Machine Learning (ML) uses statistics to find patterns in high dimensional data. The Swedish Board of Student Finance (CSN) wants to improve the way they classify new loan takers. Using Machine Learning (ML) on data from previous loan takers can establish patterns to use on new loan takers. The aim of this study is to investigate if CSN can improve the way they classify loan takers by their ability to pay back their loan. In this study, different ML models are applied to a data set from CSN, their performance are compared and investigated by the most related factors affecting an individuals repayment rate. A data set of a total of 2032095 individuals were analysed and used in the different models. Using Random Forest (RF) for binary classification produced the best result with a sensitivity of 0.9695 and a specificity of 0.8058.

Historically, welfare assessments have focused on indicators of reduced welfare. However, positive welfare indicators in animals have recently captured the interest of researchers, animal owners and the general public. Regarding the behavior of pet rabbits, there are several positive welfare indicators described in scientific articles. There are for example expressions of joy in the form of so-called "binkies" and "zoomies", social rabbit companionship and what is called "allogrooming", exploratory behavior and a couple of different kinds of resting positions when the rabbit obviously feels relaxed, safe and secure. The Swedish animal welfare legislation would need to be adjusted to ensure that companion rabbits can display the behaviors that are classified as positive welfare indicators. Even if rabbits are kept in hutches with approved sizes, access to larger areas is required in order for several of the positive welfare behaviors to be expressed. In addition, today it is far too easy to circumvent the requirement for rabbit companionship. From an animal welfare point of view, it would also be advisable to call for supervision and attention more than just once a day. Given how common but complex pet rabbits are, more research is needed on their behavior and welfare needs, but also more information and knowledge for both current and future rabbit owners.

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The fifth generation of mobile internet is upon us, but still, there is work to do before the new technology is fully utilized. The new generation of cellular network promises frequencies ranging from the sub – 6 GHz to 39 GHz, the latter being in the mmWave spectrum. At these frequencies, we can utilize geometrical optics to calculate the radio wave propagations. The purpose of this work is to explore how raytracing can be used to predict wireless radio wave channels and pathloss in indoor and urban environment settings. The model presented in this work explores line of sight, reflection, refraction, diffraction and scattering. The model utilizes Frii’s pathloss model for pathloss in the line-of-sight case. For reflection and refraction, Snell’s laws of reflection and refraction were used. For diffraction, the uniform theory of diffraction was used, and the scattering explored in this work was created using a physics based bidirectional reflectance diffusion function. With this we create a basic raytracing program for simple environments with potential for expansion in future work. The simple environment is a cube made in an STL file. The algorithms for the different parameter were a hybrid method of shoot- and bounce and image method for reflection, a double counting method for refraction. The transitions between different shadow boundaries were smooth. While scattering was explored, more work needs to be done to implement scattering into the code. / Den femte generationen mobilt internet är över oss, men det återstår fortfarande arbete innan den nya tekniken utnyttjas fullt ut. Den nya generationen av mobilnät lovar frekvenser som sträcker sig från sub-6 GHz till 39 GHz, där det senare ligger i millimeter-spektrumet. Vid dessa frekvenser kan vi använda geometrisk optik för att beräkna radiovågsutbredningen. Syftet med detta arbete är att utforska hur raytracing kan användas för att förutsäga trådlösa radiovågskanaler och vägförluster i inomhus- och stadsmiljö. Modellen som presenteras i detta arbete utforskar synlinje, reflektion, brytning, diffraktion och spridning. Modellen använder Friis pathloss-modell för pathloss i siktlinjefallet. För reflektion och brytning användes Snells lagar för reflektion och brytning. För diffraktion användes den enhetliga teorin om diffraktion, och spridningen som utforskades i detta arbete skapades med hjälp av en fysikbaserad dubbelriktad reflektansdiffusionsfunktion. Med detta skapar vi ett grundläggande strålspårningsprogram för enkla miljöer med potential för expansion i framtida arbete. Algoritmerna för de olika parametrarna var en hybridmetod för skjut- och studs och bildmetod för reflektion, en dubbelräkningsmetod för refraktion. Övergångarna mellan olika skugggränser var kontinuerliga. Även om spridning undersöktes, så behövs mer arbete för att implementera spidning i koden.

The use of Stereotactic Radiation Therapy (SRT) employing one large fraction of radiation, as in stereotactic radiosurgery (SRS), or few fractions of high doses, has continuously increased due to the technical development and the progress in dose delivery complemented by the positive clinical experience. The success of stereotactic radiation therapy depends on many clinical, dosimetric and radiobiological factors. For SRS in particular, the delivery of a highly conformal dose distribution to the target in one fraction allowing at the same time the sparing of the normal tissue and the critical structures is part of the basic concept of the technique. Provided that the highly accurate radiosurgical equipment available today is used, planning and delivering the prescribed dose distribution is an achievable goal, and therefore the main issue to be solved is the definition of the target. As the target volume in radiosurgery is usually defined without margins, the success of the stereotactic approach critically depends on the accurate delineation of the target which could be identified as a factor of key importance. In addition, the delineation of the Organs At Risk (OAR) is also critical. The purpose of this work was to evaluate the current degree of variability for target and OAR contouring and to establish methods for analysing multi-observer data regarding structure delineation variability. A multi-center target and OAR delineation study was initiated. Two complex and six common cases to be treated with SRS were selected and subsequently distributed to centers around the world performing Gamma Knife® radiosurgery for delineation and treatment planning. The resulting treatment plans and the corresponding delineated structures were collected and analysed.    Results showed a very high variability in contouring for four complex radiosurgery targets. Similar results indicating high variability in delineating the OAR and reporting the doses delivered to them were also reported. For the common radiosurgery targets however, a higher agreement in the delineation was observed, although lower than expected. The assessment of the quality of treatment planning for radiosurgery is usually performed with respect to the coverage of the target, the planning specificity, and dose to the sensitive structures and organs close to the target. However, physical dose conformity to the target does not guarantee the success of the treatment. The assessment of the plan quality should also be performed with respect to the clinical outcome expressed as probability of controlling the target that should be irradiated. In this respect, this study also aimed to create the framework for assessing the impact of the inaccuracy in delineating the target on the predicted treatment outcome for radiosurgery targets known for their high potential to invade the neighbouring normal tissue, using radiobiological models. In addition, radiobiological models have also been used to determine the tumour control probability accounting for the oxygenation for stereotactic radiation therapy targets. The results suggest that radiobiological modelling has the potential to add to the current knowledge in SRS by theoretically assessing the key factors that might influence the treatment outcome.

The beneficiary effects of WS2 inorganic fullerene-like nanoparticles in the lubrication industry were shown in recent years. The incorporation of the nanoparticles into lubricants (oils, greases) is however not straightforward. When two surfaces are sliding against each other and a lubricant is used, a thin layer (tribofilm) is formed on the contact area, which effects the friction process. Lubricants usually contain several additives. These additives can impair the friction reducing behaviour of the WS2 inorganic fullerene-like nanoparticles. This thesis investigates the effects of several additives in the lubrication process by analysing the tribofilms formed on the worn surfaces using energy-dispersive X-ray spectroscopy in a scanning electron microscope.

Measurements play a central role in quantum information. This thesis looksat two types: contextual measurements and symmetric measurements. Contextualityoriginates from the Kochen-Specker theorem about hidden variablemodels and has recently undergone a subtle shift in its manifestation. Symmetricmeasurements are characterised by the regular polytopes they formin Bloch space (the vector space containing all density matrices) and are thesubject of several investigations into their existence in all dimensions.We often describe measurements by the vectors in Hilbert space ontowhich our operators project. In this sense, both contextual and symmetricmeasurements are connected to special sets of vectors. These vectors areoften special for another reason: they form congurations in a given incidencegeometry.In this thesis, we aim to show various connections between congurationsand measurements in quantum information. The congurations discussedhere would have been well-known to 19th and 20th century geometers andwe show they are relevant for advances in quantum theory today. Specically,the Hesse and Reye congurations provide proofs of measurement contextuality,both in its original form and its newer guise. The Hesse congurationalso ties together dierent types of symmetric measurements in dimension3called SICs and MUBswhile giving insights into the group theoreticalproperties of higher dimensional symmetric measurements.

The work was done in collaboration with Lantmännen's research foundation to produce a new and health-promoting bread. The dietary fiber beta-glucan was added to bread at a sufficiently high content to have positive health effects on blood cholesterol and blood sugar levels. The bread should also have a high sensory quality. In this project the effects of addition of beta-glucan on the theoretical GI (glycemic index) and GL (glycemic load) were investigated. An in vitro analysis was used, and the GL was calculated from the GI. These analyses were carried out on both freeze-dried bread and fresh bread containing different concentrations of beta-glucan. A sensory analysis was also done to see if there was any difference between the control bread and the bread containing the beta-glucan. The purpose of the work was to investigate how the theoretical GI value and the theoretical GL value are affected by two different preparations of beta-glucan (with concentration of 32% respectively 75% beta-glucan) in bread with end concentrations of 0.2 and 2.0 % beta-glucan of the total quantity of flour. The result indicates that there is significant effect on GI and GL of beta-glucan in wheat-based bread. Between the reference bread and the 0.2% bread of the freeze-dried bread, a significant difference was seen with a p-value of 0.048 in a paired t-test. It also was a significant difference between the reference bread and the 2.0% bread with a pvalue of 0.014 in a paired t-test. The GI values were calculated to 65 and 63 respectively for 0.2 and 2.0% beta glucan for the freeze-dried bread. The GI value for the fresh bread were calculated to 68 and 52 respectively for 0.2 and 2.0% beta glucan. The GL-values for the fresh-bread were calculated to 79 and 60 respectively for 0.2 and 2.0% beta glucan. The GL-values for the freeze-dried bread were calculated to 38 and 37 respectively for 0.2 and 2.0% beta glucan. A significant difference was seen between the reference bread and thefresh bread containing 2% added betaglucan (p-value = 0.002using t-test). The fresh bread with 0.2% added betaglucan had at about the same GI value as the reference bread and a significant difference could not be seen (p = 0.7642). In other studies, whole grain flour and a dietary fiber content of 15-45 g / serving have been shown to have an effect on the GI and GL values. The desired result is to have attenuated effects on blood sugar levels in the blood after food intake and thus be able to achieve prerequisites for blood sugar claims. To achieve the desired effect a whole-wheat flour should be used to raise the dietary fiber content and reduce the proportion of wheat flour and glucose available.

Bin har utsetts till den viktigaste och mest oersättliga levande arten på planeten. En av 10 vilda bi-arter (Apiformes) i Europa är hotade och i Sverige är 84 vilda arter rödlistade 2020. Minskad flygaktivitet och överlevnad av honungsbin (Apis) till följd av klimatförändringar medför konsekvenser för pollinering och därmed biologisk mångfald. Förståelse för hur bin påverkas av och anpassar sig till ett förändrat klimat är avgörande för arbetet med att bevara världens bipopulationer. EU-projektet Sverige-Norge INTERREG ”BIstånd till nordiska bin- unik resurs för framtidens ekosystemtjänster”, studerar nordiska bins anpassning till miljö och klimat. Med aktivitetsdata från forskningsprojektet syftar denna studie till att analysera hur lokala väderförhållanden påverkar flygaktiviteten hos honungsbiet (Apis mellifera), undersöka beteendemönster och utvärdera potentialen i att använda väderförhållanden som grund för prediktiv modellering. Två startmodeller av enkla och kombinerade väderparametrar som oberoende variabler med flygaktivitet/individ som responsvariabel analyserades med automatiserade multipla regressionsanalyser genom tre metoder av Stepwise selection med AIC (Akaike Information Criterion) för att hitta enklaste regressionsmodell som bäst beskriver datan. Inga statistiskt signifikanta linjära samband mellan flygaktivitet och additiva/kombinerade lokala väderförhållanden kunde konstateras baserat på data från samtliga metoder. Av alla testade kombinationer hade vind mest påverkan på responsvariabeln. Totalt registrerade 52 individer 2880 flygaktiviteter under insamlingsperioden varav en unik individ utförde 38% av alla registrerade aktiviteter. Vind visade ingen signifikant påverkan, emellertid, på dagar med vindhastighet över 4 m/s, minskade flygaktiviteten markant. Individuella variationer inom populationen, liten datamängd och osäker väderdata kan ha påverkat resultatet / Bees have been named the most important and irreplaceable living species on the planet. One in 10 wild bee species (Apiformes) in Europe are threatened and 84 wild species are redlisted in Sweden 2020. Reduced flight activity and survival of honey bees (Apis) as a result of climate change have consequences for pollination and therefore also for biodiversity. Understanding how bees are affected by and adapt to a changing climate is crucial to the work of preserving the world's bee populations. The EU-project Sweden-Norway INTERREG "BIstånd till nordiska bin- unik resurs för framtidens ekosystemtjänster", studies Nordic bees' adaptation to environment and climate. Using activity data from the research project, this study aims to analyze how local weather conditions affect the flight activity of the Western honey bee (Apis mellifera), examine behavioral patterns and evaluate the potential in using weather conditions as a basis for predictive modeling. Two starting models of simple and combined weather parameters as independent variables with flight activity/individual as response variable were analyzed with automated multiple regression analyzes using three methods of Stepwise selection with AIC (Akaike Information Criterion) to find the simplest regression model that best describes the data. No statistical significant linear relationship between flight activity and additive/combined local weather conditions was found based on data from all methods. Of all combinations tested, wind had the most impact on the response variable. A total of 52 individuals registered 2880 flight activities during the collection period, of which a unique individual performed 38% of all registered activities. Wind showed no significant impact, however, for days with winds above 4 m/s, the flight activity decreased significantly. Individual variations within the population, small amount of data and uncertain weather data may have affected the result.

Genom att filtrera vattnet i vattendrag och sjöar bidrar musslor till renare och klarare vatten. Debidrar till friskare ekosystem som i sin tur ger människor värdefulla ekosystemtjänster.Sötvattensmusslor har också en viktig roll i näringsvävar som föda för andra djurarter. I Sverigefinns det 24 arter som räknas till ärt- och klotmusslor (Sphaeriidae). Lite är känt om ärt- ochklotmusslorna och följderna om de försvinner från ekosystemen är än så länge oklart. Relativtlite forskning har bedrivits inom området och den här studien är menad att bidra till ökadförståelse av ärt- och klotmusslor. I denna rapport studeras bottensubstratets betydelse för ärtochklotmusslor. Det studeras också om det finns skillnader mellan olika vattendjup. Fyra sjöarinventerades i Skaraborgsregionen. Studien visar att det inte finns något samband mellanförekomst och vattendjup. De vattendjup som undersöktes var 20cm och 100cm. Studien visarockså att det finns en signifikant skillnad mellan mjukt bottensubstrat och övriga bottentyper.Tidigare forskning uppvisar liknande resultat. Beroende på art kan habitatvalen skilja sigkraftigt då ärt- och klotmusslor har ett brett spektrum av habitatval. Största andelenmusselarter hittas i mjukt bottensubstrat men musslor hittades i alla typer av bottensubstrat.Var arten hittas beror också på om arten lever i strömmande eller stillastående vatten. / By filtering the water in streams and lakes, clams make waters cleaner and clearer and this inturn contributes to a healthier ecosystem and provides ecosystem services for humans.Freshwater clams also play an important role as food for other animals. In Sweden there are 24different species of pea clams (Sphaeriidae). Not much is known about pea clams and theconsequences if they would disappear from the ecosystem are so far unclear. Relatively smallamounts of research have been done about them and this study is meant to contribute toincreased understanding of pea clams. In this report the significance of sediments for pea clamswere studied. Differences in water depth was also studied. Four lakes in the area aroundSkaraborg was investigated. The study showed that there was no correlation between presenceand water depth. The studied depths were 20cm and 100cm. The study found that there exists asignificant difference between soft and other types of sediments. Previous research showedsimilar results. Depending on the species the habitat may differ since pea clams have a widespectrum of ecological niches. Most clams were found in soft sediments, but they were alsodetected in other sediment types (middle and hard). Their occurrence also depended on the flowproperties of the water (calm vs. flowing).