Examines whether the reinforcing properties of drugs of abuse were altered in adulthood by methylphenidate, more commonly known as Ritalin. Subjects were 108 rats of Sprague-Dawley descent (Harlan). Methylphenidate, or saline was administered daily to the subjects from the postnatal period (11-20 days old). The rats preference for morphine during early adulthood was measured using conditioned place preference. The number of dopamine D₂ receptors was measured in each rat and the correlation between receptor number and morphine preference was determined. Results indicate that rats pretreated with methylphenidate showed greater preference for morphine than saline pretreated rats and suggests that exposure to methylphenidate during the postnatal period increases the rewarding value of morphine.

Protokol TLS je komplexní a jeho použití je široce rozšířené. Mnoho zařízení používá TLS na ustanovení bezpečné komunikace, vzniká tak potřeba tento protokol důkladně testovat. Tato diplomová práce se zaměřuje na útoky přes časové postranní kanály, které se znovu a znovu objevují jako variace na už známé útoky. Práce si klade za cíl usnadnit korektní odstranění těchto postranních kanálů a předcházet vzniku nových vytvořením automatizovaného frameworku, který pak bude integrován do nástroje tlsfuzzer, a vytvořením testovacích scénářů pro známé útoky postranními kanály. Vytvořené rozšíření využívá program tcpdump pro sběr časových údajů a statistické testy spolu s podpůrnými grafy k rozhodnutí, zda se jedná o možný postranní kanál. Rozšíření bylo zhodnoceno pomocí nových testovacích skriptů a byla předvedena jeho dobrá schopnost rozlišit postranní kanál. Rozšíření spolu s testy je nyní součástí nástroje tlsfuzzer.

This thesis is focused on the side-channels in the cryptology. The main attention is paid to the side-channels, which allow an attack on a computer keyboard. Especially the acoustic side-channel is focused on. Through this channel are demonstrated two attacks on the keyboard. At first, the method of recognizing is described. The neural network was used for the recognition. Then, the demonstration attacks on the keyboard are described. The first demonstration is an attack in laboratory conditions and the other in terms of household conditions. The thesis describes two attacks from the record, through data recognition by neural networks to evaluate the actual demonstration of attack. The following describes the recommendations for disabling attack. The results are supplemented by graphs and discussed.

Today, companies are developing processor demanding applications on the web, for example, 3D visualization software and video and audio software. Some of these companies have a native desktop application written in for example C++. These C++ codebases can consist of several hundred thousand lines of code, and companies would therefore like to reuse their codebase in the web version of the software. This thesis makes a performance comparison between two different approaches that can be taken to reuse the C++ codebase. The first approach is to compile the C++ codebase to WebAssembly and run it on the client-side. The second approach is to compile the C++ codebase to native code and run it on the server-side. It is not clear which approach to take if the goal is to achieve low execution times. This thesis will therefore answer the question of whether a client-side solution inWebAssembly is faster than a server-side solution in native code. To answer this question, this project work looked at one use case namely image processing. Two different web applications were developed, one that did image processing on the server-side in native code, and another one that did image processing on the client-side in WebAssembly. Execution time measurements were collected from both web applications. The results showed that for most algorithms WebAssembly was a factor of 1.5 slower than native code, without considering the additional delay from the internet that will affect the web application that performs image processing on the server-side. If this delay is taken into account, the web application that performs image processing on the client-side inWebAssembly will be faster than the server-side solution in native code for most users in the world. If the Round-Trip Time (RTT) is 1 ms the required average throughput needed to make the two web applications equally fast is 249 Mbps (Google Chrome) or 226 Mbps (Firefox). Most users in the world do not have such a high average throughput. / Idag utvecklar företag processorkrävande applikationer på webben, till exempel 3D-visualiseringsprogramvara och video- och ljudprogramvara. Några av dessa företag har även skrivbordsprogram skrivna i exempelvis C++. Dessa C++ kodbaser kan bestå av flera hundra tusen rader kod, och företag vill därför återanvända sin kodbas i webbversionen. Detta projektarbete gör en jämförelse mellan två olika tillvägagångssätt för att återanvända C++ kodbasen. Det första tillvägagångssättet är att kompilera C++ kodbasen till WebAssembly och köra koden på klientsidan. Det andra tillvägagångssättet är att kompilera C++ kodbasen till maskinkod och köra koden på serversidan. Det är inte klart vilken metod man ska ta om målet är att uppnå optimal prestanda. Detta projektarbete kommer därför att besvara frågan om en klientsidslösning i WebAssembly är snabbare än en serversidslösning i maskinkod. För att svara på den här frågan tittade projektarbetet på ett användningsfall, nämligen bildbehandling. Två olika webbapplikationer utvecklades, en som gjorde bildbehandling på serversidan i maskinkod och en annan som gjorde bildbehandling på klientsidan i WebAssembly. Körtidsmätningar samlades in från båda webbapplikationerna. Resultaten visade att för de flesta algoritmer var WebAssembly en faktor 1,5 långsammare än maskin kod, utan att ta hänsyn till den extra fördröjningen från internet som kommer att påverka webbapplikationen som utför bildbehandling på serversidan. Om denna fördröjning tas med i beräkningen kommer webbapplikationen som utför bildbehandling på klientsidan i WebAssembly att vara snabbare än serversidslösningen i maskinkod för de flesta användare i världen. Om tur och retur tiden (RTT) är 1 ms är den genomsnittliga genomströmning som krävs för att göra de två webbapplikationerna lika snabba 249 Mbps (Google Chrome) eller 226 Mbps (Firefox). De flesta användare i världen har inte så hög genomsnittlig genomströmning.

Durch den Ausbau an Wind- und PV-Anlagen in Deutschland wird der Flexibilitätsbedarf im Stromsystem steigen. Der Flexibilitätsbedarf kann zum einen durch verschiedene Technologien, z.B. Speicher oder Netze, und zum anderen durch die Stromnachfrage bereitgestellt werden. Eine gezielte Steuerung der Stromnachfrage wird als Demand Side Management (DSM) bezeichnet. Der zunehmend wetterabhängigen und fluktuierenden Stromerzeugung in Deutschland steht jedoch eine bis heute weitgehend unelastische Nachfrage gegenüber. In der Literatur sind verschiedene Arbeiten zu finden, die das Potential zur Lastabschaltung und verschiebung in Deutschland untersuchen. Hierbei liegt der Fokus auf absoluten Werten. Saisonale oder tageszeitliche Unterschiede bleiben dabei häufig unberücksichtigt. Die vorliegende Dissertation greift an dieser Stelle an und untersucht das Potential ausgewählter DSM-Anwendungen in stündlicher Auflösung. Die Ergebnisse zeigen, dass das verfügbare Potential starken saisonalen und tageszeitlichen Schwankungen unterliegt. Dementsprechend wird das DSM-Potential überschätzt, wenn nur absolute Werte betrachtet werden. Darüber hinaus zeigt die Autorin, welche Entwicklungen in den nächsten Jahren hinsichtlich der Verfügbarkeit des DSM-Potentials zu erwarten sind. Basierend auf der Potentialermittlung wird in der Dissertation die Rolle von DSM in einem EE-geprägten Stromsystem modellbasiert untersucht. Hierfür wird das lineare Optimierungsmodell ELTRAMOD, das den deutschen und europäischen Strommarkt abbildet, weiterentwickelt. Anhand verschiedener Szenarien wird zum einen der Beitrag von DSM zur Systemintegration von erneuerbaren Energien in Deutschland und zum anderen die Wechselwirkungen mit anderen Flexibilitätsoptionen (z.B. Speicher) untersucht. Die Ergebnisse zeigen, dass die DSM-Kategorien Lastabschaltung und verschiebung nur kurzzeitig auftretende Schwankungen der Einspeisung aus erneuerbaren Energien ausgleichen können. Zum Ausgleich großer Überschussmengen aus erneuerbaren Energien sind hingegen Power-to-X-Technologien, z.B. Power-to-Heat, besser geeignet.

This thesis investigates overeducation as an aspect of integration among the second generation in Western Europe. As the second generation grows and establishes themselves in the labour market, research about their labour market outcomes becomes increasingly important. Using nine rounds (2002-2018) of the European Social Survey (ESS), this thesis investigates the impact of being a second generation on the probability of being overeducated in Western Europe. An overeducation-measure is developed using the realised matches-approach and weighted linear probability models are performed on pooled and country-stratified samples. The thesis takes into account labour market supply-and demand-side characteristics to discuss possible mechanisms behind the results. The results show that across Western Europe, the second generation faces a higher probability of being overeducated compared to their native counterparts. The UK stands out, where the second generation is subject to an 8,53-percentage point higher probability of being overeducated than the natives. Parental origin and level of education are important supply-side factors, where the second generation with parents from non-EU countries and those with non-tertiary educated parents have higher probabilities of being overeducated. On the demand-side, employment and unemployment protection regulations are associated with overeducation, where stricter employment protection and higher net replacement rates in unemployment is associated with lower probabilities of overeducation among the second generation. This thesis highlights the importance of assessing the labour market supply- and demand-side characteristics in research about labour market outcomes for the second generation, and contributes to the research field with the comparative perspective.

In many situations, fluid flows can exhibit a wide range of temporal and spatial phenomena. It has become common to extract physically important features, called modes, as a first step in the analysis of flows with high complexity. One of the most prominent modal analysis techniques in the context of fluid dynamics is Proper Orthogonal Decomposition (POD), which enables extraction of energetically coherent structures present in the flow field. This method does, however, suffer from the lack of connection with the mathematical theory of dynamical systems and its utility in the analysis of arbitrarily complex flows might therefore be limited. In the present work, we instead consider application of the Koopman Mode Decomposition (KMD), which is an approach based on spectral decomposition of the Koopman operator. This technique is employed for modal analysis of the incompressible, two-dimensional ow past two side-by-side cylinders at Re = 60 and with a non-dimensional cylinder gap spacing g* = 1. This particular configuration yields a wake ow which exhibits in-phase vortex shedding during finite time, while later transforming into the so-called flip-flopping phenomena, which is characterised by a slow, periodic switching of the gap ow direction during O(10) vortex shedding cycles. The KMD approach yields modal structures which, in contrary to POD, are associated with specific oscillation frequencies. Specifically, these structures are here vorticity modes. By studying these modes, we are able to extract the ow components which are responsible for the flip-flop phenomenon. In particular, it is found that the flip-flop instability is mainly driven by three different modal structures, oscillating with Strouhal frequencies St1 = 0:023, St2 = 0:121 and St3 = 0:144, where it is noted that St3 = St1 + St2. In addition, we study the in-phase vortex shedding regime, as well as the transient regime connecting the two states of the flow. The study of the in-phase vortex shedding reveals| - not surprisingly - the presence of a single fundamental frequency, while the study of the transient reveals a Koopman spectrum which might indicate the existence of a bifurcation in the phase space of the flow field; this idea has been proposed before in Carini et al. (2015b). We conclude that the KMD offers a powerful framework for analysis of this ow case, and its range of applications might soon include even more complex flows.

Autonomous underwater vehicle (AUV) navigation has been a challenging problem for a long time. Navigation is challenging due to the drift present in underwater environments and the lack of precise localisation systems such as GPS. Therefore, the uncertainty of the vehicle’s pose grows with the mission’s duration. This research investigates methods to form constraints on the vehicle’s pose throughout typical surveys. Current underwater navigation relies on acoustic sensors. Side Scan Sonar (SSS) is cheaper than Multibeam echosounder (MBES) but can generate 2D intensity images of wide sections of the seafloor instead of 3D representations. The methodology consists in extracting information from pairs of side-scan sonar images representing overlapping portions of the seafloor and computing the sensor pose transformation between the two reference frames of the image to generate constraints on the pose. The chosen approach relies on optimisation methods within a Simultaneous Localisation and Mapping (SLAM) framework to directly correct the trajectory and provide the best estimate of the AUV pose. I tested the optimisation system on simulated data to evaluate the proof of concept. Lastly, as an experiment trial, I tested the implementation on an annotated dataset containing overlapping side-scan sonar images provided by SMaRC. The simulated results indicate that AUV pose error can be reduced by optimisation, even with various noise levels in the measurements. / Navigering av autonoma undervattensfordon (AUV) har länge varit ett utmanande problem. Navigering är en utmaning på grund av den drift som förekommer i undervattensmiljöer och bristen på exakta lokaliseringssystem som GPS. Därför ökar osäkerheten i fråga om fordonets position med uppdragets längd. I denna forskning undersöks metoder för att skapa begränsningar för fordonets position under typiska undersökningar. Nuvarande undervattensnavigering bygger på akustiska sensorer. Side Scan Sonar (SSS) är billigare än Multibeam echosounder (MBES) men kan generera 2D-intensitetsbilder av stora delar av havsbotten i stället för 3D-bilder. Metoden består i att extrahera information från par av side-scan sonarbilder som representerar överlappande delar av havsbotten och beräkna sensorns posetransformation mellan bildens två referensramar för att generera begränsningar för poset. Det valda tillvägagångssättet bygger på optimeringsmetoder inom en SLAM-ram (Simultaneous Localisation and Mapping) för att direkt korrigera banan och ge den bästa uppskattningen av AUV:s position. Jag testade optimeringssystemet på simulerade data för att utvärdera konceptet. Slutligen testade jag genomförandet på ett annoterat dataset med överlappande side-scan sonarbilder från SMaRC. De simulerade resultaten visar att AUV:s poseringsfel kan minskas genom optimering, även med olika brusnivåer i mätningarna.

Caching is a fundamental technique widely used in the field of computing to reduce network traffic, server load, and latency. Storing frequently accessed data in a high-speed cache layer can make future requests process faster by involving fewer system components when generating and serving the response. Kalix is a software product that demands a caching solution since it faces latency and is frequently processing partially repeated queries. However, a cache does not guarantee improved performance, which is why the main problems of caching are: determining what content to cache, when to insert or remove cache content, implementing the caching logic, and deciding where to store the cache efficiently. Therefore, this paper theoretically investigates where a cache solution should be implemented within the Kalix system architecture to decrease latency and server load, and evaluates the subsequent cache implementation experimentally. As a result, a client-side cache is implemented which decreases the latency of Kalix by up to 74%, while reducing the I/O load and memory utilization on the server by 98%. The reason for the decrease is that the cache in the client can directly serve the majority of the content, allowing the servers of Kalix to do substantially fewer computations. The evaluation acts as a recommendation for the company behindKalix, Polystar, as to if a cache is beneficial and where the cache can efficiently be deployed, and this paper gives valuable insights into the decision-making of cache placement. Concludingly, implementing the cache positively impacts the Kalix user experience.

Utbudet av ekonomiskt överkomliga bostäder har varit begränsat i många delar av världen och möter inte konsumenternas efterfrågan, bland annat i Sverige, Finland, Australien och England. Till följd av detta har bostadsbrist, ökade bostadspriser,  bostäder med höga hyror och långa kötider ökat med åren. Subventioner infördes som ett försök till att minska produktionskostnader för byggherren och därmed erbjuda billiga hyresrätter genom subventioner till utbudssidan eller genom att bidra med med subventioner direkt till efterfrågesidan, vilket omfattar hyresgästerna i form av bostadsbidrag.  De här arbetet syftar till att fastställa de olika subventionerna som används i Australien, England, Sverige och Finland. Samtidigt undersöks vilka typ av direkta subventioner som används i dessa länder för att slutligen undersöka vilka konsekvenser utbudssidan subventioner har haft på respektive bostadsmarknad. Studien är en kvalitativ forskning baserad på en litteraturgenomgång av de olika länderna. Stödet till hyresbostäder skiljer sig åt i olika delar av världen. Regeringarna i var av dessa länder bestämmer hur finansieringen ska fördelas på bostadsmarknaden.Finansieringen kan gå till efterfrågesidan som hyreskompensation alternativt till utbudssida som subvention till konstruktören för att sänka sin produktionskostnad med förbehållet att den nya hyran för bostäderna är lägre än marknadshyran. Resultatet visar på att regeringarna har olika typer av av bostadsmarknader, men att samtliga undersökta länder föredrar hyres kompensationer framför subventioner till utbudssidan. Resultaten visar också att det största behovet av finansiell stöd till konstruktören är under lågkonjunktur, där den privata finansieringen är som lägst. Studien visar även de olika kraven för subventioner till utbudssidan, där Sverige och England har mer specifika krav än Australien och England. Under slutsatsen diskuteras för- och nackdelar med båda typerna av subventioner, där samtliga regeringar föredrar subventioner till efterfrågesidan eftersom dessa är lättare att utföra på en individbasis. De hjälper till med bostäder till rimliga priser men inte bostadsproblemet. Subventioner till utbudssidan har varit väl utnyttjade under lågkonjunkturer som en säkerhet för byggherren. Ett problem som lyfts upp med denna typ av subvention är dess kapitalintensiva natur då stora summor pengar går in i ett långt projekt, och anses av vissa inte vara en lösning på problemet med överkomliga bostäder eftersom den reglerade hyran övergår till marknadshyra efter en period. / The range of affordable housing prices has been limited in many parts of the world and does not meet consumer demand, such is the case in Sweden, Finland, Australia and England. As a result of this housing shortage, rising housing prices, homes with high rents and long queue times have increased over the years. Subsidies were introduced as an attempt to reduce production costs for the developer and thereby offer cheap rental apartments through subsidies to the supply side or by contributing a subsidy directly to the demand side, which includes the tenants in the form of housing subsidies. This paper aims to determine the different subsidies used in Australia, England, Sweden and Finland, while also researching what type of direct subsidies are used in these countries, and finally viewing what consequence the supply-side subsidies have had on their respective housing markets. The study is qualitative research based on a literature review of the different countries. The support for rental housing differs in different parts of the world, by where the government chooses to focus their financing. The financing can go to the demand side as rent compensation or to the supply side, as payment to the constructor to reduce their cost on the caveat that the new rent for this building is lower than the market rent. The results show that while different governments have different housing markets, they all favor the option for rent compensation over subsidies to newly produced real estate with lower market average rent. The results also show that the biggest need for financial support to the constructor is during a recession, where the private financing is at its lowest. The study also shows the differing local requirements for where the supply-side subsidies can go, with England and Sweden having certain requirements, while Australia and Finland have a lack of these.The conclusion discusses the advantages and disadvantages of both types of subsidies, where all governments prefer subsidies to the demand side as these are easier to perform on an individual basis. They help with affordable housing but not the housing problem. Subsidies to the supply side have been well utilized during recessions as a security for the house developers. A problem that is highlighted with this type of subsidy is its capital-intensive nature as large sums of money go into a long project, and is considered by some not to be a solution to the problem of affordable companies as regulated rents change to market rents after a period.