signless Laplacian eigenvalues. This paper establishes some new bounds, both lower and upper, for ...

(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 / 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 / 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 / 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 ...

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 ...

(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 / 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 ...

(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)

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 parallel to sustainable growth in solar fraction, continuous reductions in Photovoltaic (PV) module and installation costs fuelled a profound adoption of residential Rooftop Mounted PV (RMPV) installations already ...

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

Bayesian hypothesis testing procedures are constructed by means of test statistics which are functions of the posterior distribution. Usually, the whole sample vector is selected to form the sufficient empirical part of ...

(Doctoral thesis / Doktoravhandling, 2019)

A particular class of Partial differential Equations (PDEs) is the hyperbolic conservation laws which play an instrumental role in numerous real life applications such as synchronization of cardiac pacemakers, traffic flow ...

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

(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)

This article presents a novel comprehensive learning bat algorithm (CLBAT) for the optimal coordinated design of power system stabilizers (PSSs) and static VAR compensator (SVC) for damping electromechanical oscillations ...

(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 ...

(Doctoral thesis / Doktoravhandling, 2019)

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

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

(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 / 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 ...

(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)