Browsing Department of Mathematics by Title
Now showing items 790-809 of 1118
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Physical activity level at work and risk of chronic low back pain: A follow-up in the Nord-Trøndelag Health Study
(Peer reviewed; Journal article, 2017-04-10)Background: Physical activity in leisure time seems to reduce the risk of low back pain, but it is not known whether occupational activity, as recorded in a representative working population, produces a higher or lower ... -
Physics Informed Neural Networks for Inverse Advection-Diffusion Problems
(Master thesis, 2021-11-22)In this study, we will address the problem of localising a source of pollutant given a sparse set of noisy data. By sparse we mean spatially separated time-series measurements in space. To this end, we will be adopting a ... -
Plant Identification with Computer Vision and Improvement Through Location Data
(Master thesis, 2024-06-03)Det ˚a kunne riktig identifisere arter er et veldig viktig verktøy i kampen for ˚a bevare artsmangfoldet i verden, men dette er kunnskap som er enten forbeholdt eksperter, eller s˚a er det veldig tidskrevende for ufagkyndige. ... -
Polariseringer av artinske monomidealer assosiert til simplisielle komplekser
(Master thesis, 2024-12-03) -
Polarizations of powers of graded maximal ideals
(Journal article; Peer reviewed, 2022)We give a complete combinatorial characterization of all possible polarizations of powers of the graded maximal ideal (x1, x2, . . . , xm) n of a polynomial ring in m variables. We also give a combinatorial description of ... -
Polish Translation and Validation of the Tinnitus Handicap Inventory and the Tinnitus Functional Index
(Peer reviewed; Journal article, 2016-11-29)Objective: The need for validated measures enabling clinicians to classify tinnitus patients according to the severity of tinnitus and screen the progress of therapies in our country led us to translate into Polish and to ... -
Polynomials homologically supported on determinantal loci
(Department of Pure Mathematics report no. 61, Research report, 1991-10) -
A pore network model for calculation of interfacial velocities
(Peer reviewed; Journal article, 2003)Two-phase flow in porous media is characterized by fluid-fluid interfaces that separate the fluid phases at the pore scale. These interfaces support pressure differences between phases, and their dynamics allow for saturation ... -
A pore-scale model for permeable biofilm: Numerical simulations and laboratory experiments
(Peer reviewed; Journal article, 2019)In this paper, we derive a pore-scale model for permeable biofilm formation in a two-dimensional pore. The pore is divided into two phases: water and biofilm. The biofilm is assumed to consist of four components: water, ... -
PorePy: an open-source software for simulation of multiphysics processes in fractured porous media
(Journal article; Peer reviewed, 2021)Development of models and dedicated numerical methods for dynamics in fractured rocks is an active research field, with research moving towards increasingly advanced process couplings and complex fracture networks. The ... -
PoroTwin: A Digital Twin for a FluidFlower Rig
(Journal article; Peer reviewed, 2023)We present a framework for integrated experiments and simulations of tracer transport in heterogeneous porous media using digital twin technology. The physical asset in our setup is a meter-scale FluidFlower rig. The digital ... -
Portfolio allocation under asymmetric dependence in asset returns using local Gaussian correlations
(Journal article; Peer reviewed, 2021)It is well known that there are asymmetric dependence structures between financial returns. This paper describes a portfolio selection method rooted in the classical mean–variance framework that incorporates such asymmetric ... -
Portfolio Optimization and Diversification Benefits: A Local Gaussian Correlation Approach
(Master thesis, 2019-06-22) -
Portfolio Optimization in a Lévy Market with Intertemporal Substitution and Transaction Costs
(Department of Applied Mathematics report, Research report, 2000-05) -
Portfolio Optimization with PCC-GARCH-CVaR model
(Master thesis, 2014-06-02)This thesis investigates the Conditional Value-at-Risk (CVaR) portfolio optimization approach combined with a univariate GARCH model and pair-copula constructions (PCC) to determine the optimal asset allocation for a ... -
Portfolio Selection with a Rank-Deficient Covariance Matrix
(Journal article; Peer reviewed, 2024)In this paper, we consider optimal portfolio selection when the covariance matrix of the asset returns is rank-deficient. For this case, the original Markowitz’ problem does not have a unique solution. The possible solutions ... -
Post-lie algebras and isospectral flows
(Peer reviewed; Journal article, 2015-11-20)In this paper we explore the Lie enveloping algebra of a post-Lie algebra derived from a classical R-matrix. An explicit exponential solution of the corresponding Lie bracket flow is presented. It is based on the solution ... -
A posteriori error estimates for hierarchical mixed-dimensional elliptic equations
(Journal article; Peer reviewed, 2022)Mixed-dimensional elliptic equations exhibiting a hierarchical structure are commonly used to model problems with high aspect ratio inclusions, such as flow in fractured porous media. We derive general abstract estimates ... -
A posteriori error estimation and adaptivity for multiple-network poroelasticity
(Journal article; Peer reviewed, 2023)The multiple-network poroelasticity (MPET) equations describe deformation and pressures in an elastic medium permeated by interacting fluid networks. In this paper, we (i) place these equations in the theoretical context ... -
A posteriori error estimation and modeling of unsaturated flow in fractured porous media
(Doctoral thesis, 2022-06-17)This doctoral thesis focuses on three topics: (1) modeling of unsaturated flow in fractured porous media, (2) a posteriori error estimation for mixed-dimensional elliptic equations, and (3) contributions to open-source ...