Mikrotransaktioner är en stor del av dagens internethandel. Det används flitigt på både websidor och i datorspel. Denna rapport tar upp hur ett företag eller en privatperson kan, genom A/B-testning, testa vilken transaktionstyp som är bäst för just deras applikation. Problemet är att det finns många olika transaktionstyper att välja mellan och att det inte finns något bra sätt att få fram vilket som är det bästa för just din applikation. För att försöka hitta den optimala transaktionstypen utnyttjades en testapplikation med olika transaktionstyper. Genom att mäta en transaktiontyps effektivitet kan vi få fram en mätpunkt med vilken man kan jämföra med andra transaktionstyper. Resultaten visar att A/B-testning av mikrotransaktioner går att genomföra genom att följa de arkitekturerna som tillhandahålls av rapporten. / Micro transactions are a big part of today's internet commerce. They are used diligently in both web applications and in computer games. This report will explore how a company or private developer, through A/B-testing, can test which transaction type is the best for their specific application. The problem is that there's a large amount of transaction types to choose from and there is not any good way to find out which one is the best for your application. To do this there needs to be some way to test the different types to receive the optimal one. By measuring a transaction type's efficiency, we can get a point of measure which can be compared to other transaction types. The results show that A/B-testing is applicable on micro transactions by following the architectures provided by this report.

The urge to consume does not seem to stop, thus, the need for transportation of goods will most likely not decrease. At the same time jurisdictions and regulations around greenhouse gas emissions are sharpening and pushing the industry towards a more environmentally friendly state. The freight and transportation industry is facing a huge challenge in the upcoming years and solutions are needed to feed the demand of society. Two, of many, proposals of solving, at least, parts of the above mentioned problem is platooning and the look-ahead controller. Platooning denotes the concept of slipstream where maximum utilization of aerodynamic drag reduction is endeavoured. The lookahead controller exploits the surrounding topographical information in order to yield an optimal driving strategy, often resulting in that the vehicle initiates the phenomenon of pulse and glide, which denotes alternating between high load operation points and freewheeling, i.e. engaging neutral gear. This work has sought to investigate these concepts to determine whether or not additional fuel-efficiency can be added by manipulating and re-designing the control unit of the system. The proposed addition is built upon the look-ahead controller and supplements it by enabling communication between vehicles such that micro-transactions may occur in order to aid decision making regarding the choice of driving strategies. A vehicle model, a platoon model and the novel optimization based look-ahead-controller was synthesized and developed, where dynamic programming was used as the optimization solver of the controller. The look-ahead controller was verified such that one can conclude that it behaves according to the assumptions of such a system. The proposed micro-transaction system was also verified to conclude that it behaves as assumed, yielding a reduction in fuel consumption. For a platoon of two members, a 1.2% and 1.7% reduction in fuel consumption for the leading and following vehicle respectively was obtained, compared to an identical platooning setup, using a lookahead controller, but where no negotiations using micro-transactions are allowed between the vehicles.

Cette thèse étudie le comportement des investisseurs des fonds mutuels ouverts et ses implications au risque de liquidité. Ces travaux de recherche ont pour objectif d’aider les gérants de fonds à éviter le scénario de "fund run" où ils perdent leurs clients de manière soudaine. La première étape de cette étude est de collecter une nouvelle base de données qui enregistre les "micro-transactions" des investisseurs. Cela nous permet d’analyser leurs comportements au niveau individuel et d’effectuer trois articles de recherche autours de ce sujet. Dans le premier article, nous développons un modèle de comptage auto-excitant qui capture des faits stylisés des séries des flux du fonds. De là, nous montrons un risque lié au passif du fonds qui est différent de celui lié à l’actif déjà documenté par la littérature précédente. Nous identifions également une contagion des chocs de liquidité entre les différents clients dans un même fonds. Dans le chapitre suivant, nous étudions les horizons d’investissement des clients individuels. Ces horizons sont fortement liés aux caractéristiques des investisseurs et aux conditions économiques. Nous montrons également que les gérants de fonds subissent un risque de sortie pré-maturée relatif au raccourcissement des horizons d’investissement de ses clients. Nous observons ensuite une hétérogénéité entre les investisseurs: ceux de long-terme comportent différemment que ceux de court-terme. Enfin, dans le dernier chapitre, nous nous intéressons aux activités de rééquilibre. Nous trouvons que de nombreux investisseurs détiennent un portefeuille contenant plusieurs fonds et le rééquilibrent afin de garder la même allocation d’actifs / This thesis studies the behaviour of investors in open-end mutual funds and its implications to the liquidity risk. We seek to help the fund managers to avoid the "fund run" scenarios where they loss their clients in a sudden way. We begin our research by collecting a unique data set which records the micro-transactions of fund investors. It allows us to monitor investors’ behaviour at the individual level and to accomplish three research articles around this topic. In the first article, we develop a self-exciting counting process to model the stylized facts of fund flows. Therefrom, we highlight a novel risk linked to the fund liability which is different than the asset-related risk documented by the previous literature. We also identify a liquidity contagion among different investors in a same fund. In the next chapter, we study the dispersion in the investing horizons of individual fund clients. These horizons are strongly determined by investors’ characteristics and economic conditions. We show that the fund managers suffer a pre-mature redemption risk, i.e. clients shorten their investing horizons and redeem pre-maturely. Especially, we observe a heterogeneity among investors: long-term ones bring a higher pre-mature redemption risk. In the last chapter, we are interested in the rebalance behaviour. We find that numerous investors hold a multi-funds portfolio and rebalance it to keep the target asset allocation.