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(Doctoral thesis / Doktoravhandling, 2024)
When a new product is launched on a customer base, its adoption process begins. From here on out, two main drivers will inform how new adoptions are made. New adoptions might spur out peer-to-peer interactions between ...
(Doctoral thesis / Doktoravhandling, 2023)
Mathematical objects often possess some sort of 'symmetry'. For instance, the circle has rotational symmetry; It 'looks the same' even if we rotate it around its center by some angle. Formally this type of symmetry is an ...
(Doctoral thesis / Doktoravhandling, 2023)
Solving equations has always been one of the core areas of mathematics. One important class of equations are so-called polynomial equations. These appear naturally in a broad collection of fields, such as number theory, ...
(Doctoral thesis / Doktoravhandling, 2023)
Mathematical modelling of brain parenchyma mechanics and fluid dynamics is a powerful tool to better understand clearance mechanisms, and investigate mechanistic hypotheses that cannot be verified with in vivo experiments. ...
(Doctoral thesis / Doktoravhandling, 2023)
Most forms of dementia, including Alzheimer’s, are incurable and their causes are not properly understood. In recent years, it has been suggested that the cerebrospinal fluid, a water-like fluid that surrounds the brain, ...
(Doctoral thesis / Doktoravhandling, 2023)
Internal waves are a phenomenon that occurs in stratified oceans. These waves play a vital role in the oceanic ecosystem, e.g., influencing the distribution of nutrients. I have conducted high-resolution simulations of ...
(Doctoral thesis / Doktoravhandling, 2023)
Artificial intelligence and machine learning are increasingly used in many industries and applications, where more and more important decisions are being made based on machine learning models. However, recent research has ...
(Doctoral thesis / Doktoravhandling, 2023)
Operator algebras were born out of the attempt to give mathematically rigorous foundations to quantum mechanics, and its development has been higly influenced by the mathematical approaches to understanding quantum field ...
(Doctoral thesis / Doktoravhandling, 2023)
This thesis is motivated by the following questions:
- Does there exist a weakest theory for which Gödel’s first incompleteness theorem holds?
- Does there exist a weakest structure for which solvability of systems of ...
(Doctoral thesis / Doktoravhandling, 2023)
The societal importance of weather drives a continuous effort to improve short- and long-term numerical weather prediction. A better knowledge of the conditions in the stratosphere, the atmospheric region from 10 to 50 ...
(Doctoral thesis / Doktoravhandling, 2023)
In this thesis we study stochastic optimal control problems for Volterra type dynamics. To this end, we consider two different approaches: maximum principle and dynamic programming. We use the maximum principle when working ...
(Doctoral thesis / Doktoravhandling, 2022)
Renewable energy sources receive increasingly more attention as the world seeks cheap, reliable and less CO2-intensive ways of producing electricity. Wind is recognized as an important source of renewable energy and reaches ...
(Doctoral thesis / Doktoravhandling, 2022)
Functional data analysis (FDA) comprises statistical methods for data that can be considered as partial or full observations of random curves, surfaces, or related smooth objects. Although much progress has been made in ...
(Doctoral thesis / Doktoravhandling, 2022)
The last decades have witnessed an exponential growth in the amounts of data that are collected, stored, and shared worldwide daily.
In many scientific disciplines, information consists of a set of sample points describing ...
(Doctoral thesis / Doktoravhandling, 2022)
One of the biggest open problems in Complex Geometry is whether every open Riemann Surface admits a proper holomorphic embedding into the 2-dimensional euclidean complex space, as this provides a good representation of ...
(Doctoral thesis / Doktoravhandling, 2022)
In this thesis we consider two different kinds of brain malfunctions. The Chiari 1 malformation is characterised by abnormal cerebrospinal fluid (CSF) flow conditions surrounding the brain. The other malfunction we consider ...
(Doctoral thesis / Doktoravhandling, 2022)
Real algebraic geometry is the study of geometric objects defined by polynomial equations with real coefficients. This domain has connections with many areas of mathematics, such as analytic geometry, algebraic topology ...
(Doctoral thesis / Doktoravhandling, 2022)
Financial markets have extremely complex behavior that cannot be fully modeled using classical approaches. In particular, numerous empirical studies show that market volatility exhibits some form of long-range dependence ...
(Doctoral thesis / Doktoravhandling, 2022)
A tensor is a multi-dimensional data array, occurring ubiquitously in mathematics, physics, engineering and, more generally, in all the situations where one needs to organize data by more than two indices. If tensors remain ...
(Doctoral thesis / Doktoravhandling, 2022)
Quantum groups first arose out of the study of integrability in quantum mechanics, presenting a new notion of symmetry extending beyond the traditional group concept. Quantum groups can be thought of as the collection of ...
(Doctoral thesis / Doktoravhandling, 2022)
To a mathematician, a surface is a shape that, upon close enough inspection, looks like a flat piece of paper around each of its points. Thus, to an ant, the surface of a bagel is conceived as flat, while the (roughly) ...
(Doctoral thesis / Doktoravhandling, 2022)
Hyperbolic conservation laws are used to model various important applications such as gas flow or traffic flow. Those phenomena are interesting to study in a one-dimensional setting, it would be even more relevant for real ...
(Doctoral thesis / Doktoravhandling, 2022)
Traffic volumes are increasing in most of the major modes of transportation. As population centers grow in size and density, the increasing demand for public transit and delivery services leads to increased rail and road ...
(Doctoral thesis / Doktoravhandling, 2021)
Submarine mass movements are important sources for tsunamis with potential destructive consequences at coastlines. A famous example from historical records is, for instance, the 1929 Grand Banks tsunami in Canada. This ...
(Doctoral thesis / Doktoravhandling, 2021)
The polar oceans consist of open water, continuous ice covers and zones of broken ice floes of various sizes in the transition between water and ice. As the waves from the open ocean travel into the zone of ice floes, the ...
(Doctoral thesis / Doktoravhandling, 2021)
In this thesis, two-phase flow in an annular pipe geometry is studied using an open-source software known as OpenFOAM. The data collected through the simulations in this thesis are compared to experimental data collected ...
(Doctoral thesis / Doktoravhandling, 2021)
Artificial Intelligence (AI) and data-driven decisions based on Machine Learning (ML) are making an impact on an increasing number of industries. As these autonomous and self-learning systems become more and more responsible ...
(Doctoral thesis / Doktoravhandling, 2021)
The production of renewable energy is growing world-wide, and -- as a result -- power production is becoming increasingly dependent on weather factors such as temperature, wind and precipitation. All of these factors are ...
(Doctoral thesis / Doktoravhandling, 2021)
Thin viscous films are ubiquitous in Nature and biology and they are indispensable in industrial applications through lubrication and coating. In order to utilize the potential of thin viscous films on the micro and nano ...
(Doctoral thesis / Doktoravhandling, 2021)
Landslides can generate large tsunamis when falling into lakes and the sea. In order to protect coastal areas and communities we need to predict these events. Mathematical models have become a popular method for this task. ...
(Doctoral thesis / Doktoravhandling, 2021)
Both in science and industry, the sizes of data sets are growing. It is not uncommon to encounter sets containing millions or even billions of measurements. Without appropriate tools for turning such enormous amounts of ...
(Doctoral thesis / Doktoravhandling, 2021)
In our modern society, with the bourgeoning of e-commerce and online streaming platforms, customers are overwhelmed by the choices. One important approach to solve this problem is recommender systems. Recommender systems ...
(Doctoral thesis / Doktoravhandling, 2021)
The development of research and exploration in Arctic waters is very common nowadays. One of the environmental difficulties to carry out research in these regions is the icing of surfaces. After short periods of time, ice ...
(Doctoral thesis / Doktoravhandling, 2021)
Rogue waves are unexpected and unusually larger waves than their surrounding and can be dangerous to ship and offshore structures. In normally distributed wave fields also known as Gaussian sea, rogue waves actually exist, ...
(Doctoral thesis / Doktoravhandling, 2021)
Many important results in mathematics deal with the question of figuring out what objects are ‘the same’. One way of rigorously dealing with this is through the notion of isomorphic objects. However, it is sometimes better ...
(Doctoral thesis / Doktoravhandling, 2020)
This thesis presents new statistical methodology, models, and estimators that are geared towards answering scientific questions in epidemiology and medicine, and in economics and finance. The questions are: (i) What is the ...
(Doctoral thesis / Doktoravhandling, 2020)
This thesis is a collection of four papers about symmetric and Hermitian determinantal representations of quartic hypersurfaces.
- Paper I classifies rational quartic symmetroids in 3-space.
- Paper II classifies rational ...
Stochastic Modeling with Fractional and non-Fractional Noises: Applications to Finance and Insurance
(Doctoral thesis / Doktoravhandling, 2020)
In my doctoral work, I have developed stochastic models that use different type of noises, to price financial derivatives and insurance products.
Stock prices have a random component in their behavior that characterizes ...
(Doctoral thesis / Doktoravhandling, 2020)
(Doctoral thesis / Doktoravhandling, 2020)
(Doctoral thesis / Doktoravhandling, 2020)
This thesis describes a finite element method for simulation of free-surface flows, such as ocean waves, using the discontinuous Galerkin method. Free-surface flows where there is a large difference in density between two ...
(Doctoral thesis / Doktoravhandling, 2020)
In the last decades the analytical value of data has really become apparent and the amount of data collected has vastly increased. This enables us to approach problems in more data driven manners. In the thesis, I have ...
(Doctoral thesis / Doktoravhandling, 2020)
It is well known that randomness can be used as an effective tool to turn a priori ill-posed problems into well-posed ones. This is useful both for answering questions at the theoretical as well as the practical levels. ...
(Doctoral thesis / Doktoravhandling, 2020)
The main way to study a periodic signal is to decompose it into a sum of simple signals, namely sine waves. However, when a signal changes substantially over time, such as a piece of music, different methods are needed. ...
(Doctoral thesis / Doktoravhandling, 2020)
There are currently two paradigm shifts happening in society and scientific computing: (1) Artificial Intelligence (AI) is replacing humans in problem solving, and, (2) AI is replacing the standard algorithms in computational ...
(Doctoral thesis / Doktoravhandling, 2020)
Dementia is a growing concern for the health-care in the world and most treatment strategies are not successful. Dementia is associated with accumulation of metabolic waste in the form of protein fragments. Recent breakthroughs ...
(Doctoral thesis / Doktoravhandling, 2020)
(Doctoral thesis / Doktoravhandling, 2020)
(Doctoral thesis / Doktoravhandling, 2020)
Airflow above water waves represents a challenging problem, relevant both in air-sea interactions and for multiphase pipe flows. Understanding this interaction is important to accurately predict the exchange of heat, ...
(Doctoral thesis / Doktoravhandling, 2020)
Biological membranes have fundamental implications in a large number of processes in the cell. As such, membranes possess important properties: they can change their shape as an elastic surface, and they are fluid, which ...
(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 ...
(Doctoral thesis / Doktoravhandling, 2019)
A particular class of Partial differential Equations (PDEs) is the hyperbolic conservation laws which play an instrumental role in numerous real life applications such as synchronization of cardiac pacemakers, traffic flow ...
(Doctoral thesis / Doktoravhandling, 2019)
(Doctoral thesis / Doktoravhandling, 2019)
(Doctoral thesis / Doktoravhandling, 2019)
(Doctoral thesis / Doktoravhandling, 2018)
(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 ...
(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 ...
(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 ...
(Doctoral thesis / Doktoravhandling, 2018)
(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, ...
(Doctoral thesis / Doktoravhandling, 2017)
(Doctoral thesis / Doktoravhandling, 2017)
(Doctoral thesis / Doktoravhandling, 2016)
(Doctoral thesis / Doktoravhandling, 2016)
(Doctoral thesis / Doktoravhandling, 2016)
(Doctoral thesis / Doktoravhandling, 2016)
(Doctoral thesis / Doktoravhandling, 2016)
(Doctoral thesis / Doktoravhandling, 2016)
(Doctoral thesis / Doktoravhandling, 2015)
Banebrytende forskningsmodeller innenfor viktige tema/fagområder som blant annet klima, menneskekroppen og jordskorpen tar alle utgangspunkt i kompliserte dataprogrammer, og krever ofte flere dager for en super-datamaskin ...
(Doctoral thesis / Doktoravhandling, 2015)
The present thesis is motivated by the desire to understand and to predict the effects of stable stratification on turbulent flow and passive scalar dispersion.
A methodology which enables the simulation of stably stratified, ...
(Doctoral thesis / Doktoravhandling, 2015)
Microfluidics is considered as both science and technology that deal with fluids in microchannels or in micro scale space. During the past two decades, microfluidic has been the hot spot in various research areas, e.g., ...
(Doctoral thesis / Doktoravhandling, 2015)
(Doctoral thesis / Doktoravhandling, 2015)
(Doctoral thesis / Doktoravhandling, 2015)
(Doctoral thesis / Doktoravhandling, 2015)
(Doctoral thesis / Doktoravhandling, 2014)
(Doctoral thesis / Doktoravhandling, 2014)
(Doctoral thesis / Doktoravhandling, 2014)
The subject of this thesis concerns deformation quantization for operator algebras, with considerations of some aspects of K-theory and certain concepts from non-commutative geometry.
The thesis studies deformation ...
(Doctoral thesis / Doktoravhandling, 2014)
In epidemiological research it is common to follow large cohorts over time with respect to exposure and outcome development. This can, however, be expensive, time consuming or even logistically impossible. A much used ...
(Doctoral thesis / Doktoravhandling, 2014)
(Doctoral thesis / Doktoravhandling, 2014)
(Doctoral thesis / Doktoravhandling, 2013)
(Doctoral thesis / Doktoravhandling, 2013)
(Doctoral thesis / Doktoravhandling, 2013)
(Doctoral thesis / Doktoravhandling, 2013)
(Doctoral thesis / Doktoravhandling, 2013)
(Doctoral thesis / Doktoravhandling, 2013)
(Doctoral thesis / Doktoravhandling, 2013)
The current study is comprised of two aspects of research i.e. numerical and experimental. The Numerical investigations enhance and verify experimental observations. In the first task, an effort was made to numerically ...
(Doctoral thesis / Doktoravhandling, 2013)
(Doctoral thesis / Doktoravhandling, 2013)
The first part of this thesis deals with cuspidal curves on Hirzebruch surfaces. Bounds are given on the number and type of cusps on cuspidal curves, and rational cuspidal curves are constructed using birational ...
(Doctoral thesis / Doktoravhandling, 2012)
Calabi-Yau manifolds are important objects in algebraic geometry and theoretical physics. A hypothesis of mirror symmetry is that Calabi-Yau manifolds of dimension 3 come in pairs, with the Hodge numbers of one manifold ...
(Doctoral thesis / Doktoravhandling, 2012)
(Doctoral thesis / Doktoravhandling, 2012)
(Doctoral thesis / Doktoravhandling, 2012)
In the process of modeling, the agent has to make a number of decisions. Therefore two agents can set up different models. This thesis compares the influence of different model choices to stochastic control theory and ...
(Doctoral thesis / Doktoravhandling, 2012)
(Doctoral thesis / Doktoravhandling, 2012)
(Doctoral thesis / Doktoravhandling, 2012)
(Doctoral thesis / Doktoravhandling, 2011)
(Doctoral thesis / Doktoravhandling, 2011)
The thesis studies certain mathematical aspects of model selection, statistical estimation theory and probability using stochastic process tools.
The paper “The copula information criterion” is the paper with most direct ...