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  • 1.
    Westerholm, Gustaf
    Linköping University, Department of Computer and Information Science.
    Automatic Configuration of Aircraft and Simulators2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    For development, sales, verification and validation purposes, flight simulations of the Saab JAS 39 Gripen E/F are often performed. For these type of simulations, one needs to be able to choose both a specific aircraft variant and a specific simulation setup and then generate the appropriate build files to build the simulator. This configuration process is currently mainly done manually and has numerous points of variation, some of these are in:

    ·       ACSim Kernel which simulates the components and systems of the aircraft. Around 150 models can be chosen out of almost 1000 total.

    ·       ACCS, the aircraft computers containing the aircraft software applications. Here, dozens of configuration-specific applications can be included in a configuration.

    Restricting the configuration possibilities are relations and constraints between components, systems, models and applications, but also credentials of the user, limiting available options.

    In this thesis it is examined to what degree this configuration process can be automated with a variant management tool, such as pure::variants, and possible ways of implementation are presented. A conclusion is that that the configuration of ACSim Kernel build files can be automated to a high degree, and for the ACCS system architecture studied in this thesis, build files can be automated to a lower degree. It is also shown how pure::variants can be used to filter its models for secrecy purposes, and how helpful system properties can be represented in pure::variants models. A suggestive example of how pure::variants can be used with short implementation time is provided and more labour intensive implementation suggestions are discussed.

  • 2.
    Delvert, Simon
    et al.
    Linköping University, Department of Computer and Information Science.
    Nåtoft, Johan
    Linköping University, Department of Computer and Information Science.
    Engaging novice programmers through gamification: Puzzles to teach and motivate programming learning2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With an increasing number of primary schools having programming as a mandatory subject, students and teachers face new challenges by having to teach and learn a subject that is often difficult to engage students in. Many tools exist that introduce the problem solving aspect of programming, using a programming language not used in actual software. The programming languages used in these tools are often easier to understand and therefore engage the students more. In this study, an application teaching programming in Python is proposed while still engaging the students by including gamification elements. By having two groups of users, one group with gamification elements available in the software, and the other with them unavailable, the engagement could be compared between the two groups. With the data collected from Google Analytics, completion rate and surveys, it was shown that users with gamification elements available are slightly more engaged. Through the results gathered from this study, the use of gamification elements in this type of software can have an impact on user engagement and should therefore be considered when building similar types of systems.

  • 3.
    Mehari, Simon
    Linköping University, Department of Computer and Information Science.
    Low Latency Fog Computing Architecture for a Fire Safety Application2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis presents an architectural design for location-aware fire safety application (Fire-fly) based on cloud and fog computing. The Fire-fly application is designed to assist the residents of a building to be notified and evacuate individually in a fire emergency that is happening in the building by the help of sensor readings collected from within the building. A part of this thesis explains how this application is implemented using different types of communication models and protocols between different clients of the Fire-fly application. The communication latency is then measured and compared between cloud and fog architectures.

    When it comes to communication between different clients, the fog architecture might be a preferred choice because it has lower latency than the cloud based architecture. However this preference is questioned when it comes to dependability aspect. Therefore, this thesis also studies the dependability trade-off the fog architecture has by studying the availability of the fog architecture in a simulated failure of part of the fog architecture. The system restoration period of the fog architecture is measured by suddenly shutting down parts of the fog structure that are most likely expected to be exposed to physical damages because of fire. The following results are achieved after testing the whole system on a test site: the average time it takes for data that contains location information from the resident client to arrive at the fire brigade client for the cloud infrastructure was 277 ms and for the fog was 14 ms. The results achieved from the service restoration period will approximately take on average 530 ms for a resident client to reconnect to a another functioning fog-cell in case of disconnection due to fire, and it takes on average 940 ms to reconnect to the cloud.

  • 4.
    Eriksson, John
    Linköping University, Department of Computer and Information Science.
    Machine Learning for Predictive Maintenance on Wind Turbines: Using SCADA Data and the Apache Hadoop Ecosystem2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis explores how to implement a predictive maintenance system for wind turbines in Apache Spark using SCADA data. How to balance and scale the data set is evaluated, together with the effects of applying the algorithms available in Spark mllib to the given problem. These algorithms include Multilayer Perceptron (MLP), Linear Regression (LR), Random Forest (RF), Decision Tree (DT), Support Vector Machine (SVM) and Gradient Boosted Tree (GBT). This thesis also evaluates the effects of applying stacking and bagging algorithms in an attempt to decrease the variance and improve the metrics of the model. It is found that the MLP produces the most promising model for predicting failures on the given data set and that stacking multiple MLP models is a good way of producing a model with a lower variance than the individual base models. In addition to this, a function that creates a savings estimation is developed. Using this function, a time window function that explores the decisiveness of a model is created. The conclusion is made that a model is more decisive if the failure it predicts occurs in a turbine where it has been trained on failure data from that same component, indicating that there are unknown variables that affect the sensor data.

  • 5.
    Tyrsing, William
    et al.
    Linköping University, Department of Computer and Information Science.
    Nilsson, Jacob
    Linköping University, Department of Computer and Information Science.
    Mission Partitioner Framework: Ett utökningsbart och flexibelt designförslag2020Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [sv]

    Samhällssäkerhet är en av de viktigaste prioriteringarna i ett land. För att effektivisera utvecklingen av säkerhet behövs en stor satsning. I projektet WASP Research Arena - Public Safety (WARA-PS) utforskas framtida möjligheter i sjöräddningstjänst. Genom att automatisera delar av sjöräddningstjänst kan det avsevärt effektiviseras och rädda fler liv än vad vi idag är kapabla att rädda. I denna rapport skapas ett designförslag för modulen Mission Partitioner (MP), en komponent i automatiserad sjöräddningstjänst. MP skapar och optimerar högnivå-uppdrag snabbare än någon människa. MP designas med aspekterna flexibilitet och utökningsbarhet för att enkelt kunna anpassas till nya användningsområden. Komponenterna Mission, Environment, Operation och Planner identifieras som de mest kritiska komponenterna för MP:s funktionalitet. Komponenten Planner representerar möjliga planeringsmetoder, i den skapade prototypen används GOAP. De resterande komponenterna designas med metoder som ger upphov till flexibilitet och utökningsbarhet såsom polymorphism. Analysen visar att systemet är flexibelt och utökningsbart för de kritiska komponenterna som tillhör MP.

  • 6.
    Lindberg, Adam
    Linköping University, Department of Computer and Information Science.
    Performance Evaluation of JavaScript Rendering Frameworks2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    When developing interactive web applications a number of different technologies and frameworks could be used. This thesis is set to evaluate a number of popular frameworks that are using different native web rendering techniques. More specifically, the goal of this study is to find what JavaScript visualization framework is best suited for developing a visualization module capable of handling up to 1000 continuously moving nodes with retained frame rate. In this case, retained frame rate refers to keeping the average frame rate above 20 FPS. The frameworks investigated in this study are D3.js using SVG and Canvas, and PixiJS using WebGL 2D rendering. The evaluation was conducted by first developing a visualization module containing a force-directed graph. This was done three times over, once with each rendering technique. Next, the average frame rate was measured during the first 10 seconds of loading a fixed size data set. Data sets of increasing volume were then loaded to examine how the different modules handle data sets of various sizes. The results showed that the SVG module was far behind the other two in terms of retained FPS on larger data sets. The Canvas and WebGL modules were closer in the level of performance, where WebGL outperformed the Canvas implementation in the base case. However, when a Gaussian blur filter was activated in both modules, the Canvas module prevailed. This blur filter was a requested feature for the final product, which led to the choice of using D3.js with Canvas rendering for further development.

  • 7.
    Härnström, Felix
    Linköping University, Department of Computer and Information Science.
    Product Line Engineering for large-scale simulators: An exploratory case study2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis takes a process-centric approach to Product Line Engineering (PLE) with the purpose of evaluating the suitability of PLE practices and processes in the context of large-scale industrial simulator products. This human-centered approach sets itself apart from previous research on the subject which has been mostly focused on architectural and technical aspects of PLE. The study took place at Saab, a Swedish aerospace and defense company whose primary product is the Saab 39 Gripen fighter aircraft. The study was conducted as a series of interviews with participants across three product lines, each responsible for a different line of simulators. By investigating their current working processes using the Family Evaluation Framework, a maturity rating was derived for each product line. This maturity rating was then considered alongside commonly reported issues and experiences in order to evaluate the usefulness of PLE practices for each product line. It was found that the studied organization could likely benefit from implementing PLE. PLE and the Family Evaluation Framework promotes practices that would alleviate some of the major issues found in the studied organization such as unclear requirements, issues with product integration and external dependencies, and a lack of quantitative data. Due to the relative immaturity of PLE processes in the studied organization, these conclusions are based on a review of existing literature and the stated goals and practices of PLE applied to the context of the studied organization.

  • 8.
    Bergsten, Linnea
    Linköping University, Department of Computer and Information Science.
    Supporting Resilient Behaviour in Simulation Studies: A study of how resilient behaviour can be enhanced in a crisis management exercise based on participants experiences2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A major disruption in the payment system would be a considerable societal crisis and is studied by a project called Creating Collaborative Resilience Awareness, Analysis and Action for Finance, Food and Fuel Systems in INteractive Games (CCRAAAFFFTING), using serious gaming and simulation. This study examines the experiences of the participants in the crisis management exercises. The research questions of this study are as follows: “How do the participants of the simulation studies of CCRAAAFFFTING understand the games?” and “How can the simulation environment be developed in order to encourage the participants to improve monitoring strategies during the games?”. 

    The study uses thematic analysis of qualitative interviews of the participants supported by questionnaires. The questionnaires were conducted directly after the games, and telephone interviews were conducted after the exercise.

    This study found the following main themes in the participants’ experiences of the games: the crisis, the society that is handling the crisis, the game’s relation to reality, the importance of the group, and the exercise’s ability to support the interpretation of what is simulated. Some consideration for the project to work further with are that the simulation needs to be centred, simplified and made more available to the participants. The division of roles could divide the monitoring of different actions affecting different parts of the society between the participants. Furthermore, a representation of the overall payment system, its actors and the groups, might support the participants in sharing and understanding the actors of the payment system, and the effects their actions have on them, as well as the participants’ ability to monitor the changes.

  • 9.
    Silversved, Nicklas
    et al.
    Linköping University, Department of Computer and Information Science.
    Runesson, Hampus
    Linköping University, Department of Computer and Information Science.
    A comparison of the security in ZigBee and the IEEE 802.15.9 standard and an experimental analysis of communication over IEEE 802.15.42019Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    The increasing number of IoT devices used in today’s society has led to a demand for better security in order to prevent attackers from gaining access to private information. The IoT brings a wide application scope and because of that there are a lot of ways to set up a secure network and manage keys in these kinds of networks. This paper presents a comparison between the security model in Zigbee and the new recommended practice for Key Management Protocols defined by the IEEE 802.15.9 standard. We investigate key establishment and transportation together with the vulnerabilities that this might bring regarding potential attacks like DoS and MitM. Since these protocols are built on the IEEE 802.15.4 standard, experimental tests have been made where we analyze the throughput, RTT and packet loss over varied distances and we try to determine the maximum transmission range for devices using IEEE 802.15.4 modules. The IEEE 802.15.9 standard works with different KMPs and depending on the KMP being used we can see both similarities and differences regarding key management and possible attacks when comparing it to ZigBee. Furthermore, we found that attacks on a ZigBee device is more likely to compromise the whole network while similar attacks would only affect the specific peers in an IEEE 802.15.9 communication. Based on the experiments we find that open areas, distance and interference have a negative effect on the throughput, RTT and packet loss of the communication.

  • 10.
    Vupparige Vijaykumar, Sanjana
    Linköping University, Department of Computer and Information Science.
    A Cost-Efficient Bluetooth Low Energy Based Indoor Positioning System for IoT Applications2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The indoor positioning system is a series of networking systems used to monitor/locate objects at indoor area as opposed that of GPS which does the same at outdoor. The increase in the popularity of the Internet of Things made the demand for Bluetooth Low Energy technology more and more essential due to their compatibility in the smartphones which makes it to access easier. The BLE’s reliable signal and accuracy in calculating the distance has a cutting edge on others in IPS. In this thesis, the Bluetooth Low Energy indoor positioning system was designed and implemented in the office area, and the positionofIoTdevicesweremonitored. OntheIoTdevices,thebeaconswereplaced. And thesebeaconswerecoveringtheofficearea. Thereceiver,smartphoneinourcase,recorded theReceivedSignalStrengthIndicationofthetransmittedsignalsfromthebeaconswithin the range of the signal and stored the collected data in a database. Two experiments have beenconducted. Oneisforbeaconsthatarestationaryandonethatismoving. Toevaluate these experiments, a few tests were performed to predict the position of beacons based on therecordedreceivedsignalstrength’s. Inthecaseofstationarybeacons, itoffersaccuracy range from 1 m to 5 m, and 3 m to 9.5 m in anticipating the position of each beacon in the case of moving beacon. This methodology was a mixture of fingerprinting and an algorithm of multilateration. Finally, the experiments show that the algorithm used provides the most accurate indoor position using BLE beacons that can be monitored through an Android-based application in real-time.

  • 11.
    Hu, Yi
    Linköping University, Department of Computer and Information Science. Linköping University, Faculty of Science & Engineering.
    A Framework for Using Deep Learning to Detect Software Vulnerabilities2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In recent years, with the rise of Internet technology, software vulnerabilities have also flooded, making the software security of enterprises or individuals seriously threatened. Although it is difficult to avoid the occurrence of software vulnerabilities in the process of software development, it is also a way to find and modify the vulnerabilities as early as possible. At present, research on static vulnerability detection system can be divided into methods based on code similarity and pattern-based method. The method based on code similarity is mainly used to detect vulnerabilities caused by code cloning, while the vulnerabilities caused by other reasons have high false negative. Patterns-based approaches require experts to define vulnerability characteristics manually, which leads to a waste of time and effort. Besides, since defining characteristics is a subjective task, the judgement of experts will affect the results of detection. At this point, there is an urgent need for an approach that can detect vulnerabilities for various reasons and is less dependent on experts.           

    Deep learning is a new field of machine learning research, which has received extensive attention in recent years. Its use has greatly liberated human resources, which makes us think whether deep learning can also be applied to vulnerability detection research, and whether it can also solve the problem of waste of expert resources.           

    This thesis studies a software vulnerability detection framework based on deep learning. The main research contents are as follows:           

    1. Collect the source code of four types of software vulnerabilities in C/C++ (Function Call, Array Usage, Pointer Usage and Arithmetic Expression) as the dataset of the experiment in this thesis. Extract the vulnerability syntax characteristics of four kinds of software vulnerabilities, match the dataset with the vulnerability syntax characteristics, and generate syntax-based code fragments. Program slices for syntax-based code fragments are then generated and converted into semantic-based code fragments.            

    2. Data processing for semantic-based code fragments includes: replacing all strings in semantic-based code fragments with a unified string. And perform word segmentation on semantic-based code fragments. Then replace all user-defined variables in semantic-based code fragments and user-defined function names. Finally, the processed semantic-based code fragments are converted into vector representations.           

    3. According to the characteristics of software vulnerabilities, select deep learning methods suitable for text analysis: Long Short-Term Memory, Bi-directional Long Short-Term Memory, Gate Recurrent Unit, Bi-directional Gate Recurrent Unit. The four deep learning methods are designed and implemented to make the accuracy of software vulnerability detection as high as possible.            

    4. Select reasonable measurement methods to evaluate the framework, and compare it with other tools for detecting software vulnerabilities, to judge the effectiveness of the framework. 

  • 12.
    Larsson, Niklas
    et al.
    Linköping University, Department of Computer and Information Science.
    Ågren Josefsson, Fredrik
    Linköping University, Department of Computer and Information Science.
    A study of slow denial of service mitigation tools and solutions deployed in the cloud2019Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Slow rate Denial of Service (DoS) attacks have been shown to be a very effective way of attacking vulnerable servers while using few resources. This thesis investigates the effectiveness of mitigation tools used for protection against slow DoS attacks, specifically slowheader and slow body. Finally, we propose a service that cloud providers could implement to ensure better protection against slow rate DoS attacks. The tools studied in this thesis are, a Web Application firewall, a reverse proxy using an event-based architecture and Amazon’s Elastic Load Balancing. To gather data a realistic HTTP load script was built that simulated load on the server while using probe requests to gather response time data from the server. The script recorded the impact the attacks had for each server configuration.The results show that it’s hard to protect against slow rate DoS attacks while only using firewalls or load balancers. We found that using a reverse proxy with an event-based architecture was the best way to protect against slow rate DoS attacks and that such a service would allow the customer to use their server of choice while also being protected.

  • 13.
    Danielsson, Benjamin
    Linköping University, Department of Computer and Information Science.
    A Study on Text Classification Methods and Text Features2019Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [en]

    When it comes to the task of classification the data used for training is the most crucial part. It follows that how this data is processed and presented for the classifier plays an equally important role. This thesis attempts to investigate the performance of multiple classifiers depending on the features that are used, the type of classes to classify and the optimization of said classifiers. The classifiers of interest are support-vector machines (SMO) and multilayer perceptron (MLP), the features tested are word vector spaces and text complexity measures, along with principal component analysis on the complexity measures. The features are created based on the Stockholm-Umeå-Corpus (SUC) and DigInclude, a dataset containing standard and easy-to-read sentences. For the SUC dataset the classifiers attempted to classify texts into nine different text categories, while for the DigInclude dataset the sentences were classified into either standard or simplified classes. The classification tasks on the DigInclude dataset showed poor performance in all trials. The SUC dataset showed best performance when using SMO in combination with word vector spaces. Comparing the SMO classifier on the text complexity measures when using or not using PCA showed that the performance was largely unchanged between the two, although not using PCA had slightly better performance

  • 14.
    Bäckström, Madeleine
    et al.
    Linköping University, Department of Computer and Information Science.
    Hallonqvist, Linn
    Linköping University, Department of Computer and Information Science.
    A three-phase user study evaluating the integration of a generalized playback bar for a branched video player2019Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    When watching interactive branched video, the viewer is given the opportunity to tailor the storyline of the video playback. This type of video puts the users in control of their viewing experiences and provides content creators with great flexibility how to personalize the viewing experience for individual viewers. When it comes to regular linear videos, the concept of having a playback bar visually presenting the playback is a well established implementation used for most (if not all) video players, but for interactive branched videos, that is not the case. Instead, most branched video implementations are typically custom-made on a per-video basis (e.g., see custom-made Netflix and BBC movies) and do not use a playback bar.

    With the goal to fill this void, a branched video player with a generalized playback bar that visualizes the tree-like video structure was developed in 2018 by students of the Information Technology program at Linköping University and will be made public with a publication in the near future. Within the preparatory work prior to making this branched video player public, this project included a three-phase user study, where we evaluated the playback bar and its implemented features and compared the video player with alternative designs.

    With this thesis, we highlight the value of a branched video playback bar and provide interesting insights into how it, and other design customization features, may best be integrated into a branched video player. Furthermore, we present an improved version of the video player in which the new implementations are based on, and motivated by, the results from the user study. Finally, we describe how further investigations may be done to evaluate the improved version of the video player.

  • 15.
    Olsson, Linn
    Linköping University, Department of Computer and Information Science.
    AI-systems möjligheter i enavancerad support- och industrikontext2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A case studie at Siemens supportorganisation is studied and the possibilities to use an AI-system for improvements. This is studied with theories in distributed cognition and what is available in AI-systems such as chatbots. Through contextual inquiry, which is a part of the method Contextual Design, affinity diagrams were made and a analysis through DiCoT to create a relevant image. This is used to discuss consequences for the design of an AI-system that the supporttechnicians need.  Through the result the many systems that the supporttechnicians use are illustrated and how they depend on eachother to solve difficulties. In the conclusion different suggestions are made about a AI-system for the support technicians but also an alternative that is customer related.

  • 16.
    Wallin, Moa
    Linköping University, Department of Computer and Information Science.
    Ambiguous synonyms: Implementing an unsupervised WSD system for division of synonym clusters containing multiple senses2019Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [en]

    When clustering together synonyms, complications arise in cases of the words having multiple senses as each sense’s synonyms are erroneously clustered together. The task of automatically distinguishing word senses in cases of ambiguity, known as word sense disambiguation (WSD), has been an extensively researched problem over the years. This thesis studies the possibility of applying an unsupervised machine learning based WSD-system for analysing existing synonym clusters (N = 149) and dividing them correctly when two or more senses are present. Based on sense embeddings induced from a large corpus, cosine similarities are calculated between sense embeddings for words in the clusters, making it possible to suggest divisions in cases where different words are closer to different senses of a proposed ambiguous word. The system output is then evaluated by four participants, all experts in the area. The results show that the system does not manage to correctly divide the clusters in more than 31% of the cases according to the participants. Moreover, it is discovered that some differences exist between the participants’ ratings, although none of the participants predominantly agree with the system’s division of the clusters. Evidently, further research and improvements are needed and suggested for the future.

  • 17.
    Hellberg, Tim
    et al.
    Linköping University, Department of Computer and Information Science.
    Keyvanpour, Daniel
    Linköping University, Department of Computer and Information Science.
    An analysis of reported phishing domains2019Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    As we become more digitalized and we rely more heavily on the internet, the more important it is to protect ourselves against phishing attacks and other types of internet frauds. Users who fall for phishing attacks risk getting sensitive information stolen such as their bank accounts. In this thesis we describe and analyze domains that use Hypertext Transfer Protocol Secure (HTTPS), an extension to the Hypertext Transfer Protocol (HTTP) used for secure communication, and the impact that these domains have on phishing. We have analyzed and performed experiments that quantify how many of the phishing domains reported to PhishTank are HTTP and HTTPS, and why phishing sites can use HTTPS and still fail to be safe. We have created a script in Java that takes a set of URLs and creates a dataset containing the domains and all certificates that have been issued to these domains, making it a useful tool to analyze phishing domains. Furthermore, we present analyses and results describing how hashing algorithms are used in different certificates and their impact in securing the web. Through analyses and experiments we gained an understanding of how easy it is to create a certificate and claim to be behind a website. Phishing domains being able to use HTTPS is a good example of this and our results have shown that many imposter websites use HTTPS. Thankfully, there are tools in place to secure the web and avoid phishing, such as browsers having a set of Certificate Authorities (CAs) that they trust, meaning that any HTTPS site that does not have a certificate from one of these CAs will be flagged as not secure. Another countermeasure is increasing people's knowledge about how to handle websites that seem to be secure and have the necessary parameters, such as HTTPS, but nevertheless are phishing sites.

  • 18.
    Tinnerholm, John
    Linköping University, Department of Computer and Information Science.
    An LLVM backend for the Open Modelica Compiler2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis presents the construction and evaluation of an LLVM based codegenerator, an LLVM backend. The introduction of an LLVM based backend into the OpenModelica compiler was done to examine the advantages and disadvantages of compiling Modelica and MetaModelica to LLVM IR instead of C. To answer this question, the LLVM backend was compared against the existing interpreter and C code generator using four different schemes with corresponding cases. This comparison was made both for both optimised and unoptimised code. From the experiments, it was concluded that an LLVM backend can be used to improve runtime and compile time performance in the OpenModelica Interactive environment.

  • 19.
    Krig, Billy
    Linköping University, Department of Computer and Information Science.
    Analysis and Optimization of the User Interface for an Effective Altruism Charity Application: Implementing gamification with the purpose to enhance user engagement and increase user retention2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Gamification has previously demonstrated successful results when it comes to increasing the user retention rate in many different sectors. Non-profit charity organisations have for the last 10 years had a retention rate that is below 50%. This thesis investigates the possibility of increasing the user retention rate in the non-profit charity application The Life You Can Save(TLYCS) by implementing gamification. The gamification mechanic that was chosen for implementation was achievements. To measure understandability the Post-Study System Usability Questionnaire was used, the four satisfaction scores of the questionnaire were measured with a number between one and seven. Sven represented the highest number and one represented the lowest number. All four satisfaction scores had an average number that was higher than 6. Because of the previously proved successful results of gamification and a usable implementation of achievements in the mobile application TLYCS the possibility of an increased user retention rate is assessed to be high. 

  • 20.
    Holmstedt, David
    Linköping University, Department of Computer and Information Science.
    Analyzing and implementing a third-party state machine library for FriendlyReader and TeCST2019Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [en]

    FriendlyReader and TeCST are text simplification tools developed at Linköping University, using an API service at the university called SAPIS. Both tools are web services that run in the browser for users. To improve the services an implementation of state-transition tracking was chosen as a way to both improve the website by enabling the user to undo actions, but also enable the client to cache information which lowers the amount of requests required to SAPIS. Two libraries, called MobX and Redux, where compared to find the one which worked best for FriendlyReader and TeCST. The main difference between MobX and Redux is the programming paradigms, MobX is object-oriented while Redux is functional. In the end MobX was chosen due to the object-oriented nature of the library which is more familiar for beginners while also requiring less code to achieve similar results. MobX lacks native support to keep track of previous state transitions which is required to be able to go back to a previous state. Using MobX a new library called GlobalStore was created to solve this problem. An implementation example for synonyms was produced as a proof of concept for FriendlyReader.

  • 21.
    Folkesson, Carl
    Linköping University, Department of Computer and Information Science.
    Anonymization of directory-structured sensitive data2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Data anonymization is a relevant and important field within data privacy, which tries to find a good balance between utility and privacy in data. The field is especially relevant since the GDPR came into force, because the GDPR does not regulate anonymous data. This thesis focuses on anonymization of directory-structured data, which means data structured into a tree of directories. In the thesis, four of the most common models for anonymization of tabular data, k-anonymity, ℓ-diversity, t-closeness and differential privacy, are adapted for anonymization of directory-structured data. This adaptation is done by creating three different approaches for anonymizing directory-structured data: SingleTable, DirectoryWise and RecursiveDirectoryWise. These models and approaches are compared and evaluated using five metrics and three attack scenarios. The results show that there is always a trade-off between utility and privacy when anonymizing data. Especially it was concluded that the differential privacy model when using the RecursiveDirectoryWise approach gives the highest privacy, but also the highest information loss. On the contrary, the k-anonymity model when using the SingleTable approach or the t-closeness model when using the DirectoryWise approach gives the lowest information loss, but also the lowest privacy. The differential privacy model and the RecursiveDirectoryWise approach were also shown to give best protection against the chosen attacks. Finally, it was concluded that the differential privacy model when using the RecursiveDirectoryWise approach, was the most suitable combination to use when trying to follow the GDPR when anonymizing directory-structured data.

  • 22.
    Paulsén, Rickard
    Linköping University, Department of Computer and Information Science.
    Användning av spel för att utbilda och engagera människor om klimatförändringarna2019Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [sv]

    Följande studie har genomförts i syfte att undersöka om spelande i samband med klimatinformerande påverkade och motiverade deltagaren mer till klimatagerande jämfört med då deltagaren endast fick läsa information om klimatet. Detta undersöktes med hjälp av en spelprototyp som skapats i detta syfte. Spelprototypen skapades i Scratch, vilket är ett interpreterande dynamiskt visuellt programmeringsspråk, och spelet innehöll tre olika nivåer. Mellan dessa nivåer så fick deltagaren information om klimatet som var relaterat till nivån de precis spelat. Efter att ha gjort experimentet skulle deltagaren besvara en enkät, som innehöll frågor där deltagaren skulle uppskatta, med hjälp av likertskalor, om denne kände sig påverkad och motiverad. Svaren på enkäten analyserades med ett Mann Whitney U test. Resultaten från dessa frågor var inte signifikanta, och därför kan inga slutsatser dras om spelet i samband med informationen hade en positiv påverkan. Även om resultaten inte var signifikanta så bör ytterligare forskning utföras inom ämnet, då tidigare forskning visat hur spel kan påverka beteende, och hur människors klimatagerande kan påverkas till det bättre genom spel.

  • 23.
    Algvere, Ebba
    Linköping University, Department of Computer and Information Science.
    Att designa effektivt lärande med blandade lärmiljöer: Hur lärmiljöer och dess aktiviteter inom blandade lärmiljöer påverkar kunskapsutveckling och förtroende för organisationen2019Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [sv]

    Denna studie har undersökt hur olika lärmiljöer inom ett utbildningsupplägg med blandade lärmiljöer skiljer sig i upplevelse, kunskapsutveckling samt förtroende. Vidare har studien undersökt om det finns någon skillnad mellan grupper, med prefererad ordning på lärmiljöer inom ett utbildningsupplägg med blandade lärmiljöer, och prefererad inläringsstil. Fyra olika inläringsstilar, av Honey och Mumford (2000), har använts i studien. Frågeställningarna har undersökts och besvarats genom en triangulering, en kombination av kvalitativa och kvantitativa metoder. Kvalitativ data har samlats in genom semistrukturerade intervjuer och har sedan följt en tematisk analysprocess. Kvantitativ data har erhållits genom ett frågeformulär som sedan har analyserats med statistiska tester. Resultaten från den kvalitativa intervjudelen har visat på att olika lärmiljöer, e-lärande och föreläsning, skiljer sig samt kompletterar varandra med avseende på upplevelse, kunskapsutveckling och förtroende för arbetsgivare. Kvantitativa resultat från frågeformulär har visat på att det inte finns någon signifikant skillnad mellan grupper, som föredrar att börja ett utbildningsupplägg med blandade lärmiljöer med olik första lärmiljö, och styrka i prefererad inläringsstil. Detta innebär att det inte finns någon direkt koppling mellan föredragen ordning på lärmiljöer inom blandade lärmiljöer och prefererad inläringsstil. Denna studie har studerat ett kunskapsgap för hur blandade lärmiljöer bör struktureras. Studiens fynd kan därmed bidra till en bättre förståelse för hur framtida utbildningsupplägg med blandade lärmiljöer bör designas för effektivt lärande och maximal kunskapsutveckling.

  • 24.
    Carolina, Löf
    Linköping University, Department of Computer and Information Science.
    Att mäta stress: Adaptering och validering av Dundee Stress State Questionnaire2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study was to adapt and validate the Dundee Stress State Questionnaire (DSSQ), which measures stress based on 12 scales that cohere around three higher order dimensions: task engagement, distress and worry. DSSQ is adapted from its original language, English, to Swedish. The applicability of the Swedish version of DSSQ is tested by studying the questionnaire's reliability and validity, and by applying the survey in two different contexts, where two different tasks are performed, a work memory task and a police student exam task.

    Overall, the result showed that the Swedish adaptation of DSSQ has high reliability. However, it was not possible to confirm that the Swedish adaptation of DSSQ maintained the same factor model as the original DSSQ has. The statistical analysis showed the changes identified in the participants' moods partly in lines with previous research. The conclusion is that more participants are needed to validate the factor model for the Swedish adaptation of DSSQ and since the Swedish adaptation of DSSQ shows good reliability, it can be applied in research.

  • 25.
    Albrektson, Maja
    Linköping University, Department of Computer and Information Science.
    Att skapa en användarcentrerad återkopplingsrapport: En designprocess kring data2019Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [sv]

    Människor utsätts för mer information än någonsin tidigare. För att underlätta processandet av information är det viktigt att presentera informationen på rätt sätt - anpassat efter användaren. Detta projekt genomfördes i samarbete med Linköpings kommun och det övergripande syftet var att undersöka hur man kan utforma ett gränssnitt för de återkopplingsrapporter som ska nå ut till anställda på företaget. För den första frågeställningen “Vad önskar förvaltningarna för information/data i en återkopplingsrapport?” valdes en kvalitativ ansats och en tematisk analys utfördes utifrån data från nio intervjudeltagare som arbetade på kommunen. Analysen visade att den data förvaltningarna var mest intresserad av handlade om volym, kategorier, vidarekopplingar, service och jämförelser med andra förvaltningar. Resultaten av den tematiska analysen lade även grunden för att besvara resterande två frågeställningar - “Hur bör denna information visualiseras för att den lättast ska kunna förstås och användas?” samt “Hur skulle ett gränssnitt för återkopplingsrapporten till förvaltningarna kunna se ut?”. För att besvara dessa frågeställningar presenterades tidigare forskning om hur rapporter utformas idag och teori kring existerande gestaltlagar samtidigt som det producerades en persona, kontextscenarier, en kravspecifikation samt skisser och en temporär prototyp av dashboard-karaktär.

  • 26.
    Uppugunduri, Arun
    et al.
    Linköping University, Department of Computer and Information Science.
    Hansen, Daniella
    Linköping University, Department of Computer and Information Science.
    Barkino, Delmon
    Linköping University, Department of Computer and Information Science.
    Jeppsson, Emmelie
    Linköping University, Department of Computer and Information Science.
    Öst, Ellinor
    Linköping University, Department of Computer and Information Science.
    Conner, Gustaf
    Linköping University, Department of Computer and Information Science.
    Fredriksson, Henrik
    Linköping University, Department of Computer and Information Science.
    Kull, Nicklas
    Linköping University, Department of Computer and Information Science.
    Att utforma en e-handel för kvinnor med god navigerbarhet2019Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [en]

    After conducting a survey at Linköping University it was shown that few women choose to use protein powder. The same survey also showed that only a fraction of these women possessed knowledge regarding their optimal protein consumption. A web application that sells protein and training related products were therefore developed. This application is designed to have satisfactory navigability and an appealing graphic profile for women. The navigability is intended to, in an efficient manner, eliminate the information gap regarding protein supplements for the intended target group. The web application’s functionality anddesign has been based on scientific theory. Development occurred in iterations after which end users had the possibility to test and leave suggestions for improvements. Improvements to the web application’s navigability has been measured in numerous aspects through all iterations. Time, lostness and certainty have been central for the configuration of the final version of the web application. This report enhances the group’s thesis and exhibits that a web application can have good navigability and be graphically appealing to women.

  • 27.
    Westfelt, Vidar
    et al.
    Linköping University, Department of Computer and Information Science.
    Aleksandrauskas, Arturas
    Linköping University, Department of Computer and Information Science.
    Automated migration of large-scale build systems2019Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Upgrading or migrating a build system can be a daunting task. Complete build system migration requires significant effort. To make the process more effective, we automated the first steps of migration, and attempted to analyze the new build results to find anomalies. Our findings show promise for automation as a first step of migration, and we see that automated evaluation could have some potential.

  • 28.
    Olsson, Oskar
    et al.
    Linköping University, Department of Computer and Information Science.
    Eriksson, Moa
    Linköping University, Department of Computer and Information Science.
    Automated system tests with image recognition: focused on text detection and recognition2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today’s airplanes and modern cars are equipped with displays to communicate important information to the pilot or driver. These displays needs to be tested for safety reasons; displays that fail can be a huge safety risk and lead to catastrophic events. Today displays are tested by checking the output signals or with the help of a person who validates the physical display manually. However this technique is very inefficient and can lead to important errors being unnoticed. MindRoad AB is searching for a solution where validation of the display is made from a camera pointed at it, text and numbers will then be recognized using a computer vision algorithm and validated in a time efficient and accurate way. This thesis compares the three different text detection algorithms, EAST, SWT and Tesseract to determine the most suitable for continued work. The chosen algorithm is then optimized and the possibility to develop a program which meets MindRoad ABs expectations is investigated. As a result several algorithms were combined to a fully working program to detect and recognize text in industrial displays.

  • 29.
    Lehto, Niko
    et al.
    Linköping University, Department of Computer and Information Science.
    Sjödin, Mikael
    Linköping University, Department of Computer and Information Science.
    Automatic text summarization of Swedish news articles2019Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    With an increasing amount of textual information available there is also an increased need to make this information more accessible. Our paper describes a modified TextRank model and investigates the different methods available to use automatic text summarization as a means for summary creation of swedish news articles.

    To evaluate our model we focused on intrinsic evaluation methods, in part through content evaluation in the form of of measuring referential clarity and non-redundancy, and in part by text quality evaluation measures, in the form of keyword retention and ROUGE evaluation.

    The results acquired indicate that stemming and improved stop word capabilities can have a positive effect on the ROUGE scores. The addition of redundancy checks also seems to have a positive effect on avoiding repetition of information. Keyword retention decreased somewhat, however. Lastly all methods had some trouble with dangling anaphora, showing a need for further work within anaphora resolution.

  • 30.
    Widerberg, Lisa
    Linköping University, Department of Computer and Information Science.
    Behov relaterade till välfärdsteknik i svensk hemtjänst i ordinärt boende2019Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [sv]

    Personalresurserna inom Sveriges äldreomsorg förutspås inte växa i samma takt som Sveriges befolkning över 80 år ökar, ett problem som de flesta är enade om måste adresseras. I ljuset av påtaglig utveckling inom områden som smarta hem och artificiell intelligens samt den nationella satsningen på välfärdsteknik som ett potentiellt svar på problemen är det högst relevant att utforska vilka behov som i dagsläget inte är tillgodosedda i svensk hemtjänst. Denna studie syftar till att identifiera existerande behov inom svensk hemtjänst i ordinärt boende relaterade till välfärdsteknologi samt identifiera faktorer som bör tas i hänsyn vid design för hemtjänstens verksamheter. Genom en kvalitativ ansats och människocentrerad design identifieras problematik i äldreomsorgen via semistrukturerade intervjuer och tematisk analys. Utifrån resultatet av den tematiska analysen identifierades åtta stycken olika behov relaterade till informationsbrist, brist på individanpassning och flexibilitet samt brist på proaktivt arbete. Tekniska områden som smarta hem och AI tycks erbjuda intressanta möjligheter att effektivt tillgodose dessa behov. Flertalet faktorer som är viktiga att ta i hänsyn vid design för studiens tre målgrupper presenteras.

  • 31.
    Fredriksson Franzén, Måns
    et al.
    Linköping University, Department of Computer and Information Science.
    Sandberg, Kristoffer
    Linköping University, Department of Computer and Information Science.
    Beneficial Limitations: Rate caps for Enhanced Branched Video Streaming Experience2019Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    The demand for on-demand video streaming has seen an enormous increased usage and is today the main contributor to Internet traffic. Technological developments combined with the accessibility of sufficiently powerful end-user hardware, large bandwidth capacities and significantly reduced storage cost are major contributors to this trend. We have built a simulation environment where multiple clients stream linear and branched video while competing over a shared bottleneck network. We examine how rate caps can be implemented to increase the overall Quality of Experience (QoE). First we present simulation results demonstrating the impact that rate caps have on clients playing linear video and compare and relate the results with prior work. Second we simulate the performance implementation of branched video and consider how its performance is affected by rate caps. Here, we highlight and discuss the trade-off patterns between playback quality and stability observed when a cap is implemented. To derive our conclusions we consider a range of scenarios, in which we vary different variables when a rate cap is set or not and measure the (i) requested encodings, (ii) buffer occupancy, and (iii) the amounts of switches between encodings made by the clients during the playback sequence. The rate cap implementation is shown to generate less switches between encodings, providing an enhanced stability and thus contributing to a better QoE in both the linear and branched environment.

  • 32.
    Herkevall, Jonas
    Linköping University, Department of Computer and Information Science.
    Bättre administration för en effektivare hemtjänst: En undersökning av den administrativa sidan av nyckelfri hemtjänst2019Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [en]

    What we are witnessing today is an increasingly older population. This change in demographics will drastically change the demands of elder care and especially home care services to ensure that more people will be able to stay at home for larger parts of their lives. In addition, statistical projections suggest a critical lack of manpower in home care services in the coming decade, and an increasing amount of faith is put into technical and digital solutions to streamline the organizations.

    On behalf of Phoniro, one of the largest distributors of welfare technologies for elder care in Sweden, this thesis has investigated how the administrative work attending to digital key management can be improved and streamlined with an updated interface. Through use of an online survey and semi structured interviews a more comprehensive understanding of the users working with the administrative system Phoniro Care have been acquired. The findings have been modelled in user stories meant to guide future design work in the development of Phoniro Care.

    The results indicate the need for a design that supports multiple user types and better tools for overviewing the information available in the system. Furthermore, the differences in organizational structure between different organizations implementing digital key management raises questions regarding digitization competences in public sector organizations and understanding the effect of implementing new digital tools. In turn, that raises questions regarding a possible future need for adaptation for companies like Phoniro in handling an increasing digital competence in the organizations that constitutes their clients.

  • 33.
    Ouvrier, Gustaf
    Linköping University, Department of Computer and Information Science.
    Characterizing the HTTPS Trust Landscape: - A Passive View from the Edge2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Our society increasingly relies on the Internet for common services like online banking, shopping, and socializing. Many of these services heavily depend on secure end-to-end transactions to transfer personal, financial, or other sensitive information. At the core of ensuring secure transactions are the TLS/SSL protocol and the ``trust'' relationships between all involved partners. In this thesis we passively monitor the HTTPS traffic between a campus network and the Internet, and characterize the certificate usage and trust relationships in this complex landscape. By comparing our observations against known vulnerabilities and problems, we provide an overview of the actual security that typical Internet users (such as the people on campus) experience. Our measurements cover both mobile and stationary users, consider the involved trust relationships, and provide insights into how the HTTPS protocol is used and the weaknesses observed in practice.

  • 34.
    Jaeger Tronde, Emma
    Linköping University, Department of Computer and Information Science.
    Chefers behov vid verksamhetsstyrning: En utredande kravanalys inför ett digitalt beslutsstöd2019Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [sv]

    Det råder en situation på arbetsplatser där fler och fler system förväntas tillämpas i arbetslivet. Linköpings kommun ingår just nu i en digital satsning för att påverka anställdas arbetssätt och arbetsbörda och den här studien är en utveckling av ett projekt som utförts tidigare inom kommunen. Studiens syfte var att undersöka arbetssättet som en grupp chefer tillämpar vid verksamhetsstyrning. Genom en kravanalys identifierades chefernas behov och krav de har på ett framtida digitalt beslutsstöd som kan användas vid just verksamhetsstyrning. Dessutom syftade studien till att undersöka chefernas användning av digitala verktyg och deras attityder gentemot digitalisering av arbetsprocesser. Det nuvarande arbetssättet uppfattades som tryggt men också långsamt med eftersatta strukturer. Chefernas upplevelse är att detta hindrar möjligheten att hjälpa fler personer. Tillika har de positiva attityder gentemot digitalisering då det har förutsättningen att förenkla arbetsprocesser. Däremot bemöts de idag av långa och krångliga vägar till information som tar energi från huvudsakliga uppgifter. Som konsekvens har egna påhittade strukturer skapats för att täcka upp för de rådande bristerna i de befintliga systemen. Förhoppningen på ett nytt digitalt beslutsstöd är att det inte ska vara ännu ett till verktyg, utan att det bemöta de problemen och bristerna som idag orsakar att digitala verktyg inte upplevs som hjälpmedel. Resultatet för denna studie är relevant för att utifrån ett användarcentrerat perspektiv ge de digitala verktygen ett mervärde och som kan förenkla och effektivisera arbetsprocesser och således också förbättra den digitala arbetsmiljön.

  • 35.
    Andell, Anton
    et al.
    Linköping University, Department of Computer and Information Science.
    Cole, Nigel
    Linköping University, Department of Computer and Information Science.
    Karlsson, Wiktor
    Linköping University, Department of Computer and Information Science.
    Lilja, Eric
    Linköping University, Department of Computer and Information Science.
    Rezaie, Diba
    Linköping University, Department of Computer and Information Science.
    Thimren, David
    Linköping University, Department of Computer and Information Science.
    Zeijlon, Andreas
    Linköping University, Department of Computer and Information Science.
    CI/CD i molnapplikationer som Google Cloud, Azure och AWS2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Under VT 2019 ägde projektet rum varav denna rapport är ett av resultaten. Projektets mål var att skapa en CI/CD pipeline vars syfte var tänkt att frekvent kunna leverera färdigtestad kod till olika molntjänster som Google Cloud Platform, Amazon Web Services och Azure. Projektspecifikationerna gavs av företaget Skira för att skapa en snabbare integrationsprocess för nya utvecklare. Detta så en ny utvecklare skulle kunna lägga mer tid på att koda istället för att gräva ner sig i leverans-/testningsprocessen. Slutprodukten ger företag möjligheten att koda direkt på sitt utvecklingskluster.

  • 36.
    Karlsson, Tobias
    Linköping University, Department of Computer and Information Science.
    Climate change beliefs and attitudes relationship to informational influences and demographic factors2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    One of the biggest challenges for the modern society is that of climate change. Despite the growing accumulation of scientific evidence that points towards a strong need for action to be made regarding anthropogenic (human made) climate change, there is a lack of unity in what actions are needed and an outspread passivity amongst both establishments and the public. The reason behind this is attributed to lack of belief in anthropogenic climate change, and lack of pro-environmental attitudes amongst the public. Furthermore, these issues have been found to relate to identity related beliefs and attitudes that conflict with pro-environmental beliefs and attitudes, where political orientation has proven to be a strong factor. One way of dealing with these issues could be through informational influences. By presenting people to information shaped in different ways, one could increase the belief in anthropogenic climate change and pro-environmental attitudes. This study examined the relationship between three different informational influences, and its potential effect on climate change beliefs and attitudes. Furthermore, this study examined the relationship between demographic factors such as age, gender and political orientation with regards to their potential effect on climate change beliefs and attitudes. 449 participants completed a survey with intent to measure the potential effects informational influences and demographic factors had on climate change beliefs and attitudes. Despite that indications where found, no significant results could be identified for the informational influences. All demographic factors had some significant effect on climate change beliefs or attitudes, where political orientation was the strongest influencing factor. This relates to earlier research and further implications were discussed for future studies.

  • 37.
    Sääf, Alexander
    Linköping University, Department of Computer and Information Science.
    Cloud Services for Building the Modern Internet of Things: An Examination of IoT Cloud Service Providers2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As the IoT has grown in popularity, modern Cloud Providers have begun offering IoT-specific features. These features could provide IoT developers with a lot of aid, but they are new and relatively unexplored. This study aims to explore these IoT-specific features in order to build a better foundation for developers looking to leverage them to improve their IoT systems or development process. To do this, a literature study combined with a case study was carried out. The literature study gives insight into the current research around IoT and IoT cloud providers, for example with common issues and possible applications. The case study provides a reference of how a simple proof-of-concept system can be developed using two of the available providers: AWS IoT and Azure IoT.

  • 38.
    Seger, Johanna
    Linköping University, Department of Computer and Information Science.
    Coagency of humans and artificial intelligence in sea rescue environments: A closer look at where artificial intelligence can help humans maintain and improve situational awareness in search and rescue operations2019Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [en]

    This paper aims to answer the question of how artificial intelligence could help humans maintain and/or improve situational awareness in search and rescue operations at sea, as well as where in such processes artificial intelligence could be incorporated to most efficiently compensate for human vulnerabilities and support human strengths. In order to answer this, a joint cognitive system perspective has been adopted whilst joining in search and rescue practice operations. These operations have been observed and persons participating in them have been interviewed, in order to gather insights about the process and the persons conducting it. The results from these insights coupled with experience with artificial intelligence and automation, show that artificial intelligence could help improve and/or maintain situational awareness by adopting functions which take up unnecessary time from man. According to the joint cognitive system view, these functions should never be solely performed by artificial intelligence however, but in coagency with man; allocated functions should overlap between man and machine. Suggestions have been given regarding which functions in particular an artificial intelligent agent could perform in terms of search and rescue and where these functions occur in the process. None of these suggestions are without man involvement, as they should not be. To summarise, these suggestions include; a UAV equipped with an infrared camera to search large areas quickly, a decision support system equipped with image recognition to analyse images gathered from the UAV, as well as a communication tool which allows for shared search patterns and hotspots between search and rescue units.

  • 39.
    Grönberg, David
    et al.
    Linköping University, Department of Computer and Information Science.
    Denesfay, Otto
    Linköping University, Department of Computer and Information Science.
    Comparison and improvement of time aware collaborative filtering techniques: Recommender systems2019Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Recommender systems emerged in the mid '90s with the objective of helping users select items or products most suited for them. Whether it is Facebook recommending people you might know, Spotify recommending songs you might like or Youtube recommending videos you might want to watch, recommender systems can now be found in every corner of the internet. In order to handle the immense increase of data online, the development of sophisticated recommender systems is crucial for filtering out information, enhancing web services by tailoring them according to the preferences of the user. This thesis aims to improve the accuracy of recommendations produced by a classical collaborative filtering recommender system by utilizing temporal properties, more precisely the date on which an item was rated by a user. Three different time-weighted implementations are presented and evaluated: time-weighted prediction approach, time-weighted similarity approach and our proposed approach, weighting the mean rating of a user on time. The different approaches are evaluated using the well known MovieLens 100k dataset. Results show that it is possible to slightly increase the accuracy of recommendations by utilizing temporal properties.

  • 40.
    Sestorp, Isak
    et al.
    Linköping University, Department of Computer and Information Science.
    Lehto, André
    Linköping University, Department of Computer and Information Science.
    CPDLC in Practice: A Dissection of the Controller Pilot Data Link Communication Security2019Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Controller-Pilot Data Link Communication, a technology that has been introduced to help offload the congested, previously used voice communication in larger airports, has in recent years started being questioned on its sufficiency in security. As the traffic load in air traffic communication keeps demanding more reliable and secure systems, we will in this thesis look at how widely CPDLC is actually used in practice in Europe. By using the newly introduced technology in software defined radios, we show that it is possible to capture and decode CPDLC messages to readable plain text. We furthermore discuss which type of attacks that could be possible with information retrieved from CPDLC communication.

  • 41.
    Lam, Benny
    et al.
    Linköping University, Department of Computer and Information Science.
    Nilsson, Jakob
    Linköping University, Department of Computer and Information Science.
    Creating Good User Experience in a Hand-Gesture-Based Augmented Reality Game2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The dissemination of new innovative technology requires feasibility and simplicity. The problem with marker-based augmented reality is similar to glove-based hand gesture recognition: they both require an additional component to function. This thesis investigates the possibility of combining markerless augmented reality together with appearance-based hand gesture recognition by implementing a game with good user experience.

    The methods employed in this research consist of a game implementation and a pre-study meant for measuring interactive accuracy and precision, and for deciding upon which gestures should be utilized in the game. A test environment was realized in Unity using ARKit and Manomotion SDK. Similarly, the implementation of the game used the same development tools. However, Blender was used for creating the 3D models.

    The results from 15 testers showed that the pinching gesture was the most favorable one. The game was evaluated with a System Usability Scale (SUS) and received a score of 70.77 among 12 game testers, which indicates that the augmented reality game, which interaction method is solely based on bare-hands, can be quite enjoyable.

  • 42.
    Haglund, Carl
    et al.
    Linköping University, Department of Computer and Information Science.
    Söderholm, Gustaf
    Linköping University, Department of Computer and Information Science.
    Wase, Jonathan
    Linköping University, Department of Computer and Information Science.
    Al-Hashimi, Mustafa
    Linköping University, Department of Computer and Information Science.
    Norsbo, My
    Linköping University, Department of Computer and Information Science.
    Skoglund, Oskar
    Linköping University, Department of Computer and Information Science.
    Wrede, Simon
    Linköping University, Department of Computer and Information Science.
    Dashboard för kirurgiska avdelningar2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta är en kandidatrapport utfärdad av sju studenter i kursen Kandidatprojekt i programvaruutveckling, TDDD96, på Linköpings universitet. Rapporten innefattar en sammanfattning av det arbete som har utförts i detta projekt. Slutprodukten resulterade i en dashboard som underlättar planeringen kring operationssalar för Region Östergötland. Produkten är en webbapplikation utvecklad i ramverket Angular. Utöver arbetet besvaras vad för värde som skapas för kunden, vilka intressanta erfarenheter, vad för stöd ges av en systemanatomi och hur ett planeringsverktyg som Asana underlättar, i ett mjukvaruprojekt. Slutsatserna av rapporten förklarar att produkten är redo att ersätta befintliga system hos kunden, samt med stor sannolikhet kommer att förbättra arbetsförhållanden för personalen hos kunden. Erfarenheter, som att arbeta i grupp och tekniska kunskaper kring webbutveckling, har införskaffats under projektets gång. En systemanatomi konstaterades att ha en positiv påverkan på projektet, genom att ge en bättre överblick och underlättade uppdelningen vid parallellutveckling. Slutsatsen av att använda ett planeringsverktyg visar att det har varit till stor hjälp under utvecklingen, främst för att fördela arbete som ska göras mellan gruppmedlemmarna och utvärdera vad som har gjorts. Planeringsverktyget ser också till att inget dubbelt arbete sker. I rapporten finns också individuella delar skrivna av gruppmedlemmarna, dessa innehåller djupgående analyser av olika ämnen.

  • 43.
    Schmidt, Simon
    et al.
    Linköping University, Department of Computer and Information Science.
    Nils, Tyrén
    Linköping University, Department of Computer and Information Science.
    Design of an interactive authoringtool for creating branchedvideo: Design av ett interaktivt författarverktyg för att skapa grenadevideor2019Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    With the release of ”Bandersnatch” in 2018, an interactive movie where the viewermakes choices that affects the outcome of the story, we know that successful interactivemovies are possible and appreciated. Although this technology already exists the possibilitiesare seemingly limitless. Perhaps in the future, movies could take certain paths basedon a predetermined profile of a viewer or by scanning facial expressions during the filmto determine what path that best suits the viewer. Interactive films and videos allows theviewer to interact with the storyline of the video. This technique is interesting from boththe user and developer perspective and introduces new challenges. To be able to have anoverview of the different possible branches of the video is helpful and needed in developmentof the media player and the branched video. When different possibles paths of thevideo emerges it can be difficult to keep track of all the different story lines. In this thesis,we make significant improvements to an existing authoring tool for a branched videoplayer. The authoring tool is to be used along side with a media player in order to facilitatethe development of a non-linear branched video. We will also be exploring what featuresof the authoring tool offer the most value to the user.

  • 44.
    Cromsjö, Mimmi
    et al.
    Linköping University, Department of Computer and Information Science.
    Christensson, Martin
    Linköping University, Department of Computer and Information Science.
    Design of video player and user interfaces for branched 360 degree video2019Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    Branched video enables users to interact with the video content and to choose a unique path through that content. With the further development of Virtual Reality (VR) technology the integration of branched video in these systems becomes increasingly convincing. This thesis develops a 360 degree branched video player in Unity Editor and three different user interfaces (UI) tailored for the needs of branched 360 degree video content, both the design and implementation focus on the aspects of usability. To expedite development of the UIs ,a preliminary user study was conducted to identify a promising design direction. From the study it was established that plain buttons with descriptive text attached, anchored in front of the field of view at the time of appearing, was to be preferred for the selection of the subsequent branch. This design was preferred both in a short motion picture and exploratory film setting. However, world-space anchored symbols as depicted to appear transporting the user to that world-space location showed promise in an exploratory video setting. Based on the result of the study and subjective feedback from study participants, additional features was implemented to the user interfaces. Lastly, further development of both features for the user interface, tools regarding the video player, and a follow-up user study are suggested.

  • 45.
    Hjalmarsson, Johanna
    Linköping University, Department of Computer and Information Science.
    Designa ett gränssnitt för enkel installation: Informationsarkitektur, mentala modeller och användarcentrerat arbetssätt2019Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [sv]

    Föreliggande arbete ämnade undersöka hur mentala modeller kan stödjas i en informationsarkitektur i ett administratörsgränssnitt (specifikt för systemet Phoniro Care) samt ta fram riktlinjer för fortsatt och framtida design. Arbetet utfördes i samarbete med företaget Phoniro med målet att anpassa installationsprocessen för larmmodulen i systemet Phoniro Care till användare i verksamheten. Genom designprocessen tillämpades ett användarcentrerat arbetssätt genom metodik såsom kontextuella observationer, card sorting och deltagande design. Utifrån detta framkom resultatet att användarnas mentala modeller av systemet motsvarade en hierarkisk struktur med grupperingar. Ytterligare resultat var ett flöde för installationsprocessen. Med detta som grund bildades en ny informationsarkitektur som visualiserades med stöd från data samt designprinciper. Den visuella designen som skapades anses kunna fungera som ett underlag för framtida arbete med utformningen liksom de dokumenterade designmål och designbeslut som tagits genom arbetets gång. 

  • 46.
    Björnqvist, Anton
    Linköping University, Department of Computer and Information Science.
    Det perifera seendets betydelse bland gångtrafikanter i naturlig miljö2019Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [en]

    The importance, and the role, of peripheral vision amongst pedestrians, is an area which for a long time has remained unexplored. Previous studies regarding peripheral vision and pedestrians have mostly studied the characteristics of peripheral vision, the general visual behaviours amongst pedestrians and whether people affected by a natural loss of peripheral vision fixate on different objects compared to those with normal vision. To examine the role of peripheral vision amongst pedestrians, an experiment consisting of 20 participants was conducted. The experiment took place in a car park, where head movements (i.e. how many times each participant moved their head) and head directions (i.e. in which direction the participants’ moved their heads) of the participants were recorded using three action cameras. Two of the cameras were mounted on a helmet which the participants used during the experiment. The third camera was in the hands of the experimenter, recording the participants from behind.

    The experiment consisted of four different conditions. Two conditions where the participants’ peripheral vision was blocked to different extents, one with no manipulation of the visual field and one where the participants were told to watch a video on a cell phone during the walk. The results demonstrated a significant difference in the number of head movements between all four conditions. Furthermore, the results also demonstrated a significant difference in the relative frequency of downwards head directions between the first three conditions. After the experiment, the participants answered a short survey which included questions related to each condition. The answers from the survey showcased, amongst other things, that the participants thought that the condition where their peripheral vision was blocked to the largest extent was the most difficult one. A thematic analysis was conducted based on the recordings of a think-aloud-protocol which the participants were told to conduct during the experiment. The thematic analysis demonstrated, amongst other things, that the participants thought that the condition performed with no manipulation of the visual field was easy, that they felt insecure when their peripheral vision was blocked and therefore had to increase the number of head movements, and that they sometimes felt the need to redirect their gaze away from the cell phone during that condition.

    The conclusion which can be drawn based on the results is that the peripheral vision is widely used amongst pedestrians in natural settings, which in part is based on the fact that the participants increased their number of head movements when their peripheral vision was limited and by their own expressed thoughts regarding the different conditions. However, the results are not able to explain exactly how the peripheral vision is used amongst pedestrians.

  • 47.
    Soames, Kieron
    et al.
    Linköping University, Department of Computer and Information Science.
    Lind, Jonas
    Linköping University, Department of Computer and Information Science.
    Detecting Cycles in GraphQL Schemas2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    GraphQL is a database handling API created by Facebook, that provides an effective al-ternative to REST-style architectures. GraphQL provides the ability for a client to spec-ify exactly what data it wishes to receive. A problem with GraphQL is that the freedomof creating customized requests allows data to be included several times in the response,growing the response’s size exponentially. The thesis contributes to the field of GraphQLanalysis by studying the prevalence of simple cycles in GraphQL schemas. We have im-plemented a locally-run tool and webtool using Tarjan’s and Johnson’s algorithms, thatparses the schemas, creates a directed graph and enumerates all simple cycles in the graph.A collection of schemas was analysed with the tool to collect empirical data. It was foundthat 39.73 % of the total 2094 schemas contained at least one simple cycle, with the averagenumber of cycles per schema being 4. The runtime was found to be on average 11 mil-liseconds, most of which consisted of the time for parsing the schemas. It was found that44 out of the considered schemas could not be enumerated due to containing a staggeringamount of simple cycles. It can be concluded that it is possible to test schemas for cyclicityand enumerate all simple cycles in a given schema efficiently.

  • 48.
    Sjöström, Linus
    Linköping University, Department of Computer and Information Science.
    Detecting SQL Injection Attacks in VoIP using Real-time Deep Packet Inspection: Can a Deep Packet Inspection Firewall Detect SQL Injection Attacks on SIP Traffic with Reasonable Performance?2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The use of the Internet has increased over the years, and it is now an integral part of our daily activities, as we often use it for everything from interacting on social media to watching videos online. Phone calls nowadays tend to use Voice over IP (VoIP), rather than the traditional phone networks. As with any other services using the Internet, these calls are vulnerable to attacks. This thesis focus on one particular attack: SQL injection in the Session Initial Protocol (SIP), where SIP is a popular protocol used within VoIP. To find different types of SQL injection, two classifiers are implemented to either classify SIP packets as "valid data" or "SQL injection". The first classifier uses regex to find SQL meta-characters in headers of interest. The second classifier uses naive Bayes with a training data set to classify. These two classifiers are then compared in terms of classification throughput, speed, and accuracy. To evaluate the performance impact of packet sizes and to better understand the classifiers resiliance against an attacker introducing large packets, a test with increasing packet sizes is also presented. The regex classifier is then implemented in a Deep Package Inspection (DPI) open-source implementation, nDPI, before being evaluated with regards to both throughput and accuracy. The result are in favor of the regex classifier as it had better accuracy and higher classification throughput. Yet, the naive Bayes classifier works better for new types of SQL injection that we do not know. It therefore argues that the best choice depends on the scenario; both classifiers have their strengths and weakness!

  • 49.
    Cao, Linqi
    Linköping University, Department of Computer and Information Science.
    Developing an experiential design approach to gain understanding about foreign culture: challenges and solutions2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    China’s economy is growing. It has been said that “the question like ‘how to do business with Chinese people’ have occupied the minds of international business people who are planning to enter China.” (Fan & Zigang, 2004). Sweden as a country which listed China as its largest trading partner in Asia and a priority country in Sweden's export strategy, has a need to gain understanding about guanxi –an important concept in Chinese business culture. In this thesis, the author will present the development of three exercises inspired by design methods (role play, visualization and customer journey map) which aim to help Swedish business managers to learn guanxi in an experiential way. It includes the challenges the design team went through, how did they solve it and what are the latest version of the exercises looks like. The main challenges presented in this thesis are: how to embed specific knowledge smoothly into exercise; how to set up the role of facilitator(s); and how to increase the level of satisfaction for the users. Those challenges are not only specific to our project, but also could be inspirational for other people (e.g. designers, business culture scholars and so on) who want to create similar exercises or looking for new ways to deliver the knowledge about cross-cultural business communication.

  • 50.
    Ayoub, Yohan
    et al.
    Linköping University, Department of Computer and Information Science.
    Barr, Viktor
    Linköping University, Department of Computer and Information Science.
    Fallström, Johan
    Linköping University, Department of Computer and Information Science.
    Gustavsson, Simon
    Linköping University, Department of Computer and Information Science.
    Jirénius, Martin
    Linköping University, Department of Computer and Information Science.
    Olausson, Jacob
    Linköping University, Department of Computer and Information Science.
    Rashid, Arin
    Linköping University, Department of Computer and Information Science.
    Digital 3D-rekonstruktion av personskador2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna rapport behandlar ett arbete utfört under kursen TDDD96 Kandidatprojekt i programvaruutveckling vid Linköpings Universitet. Arbetet är efterfrågat av Nationellt Forensiskt Centrum (NFC) och utfört av 7 datateknologstudenter. Arbetet bestod i att ta fram och utveckla ett färdigt program som ska göra det enkelt för kriminaltekniker och obducenter att rekonstruera personskador samt presentera det på ett pedagogisk sätt.

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