Publikationer från Uppsala Universitet
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Effektiv B2G-användning för högre intäkter och uppfyllande av garantikrav
No full textWith the development of ship electrification, the Boat-to-Grid (B2G) system shows great application potential. The battery is not only used for ship propulsion, but can also participate in grid auxiliary services. However, B2G usage may accelerate battery aging. To solve this problem, this thesis builds a optimization tool to find the optimal daily usage strategy for boat batteries under B2G scenarios. The goalis to maximize profit while protecting battery lifetime. This study selects two typical battery types, Lithium Iron Phosphate (LFP) and Nickel Cobalt Aluminum (NCA), and designs daily usage profiles based on seasonal energy demand in two Swedish cities, Gothenburg and Luleå. The degradation models are considered as constrains. Two optimization methods are used. The first one is based on Model Predictive Control (MPC) with IPOPT solver, using current as the decision variable to maximize daily revenue. The second one is based on Genetic Algorithm (GA) with the DEAP framework, using power asthe decision variable to minimize daily cost. In Frequency Containment Reserve (FCR) service, the results show that in most cases both methods can generate optimal charging and discharging strategies under varying usage conditions, saving at least 4 % in summer. The battery can still achieve profits while limiting degradation, demonstrating the tool’s potential to balance revenue and battery lifetime
"Koreans will go extinct" : Unga sydkoreanska kvinnors inställning till framtida familjebildning
No full textDenna studie har ämnat undersöka unga sydkoreanska kvinnors inställning och tankar kring ett potentiellt framtida familjebildande, med bakgrund i att Sydkorea är det land i världen med lägst fruktsamhetstal på 0,75 barn per kvinna. Studien har även undersökt faktorer som påverkar fertilitetsintentionerna hos respondenterna, samt deras syn på situationen i landet. Empiriskt material har insamlats genom semistrukturerade intervjuer med femrespondenter för att utforska personliga preferenser och lyfta olika perspektiv på situationen. Resultatet visar att respondenterna vill ha 0–3 barn, vid 30–35 års ålder, efter att först ha ingått äktenskap vid 28–35 års ålder. De faktorer som respondenterna upplever som viktiga för deras beslut gällande familjebildning inkluderar; deras ekonomiska situation, personliga intention, och hur ett moderskap potentiellt påverkar deras karriär. Vidare ser respondenterna på situationen med varierande mängd oro, och flera potentiella förklaringar för de låga födelsetalenges av respondenterna. Dessa är; bristande jämställdhet i landet vilket bland annat gör det svårt att som kvinna kombinera föräldraskap och karriär, ett missnöje över hur samhället ser ut vilket medför att man ej vill sätta ett barn till den världen, och ett individualistiskt tankesätt där personliga mål och drömmar prioriteras framför familjebildning
Evaluating Physics-Informed Neural Networks for Mesh-Free Structural Analysis
No full textPredicting stress and deformation in engineering structures with high accuracy and efficiency remains a cornerstone challenge in computational mechanics. Physics‐informed neural networks (PINNs) have recently emerged as a mesh‐free alternative, capable of embedding governing partial differential equations (PDEs) directly into the training process. This study investigates the performance of PINNs on two canonical problems: a one-dimensional beam subjected to a uniform load, and a plane-stress scenario in metal plates featuring hole cutouts that introduce geometric irregularities. The PINN predicted solutions were benchmarked against analytical results and finite element method (FEM) simulations performed in Ansys Mechanical. Furthermore, transfer learning was explored by retraining pretrained PINNs on geometrically modified plates. The results demonstrate that PINNs can match FEM accuracy within a few percent error, though at a substantially higher computational cost. Importantly, PINNs yield continuous solution functions over the domain without requiring a mesh, and transfer learning substantially reduced training time for similar problems. These findings indicate that, while PINNs do not yet outperform traditional FEM in speed, their mesh‐free formulation and ability to leverage learned representations hold promise for adaptive, data‐driven structural‐analysis frameworks.
Genetic Predisposition or Environmental Accumulation? Investigating Late-Onset Multiple Sclerosis
No full textLate-onset multiple sclerosis (LOMS), often defined as symptom onset at or after age 50, is associated with a more aggressive disease course compared to the most common adult-onset MS (AOMS). However, its biological and clinical characteristics remain underexplored. There is also lack of consistent definition for individuals with onset between ages 40-49, raising questions as to which group it should be included in. Our aim was to characterize the clinical, genetic, and environmental features of LOMS and assess whether the ≥50 years cutoff best defines this subgroup. We analyzed clinical, demographic, genetic, and environmental data from 10,545 individuals in the Swedish MS registry. Disease severity was assessed using Multiple Sclerosis Severity Scores, Expanded Disability Severity Score milestones, and progression to secondary progressive MS. Key HLA alleles, severity-associated SNPs, and genetic risk scores were evaluated, as well as environmental exposures including smoking, sun exposure, BMI, education, and EBV serostatus. Individuals with LOMS showed more rapid disease progression, greater disability, and lower treatment exposure compared to younger onset groups. Genetic risk variants had a limited impact on LOMS susceptibility; while smoking and low sun exposure were consistently associated with increased disease severity and risk, even after adjusting for birth-year and covariates. Higher educational attainment was protective against both disease severity and LOMS. Individuals with onset between 40-49 years (IOMS) exhibited intermediate clinical and biological features. These findings support age-at-onset ≥50 years as the most appropriate definition for LOMS. The results highlight the dominant role of lifelong environmental exposures over genetic burden in influencing MS trajectory in older adults
Subsurface vibrations underground from windturbines : An exploratory report of subsurface vibrations
No full text As noise can have detrimental effects on our health it is important to understand how vibrations from wind turbines can contribute to noise levels in rooms below ground. We simulated a point force and measured the noise level in a chamber 95 m away and 2 meter below the surface. We ran roughly 100 simulations with different frequencies, materials and depth of the room. We solved the partial differential equations using the upwind finite-difference operator. We could see in our graphs that there is a non-linear relationship between the noise level and the source frequency. The noise level increases and resulted in three clear peaks. Our results showed us that the Rayleigh wave has the most impact on the noise level. The point force’s vertical vibrations produced more Rayleigh waves than its horizontal vibrations. Different materials had a big impact on the noise level as well, where concrete with vertical vibrations caused the highest noise levels over all simulations. When the chamber was located 13 m below the surface, a generally lower noise level was produced
Global Greenhouse Gas Emissions of Video Games based on 2022 Market Data : An extended study to “From One Edge to the Other: Exploring Gaming’s Rising Presence on the Network”
No full textThe environmental impact of digital entertainment has become increasingly significant, with the video game industry emerging as anotable contributor to global greenhouse gas emissions. This study presents a comprehensive life-cycle assessment (LCA) of gamingplatforms and services based on 2022 market data, expanding upon prior work by Marsden et al. (2020). It examines the carbon footprintacross five categories: gaming consoles, handheld devices, personal computers and laptops, game streaming services, and gamedownloads. Findings indicate that PC and laptop hardware account for the highest emissions, followed by game streaming services, andconsoles. Handheld gaming consoles and downloads exhibit significantly lower emissions. The study evaluates the validity of pastprojections on the adoption of streaming technologies and identifies a sharp increase in cloud gaming users since 2019, suggesting a shiftin consumption trends. Design and policy recommendations are offered to mitigate emissions, including energy-efficient hardware, useof sustainable materials, and features promoting shared device use. This work also concludes with actionable insights for HCI researchers,platform designers, and sustainability advocates seeking to balance technological engagement with ecological responsibilityThis work was submitted in partial fulfilment for a master’s degree in Human – Computer Interaction at Uppsala University, Sweden, onJune 05, 2025. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without feeprovided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citationon the first page. Copyrights for components of this work owned by others than the author must be honoured. </p
Ensamhet och isolering i forntida Egypten
No full textLoneliness is a rarely studied emotion in ancient societies, particularly in ancient Egypt. This study investigates the ancient Egyptian conceptions of loneliness and related notions during the Pharaonic period, from the Old Kingdom to the Third Intermediate Period. To do this, Monique Scheer's theoretical framework of 'emotional practice' is used to identify how loneliness was expressed in textual sources. Both fictional texts and personal correspondence were analysed to identify loneliness and its specific circumstances, allowing for the development of recurring themes that reveal how ancient Egyptians conceptualised loneliness. In general, emotional isolation, homesickness, and separation from loved ones caused distress. A strong social character was visible in most themes, where rejection, indifference, and abandonment were primarily caused by others failing to uphold social obligations.Hur ensamhet har uppfattats i forntida samhällen, såsom det forntida Egypten, har sällan studerats. Denna studie syftar till att undersöka de forntida egyptiernas föreställningar om ensamhet och relaterade föreställningar under perioden mellan gamla riket och tredje intermediet. Målet är att identifiera hur ensamhet uppfattades och beskrevs som fenomen och känsla. Monique Scheers teoretiska ramverk 'emotional practice' tillämpas för att undersöka hur ensamhet uttrycktes i textuella källor. Personliga brev och fiktiva texter analyserades för att identifiera ensamhet och dess omständigheter samt att utveckla teman. Resultatet visar flera återkommande mönster av hur de antika egyptierna uppfattade ensamhet. Generellt orsakade känslomässig isolering, hemlängtan och separation från nära och kära lidande. En stark social dimension identifierades i de flesta teman där avvisande, likgiltighet och övergivenhet främst uppfattades som resultatet av andras misslyckande i att upprätthålla sociala förpliktelser
Baltic boat graves and settlements : A study of Salme boat graves in Estonia and its connections to the Grobiņa settlement in Latvia
No full textDenna studie undersöker Salme båtgravar på ön Ösel, Estland samt den skandinaviska bosättningen Grobiņa i Lettland och de möjliga kopplingarna mellan dessa två platser. Salme båtgravar upptäcktes 2008 och har med dess unika karaktär förändrat synen på tidig vikingatida aktivitet. Likt detta var även boplatsen Grobiņa ett storslaget fynd för sin tid när det grävdes ut 1929 och har också givit en unik insikt i det baltiska och skandinaviska järnålderssamhället. Denna studie utför en komparativ analys för att belysa Salme båtgravar ur en östlig kontext genom att dra kopplingar till andra platser inom Baltikum som påvisar spår av skandinavisk aktivitet, såsom Grobiņa i Lettland. Materialet som analyserades var gravmaterialet från båda båtgravarna i Salme såväl som det samtida materialet från Grobiņa som främst kommer från dess gravfält. Studien visade att det fanns vissa aspekter av platserna som potentiellt kunde sammankopplas men inget av detta var konkret nog för att kunna säkerställa en definitiv koppling mellan de två platserna. Dock lämnar de upptäckta likheterna potentialen för vidare forskning som skulle kunna stärka denna koppling och mer konkret binda samman den tidiga vikingatida skandinaviska närvaron i Baltikum. This study examines Salme boat graves on Sareema, Estonia as well as the Scandinavian settlement Grobiņa in Latvia and the possible connection between these two sites. The Salme boat graves were discovered in 2008 and has with its unique character changed the view of early Viking-age activity. Much like this, the site Grobiņa was a monumental find for its time of discovery in 1929 and has given a unique insight in the Baltic and Scandinavian iron age society. This study makes a comparative analysis to illustrate the Eastern context of Salme boat graves by drawing connections to the Scandinavian presence in the Baltic area. The studied material consists of the grave goods from both boat graves as well as the contemporary material from Grobiņa of which a majority comes from the grave sites. The results of the study indicated that some aspects of the sites that could potentially be connected, although none of the finds established a connection concrete enough to definitively link the two sites. However, these similarities show the potential for further investigation that could strengthen this connection and possibly more concretely bind together the early Scandinavian Viking-age presence in the Baltic area.
Why do professional Esports players choose characters and strategies even after developers make great effort to weaken it? : An analytical study about Jett in Valorant
No full textThe focus of this study is to get a deeper understanding about the intentions behind players of high skill choosing certain characters over others despite developers trying to limit the variability of said character. This study does this by analysing the presence of the VALORANT agent character Jett in the video games professional competitive tournaments called VALORANT Champions Tour (VCT). Utilizing a mixed-method data collection approach in order to analyze data trends in gameplay and get insight into professional players decision making and preferences, presented that Jett in the early days of the game did in fact provide players with great tools for aggressive gunfighting and easy escape options. Using the Game Theory (Osborne & Rubinstein, 1994) framework we could easily decipher the professional players intent behind their strategic decision making and gain greater understanding as to why Jett was so prevalent above other characters fulfilling the same role. These findings should provide great insight into the strategic decision making of professional VALORANT players, with everything from mechanical performances, use of most efficient tactics available (META) and player preferences. These insights bring a valuable understanding to developers to easier understand what design changes truly impact the players strategic decision making and play style preferences
Centralisation of extremely preterm births and decreased early postnatal mortality in Sweden, 2004‐2007 versus 2014‐2016
No full textAim We evaluated the increased centralisation of extremely preterm (EPT) births in Sweden in relation to the changes in mortality and morbidity. Methods Population-based data covering Swedish live births from 22 + 0 to 26 + 6 weeks of gestation during 2004–2007 and 2014–2016 were analysed for associations between time-period, birth within (inborn) or outside (outborn) regional centres, and outcomes. Results Among 1626 liveborn infants, 703 were born in 2004–2007 and 923 in 2014–2016. Birth outside (vs. within) regional centres was associated with a higher infant mortality even after adjustment for birth cohort, gestational age, birthweight standard deviation score and infant sex (adjusted odds ratio 2.01, 95% confidence interval 1.31–3.07, p = 0.001). The higher 1-year mortality in outborn infants was mainly due to more deaths within 24 h after birth. Outborn infants had a higher incidence of intraventricular haemorrhage grade 3–4 than inborn infants (22% vs. 14% in 2004–2007, and 22% vs. 13% in 2014–2016, both p < 0.05). While survival to 1 year without major morbidity increased in inborn infants (33%–40%, p = 0.008), it remained unchanged in outborn infants (29% vs. 30%, p = 0.88). Conclusion Centralisation of EPT births contributed to a lower 1-year mortality in 2014–2016 than that in 2004–2007, attributed to a decrease in deaths before 24 h among inborn infants