Blar i NTNU Open på forfatter "Owren, Brynjulf"
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Kombinasjonen av eksplisitt og implisitt løser for simulering av den elektriske aktiviteten i hjertet.
Kaarby, Martin (Master thesis, 2007)Å skape realistiske simuleringer av et ECG-signal på en datamaskin kan være til stor nytte når man ønsker å forstå sammenhengen mellom det observerte ECG-signalet og hjertets tilstand. For å kunne få en realistisk simulering ... -
Learning Hamiltonians of constrained mechanical systems
Celledoni, Elena; Leone, Andrea; Murari, Davide; Owren, Brynjulf (Peer reviewed; Journal article, 2022)Recently, there has been an increasing interest in modelling and computation of physical systems with neural networks. Hamiltonian systems are an elegant and compact formalism in classical mechanics, where the dynamics is ... -
Lie Group Integrators for Cotangent Bundles of Lie Groups and Their Application to Systems of Dipolar Soft Spheres
Kjer, Vanje Rebni (Master thesis, 2017)The objective of this thesis is to study numerical integrators and their application to solving ordinary differential equations arising from mechanical systems. Many mechanical problems are naturally formulated on Lie ... -
Lie Group integrators for mechanical systems
Celledoni, Elena; Çokaj, Ergys; Leone, Andrea; Murari, Davide; Owren, Brynjulf (Peer reviewed; Journal article, 2021)Since they were introduced in the 1990s, Lie group integrators have become a method of choice in many application areas. These include multibody dynamics, shape analysis, data science, image registration and biophysical ... -
Minimal Surfaces in Sub-Riemannian Geometries with Applications to Perceptual Completion
Viddal, Per Martin (Master thesis, 2009)A preliminary study of the papers ``A Cortical Based Model of Perceptual Completion in the Roto-Translation Space'' and ``Minimal Surfaces in the Roto-Translation Group with Applications to a Neuro-Biological Image Completion ... -
A novel approach to rigid spheroid models in viscous flows using operator splitting methods
Tapley, Benjamin; Celledoni, Elena; Owren, Brynjulf; Andersson, Helge Ingolf (Peer reviewed; Journal article, 2019)Calculating cost-effective solutions to particle dynamics in viscous flows is an important problem in many areas of industry and nature. We implement a second-order symmetric splitting method on the governing equations for ... -
Numerical Methods for Highly Oscillatory Problems
Asheim, Andreas (Doktoravhandlinger ved NTNU, 1503-8181; 2010:115, Doctoral thesis, 2010)Classical quadrature methods, i.e. methods for numerical integration,require discretizations that become more fine the more the integrandis oscillating. Conversely, asymptotic methods provide approximationsof the same ... -
Numerical Methods for Optical Interference Filters
Marthinsen, Håkon (Master thesis, 2009)We present the physics behind general optical interference filters and the design of dielectric anti-reflective filters. These can be anti-reflective at a single wavelength or in an interval. We solve the first case exactly ... -
Numerical Simulation of Interacting Bodies with Delays; Application to Marine Seismic Source Arrays.
Wisløff, Jens Fredrik Barra (Master thesis, 2007)This master thesis has looked at numerical simulation of interacting bodies with delays, especially the situation involving interacting airguns in seismic source arrays. The equations describing the airguns have been ... -
Obtaining Numerical Solutions to Ordinary Differential Equations on Differentiable Manifolds with Lie Group Integrators
Jakobsen, Erik André (Master thesis, 2021)Ordinære differensiallikningar (ODE-ar) er sentralt i fleire fagfelt; til dels mekanikk, finans, og det å lage vêrmeldingar. Dei velkjende Runge-Kutta metodane er ein av dei vanlegaste måtane å finne numeriske løysingar ... -
Predicting football tables by a maximally parsimonious model
Haugen, Kjetil K.; Owren, Brynjulf (Journal article; Peer reviewed, 2018)This paper presents some useful mathematical results concerned with football table prediction. In addition, some empirical results indicate that an alternative methodology for football table prediction may produce high ... -
Preservation of multiple first integrals in partial differential equations
Aune, Trygve (Master thesis, 2017)A wide variaty of partial differential equations have preserved entities like invariants and first integrals. In this thesis we will go into theory regarding preservation of such first integrals. Finally we will have the ... -
Riemannian Optimization for Deep Learning
Hellan, Ottar Passano (Master thesis, 2022)Sentrale konsepter og strukturer i riemannsk optimering presenteres og diskuteres for å gi en uavhengig behandling av Riemannian gradient descent-metoden (RGD). Egenskaper ved RGD diskuteres og sammenliknes med de av ... -
Robustness in supply chain management and design
Sværen, Martin Aspebakken (Master thesis, 2010)We have studied a supply chain for delivering biomass to heating plants where there are uncertainty in demand. Design of such supply chains considers finding the optimal terminal structure and an optimal inventory policy. ... -
Structure-preserving numerical methods with application to problems in particle dynamics
Tapley, Benjamin (Doctoral theses at NTNU;2021:189, Doctoral thesis, 2021) -
The Heterogeneous Multiscale Method and the Spinning Top
Fredbo, Maren (Master thesis, 2011)The heterogeneous multiscale method (HMM) was proposed by E and Engquist and is considered to be an efficient method for problems with multiple time scales. We give a short introduction to the HMM for multiscale problems ... -
THE INVESTIGATION OF APPROPRIATE CONTROL ALGORITHMS FOR THE SPEED CONTROL OF WIND TURBINE HYDROSTATIC SYSTEMS
Gulstad, Magnus Johan (Master thesis, 2007)This report consists of two chapters. The first is concerned with a new approach to pipe flow modelling and the second has to do with the simulation of the hydrostatic system which will be applied to a wind turbine.For the ... -
Three classes of quadratic vector fields for which the Kahan discretization is the root of a generalised Manin transformation
van der Kamp, Peter H.; Celledoni, Elena; Mclachlan, Robert, i; McLaren, David I.; Owren, Brynjulf; Quispel, Gilles Reinout Willem (Peer reviewed; Journal article, 2019)Three classes of quadratic vector fields for which the Kahan discretization is the root of a generalised Manin transformation -
Two classes of quadratic vector fields for which the Kahan discretization is integrable
Celledoni, Elena; McLachlan, I. Robert; McLaren, David; Owren, Brynjulf; Quispel, Reinout (Journal article, 2016) -
Using discrete Darboux polynomials to detect and determine preserved measures and integrals of rational maps
Celledoni, Elena; Evripidou, Charalambos; McLaren, David I.; Owren, Brynjulf; Quispel, Gilles Reinout Willem; Tapley, Benjamin; van der Kamp, Peter H. (Peer reviewed; Journal article, 2019)In this letter we propose a systematic approach for detecting and calculating integrals and preserved measures of rational maps. The approach is based on the use of cofactors and discrete Darboux polynomials and relies on ...