## Search

Now showing items 1-100 of 1263

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2018)

We discuss the internal structure of graph products of right LCM semigroups and prove that there is an abundance of examples without property (AR). Thereby we provide the first examples of right LCM semigroups lacking ...

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2018)

We introduce algebraic dynamical systems, which consist of an action of a right LCM semigroup by injective endomorphisms of a group. To each algebraic dynamical system we associate a C*-algebra and describe it as a semigroup ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2018)

We use Matsui and Takeuchi's formula for toric A-discriminants to give algorithms for computing local Euler obstructions and dual degrees of toric surfaces and 3-folds. In particular, we consider weighted projective spaces. ...

Approximations of Fractional Brownian Motion Restricted Access

(Master thesis / Masteroppgave, 2018)

(Master thesis / Masteroppgave, 2018)

The timing of cardiac events is essential for the analysis of certain components of myocardial function [36]. Finding an algorithm that detects these timings has therefore been the subject of several studies[36]. In this ...

(Master thesis / Masteroppgave, 2018)

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2018)

We propose a non-Gaussian operator-valued extension of the Barndorff-Nielsen and Shephard stochastic volatility dynamics, defined as the square-root of an operator-valued Ornstein–Uhlenbeck process with Lévy noise and ...

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2017)

We study the cones of surfaces on varieties of lines on cubic fourfolds and Hilbert schemes of points on K3 surfaces. From this we obtain new examples of nef cycles which fail to be pseudoeffective.

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

The final publication is available at IOS Press.

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

The final publication is available at IOS Press through http://dx.doi.org/10.3233/COM-170081

(Master thesis / Masteroppgave, 2017)

Conventional 2D medical ultrasound imaging is based on analyzing the backscatter (echoes) from multiple, focused, transmitted acoustic beams. Most imaging systems are very similar in the way they create and record beams. ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

We show that a cubic fourfold F that is apolar to a Veronese surface has the property that its variety of power sums V SP ( F, 10) is singular along a K 3 surface of genus 20 which is the variety of power sums of a sextic ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

We study the problem of optimal insider control of an SPDE (a stochastic evolution equation) driven by a Brownian motion and a Poisson random measure. Our optimal control problem is new in two ways:
- The controller has ...

(Master thesis / Masteroppgave, 2017)

The estimation of inverse covariance matrices plays a major role in portfolio optimization, for the global minimum variance portfolio in mean-variance analysis it is the only parameter used to determine the asset allocation. ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

The spatial and temporal development of shear-induced overturning billows associated with breaking internal solitary waves is studied by means of a combined laboratory and numerical investigation. The waves are generated ...

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2017)

We study how the geometry of a projective variety X is reflected in the positivity properties of the diagonal ΔX considered as a cycle on X×X. We analyze when the diagonal is big, when it is nef, and when it is rigid. In ...

(Master thesis / Masteroppgave, 2017)

Rubin (1987)’s combination formula for variance estimation in multiple imputation (MI) requires a imputation method to be Bayesian-proper. However, many census bureau have heavily relied on non-Bayesian imputations. Bjørnstad ...

(Master thesis / Masteroppgave, 2017)

(Master thesis / Masteroppgave, 2017)

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)

As modern biotechnologies advance, it has become increasingly frequent that different modalities of high-dimensional molecular data (termed “omics” data in this paper), such as gene expression, methylation, and copy number, ...

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2017)

The Grassmannian Gr(2,5) is embedded in ℙ9 via the Pl\"ucker embedding. The intersection of two general PGL(10)-translates of Gr(2,5) is a Calabi-Yau 3-fold X, and the intersection of the projective duals of the two ...

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2017)

We consider systems with memory represented by stochastic functional differential equations. Substantially, these are stochastic differential equations with coefficients depending on the past history of the process itself. ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)

Intrathecal drug and gene vector delivery is a procedure to release a solute within the cerebrospinal fluid. This procedure is currently used in clinical practice and shows promise for treatment of several central nervous ...

(Master thesis / Masteroppgave, 2017)

This thesis is devoted to presenting and illustrating a novel estimation method offering a way to reduce confounding bias in time-to-event situations. In order to reduce this bias, without having to observe all of the ...

(Research report / Forskningsrapport, 2017)

We consider a Navier-Stokes equation in two and three space dimensions subject to periodic boundary conditions and perturbed by a transport type noise. The perturbation is sufficiently smooth in space, but rough in time. ...

Strong solutions of d-dimensional SDE's with generalized drift and fractional Brownian initial noise

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2017)

In this paper we prove the existence of strong solutions to a SDE with a generalized drift driven by a multidimensional fractional Brownian motion for small Hurst parameters H<1/2. Here the generalized drift is given as ...

(Master thesis / Masteroppgave, 2017)

(Master thesis / Masteroppgave, 2017)

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2017)

We propose and investigate a valuation model for the income of selling tradeable green certificates (TGCs) in the Swedish–Norwegian market, formulated as a singular stochastic control problem. Our model takes into account ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

Let ℓ be a prime and q=pν, where p is a prime different from ℓ. We show that the ℓ–completion of the nth stable homotopy group of spheres is a summand of the ℓ–completion of the (n,0) motivic stable homotopy group of spheres ...

(Master thesis / Masteroppgave, 2017)

The traditional, linear representation of the genetic information in populations cause a loss of data, as it can not fully represent sites where the sequences differ. Conversely, a graph may incorporate the variation, ...

(Master thesis / Masteroppgave, 2017)

The mechanical behavior of the heart has been modeled for decades by using continuum mechanics and numerical methods. A widely used, but rarely discussed, assumption is that inertial effects can be neglected in these models. ...

(Master thesis / Masteroppgave, 2017)

OpenFOAM and FEniCS are two solver frameworks for solving computational fluid dynamics problems. The former employs the finite volume method to discretize the governing equations, while the latter employs the finite element ...

(Master thesis / Masteroppgave, 2017)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

We consider a scalar conservation law with zero-flux boundary conditions imposed on the boundary of a rectangular multidimensional domain. We study monotone schemes applied to this problem. For the Godunov version of the ...

(Master thesis / Masteroppgave, 2017)

The main goal of this thesis is to reproduce the article [SW16] by Sims and Williams, categorising the primitive ideal space of the class of Deaconu- Renault groupoid C*-algebras generated by N_0^k-actions. We go through ...

(Master thesis / Masteroppgave, 2017)

Muscle ultrasound imaging is a convenient technique to visualize normal and pathological muscle tissue. Studying muscle fascicle pennation angle and fascicle length and their dynamic changes during contraction are important ...

Pricing Freight Derivatives Restricted Access

(Master thesis / Masteroppgave, 2017)

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)

Background
It has been proposed that future reference genomes should be graph structures in order to better represent the sequence diversity present in a species. However, there is currently no standard ...

(Master thesis / Masteroppgave, 2017)

Computational models of fluids, structures, and the interaction between them shows good promise in science and engineering, with nearly infinitely many applications. However, fluid-structure interaction (FSI) is poorly ...

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2017)

We lift ambit fields to a class of Hilbert space-valued volatility modulated Volterra processes. We name this class Hambit fields, and show that they can be expressed as a countable sum of weighted real-valued volatility ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

We comment on the discretization of the Dirac equation using finite element spaces of differential forms. In order to treat perturbations by low order terms, such as those arising from electromagnetic fields, we develop ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

We propose a boundary quotient diagram for right LCM semigroups with property (AR) that generalizes the boundary quotient diagram for N⋊N×. Our approach focuses on two important subsemigroups: the core subsemigroup and the ...

(Master thesis / Masteroppgave, 2017)

In this thesis, we study what can be said about Fermat's Last Theorem using only elementary methods. We will study the work of Sophie Germain and Niels Henrik Abel, both who worked with Fermat’s Last Theorem in the early ...

(Master thesis / Masteroppgave, 2017)

In this thesis we consider sextactic points on plane algebraic curves and a 2-Hessian curve that identifies these points. This curve was first established by Cayley, and we prove that Cayley's 2-Hessian is wrong. Moreover, ...

(Chapter / Bokkapittel / SubmittedVersion, 2017)

Electricity infrastructure has become a critical element of modern industrial society. In order to model and analyse this infrastructure, identify weaknesses, and optimize performance, one needs to take into account its ...

(Master thesis / Masteroppgave, 2017)

Millions of people world wide suffer from asthma, and respiratory diseases are one of the leading causes of death. Patients can be treated or relieved by inhalation of medicine, but the efficiency of the treatment is often ...

(Master thesis / Masteroppgave, 2017)

(Master thesis / Masteroppgave, 2017)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

We show that a Hilbert scheme of conics on a Fano fourfold double cover of P2×P2 ramified along a divisor of bidegree (2,2) admits a P1-fibration with base being a hyper-Kähler fourfold. We investigate the geometry of such ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)

Background: Using computational fluid dynamics (CFD) to compute the hemodynamics in cerebral aneurysms has received much attention in the last decade. The usability of these methods depends on the quality of the computations, ...

Topics in Confidence Distributions Restricted Access

(Master thesis / Masteroppgave, 2017)

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)

Proper orthogonal decomposition (POD) is applied to distinct data sets in order to characterize the propagation of error arising from basis truncation in the description of turbulence. Experimental data from stereo particle ...

(Master thesis / Masteroppgave, 2017)

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)

Versatile instruments assembled from off-the-shelf sensors and open-source electronics are used to record wave propagation and damping measured by Inertial Motion Units (IMUs) in a grease ice slick near the shore in ...

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2017)

Traditional programs based on feature engineering are under performing on a steadily increasing number of tasks compared with Artificial Neural Networks (ANNs), in particular for image analysis. Image analysis is widely ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)

In this paper, we study weak solutions to the following nonlinear parabolic partial differential equation ∂tu−diva(x,t,∇u)+λ(|u|p(x,t)−2u)=0inΩT, where λ≥0 and ∂tu denote the partial derivative of u with respect to the ...

(Research report / Forskningsrapport, 2017)

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)

Landslides are the second-most important cause of tsunamis after earthquakes, and their potential for generating large tsunamis depend on the slide process. Among the world's largest submarine landslides is the Storegga ...

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2017)

In this paper we construct a new type of noise of fractional nature that has a strong regularizing effect on differential equations. We consider an equation with this noise with a highly irregular coefficient. We employ a ...

(Master thesis / Masteroppgave, 2017)

Environmental contours are used as a basis for e.g., ship designs. The traditional approach to environmental contours is based on the well-known Rosenblatt transformation. However, due to the effects of this transformation ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

The problem on identification of a limit of an ordinary differential equation with discontinuous drift that perturbed by a zero-noise is considered in multidimensional case. This problem is a classical subject of stochastic ...

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2017)

This paper proposes a Finite Difference Multilevel Monte Carlo algorithm for degener- ate parabolic convection diffusion equations where the convective and diffusive fluxes are allowed to be random. We establish a notion ...

(Master thesis / Masteroppgave, 2017)

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)

Background
We have previously reported a high incidence of colorectal cancer (CRC) in carriers of pathogenic MLH1 variants (path_MLH1) despite follow-up with colonoscopy including polypectomy.
...

(Master thesis / Masteroppgave, 2017)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

The Lagrangian paths, horizontal Lagrangian drift velocity, U L , and the Lagrangian excess period, T L − T 0 , where T L is the Lagrangian period and T 0 the Eulerian linear period, are obtained by ...

(Master thesis / Masteroppgave, 2017)

Målet ved denne artikkelen er å analysere forholdet mellom vri- og flyttespill og symmetrigruppen. Vi skal se sammenhengen mellom gruppeteori og mange populære spill, spesielt når man vil løse spillene

(Master thesis / Masteroppgave, 2017)

In the recent decade, artificial intelligence and machine learning has become increasingly popular for solving complex real-world problems. In particular problems which was believed to be very hard or in some cases impossible ...

(Master thesis / Masteroppgave, 2017)

This thesis aims at pricing Contract-for-Difference (CFD) in stock market, and Electricity Price Area Differential (EPAD) in the Nord Pool. For CFD, our model consists of Geometric Brownian Motion and Vasicek process. For ...

(Master thesis / Masteroppgave, 2017)

We consider the bidomain model of cardiac electrophysiology. Departing from a discrete cellular model we derive the bidomain equations by homogenization. Using two-scale convergence we provide a rigorous homogenization ...

Alternative models for reinsurance in Solvency II Restricted Access

(Master thesis / Masteroppgave, 2017)

(Master thesis / Masteroppgave, 2017)

Parametric representations of surfaces in Computer-Aided Geometric Design (CAGD) are often based on connected patches with rectangular parameter domains. Given a loop of four space curves and normal-derivative curves, we ...

Detecting fraud using information from social networks Restricted Access

(Master thesis / Masteroppgave, 2017)

With all the technological progress we have witnessed during the last couple of decades, it comes as no surprise that modern fraudsters use highly complex methods to disguise their suspicious activities. Traditional ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)

We study congruences of lines $X_\omega $ defined by a sufficiently general choice of an alternating 3-form $\omega $ in $n+1$ dimensions, as Fano manifolds of index $3$ and dimension $n-1$. These congruences include the ...

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2017)

The attenuation of surface gravity waves is an important process associated with air–sea and wave–current interactions. Here we investigate experimentally the attenuation of monochromatic surface gravity waves due to the ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

We analyse a semidiscrete splitting method for conservation laws driven by a semilinear noise term. Making use of fractional bounded variation (BV) estimates, we show that the splitting method generates approximate solutions ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)

We use assembly maps to study TC.AŒG I p/, the topological cyclic homology at a prime p of the group algebra of a discrete group G with coefficients in a connective ring spectrum A. For any finite group, we prove that the ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

Time change is a powerful technique for generating noises and providing flexible models. In the framework of time changed Brownian and Poisson random measures we study the existence and uniqueness of a solution to a general ...

(Chapter / Bokkapittel / SubmittedVersion, 2017)

With the shenfun Python module (github.com/spectralDNS/shenfun) an effort is made towards automating the implementation of the spectral Galerkin method for simple tensor product domains, consisting of (currently) one ...

(Master thesis / Masteroppgave, 2017)

(Chapter / Bokkapittel / PublishedVersion; Peer reviewed, 2017)

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2017)

The directional wave spectra in sea ice are an important aspect of wave evolution and can provide insights into the dominant components of wave dissipation, that is, dissipation due to scattering or dissipation due to ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

We determine the structure of equilibrium states for a natural dynamics on the boundary quotient diagram of C*-algebras for a large class of right LCM semigroups. The approach is based on abstract properties of the semigroup ...

(Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)

Let GG be an affine group scheme over a noetherian commutative ring RR. We show that every GG-equivariant vector bundle on an affine toric scheme over RR with GG-action is equivariantly extended from Spec ( R ) Spec(R) for ...

(Chapter / Bokkapittel / PublishedVersion; Peer reviewed, 2017)

Cohomology of Projective Systems on Ranked Posets Restricted Access

(Master thesis / Masteroppgave, 2017)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

Using Macaulay’s correspondence we study the family of Artinian Gorenstein local algebras with fixed symmetric Hilbert function decomposition. As an application we give a new lower bound for the dimension of cactus varieties ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

The notion of higher order dual varieties of a projective variety, introduced in \cite{P83}, is a natural generalization of the classical notion of projective duality. In this paper we present geometric and combinatorial ...

(Chapter / Bokkapittel / PublishedVersion; Peer reviewed, 2017)

(Journal article / Tidsskriftartikkel / PublishedVersion, 2017)

Through our work with teaching and learning mathematics at university level, we experience that students can benefit from tips on how to study, and in particular how to study mathematics.
The Department of Mathematics at ...

(Master thesis / Masteroppgave, 2017)

This thesis investigates the appliance of the finite element method to long wave propagation in channels. Weak formulations of potential- and velocity based Boussinesq equations were derived, with the normal dependent ...

(Master thesis / Masteroppgave, 2017)

In this thesis results from numerical simulations of long wave run-up on composite beaches are presented along with the analytical solution to the linear problem. The purpose of this study is to find out which parts of the ...

Simulating sleep. Restricted Access

(Master thesis / Masteroppgave, 2017)

(Chapter / Bokkapittel / PublishedVersion; Peer reviewed, 2017)

(Chapter / Bokkapittel / PublishedVersion; Peer reviewed, 2017)

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

A well-known application of Malliavin calculus in mathematical finance is the probabilistic representation of option price sensitivities, the so-called Greeks, as expectation functionals that do not involve the derivative ...

(Master thesis / Masteroppgave, 2017)

Computations in general insurance are often based on models such as the collective risk model, which uses a compound distribution to describe the aggregated losses. A critical part of this model is the un- certainty of ...

(Research report / Forskningsrapport, 2017)

There are many different numerical methods for solving the Navier-Stokes equations for problems with a free surface. Some examples are volume of fluid (VOF), Marker and cell (MAC), level set, smooth particle hydrodynamics ...

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2017)

We consider the problem of finding a maximum k-regular induced subgraph of a graph G. Theoretical results are established to compare upper bounds obtained from different techniques, including bounds from quadratic programming, ...