Context: In order to provide more functionalities and services, systems collaborate with each other creating more complex systems called Systems of Systems. Exploiting security vulnerabilities in such complex systems has an impact over system safety and it is not sufficient to analyze them separately in the development process. Observing these safety and security interdependencies together can be done via the process of attack modeling where attack models deploy a model for detecting vulnerabilities and possible mitigation strategies while observing system security from an adversary point of view. Objective: The aim of the thesis is to explore the interdependencies between safety and security concerns, to provide details on attack model(s) and affected safety requirements of given system, to argument that the system is acceptably safe to operate, and to contribute to the identified business challenges. Method: The thesis work consists of: (i) a literature survey on interdependencies between safety and security, and a literature survey on the existing attack models; (ii) a demonstration on a use case where the argument that the given system is acceptably safe with respect to the selected attack model has been provided using Goal Structuring Notation (GSN). Conclusion: The first literature survey conducted on the topic of interdependencies between safety and security has resulted in a number of papers addressing the importance of investigating safety and security together. Reviewed papers have been focused either on proposing new approaches or extending the existing ones in different industry domains like automotive, railway, industrial, etc. The literature survey on existing attack models has resulted in a number of papers elaborating attack models in general and showing domain-specific attack models such as those in control systems, vehicles, Cloud Computing, IoT, networks, RFID, Recommender Systems, etc. To provide an argument that the given system is acceptably safe by using GSN, investigated results from the selected attack model showed how to protect system while observing it from an adversary point of view. Including security countermeasures, i.e. data and identity authentication and implementation of access control in the system development process can produce an acceptably safe system, whilst, at the same time, affect different business aspects by introducing latency and delay to the system. However, avoiding such mitigation techniques may have catastrophic impact on the system and its environment when attacks are launched.

The Internet of Things is a growing market that creates opportunities and chal- lenges for companies. Bergeforsen Obstacle Race is an obstacle race which 2016 attracted 250 people to participate. To investigate new ways of creating a more giving event for competitors and spectators, an independent work has dur- ing its 10 weeks done a theoretical study of Internet of Things with its popular technology Radio Frequency Identification, RESTful web services and Digest authentication to lay the grounds for a RESTful web service which purpose is to enable modules of user interfaces. Impact mapping and user stories was used before construction to build a product backlog. During construction agile meth- ods from Cowboy was followed. The service was developed with modern tech- nology like Node.js and MongoDB. An overview of a scenario of the event has been used to visualize how it could be used where nodes, which are computers with RFID reader modules, can read a competitor and send their identifier with time to a server through RESTful methods. To store sent data, database objects have been created for races, competitors and readings. The security of the sys- tem has been investigated by implementing Digest authentication and database Role Base Access Control. The result is a RESTful web service with 2 routes to modify races and competitors and 2 more routes to give functionality to adding and removing competitors from races and readings. The routes have been con- trolled with functional testing, and their value investigated. At last a comparison have been made with the current used system and the constructed RESTful web service. The independent work was then examined to show that a closer cus- tomer relationship could lay the foundation for a better system and comparison but motivated a RESTful web service as there was only specifications of cus- tomer values. The work has provided ethical aspects regarding licenses, security and sensitive information. / Sakernas Internet är en växande marknad som skapar nya möjligheter och ut- maningar hos företag. Bergeforsen Obstacle Race är en hinderbanetävling som 2016 drog 250 personer till att delta. För att undersöka nya sätt att kunna skapa ett roligare evenemang för deltagare och åskådare har det självständiga arbetet som genomförts under 10 veckor genomfört en teoristudie av Sakernas Internet med populära tekniken Radiofrekvensidentifiering, REST-baserade webbtjäns- ter och Digest autentisering använts för att ligga till grunden för en REST-base- rad webbtjänst som ska kunna möjliggöra moduler av användargränssnitt. Innan konstruktion har Impact Mapping och användarhistorier använts för att bygga en product backlog. Under konstruktion har agila metoder från utvecklingsme- toden Cowboy följts för att färdigställa systemet. Systemet har utvecklats med moderna tekniker som Node.js och MongoDB. I systemet har en överblick av ett evenemang skapats för att visualisera hur systemet skulle kunna användas. I det finns de noder som med RFID-modul ska kunna läsa av en deltagare och skicka det till en server genom REST-metoder. För att kunna lagra den data som skickas har databasobjekt skapats för typerna evenemang (races), deltagare (competitors) och avläsningar (readings). Tjänstens säkerhet har tagits i åtanke då Digest autentisering och rollbaserad åtkomstkontroll till databas implemente- rats. Resultatet har blivit ett system som i öppen källkod möjliggjort modifie- ring av resurserna races och competitors genom två routes. Utöver det har ytter- ligare två routes skapats för enklare modifiering av tillägg och borttagning för deltagare av evenemang och avläsningar. För att säkerställa systemet har funk- tionella tester genomförts och mervärdet undersökts. Till sist har en jämförelse mot nuvarande bakomliggande system genomförts. Det självständiga arbetet granskades sedan för att visa på att en närmare kundrelation kunde legat till grunden för ett bättre system och jämförelse. Eftersom att det endast fanns spe- kulationer av mervärden så motiverades det REST-baserade systemet. Arbetet har gett etiska aspekter gällande licens, säkerhet och känslig information.

Paxos is an algorithm for implementing fault-tolerant distributed systems. The core of Paxos is found in many consensus algorithms. Raft and Zab are two prominent protocols that are used in the industry. They serve as the foundation of distributed key-value stores and coordination services such as Consul, Etcd and ZooKeeper. In distributed consensus, the most common way for servers to agree over a value is to use majority quorums. However in 2016, FPaxos (Flexible Paxos) was published. The authors make the observation that majority quorums are not required as intersection is mandatory only across the two phases of Paxos. By taking advantage of this, developers will have more control over the choice between performance and availability. In this paper we will look at how FPaxos can be adopted into existing systems and demonstrate the advantages through a ZooKeeper modification running on City Cloud.

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Denna rapport handlar om ett projekt åtta studenter på Linköpings universitet genomförde våren 2017, inom ramarna för kursen TDDD96: Kandidatprojekt i programvaruutveckling. Fokuset i projektet var att bygga upp en ny webbplats åt en kund, Musikaliska konstföreningen, som ska ersätta deras gamla webbplats. Projektgruppen valde att göra detta med hjälp av verktyget WordPress. Gruppen valde också att göra en alternativ webbplats med programmeringsspråket Python och ramverket Flask, för att sedan jämföra resultatet mot WordPress-resultatet. Det gruppen valde att jämföra är vilket stöd WordPress respektive Flask ger åt utvecklarna, och vilket av dem som ger lämpligast resultat för kunden. Resultatet blev en färdig hemsida uppbyggd med WordPress, och en prototypsida uppbyggd med Python och Flask. Resultatet visar att det är enklare att få en färdig sida med hjälp av WordPress, men att man genom att skriva kod från grunden i Flask kan få ett betydligt mer användaranpassat system. När det kommer till faktorer som driftkostnader och stöd så visade det sig att WordPress har en klar fördel i jämförelse med Flask.

Internet of Things (IoT) has revolutionized transportation systems by connecting vehicles consequently enabling their tracking, as well as monitoring of driver activities. The IoT platform for most vehicles typically consists of 1) an on-board system consisting of the communication unit, sensors and a set of ECU’s that are interconnected using a CAN network, 2) an off-board system consisting of the applications deployed on the servers (e.g., cloud) that processes the data send by the communication unit over the internet, and 3) mobile devices like a mobile phone or a computer that communicates with the on-board and off-board systems. Such an IoT platform requires a significant amount of data to be send from the on-board system to the off-board servers, contributing to high network usage. There are two main architectural paradigms for sending data: 1) interval based architecture, in which data is send at regular intervals and 2) event based architecture, in which data is send whenever relevant events occur. Currently, (e.g., at Scania), the data is being send at regular intervals, i.e., using an interval based approach. In this case, data is send even if it is not relevant for reporting leading to a wastage of network resources, e.g., when the data does not change considerably compared to the previously sent value. Sending data in an event-based manner, when the data is relevant for reporting, e.g., changes significantly, reduces the network usage when compared to the interval based approach.  In this thesis, we investigate the possibility of using an event based architecture to send data from the on-board system to the off-board system in order to reduce network usage and improve the accuracy of the data available off-board. We first propose an event based architecture for data transfer in the context of Internet of vehicles. We then implement a simulator to evaluate our proposed architecture for the specific case of position data. Finally, we perform extensive experiments varying different parameters and compare, for example, average message size per minute and average off-board error distance. The results show that our event based architecture improves the accuracy of data available at the off-board system, by a careful selection of events. Moreover, we found that our event based architecture significantly decreases the frequency of sending messages, particularly during highway driving, leading to reduced average data transfer rates. Our results enable a customer to perform trade-offs between accuracy and data transfer rates. Future work will aim at implementing the event based architecture on a real platform as well as investigating the possibility of using the event based architecture for more accurate prediction by incorporating additional details such as the final destination of the vehicle and odometer values.

Dependency parsing is important in contemporary speech and language processing systems. Current dependency parsers typically use the multi-class perceptron machine learning component, which classifies based on millions of sparse indicator features, making developing and maintaining these systems expensive and error-prone. This thesis aims to explore whether replacing the multi-class perceptron component with an artificial neural network component can alleviate this problem without hurting performance, in terms of accuracy and efficiency. A simple transition-based dependency parser using the artificial neural network (ANN) as the classifier is written in Python3 and the same program with the classifier replaced by a multi-class perceptron component is used as a baseline. The results show that the ANN dependency parser provides slightly better unlabeled attachment score with only the most basic atomic features, eliminating the need for complex feature engineering. However, it is about three times slower and the training time required for the ANN is significantly longer.

Data streaming nowadays is one of the most used approaches used by websites and applications to supply the end user with the latest articles and news. As a lot of news websites and companies are founded every day, such data centers must be flexible and it must be easy to introduce a new website to keep track of. The main goal of this project is to investigate two frameworks where implementing a robot for given website should take some acceptable amount of time. It is really challenging task, first of all it aims optimizing of a framework which means to put less efforts on something and have the same result and one another thing is that it will be used by professors and students at the end so quality and robustness play big role here. In order to overcome this challenge two different types of news websites were investigated and through this process the approximately time to implement a single robot was extracted. Having in mind the time spent to implement a single robot, the new frameworks were implemented with the goal to spend less time to implement a new web robot. The results are two general frameworks for two different types of websites, where implementing a robot does not take so much efforts and time. The implementation time of a new robot was reduced from 18 hours to approximately 4 hours.

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Context. Database is an essential part of any software product. With an emphasis on application performance, database efficiency becomes one of the key factors to analyze in the process of technology selection. With a development of new data models and storage technologies, the necessity for a comparison between relational and non-relational database engines is especially evident in the software engineering domain. Objectives. This thesis investigates current knowledge on database performance measurement methods, popularity of relational and non-relational database engines, defines characteristics of databases, approximates their average values and compares the performance of two selected database engines.Methods. In this study a number of research methods are used, including literature review, a review of Internet sources, and an experiment. Literature datasets used in the research incorporate over 100 sources including IEEE Xplore and ACM Digital Library. YCSB Benchmark was used as a direct performance comparison method in an experiment to compare OracleDB’s and MongoDB’s performance. Results. A list of database performance measurement methods has been defined as a result of the literature review. Two most popular database management engines, one relational and one non-relational has been identified. A set of database characteristics and a database performance comparison methodology has been identified. Performance of two selected database engines has been measured and compared. Conclusions. Performance comparison between two selected database engines indicated superior results for MongoDB under the experimental conditions. This database proved to be more efficient in terms of average operation latency and throughput for each of the measured workloads. OracleDB however, presented stable results in each of the category leaving the final choice of database to the specifics of a software engineering project. Activities required for the definition of database performance comparison methodology proved to be challenging and require study extension.