## Search

Now showing items 1-100 of 2600

(Master thesis / Masteroppgave, 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)

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)

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)

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 ...

Metoder og metodiske utfordringer for matchede kohortstudier Restricted Access

(Master thesis / Masteroppgave, 2018)

Når man estimerer effekten av en bestemt behandling eller eksponering på utfall i kohortstudier, og observasjonsstudier generelt, gir ikke standard metoder korrekte resultater i nærvær av ukontrollert konfundering. Matching ...

(Master thesis / Masteroppgave, 2018)

In this thesis we implement and employ a simplex spline basis developed by Cohen, Lyche, and Riesenfeld for the space of C1 quadratic splines on the Powell–Sabin 12-split of a triangle. A matrix recursion is used for ...

(Master thesis / Masteroppgave, 2018)

The objective of this thesis is to give a description of the rough stochastic volatility modelling based on fractional Brownian motion with Hurst exponent H less than 1/2, as well as the corresponding pricing model. ...

(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)

We investigate the Smith Normal Form (SNF) of alternating sign matrices (ASMs) and related matrices of 0’s and 1’s ((0, 1)-matrices). We identify certain classes of ASMs and (0, 1)-matrices whose SNFs are (0, 1)-matrices. ...

(Master thesis / Masteroppgave, 2018)

Cancer is a major public health problem worldwide where it is the second leading cause of death. To improve safety and efficacy of anti-cancer drugs with less side effects, nanoparticles (NPs) have been studied heavily. ...

(Master thesis / Masteroppgave, 2018)

(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 ...

(Doctoral thesis / Doktoravhandling, 2018)

(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 ...

(Master thesis / Masteroppgave, 2018)

This master thesis will demonstrate how to price perpetual American options with linear programming. American options are used both for hedging and speculation, and being able to price derivatives, without creating arbitrage ...

(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 / 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 / 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 ...

(Master thesis / Masteroppgave, 2018)

Vi har sett på hvordan kinematikken i et irregulært, langkammet bølgefelt utvikler seg når bølgefeltet beveger seg over en grunne. Vi har funnet at den generelle oppførselen til skjevheten til hastighetsmålingene reflekterer ...

(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 / 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. ...

(Master thesis / Masteroppgave, 2018)

Given a non-principal ultrafilter, we define and prove properties of ultralimits of measure spaces (including σ-algebras, filtrations and measures), random variables and discrete-time stochastic processes. Among other ...

(Master thesis / Masteroppgave, 2018)

(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)

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)

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 ...

Modelling of Total Claim Amounts with Regime Switching in the Framework of Generalized Cox Processes

(Master thesis / Masteroppgave, 2018)

(Master thesis / Masteroppgave, 2018)

(Master thesis / Masteroppgave, 2018)

(Master thesis / Masteroppgave, 2018)

Recommender systems are algorithms that suggest content or products to users on the internet. These are becoming ever more important due to the massive growth of content on popular web sites, yet their design is often only ...

(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)

In this paper, we study the dynamics of a certain Hodgkin-Huxley model describing the action potential (AP) of a cardiac muscle cell for a better understanding of the occurrence of a special type of cardiac arrhythmia, the ...

(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)

This thesis investigates cubic hypersurfaces and their Fano schemes. After introducing the Fano schemes through low-dimensional examples, we move on to investigate cubic fourfolds. For the cubic fourfolds, we give complete ...

(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 ...

(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 ...

(Master thesis / Masteroppgave, 2018)

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

Stratified air-water flow in a horizontal pipe is investigated experimentally using particle image velocimetry and conductance probes. This flow regime is characterized by a complex interplay between a turbulent airflow ...

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

This study comprises the analysis and the interpretation of the coherent and the noncoherent parts of a coherent-on-receive microwave radar at grazing incidence conditions. The Doppler measurement is an extension of standard ...

(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 ...

(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, 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 ...

(Master thesis / Masteroppgave, 2018)

In this thesis, we consider the mod 2 homology of Q≥0S0 as an E∞ space and show the
following. The homologies H*Q≥0S0 and H*C∞S0 are isomorphic as free commutative
/2-algebras. The homology H*Q≥0S0 is generated as an ...

(Master thesis / Masteroppgave, 2018)

Applying the computational fluid dynamics software openFoam, we study dead water resistance on a barge. Dead water resistance is the extra drag due to internal waves in the interface between salt water and fresh water. For ...

(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, ...

Optimal reinsurance - an examination of optimal stop-loss contracts for different lines of business Restricted Access

(Master thesis / Masteroppgave, 2018)

Reinsurance is a risk management tool for insurance companies, as it allows for transferring some of the insurance risk to reinsurance companies. From the insurer's perspective, a reinsurance contract may lead to more ...

(Master thesis / Masteroppgave, 2018)

Compressed sensing is the study of solving underdetermined systems of linear equations with unique sparse solutions. In addition to this, applications of compressed sensing require that the number of rows of the measurement ...

(Master thesis / Masteroppgave, 2018)

(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 ...

Optimal reassuranse per portefølje Restricted Access

(Master thesis / Masteroppgave, 2018)

Det forsikringsselskaper ønsker minst er stor risiko og høye erstatningsbeløp til kundene. For å unngå stor risiko, kan et forsikringsselskap reforsikre seg hos én eller flere reassurandører. Tilgjengjeld må de betale ...

(Master thesis / Masteroppgave, 2018)

Solvency II er et forsikringsdirektiv som kontrollerer all forsikringsdrift i EU/EØS. Direktivet innebærer kontrollering av kapitalreserven, SCR, for hver av forsikringsselskapets porteføljer. Dette for å sikre forbrukerens ...

Hvor er jeg? Kan jeg regne det ut? Restricted Access

(Master thesis / Masteroppgave, 2018)

(Master thesis / Masteroppgave, 2018)

A Heron triangle is a triangle with integer sides and integer area. A rational triangle is a triangle with rational sides and area. We will set out to prove van Luijks Theorem, that there exist infinitely many non-similar ...

(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 / AcceptedVersion; Peer reviewed, 2018)

Two-phase dispersed and slug flows in a pipe are investigated using proper orthogonal decomposition (POD). The data are acquired through tomographic reconstruction of X-ray measurements, where holdup, cross-sectional phase ...

(Master thesis / Masteroppgave, 2018)

In this thesis, we consider models for survival data with a high-dimensional covariate space. Most models used for such datasets are based on the Cox regression model, of which a critical assumption is that the hazard ...

(Master thesis / Masteroppgave, 2018)

Usikkerhet rundt menneskers fremtidige levealder resulterer i stor risiko for livsforsikringsselskap. Retningslinene for kalkulering av slik risiko er satt av EU-kommisjonen og heter Solvency II. Denne oppgaven vil presenteres ...

(Master thesis / Masteroppgave, 2018)

Ventricular fibrillation (VF) occurs in ~10 % of myocardial infarction (MI) patients. These patients have higher in-hospital mortality and increased risk to lethal arrhythmias. The susceptibility for VF during acute MI and ...

(Master thesis / Masteroppgave, 2018)

In this thesis we begin by looking at polynomials of m n x n matrices invariant under simultaneous conjugation. Thereafter we connect the invariant polynomials to simple representations of noncommutative plane curves, ...

Can computing help in learning linear algebra? Restricted Access

(Master thesis / Masteroppgave, 2018)

Reserve modelling in the presence of extreme insurance losses Restricted Access

(Master thesis / Masteroppgave, 2018)

(Master thesis / Masteroppgave, 2018)

In this master thesis we will prove Dirichlet's theorem on primes in arithmetic progressions. The theorem states that there are an infinite number of primes in every primitive residue class modulo any positive number q, ...

(Master thesis / Masteroppgave, 2018)

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

(Master thesis / Masteroppgave, 2018)

Modeling of the blood flow in and around aneurysms with computational fluid dynamics (CFD) is important to better understand why aneurysms form and rupture. CFD modeling requires an accurate representation of the ...

(Master thesis / Masteroppgave, 2018)

Regression analysis is a commonly used approach to modelling the relationships between dependent and independent variables. When estimating the coefficients of a regression model, the least squares estimator is often used, ...

(Master thesis / Masteroppgave, 2018)

Denne oppgaven handler om beregning av risiko for forsikringsutbetalinger ved vindkatastrofer, og hvordan Solvency II gir en forenklet måte å beregne kapitalkrav som skal sikre selskapene fra insolvens med 99.5% sikkerhet. ...

(Master thesis / Masteroppgave, 2018)

The bidomain and monodomain models describing cardiac electrophysiology are computationally demanding to solve. Employing efficient numerical methods is therefore important for the practical use of these models. In this ...

(Master thesis / Masteroppgave, 2018)

The field of compressive sensing is a modern field in applied mathematics which receives a lot of attention. In this thesis, we will give some insight into the iterative algorithms used in compressive sensing. We will study ...

(Master thesis / Masteroppgave, 2018)

(Master thesis / Masteroppgave, 2018)

(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 / 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 ...

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

(Master thesis / Masteroppgave, 2018)

The recent results on non-uniqueness of the Euler equations, all based on the theory developed in the papers by Camillo De Lellis and László Székelyhidi Jr., are believed to be connected to the theory of turbulent fluid ...

(Master thesis / Masteroppgave, 2018)

This graduate thesis has been devoted to the examination of spectral methods. The object of the research is to analyse the accuracy and precision of different numerical schemes developed on the basis of mathematical models ...

(Master thesis / Masteroppgave, 2018)

Longitudinal data arise when repeated measurements are taken on individuals over time. Commonly used models for such data are multivariate linear models, linear mixed effect models and generalised linear mixed models. This ...

(Master thesis / Masteroppgave, 2018)

(Master thesis / Masteroppgave, 2018)

Computational fluid dynamics, with the software OpenFOAM, has ben used to investi- gate the dead water phenomenon. Investigation was done by simulating a barge moving in stratified waters. Comparison of the turbulence ...

Geometric and topological analysis of cortical folding Restricted Access

(Master thesis / Masteroppgave, 2018)

(Master thesis / Masteroppgave, 2018)

(Journal article / Tidsskriftartikkel / SubmittedVersion, 2018)

This study presents a statistical analysis of interfacial waves in a turbulent stratified air-water flow inside a 10 cm diameter pipe. Wave elevation measurements were acquired using conductance probes with high sampling ...

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

Modulational instability is an efficient mechanism for the generation of rogue waves in the limit of narrow-banded and long-crested wave fields. While such wave fields are easily achieved in laboratories, there appears to ...

(Doctoral thesis / Doktoravhandling, 2018)

Quantum groups are a noncommutative extension of the notion of a group and first appeared in the context of quantum mechanics. Now the theory of quantum groups has further developed and has become interesting in its own ...

Approximations of Fractional Brownian Motion Restricted Access

(Master thesis / Masteroppgave, 2018)

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

In this paper, we study strongly robust optimal control problems under volatility uncertainty. In the G-framework, we adapt the stochastic maximum principle to find necessary and sufficient conditions for the existence of ...

(Master thesis / Masteroppgave, 2018)

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

Multivalency achieves strong, yet reversible binding by the simultaneous formation of multiple weak bonds. It is a key interaction principle in biology and promising for the synthesis of high-affinity inhibitors of pathogens. ...

(Master thesis / Masteroppgave, 2018)

Environmental contours is commonly applied in e.g. ship design. The aim of this thesis is to study different methods of constructing environmental contours of sea states, and look at properties of these. Especially we will ...

(Master thesis / Masteroppgave, 2018)

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

We analyze the relation between completely positive (CP) divisibility and the lack of information backflow for an arbitrary—not necessarily invertible—dynamical map. It is well known that CP divisibility always implies a ...

(Doctoral thesis / Doktoravhandling, 2018)

The polar regions are the focus of increased attention due to a combination of environmental, political and economic reasons. In order to help support human activities in the arctic and monitor the state of the ecosystem, ...

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

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, 2018)

The properties of directional distributions in ocean wave spectra are studied, with an emphasis on sea states with bimodal directional distributions in the high-frequency tails of single-peaked wave systems. A peak-splitting ...

(Master thesis / Masteroppgave, 2017)

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

We construct 2D and 3D finite element de Rham sequences of arbitrary polynomial degrees with extra smoothness. Some of these elements have nodal degrees of freedom and can be considered as generalisations of scalar Hermite ...

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

-stability for entropy solutions of nonlinear degenerate parabolic convection–diffusion equations with discontinuous coefficients, Skr. K. Nor. Vidensk. Selsk. 3 (2003) 1–49], singles out the vanishing viscosity solution ...