As a part of the growing movement called the “peer-to-peer” economy, Airbnb has changed the short-stay rental market and has become one of the world’s largest booking websites for finding an accommodation to stay. The platform has also affected the economy of tourism around the world, so, given the importance of the subject, in this thesis study, the impacts that the Airbnb rental accommodation model has on clients of Stockholm, Barcelona and Rio de Janeiro is studied. In this way, it has been analyzed how factors such as price, location and seasonality affect Airbnb customers in these cities. To do this, the three cities were first analyzed individually and then compared, using data from the Inside Airbnb website from 2010 to now. This research has been carried out through an exploratory analysis using the R programming language. The study has been divided into three parts: First, the Spatial Data Analysis has shown that Airbnb´s presence in all three cities has increased significantly in the past decade, growing from the most touristy parts of the city to surrounding areas. In addition, it has been observed that the largest number of Airbnb properties are apartments located near the city center and touristic places, which also are the most valued areas by Airbnb customers and the most expensive to rent a property. Secondly, a Demand and Price Analysis has been carried out. In this part, the demand for Airbnb listings has been estimated over the years since 2010 and across months. A significant increase in demand has been appreciated in the last decade, which also shows a seasonal pattern. In the three cases, the demand graph follows the city´s climate, showing the highest demand during the summer months, which corresponds to the most expensive period. Finally, through User Review Mining, customer opinion has been studied by applying text mining to reviews. In this part of the research, word clouds have been used to have a visual representation of the text data, showing the most frequent words and analyzing what makes customers feel comfortable and uncomfortable. / I detta examensarbete har effekterna som Airbnbs hyresmodell har på kunder i Stockholm, Barcelona och Rio de Janeiro studerats. På detta sätt har det varit möjligt att analysera hur faktorer som pris, plats och säsongsvaror påverkar Airbnbs kunder i dessa städer. För att göra detta analyserades först de tre städerna individuellt och jämfördes sedan med data från webbplatsen Inside Airbnb från 2010 till nu. Denna forskning har genomförts genom en undersökande analys med programmeringsspråket R. Studien har delats in i tre delar: För det första har den rumsliga dataanalysen visat att Airbnbs närvaro i alla tre städerna har ökat markant under det senaste decenniet och växte från att omfatta de delar av staden som är mest intressanta för turister till omgivande områden. Dessutom har det observerats att det största antalet objekt på Airbnb är lägenheter belägna nära centrum och platser intressanta för turister, som också är de mest värderade områdena av Airbnbs kunder och de som är dyrast att hyra i en fastighet. För det andra har en efterfrågan och prisanalys genomförts. I denna del har efterfrågan på Airbnbs registreringar uppskattats under åren sedan 2010 och över flera månader. En betydande ökning av efterfrågan under det senaste decenniet har uppskattats, vilket också visar ett säsongsmönster. I samtliga tre fall följer efterfrågan förändringarna i stadens klimat och visar den högsta efterfrågan under sommarmånaderna, vilket också motsvarar den dyraste perioden. Slutligen, i avsnittet Användarrecensioner, har återkoppling från kunderna studerats genom att använda textutvinning på recensioner. I denna del av forskningen har ordmoln använts för att få en visuell representation av textdata, som visar de vanligaste orden och analyserar vad som gör att kunderna känner sig bekväma och obekväma.

Cardiovascular disease (CVD) is the leading cause of morbidity, mortality, premature death and reduced quality of life for the citizens of the EU. It has been reported that CVD represents a major economic load on health care sys- tems in terms of hospitalizations, rehabilitation services, physician visits and medication. Data Mining techniques with clinical data has become an interesting tool to prevent, diagnose or treat CVD. In this thesis, Knowledge Dis- covery and Data Mining (KDD) was employed to analyse clinical and demographic data, which could be used to diagnose coronary artery disease (CAD). The exploratory data analysis (EDA) showed that female patients at an el- derly age with a higher level of cholesterol, maximum achieved heart rate and ST-depression are more prone to be diagnosed with heart disease. Furthermore, patients with atypical angina are more likely to be at an elderly age with a slightly higher level of cholesterol and maximum achieved heart rate than asymptotic chest pain patients. More- over, patients with exercise induced angina contained lower values of maximum achieved heart rate than those who do not experience it. We could verify that patients who experience exercise induced angina and asymptomatic chest pain are more likely to be diagnosed with heart disease. On the other hand, Logistic Regression, K-Nearest Neighbors, Support Vector Machines, Decision Tree, Bagging and Boosting methods were evaluated by adopting a stratified 10 fold cross-validation approach. The learning models provided an average of 78-83% F-score and a mean AUC of 85-88%. Among all the models, the highest score is given by Radial Basis Function Kernel Support Vector Machines (RBF-SVM), achieving 82.5% ± 4.7% of F-score and an AUC of 87.6% ± 5.8%. Our research con- firmed that data mining techniques can support physicians in their interpretations of heart disease diagnosis in addition to clinical and demographic characteristics of patients.