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Solutions to some problems related to Diophantine equation, power means and homogenization theory
(Doctoral thesis; Doktorgradsavhandling, 2017-05-19)
This Ph.D. thesis consists of an introduction and 7 papers where we investigate the requirements for finding integer or rational solutions to a selection of Diophantine equations leading to problems connected to power means and homogenization.
In Paper 1 we present a modern view of classic number theory in a historic context. In Paper 2 we introduce the Crossed Ladders Problem and present a proof ...
Atmospheric icing on wind turbines : Modeling and consequences for energy production
(Doctoral thesis; Doktorgradsavhandling, 2011)
Control of rigid bodies : with applications to leader-follower spacecraft formations
(Doctoral thesis; Doktorgradsavhandling, 2012)
Optimization models and methods for sustainable reverse logistics network design
(Doctoral thesis; Doktorgradsavhandling, 2018-11-29)
With the increased focus on sustainable development and circular economy, as never before, the value recovery and re-creation from the End-of-Use and End-of-Life products has been paid considerable attention by the whole society. Reverse logistics is believed as one of the most effective and promising means for the value recovery of the End-of-Use and End-of-Life products, which is the process for ...
Studies of some Operators of Harmonic Analysis in certain Function Spaces with Applications to PDEs
(Doctoral thesis; Doktorgradsavhandling, 2018-12-05)
The study in this PhD thesis aims at development of certain mathematical methods used in applications, in particular, in the study of regularity properties of solutions in various mathematical models described by Partial Differential Equations (PDEs). To this end, we study various operators of harmonic analysis in certain function spaces, since solutions to many PDEs may be expressed in terms of ...
Engineering methods for enhancing railway geometry and winter road assessment: A safety and maintenance perspective
(Doctoral thesis; Doktorgradsavhandling, 2020-06-22)
In many areas around the world there are limited transportation possibilities when travelling between key cities. If these areas also experience demanding weather conditions or geography, getting from A to B, during difficult conditions, is usually not optimal in regards to accessibility, safety, and comfort. Under challenging conditions, two essential elements in strengthening accessibility, safety, ...
Geometric Modeling- and Sensor Technology Applications for Engineering Problems
(Doctoral thesis; Doktorgradsavhandling, 2020-10-20)
In applications for technical problems, Geometric modeling and sensor technology are key in both scientific and industrial development. Simulations and visualization techniques are the next step after defining geometry models and data types. This thesis attempts to combine different aspects of geometric modeling and sensor technology as well as to facilitate simulation and visualization. It includes ...
An applied investigation of viscosity–density fluid sensors based on torsional resonators
(Doctoral thesis; Doktorgradsavhandling, 2020-12-04)
Real-time viscosity and density measurements give insight into the status of many chemical and biochemical processes and allow for automated controls. In many applications, sensors that enable the real-time measurements of fluid properties use resonant elements. Such sensors measure induced changes in the element’s resonance frequency and damping that can be related to the fluid properties. These ...
Representation and application of spline-based finite elements
(Doctoral thesis; Doktorgradsavhandling, 2020-03-31)
Isogeometric analysis, as a generalization of the finite element method, employs spline methods to achieve the same representation for both geometric modeling and analysis purpose. Being one of possible tool in application to the isogeometric analysis, blending techniques provide strict locality and smoothness between elements. Motivated by these features, this thesis is devoted to the design and ...
Study of the in-cloud dry ice accretion on cylinders for low values of the Stokes number
(Doctoral thesis; Doktorgradsavhandling, 2021-08-31)
The study of the atmospheric ice accretion has received some attention from the scientific community in the past, with the available knowledge spanning from the works of the Langmuir and Blodgett (1946) on the Mt. Washington Observatory till the analytical parameterization of the Finstad et al. (1988), with the latter being the current analytical benchmark and the integral part of the ISO 12494 ...