This thesis presents a Real-time Reactive platform for Data Integration and Event Stream Processing. The Data Integration part is composed of data pullers that incrementally pull data changes from REST data sources and propagates them as streams of immutable events across the system according to the Event-Sourcing principle. The Stream Processing part is a Tree-like structure of event-sourced stream processors where a processor can react in various ways to events sent by its parent and send derived sub-streams of events to child processors. A processor use case is maintaining a pre-computed view on aggregated data, which allows to define low read latency business dashboards that are updated in real-time. The platform follows the Reactive architecture principles to maximize performance and minimize resource consumption using an asynchronous nonblocking architecture with an adaptive push-pull stream processing model with automatic back-pressure. Moreover, the platform uses functional programming abstractions for simple and composable asynchronous programming. Performance tests have been performed on a prototype application, which validates the architecture model by showing expected performance patterns concerning event latency between the top of the processing tree and the leaves, and expected fault-tolerance behaviours with acceptable recovery times.

The benefits of Business Intelligence (BI) activities are widely recognized and arouse more and more interest nowadays. In particular, self-service analytics is getting more and more popular. Enabling end users to process their data by themselves allow them to be more reactive to business changes by making better decisions faster. One of the challenges in this area is to provide tools easy to use with a high computational performance to enable end users who often aren’t developers to process their data by themselves in a simple and fast manner. The BI application that we will call BITX belongs to that category. This thesis presents the integration of an in-memory columnoriented database engine that we will call DBEX as backend for this application. The purpose of this experiment is to optimize BITX’s performance by providing it with a lightweight back-end well adapted to BI analysis. The architecture and implementation of the driver developed for DBEX are detailed. The query execution mechanism and SQL functions representation in the engine are studied and performance optimizations for SQL functions implementation are proposed. The system performance is then analyzed following two axis: DBEX’s memory consumption and the respone time of the subsystem {DBEX+driver}. Improvements made further to the performance evaluation and speeding up some of the driver’s operations are presented.

The new generation of Wireless Sensor Networks, that is known as the Internet of Things enables the direct connection of physical objects to the Internet using microcontrollers. In most cases these microcontrollers have very limited computational resources. The global connectivity provides great opportunities for data collection and analysis as well as for interaction of objects that cannot be connected to the same local area network. Many of application scenarios have high requirements to security and privacy of transmitted data. At the same time security solutions that are utilized for general purpose computers are not always applicable for constrained devices. That leaves a room for new solutions that takes into account the technological aspects of the Internet of Things. In this thesis we investigate the access control solution for the IETF standard draft Constrained Application Protocol, using the Datagram Transport Layer Security protocol for transport security. We use the centralized approach to save access control information in the framework. Since the public key cryptography operations might be computationally too expensive for constrained devices we build our solution based on symmetric cryptography. Evaluation results show that the access control framework increases computational effort of the handshake by 6.0%, increases the code footprint of the Datagram Transport Layer Security implementation by 7.9% and has no effect on the overall handshake time. Our novel protocol is not vulnerable to Denial of Service or Drain Battery Attack.

This report presents the work creating and evaluating a front-end for conformance testing with the LBTest software and the viability of a tool of this kind. LBTest is a tool designed for learning-based testing of embedded systems using model checking. In order to reach a verdict the model checking uses a specification written in linear temporal logic. The front-ends desired functionality is to translate NuSMV-files into linear temporal logic. A .dot-file should also be generated in order to render a visual representation of the Nu- SMV-file. A case study where the front-end translates a model's specification and testing it on a program with LBTest is successful and shows that a frontend is possible to create and use in order to achieve conformance testing in LBTest. / Den här rapporten beskriver arbetet för att skapa och utvärdera en front-end för testningsprogramvaran LBTest och hur användbart ett sådant verktyg är för att använda sig av conformance testing. LBTest använder learning-based testing för att lära sig hur inbyggda system är uppbyggda genom att använda model checking. Det slutgiltiga front-end programmet ska översätta modellspecifikationer skrivna i NuSMV till linear temporal logic som är det logikspråk som LBTest använder sig av. Även en .dot-fil ska skapas som kan användas till att rendera en grafisk representation av modellspecifikationen. En fallstudie av programmet där en modellspecifikation översätts och körs i LBTest visar att mjukvara av den här typen går att skapa och är en lämpligt verktyg för att uppnå conformance testing med LBTest.

Creating reports with a huge amount of data can be a big help when it comes to decision making, Tele2 has collected data from a lot of di erent sources and are at the moment of writing developing a system that will easily be able to produce reports and comparisons. These reports are supposed to create the foundation for better decision making and to get a better view on how the company works today. The reporting environment Cognos is adapted to use data from various sources and make it easy to take out clear reports from this. To make their work easier we have received the task of transforming these reports from only being viewable on computers to also be viewable on tablets and other mobile devices, all to make it easier to look at these reports wherever you are and whenever you want. During our work we will install and congure the mobile package that Cognos has. We will also evaluate if this is the most e ective and best way to do this. The most important part of our work is to make these reports viewable on the mobile devices and also congured so that they are easy to view and read. To achieve this we have to adapt the reports so that they no longer only are developed to read on a big screen but also to a smaller one.

This thesis presents Instant Simulator, a tool for simulating digital signal processors (DSPs) to allow cycle-accurate benchmarking of programs. The purpose of the tool is to assist the Unison compiler when comparing generated machine code between Unison and industrial strength compilers Instant Simulator is designed to reuse parts of Unison and strike a balance between performance and ease of use. DSPs are described in machine-readable specifications and compiled into simulators, partly with the help of tools developed for Unison. A case study is conducted to evaluate Instant Simulator, where the C67x DSP from Texas Instruments is simulated during execution of small test programs. The case study ensures the correctness and completeness of the tool and the simulations executes at a clock rate between 2.6 MHz and 9.7 MHz on a modern mid-tier laptop, depending on the level of detail in simulation.

Most students study at home. When students tackle problems within their study, the answer is usually found in the course literature, searching through the web, or through various social medias. While this helps students to a certain degree, the questions will not always be answered, the information found may not always be intuitive and easy to understand. Studying at home proves inefficient for some students, due to difficulties with concentration into tasks in an environment that often is distracting. This bachelor thesis is built around a developing social service, that gives students the ability to meet other students to study and discuss together. The project is called: Radspire, and it enables its users to find students studying in the same field to find each other. With matching algorithms that bases matching results on time, subjects, and position, students will be able to help, or get help from other students studying in the same field. Discuss, share ideas or just simply watch other student study, which enhances level of concentration while studying. The thesis is dedicated to prototyping a user-friendly Graphical User Interface(GUI) of this service, by application of evaluation methods within the field of Human-Computer Interaction. / De flesta studenter studerar hemma. När studenterna försöker lösa ett problem inom deras studier, finner de svaret vanligtvis i kurslitteraturen, i webben, eller genom olika sociala medier. Även om detta hjälper eleverna till en viss grad, frågorna kommer inte alltid att besvaras, den information som finns kanske inte alltid är intuitiva och enkla att förstå. Studera hemma visar sig ineffektiv för en del studenter, på grund av svårigheter med koncentration till uppgifter i en miljö som ofta är distraherande. Detta examensarbete bygger på en utveckling av social service, som ger studenterna möjligheten att träffa andra studenter att studera och diskutera tillsammans med. Projektet heter: Radspire, och det gör det möjligt för användarna att hitta studenter som studerar inom samma område för att hitta varandra. Med matchningsalgoritmer som basera matchningens resultat på tid, plats, och ämne, kommer studenterna att kunna hjälpa till, eller få hjälp av andra studenter som studerar inom samma område. Diskutera, dela idéer eller bara agera som studievakt för andra studenter, vilket förbättrar koncentrationsnivå under studietiden. Examensarbetet är dedikerade till att utveckla en prototyp av en användarvänlig grafiska användargränssnitt för tjänsten, genom tillämpning av utvärderingsmetoder inom området människa-dator interaktion.

Av världens sex miljarder invånare lider drygt en miljard människor av någon form av funktionsnedsättning. I Sverige motsvarar denna siffra mer än en och en halv miljon människor av befolkningen. Internet är idag en stor del av vardagen för nästan alla bosatta i Sveriges. Att förbättra den digitala tillgängligheten för människor med funktionsnedsättning är därför en viktig medborgerlig rättighet. Syftet med denna studie är att undersöka hur en prototyp till en mobil mailläsare anpassad för personer med främst synnedsättningar och kognitiva nedsättningar såsom Aspergers syndrom, dyslexi och autism (SADA) bör byggas. Studien är i grund och botten en deduktiv undersökning och prototypen har utvecklats med vattenfallsmetoden som arbetsmetod. I studiens litteraturstudie undersöks bland annat hur web- och mobilapplikationer tidigare utformats och designats för att anpassas till personer med SADA-nedsättningar. Uppdragsgivaren hade innan studien genomfört fokusgrupper för att arbeta fram en kravspecifikation till applikationen och i studien finner kravspecifikationen stöd i litteraturstudien. Liksom för människor utan funktionsnedsättningar är det viktigt att förstå att de bästa förutsättningarna att tillgodogöra sig digital information för människor med SADA-nedsättningar kan skilja sig vitt från person till person. Den här studien visar på att det därför är viktigt att ge funktionsnedsatta användare så stor valmöjlighet som möjligt när det kommer till bland annat typsnitt, text- och bakgrundsfärg och textmängd på skärmen. / From more than six billions people in the world 1 billion people have some kind of disability. In Sweden this number is equivalent to 1,5 millions people. Internet has become a big part of the everyday life for almost everybody living in Sweden today. To design digital information for better accessibility is a democratic right. The purpose of this study is to investigate how to build a prototype for a mobile mail reader application suited for people primarily with sight and cognitive disabilities like Asperger syndrome, dyslexia or autism (SADA). The study is essentially a deductive analysis and the prototype has been developed with the waterfall model. The literature research of the study investigated how web and mobile applications earlier have been developed to suit people with SADA-disabilities. Before the study the commissioner had done research through focus groups in order specify software requirements specification for the application. In the study the software requirements specification is compared to the literature review to find support for the development of the application. Just like for people without disabilities it’s important to keep in mind that the best prerequisite in order to assimilate digital information for people with SADA-disabilities could differ widely from person to person. This study shows that it’s therefore important to give users with SADA-disabilities as big choice as possible. Among others the possibility to choose between font magnitudes, font and background color as well as how much text is shown on the screen.

In the last years Hadoop has been used as a standard backend for big data applications. Its most known application MapReduce provides a powerful parallel programming paradigm. Big companies, storing petabytes of data, like Facebook and Yahoo deployed their own Hadoop distribution for data analytics, interactive services etc. Nevertheless MapReduce’s simplicity in its map stage always leads to a full data scan of the input data and thus potentially wastes resources. Recently new sources of big data, e.g. the 4k video format or genomic data, have appeared. Genomic data in its raw file format (FastQ) can take up to hundreds of gigabytes per file. Simply using MapReduce for a population analysis would easily end up in a full data scan on terabytes of data. Obviously there is a need for more efficient ways of accessing the data by reducing the amount of data, considered for the computation. Already existing approaches introduce indexing structures into their respective Hadoop distribution. While some of them are specifically made for certain data structures, e.g. key-value pairs, others strongly depend on the existence of a MapReduce framework. To overcome these problems we integrated an indexing structure into Hadoop’s file system, the Hadoop Distributed File System (HDFS), working independently of MapReduce. This structure supports the definition of own input formats and individual indexing strategies. The building process of an index is integrated into the file writing processes and is independent of software, working in higher layers of Hadoop. As a proof-of-concept though MapReduce has been given the possibility to make use of these indexing structures by simply adding a new parameter to its job definition. A prototype and its evaluation will show the advantages of using those structures with genomic data (FastQ and SAM files) as a use case.

Low cost, reliable and durable solutions are required in all industries. In automotive industry, BLDC (Brushless Direct Current) motors are widely used due to its advantages over brushed DC motors, which also brings more complex commutation schemes and increased development cost. Despite the fact, BLDC motors require low maintenance and provide reliable results in compare with brushed DC motors, the cost of development of control stage and required hardware topology has been a competence area. The requirements of the application tailor the required hardware topology and control strategy. In this thesis, BLDC motor commutation control hardware topologies to implement a BLDC motor based air throttle control circuit, power dissipation and EMC considerations are addressed. BLDC motor control of a throttle were chosen as a test case due to Scania requirements. An air throttle adjusts the air intake going to a combustion engine, thus directly e ecting the performance. The better controlling the throttle means, providing reliable results with lower consumption of energy. The throttle chosen is an intelligent self positioning unit being bought from a sub-supplier and Scania steers the control by means of an angle position reference sent via CAN (Controller Area Network) bus. The sub-supplier solution results in lack of exibility in software and hardware implementation and lacking possible customization improvements. A customized hardware solution was implemented to question whether a custom hardware implementation and a control strategy planned by Scania can resolve in less power consumption. In addition, what is required to make the throttle unit better should be reected. For this purpose,a customized commutation control circuit was built and a benchmarking in compare with the original sub-supplier solution were done to enable comparison and discussion on possible improvements. One unit of sub-supplier and one unit of customized hardware were benchmarked with respect to heat dissipation, current consumption at the time angle is settled and EMI (Electromagnetic Interference). The results showed that the given Scania control strategy may yield in decreased current consumption, thus reduced heat dissipation. Despite the fact the results are prospective, from a scientic point of view, a comprehensive long term benchmarking should be done with multiple units. The outcomes of this project are a hardware platform which can be used as a development platform to further enable comparison and development, partially proven Scania control strategy to reduce dissipation and enabling cumulative future work in form of diagnostics.