## Search

Now showing items 301-400 of 2505

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

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

Consider the problem of minimizing a quadratic objective subject to quadratic equations. We study the semialgebraic region of objective functions for which this problem is solved by its semidefinite relaxation. For the ...

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

The solution of the continuous time filtering problem can be represented as a ratio of two expectations of certain functionals of the signal process that are parametrized by the observation path. We introduce a class of ...

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

Seismic exploration in complex geological settings and shallow geological targets has led to a demand for higher spatial and temporal resolution in the final migrated image. Seismic data from conventional marine acquisition ...

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

We construct a holomorphic embedding ϕ:B3→C3 such that ϕ(B3) is not Runge in any strictly larger domain. As a consequence, S≠S1 for n=3.

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

Cox’s proportional hazards regression model is the standard method for modelling censored life-time data with covariates. In its standard form, this method relies on a semiparametric proportional hazards structure, leaving ...

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

We show that there is a unique hypersurface of minimal degree passing through the non-faces of a polytope which is defined by a simple hyperplane arrangement. This generalizes the construction of the adjoint curve of a ...

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

Planning maritime surveillance activities in military operations and long-term defense planning is a huge task that is done manually today. Because maritime surveillance resources are extremely expensive, the potential ...

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

Mean value interpolation is a method for fitting a smooth function to piecewise-linear data prescribed on the boundary of a polygon of arbitrary shape, and has applications in computer graphics and curve and surface ...

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2019)

We expand the celebrated Alòs decomposition formula of the call price under the Heston model in a Taylor type series of in nite stochastic terms. This expansion is a di erent representation of a formula given in a recent ...

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

We consider a stochastic hydroelectric power plant management problem in discrete time with arbitrary scenario space. The inflow to the system is some stochastic process, representing the precipitation to each dam. The ...

(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 / PublishedVersion; Peer reviewed, 2019)

The effect of an external magnetic field on the formation of the wake in the potential distribution behind a dust grain is studied with self-consistent Particle-In-Cell numerical simulations. The collisionless plasma flow ...

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2019)

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2019)

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2019)

The Neumann problem of linear elasticity is singular with a kernel formed by the rigid motions of the body. There are several tricks that are commonly used to obtain a nonsingular linear system. However, they often cause ...

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

In this paper we study mean–variance hedging under the -expectation framework. Our analysis is carried out by exploiting the -martingale representation theorem and the related probabilistic tools, in a continuous financial ...

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

(Doctoral thesis / Doktoravhandling, 2019)

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

Two stationary and non-negative processes that are based on continuous-time autoregressive moving average (CARMA) processes are discussed. First, we consider a generalization of Cox–Ingersoll–Ross (CIR) processes. Next, ...

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

Several cardiovascular diseases are caused from localised abnormal blood flow such as in the case of stenosis or aneurysms. Prevailing theories propose that the development is caused by abnormal wall shear stress in focused ...

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

This paper studies a duopoly investment model with uncertainty. There are two alternative irreversible investments. The first firm to invest gets a monopoly benefit for a specified period of time. The second firm to invest ...

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

We study perfusion by a multiscale model coupling diffusion in the tissue and diffusion along the one-dimensional segments representing the vasculature. We propose a block-diagonal preconditioner for the model equations ...

(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 ...

(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 / 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)

Sea ice is highly complex due to the inhomogeneity of the physical properties (e.g. temperature and salinity) as well as the permeability and mixture of water and a matrix of sea ice and/or sea ice crystals. Such complexity ...

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

We present a new method for performing global redistributions of multidimensional arrays essential to parallel fast Fourier (or similar) transforms. Traditional methods use standard all-to-all collective communication of ...

(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 ...

(Research report / Forskningsrapport, 2019)

Columns in sway frames may be divided into laterally ``supporting (bracing) sway columns'', which can resist applied lateral shears, and ``supported (braced) sway columns'', which must have negative shears from the rest ...

(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 ...

(Doctoral thesis / Doktoravhandling, 2018)

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

The classical maximum principle for optimal stochastic control states that if a control û is optimal, then the corresponding Hamiltonian has a maximum at u=û. The first proofs for this result assumed that the control did ...

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

Background
Using high-dimensional penalized regression we studied genome-wide DNA-methylation in bone biopsies of 80 postmenopausal women in relation to their bone mineral density (BMD). The women showed ...

(Book / Bok / AcceptedVersion; Peer reviewed, 2018)

We develop a theory of crossed products by actions of Hecke pairs (G, Γ), motivated by applications in non-abelian C ∗ -duality. Our approach gives back the usual crossed product construction whenever G/Γ is a group and ...

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

In biomedical research, boosting-based regression approaches have gained much attention in the last decade. Their intrinsic variable selection procedure and ability to shrink the estimates of the regression coefficients ...

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

Let A be an n × n (0, ∗)-matrix, so each entry is 0 or ∗. An A-interval matrix is a (0, 1)-matrix obtained from A by choosing some ∗’s so that in every interval of consecutive ∗’s, in a row or column of A, exactly one ∗ ...

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

Aims
To the best of our knowledge, there are no systematic reviews or meta‐analyses that compare rasagiline, selegiline and safinamide. Therefore, we aimed to perform a drug class review comparing all available monoamine ...

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

In this paper we show that, with respect to the L2 norm, three classes of functions in Hr(0,1) , defined by certain boundary conditions, admit optimal spline spaces of all degrees ≥r−1 , and all these spline spaces ...

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

We prove some fundamental results like localization, excision, Nisnevich descent, and the regular blow-up formula for the algebraic K-theory of certain stack quotients of schemes with affine group scheme actions. We show ...

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

Given a finite-dimensional Hilbert space H and a collection of operators between its tensor powers satisfying certain properties, we give a short proof of the existence of a compact quantum group G with a fundamental ...

(Doctoral thesis / Doktoravhandling, 2018)

In this PhD thesis problems of Bayesian model selection and model averaging are addressed in various regression contexts. The approaches developed within the thesis are based on the idea of marginalizing out parameters ...

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

Wave statistical properties and occurrence of extreme and rogue waves in crossing sea states are investigated. Compared to previous studies a more extensive set of crossing sea states are investigated, both with respect ...

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

(Report / Rapport / SubmittedVersion, 2018)

For large multicomponent systems it is typically too costly to monitor the entire system constantly. In the present paper we consider a case where a component is unobserved in a time interval [0, T]. Here T is a stochastic ...

(Chapter / Bokkapittel / AcceptedVersion; Peer reviewed, 2018)

Slippery runways represent a significant risk to aircrafts especially during the winter season. In order to apply the appropriate braking action, the pilots need reliable information about the runway conditions. Unfortunately ...

(Chapter / Bokkapittel / AcceptedVersion; Peer reviewed, 2018)

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

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

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

We introduce a new majorization order for classes (sets) of matrices which generalizes several existing notions of matrix majorization. Roughly, the notion says that every matrix in one class is majorized by some matrix ...

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

We present a case of seismic reservoir characterization within a multi-source depositional setting. To resolve issues of non-uniqueness between intrinsic reservoir properties and the seismic data, we use a probabilistic ...

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

(Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 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 this ...

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

For large multicomponent systems it is typically too costly to monitor the entire system constantly. In the presentpaper we consider a case where a component is unobserved in a time interval [0, T]. The time T is a ...

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

We model the logarithm of the spot price of electricity with a normal inverse Gaussian (NIG) process and the wind speed and wind power production with two Ornstein–Uhlenbeck processes. In order to reproduce the correlation ...

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

The continuous-time version of Kyle [(1985) Continuous auctions and insider trading, Econometrica53 (6), 1315–1335.] developed by Back [(1992) Insider trading in continuous time, The Review of Financial Studies5 (3), ...

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

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2018)

Generalized linear mixed models (GLMM) are used for inference and prediction in a wide range of different applications providing a powerful scientific tool. An increasing number of sources of data are becoming available, ...

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

We study the Whitehead torsion of inertial h-cobordisms, continuing an investigation started in [12]. Of particular interest is a nested sequence of subsets of the Whitehead group, and a number of examples are given to ...

(Doctoral thesis / Doktoravhandling, 2018)

A simplicial set is said to be non-singular if its non-degenerate simplices are embedded. Let sSet denote the category of simplicial sets. We prove that the full subcategory nsSet whose objects are the non-singular simplicial ...

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

We propose a space–time discontinuous Galerkin (DG) method to approximate multi-dimensional non-conservative hyperbolic systems. The scheme is based on a particular choice of interface fluctuations. The key difference with ...

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

Extreme wave statistics of unidirectional and counter-propagating seas are investigated, for the special case of long-crested irregular waves, with laboratory experiments and with numerical simulations using the higher ...

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

The potential and density wake behind a finite-sized object in a magnetized collisionless plasma flow is studied with self-consistent numerical simulations. With increasing magnetization of the plasma, the standard picture ...

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

We solve affirmatively the homotopy limit problem for (effective) -theory over fields of finite virtual cohomological dimension. Our solution uses the motivic slice filtration and the first motivic Hopf map.

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

(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. ...

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

We investigate the effect of waves on the airflow in horizontal two-phase pipe flow. Velocity fields in the gaseous phase were acquired by particle image velocimetry (PIV), while interfacial elevation was measured with ...

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

We prove a Grothendieck–Lefschetz theorem for equivariant Picard groups of non-singular varieties with finite group actions.

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

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

Wave impact on a vertical wall has been investigated in a physical and numerical wave tank. Two different impact phenomena were explored. A flip-through, where the front face of the wave was moving rapidly vertical due to ...

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2018)

We study optimal control for mean-field stochastic partial differential equations (stochastic evolution equations) driven by a Brownian motion and an independent Poisson random measure, in case of partial information ...

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

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

We prove versions of the Suslin and Gabber rigidity theorems in the setting of equivariant pseudo pretheories of smooth schemes over a field with an action of a finite group. Examples include equivariant algebraic K-theory, ...

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

Powersum varieties, also called varieties of sums of powers, have provided examples of interesting relations between varieties since their first appearance in the 19th century. One of the most useful tools to study them ...

(Chapter / Bokkapittel / AcceptedVersion; Peer reviewed, 2018)

The main idea of this paper is to use the notion of buffered failure probability from probabilistic structural design, first introduced by Rockafellar & Royset (2010), to introduce buffered environmental contours. Classical ...

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

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

If a number of candidate variables are available, variable selection is a key task aiming to identify those candidates which influence the outcome of interest. Methods as backward elimination, forward selection, etc. are ...

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

We extend the Heston stochastic volatility model to a Hilbert space framework. The tensor Heston stochastic variance process is defined as a tensor product of a Hilbert-valued Ornstein–Uhlenbeck process with itself. The ...

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

The paper addresses projected changes of wave climate in the North Atlantic and their impact on the safe design of ships, with a particular focus given on associated uncertainties. The Fifth Assessment Report of the ...

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

We introduce and study a special class of ideals, called tropical ideals, in the semiring of tropical polynomials, with the goal of developing a useful and solid algebraic foundation for tropical geometry. The class of ...

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

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 ...

(Doctoral thesis / Doktoravhandling, 2018)

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

We investigate existence and uniqueness of strong solutions of mean-field stochastic differential equations with irregular drift coefficients. Our direct construction of strong solutions is mainly based on a compactness ...

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

We derive and study a Lax–Friedrichs-type finite volume method for a large class of nonlocal continuity equations in multiple dimensions. We prove that the method converges weakly to the measure-valued solution and converges ...

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

On reduced twisted group C*-algebras that are simple and/or have a unique trace

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

In this paper, we show how to approximate Heath–Jarrow–Morton dynamics for the forward prices in commodity markets with arbitrage-free models which have a finite-dimensional state space. Moreover, we recover a closed-form ...

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

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

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

We give a short proof of the convergence to the boundary of Riemann maps on varying domains. Our proof provides a uniform approach to several ad-hoc constructions that have recently appeared in the literature.

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

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

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

Knowledge about how information is stored in neurons of animals and in the human brain is still incomplete. A hypothesis related to long-term changes in synaptic efficiency has strong experimental support, but does not ...

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

We approximate smooth maps defined on non-compact totally real manifolds by holomorphic automorphisms of Cn.

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

Joint statistical models for long-term wave climate are a key aspect of offshore wind engineering design. However, to find a joint model for sea-state characteristics is often difficult due to the complex nature of the ...

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