Browsing by Author "Nilsson, Philip"

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Experiments on optimal maintenance operations with emphasis on end-of-contract constraints
(2019-06-18) Ahlman, Sebastian; Nilsson, Philip; Kamran, Tanha; University of Gothenburg/Department of Mathematical Science; Göteborgs universitet/Institutionen för matematiska vetenskaper
To minimize the unnecessary costs that arise when machines or other objects fail, perhaps needing to be replaced during less than ideal occasions through what is known as reactive maintenance, a more active maintenance policy through which objects are continuously maintained in a preventative manner based on life expectancy or from a cost-perspective, is preferred. Mathematical models can be advantageous to utilize when scheduling these maintenance occasion. No model has at this time been shown to be the best within the sub field of Operations Research known as Maintenance Scheduling. The purpose of this project is to, through the addition of constraints and simulation, analyse two of the more prevalent models within this field: The Opportunistic Replacement Problem(ORP) and The Preventative Maintenance Scheduling Problem with Interval Costs(PMSPIC). Results show that the set-up cost dt for large system in which costs are time independent, i.e, dt = d, carry little influence over the resulting optimal schedule if the quotient d ci , where ci is the replacement cost of a component, is small. The inverse is shown to be true for systems consisting of a small number of components. It can thus be inferred that greater focus should be put on product development to avoid unnecessarily high maintenance costs in systems with few components and in which set-up costs are comparatively high. A quantitative comparison of both models was, unfortunately, not possible to perform due to time constraints. The results presented for the PMSPIC thus take the form of a qualitative discussion of its theoretical properties and how it can be likened to the ORP.
Hur tolkar du den här grafen?
(2023-04-18) Nilsson, Philip; University of Gothenburg/Department of Mathematical Science; Göteborgs universitet/Institutionen för matematiska vetenskaper
This study looks at what misconceptions students have when reading linear graphs. It also looks at what consequences mathematical conventions have on students' ability to read graphs. I will attempt to provide a tentative answer to these questions “How do students link linear graphs to algebra, and what misconceptions might students have regarding this?” Later we will take a look at what consequences these might have on students' ability to solve new problems and what we as teachers need to pay attention to concerning these problems. The study was done through a survey which contained multiple questions. These were constructed using variation theory. Its aim was to investigate which aspects of the graphs, when varied, affected the students ability to interpret a graph. The study finds that students often follow conventions often used when dealing with grafs. These when revoked leads to many misinterpretations and confusion amongst the students. A recommended action for us teachers to work towards a better understanding of graphs is then both proposed and discussed.
MANAGING THE DRAGON. A comprehensive analysis of Sweden’s Relationship with China
(2023-06-20) Nilsson, Philip; Göteborgs universitet/Statsvetenskapliga institutionen; University of Gothenburg/Department of Political Science
Sweden's relationship with China is an increasingly important topic, with a growing need for a deeper understanding of the challenges and opportunities characterizing this multi-power relationship. Navigating the complex interplay of economic, military, political, and ideological domains, this thesis examines Sweden's evolving relationship with China using Michael Mann’s IEMP-model. Utilizing expert interviews and policy documents, the study investigates how Sweden has managed its interests in the face of both opportunities and challenges. The research finds that Sweden has adeptly navigated its political and economic interests, despite ideological challenges and increasing significance of military issues. Strategic adaptability is underscored in Sweden's approach, as evidenced by its multilateral engagements and the leveraging of economic relationships for constructive dialogue on human rights. The study also reflects on potential future scenarios based on current trends, emphasizing the likely importance of multilateral collaborations. This thesis provides a comprehensive analysis of Sweden's strategy in maintaining its interests against the backdrop of an evolving geopolitical landscape, offering insights into the complexities of international relations.