Browsing Institutt for matematiske fag by Title
Now showing items 61-80 of 2359
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A Nonlinear Isogeometric Finite Element Analysis of a Wind Turbine Foil
(Master thesis, 2014)In the recent years, much attention has been given to the design of offshore wind turbines. Today, the largest wind turbine has a rotor diameter of 164m. The harsh environments expose the turbines to large forces from wind ... -
A Nonlinear Partial Differential Equation and Its Viscosity Solutions
(Master thesis, 2016)We study a nonlinear partial differential equation with Lipschitz continuous coefficient functions. Existence and uniqueness of viscosity solutions is proved by approximating with minimizers of variational integrals. The ... -
A note on entire L-functions
(Journal article; Peer reviewed, 2019)In this paper, we exhibit upper and lower bounds with explicit constants for some objects related to entire L-functions in the critical strip, under the generalized Riemann hypothesis. The examples include the entire ... -
A note on the local well-posedness for the whitham equation
(Journal article; Peer reviewed, 2015)We prove local well-posedness for the Whitham equation in Hs, s>32s>32, for both solitary and periodic initial data. -
A NOTE ON WELL-POSEDNESS OF BIDIRECTIONAL WHITHAM EQUATION
(Journal article; Peer reviewed, 2019)We consider the initial-value problem for the bidirectional Whitham equation, a system which combines the full two-way dispersion relation from the incompressible Euler equations with a canonical shallow-water nonlinearity. ... -
A Novel Profit Scoring Method for Classifying Credit Card Applications
(Master thesis, 2017)This thesis presents a new scoring method for credit card applications. The method balances the risk and the expected profits an applicant represents to a credit card company. In addition, the EMP cut-off selection procedure ... -
A Parallel Implementation of Mortal Random Walkers in the Pore Network of a Sandstone
(Master thesis, 2008)Simulations of the nuclear magnetic resonance relaxation method is an important part of a digital laboratory developed by Numerical Rocks. The laboratory is used to model petrophysical properties and simulating fluid flow ... -
A Parallel Multiscale Mixed Finite-Element Method for the Matlab Reservoir Simulation Toolbox
(Master thesis, 2012)We start by giving a brief introduction to reservoirs and reservoir modelling at different scales. We introduce a mathematical model for the two-phase flow, before we look at numerical discretizations. In particular we ... -
A Parallel Solution to Large Scale Hydropower Scheduling - By reducing the number of synchronization points in the Stochastic Dual Dynamic Programming (SDDP) Algorithm
(Master thesis, 2014)Stochastic dual dynamic programming (SDDP) has become a popular algorithm used in practical long-term scheduling of hydro power systems. The SDDP algorithm is significantly more computationally demanding than most ... -
A Parametric Version of Forstnerič’s Splitting Lemma
(Journal article; Peer reviewed, 2018)We construct solution operators to the \overline{\partial }-equation that depend continuously on the domain. This is applied to derive a parametric version of Forstnerič’s splitting lemma: If both the maps and the domains ... -
A PDE Based Approach to Path Finding in Three Dimensions: Solving a Path Finding Problem for an Unmanned Aerial Vehicle
(Master thesis, 2014)This thesis presents a general three-dimensional method for pathfinding, basedon a partial differential equation. The method relies on a grid with hazard-values,describing the risk associated with every point in the domain. ... -
A PDE-Based Strategy for Reconstructing Curves from Irregular and Unstructured Sampled Data
(Master thesis, 2021)Vi ser på todimensjonal rekonstruksjon av kurver fra et PDE-perspektiv. PDE-perspektivet er en implisitt nivåsett-tilnærming med formål om å håndtere irregulære datasett med støy. All teorien i denne oppgaven kan utvides ... -
A Phase Field Approach for a Modified Mumford-Shah Functional Based on Fractional Derivatives
(Master thesis, 2016)Recovering the true image, or true signal, from a corrupted one is by no means a trivial task, and we will in this paper study some approaches to finding good approximations to this unknown true image. The main focus will ... -
A Posteriori Error Estimation for Finite Element Methods and Iterative Linear Solvers
(Dr. ingeniøravhandling, 0809-103X; 2001:98, Doctoral thesis, 2001)This thesis addresses a posteriori error estimation for finite element methods and iterative linear solvers. Adaptive finite element methods have gained a lot of popularity over the last decades due to their ability to ... -
A Reduced Basis Method for steady Stokes flow
(Master thesis, 2018)In light of the increasing demand for many-query and real-time PDE solutions, reduced basis methods stand as a promising technique for developing solvers with the desired performance. In this thesis, we present the theory ... -
A remark on the Alexandrov–Fenchel inequality
(Journal article; Peer reviewed, 2018)In this article, we give a complex-geometric proof of the Alexandrov–Fenchel inequality without using toric compactifications. The idea is to use the Legendre transform and develop the Brascamp–Lieb proof of the Prékopa ... -
A Review of Finite Approximations, Archimedean and Non-Archimedean
(Journal article; Peer reviewed, 2018)We give a review of finite approximations of quantum systems, both in an Archimedean and a non-Archimedean setting. Proofs will generally be omitted. In the Appendix we present some numerical results. -
A Roadmap to Fully Homomorphic Elections: Stronger Security, Better Verifiability
(Chapter, 2017)After the trials of remote internet voting for local elections in 2011 and parliamentary elections in 2013, a number of local referendums has renewed interest in internet voting in Norway. The voting scheme used in ... -
A robustness evaluation of the latent manifold tuning model
(Master thesis, 2020)Nye teknikker for nevrale opptak setter forskere i stand til å gjøre simultanopptak av aktiviteten til stadig flere nevroner. Teknikker for dimensjonsreduksjon kan brukes til å undersøke hvordan nevroner jobber sammen som ... -
A Security Analysis of the Helios Voting Protocol and Application to the Norwegian County Election
(Master thesis, 2014)We present Helios, an end-to-end verifiable internet voting system. We describe the existing protocol, the encryption and decryption process with corresponding proofs, and analyse an attack against ballot secrecy. Further ...