Denna rapport undersöker hur en webbapplikation inom e-handel skapas med fokus på god användbarhet. De användbarhetsområden som studerats är navigerbarhet, pålitlighet och hur en effektiv köpprocess utformas. Utifrån etablerad teori om användbarhet har en webbapplikation som säljer chilifrukter skapats. Användartester har använts som utvärderingsmetod för att granska om användbarhet åstadkommits. Under projektet har tre kvalitativa tester gjorts och utifrån resultatet av dessa, tillsammans med etablerad teori, har funktionalitet och design ändrats för att förbättra användbarheten. Slutsatsen indikerar att det är möjligt att skapa en applikation som anses ha bra användbarhet utifrån de tre huvudområdena. / This report examines how a web application in e-commerce is created with a focuson good usability. The usability areas studied are navigability, reliability and how an effective purchasing process is designed. Based on established theory of usability, a webapplication that sells chili peppers has been created. User tests have been used as an evaluation method to review if usefulness has been achieved. During the project, three qualitative tests have been made and based on the results of these, along with established theory, functionality and design have been changed to improve usability. The conclusion indicates that it is possible to create an application that is considered useful in terms of the three main areas.

During the last couple of years, there has been an immense increase in data generation. This new data era has been referred to as the big data paradigm. More and more business areas are today realizing the power of capturing more data, and by this hope to reveal hidden patterns and gain new insights of their business. ICA is one of the largest retail business in Sweden, and saw the potential of utilizing the big data technologies to take the next step in digitalisation. The objective of this thesis is to investigate the role of these techniques in combination with machine learning algorithms and highlights advantages and possible limitations. Two use cases were implemented and tested which reveals possible application areas and important aspects to consider.

The objective of this thesis is to evaluate whether or not Clojure Spec meets the goals it sets out to meet with regards to easy data validation, performance and automatically generated tests in comparison to existing specification systems in the Clojure ecosystem. A specification for a real-world data format was implemented in the three currently popular specification systems used in Clojure. They were then compared on merits in terms of performance, code size and additional capabilities. The results show that Spec shines with complex data, both in expressivity and validation performance, but has an API more complex than its competitors. For complex enough use cases where expressing regular data structures and generative testing is desired the time investment of learning Spec pays off, in simpler situations an assertions library like Truss can be recommended.

The usage of the Internet is widely implemented all over the world in a number of concepts. This generates a demand of establishing security as to sustain the integrity of data. In this thesis a service will be presented which can be used to identify various web vulnerabilities in order to regulate these and therefore prevent exploitation. As the world is today the increase of technical implementation provides with a growing amount of security flaws, this affect the organizations which may have to increase their resource financing in an effort to counter these. But what if a tremendous amount of work could be automated and avoid organizations having to spend an enormous amount of finances validating security flaws reported to them? What if these flaws could be validated in a more effective manner? With this tool being establish an individual will no longer require advanced technical knowledge in order to identify whether a web vulnerability is present or not but instead have an automated test perform the procedure for them.

This thesis researches Scania's challenge to display the position oftrucks, with high accuracy and good user experience while with minimalposition transfers from the truck. This thesis presents an eventtriggered position update (ETPU) algorithm for sending positions fromthe truck along with real time estimation on the client. The key pointwith this system is that the truck computes the same estimation toevaluate its accuracy and sends a new position if the estimate isinsufficient. This achieves a system in which position updates areonly done when needed to achieve a selected accuracy. Simulations weredone and metrics for: accuracy, data consumption and user experiencewere applied for evaluation. Results are presented to inform thereaders of the ETPU's potential.

Syftet med den här studien var att undersöka vilka lösenordsstrategier individer använder sig av vid skapandet av användarkonton på internet. Studien bygger på en enkätundersökning där fyra olika målgrupper fick svara på frågor kring deras lösenordsstrategier på internet. Bland annat studerades skillnader mellan individer som är verksamma inom området IT/datateknik och individer som inte är det. Dessutom undersöktes även skillnader mellan äldre individers lösenordsstrategier och andra målgruppers. Generellt visar resultatet att inga större förändringar i lösenordsstrategier skett de senaste tio åren, förutom att användandet av lösenordshanterare har ökat. Strategier som användes av individer verksamma inom IT/datateknik skilde sig från de strategier som användes av individer som inte är verksamma inom ämnet, och det antogs att tekniskt intresse och kompetens har viss betydelse när det kommer till val av lösenordsstrategier. Hos äldre individer sågs en trend av okunskap och bristande intresse, vilket kan förklara bristfälliga lösenordsstrategier. / The purpose of this study was to investigate password strategies used by individuals creating user accounts on the internet. The study was based on a questionnaire survey, where four different target groups answered questions about their password strategies on the internet. Differences in strategies between individuals active in the field of IT/computer engineering, and individuals not active in the field, were studied. In addition, possible differences between older individuals and other target groups were investigated. Generally, the results show that there have been no major changes in password strategies over time, except that the use of password managers has increased. Strategies used by individuals active in the field of IT/computer engineering differed from those not active in the field, and it was assumed that technical interest and competence are of some importance when it comes to choosing password strategies. Among older individuals, lack of interest and unawareness was observed, leading to inadequate password strategies. The study is written in Swedish only.

The group membership protocol is a mechanism that handle mobile nodes in a dynamic environment and provide and maintain these nodes in a membership. These nodes can, for instance, be seen as the increasing connected devices which lead to a more dynamic group of devices in systems like distributed systems. In this thesis, a synchronous leader-based group membership protocol (SLMP) is evaluated. By doing simulations where the SLMP gets to handle nodes joining and crashing in different frequencies in a noisy environment, while we vary the length of the timeout, the frequency of nodes joining and crashing, and the packet loss rate; we were able to establish that all these parameters affect the performance of the protocol in different ways. When nodes join and crash in a high frequency it is wise to have a short timeout, but if the packet loss rate also is high, then the performance of the protocol will decrease. However, if the packet loss rate is high, there still are possibilities for the protocol to deliver a good service, if the timeout is long enough and the rate that nodes join & crash is not too high.

Safety-critical systems are those in which failure can lead to loss of people’s lives, or catastrophic damage to the environment. Timeliness is an important requirement in safety-critical systems, which relates to the notion of response time, i.e., the time a system takes to respond to stimuli from the environment. If the response time exceeds a specified time interval, a catastrophe might occur.   Stringent timing requirements make testing a necessary and important process with which not only the correct system functionality has to be verified but also the system timing behaviour. However, a key issue for testers is to determine when to stop testing, as stopping too early may result in defects remaining in the system, or a catastrophe due to high severity level of undiscovered defects; and stopping too late will result in waste of time and resources. To date, researchers and practitioners have mainly focused on the design and application of diverse testing strategies, leaving the critical stop-test decision a largely open issue, especially with respect to timeliness.   In the first part of this thesis, we propose a novel approach to make a stop-test decision in the context of testing the worst-case timing characteristics of systems. More specifically, we propose a convergence algorithm that informs the tester whether further testing would reveal significant new insight into the timing behaviour of the system, and if not, it suggests testing to be stopped. The convergence algorithm looks into the observed response times achieved by testing, and examines whether the Maximum Observed Response Time (MORT) has recently increased, and when this is no longer the case, it investigates if the distribution of response times has changed significantly. When no significant new information about the system is revealed during a given period of time it is concluded, with some statistical confidence, that more testing of the same nature is not going to be useful. However, some other testing techniques may still achieve significant new findings.   Furthermore, the convergence algorithm is evaluated based on the As Low As Reasonably Practicable (ALARP)  principle which is an underpinning concept in most safety standards. ALARP involves weighting benefit against the associated cost. In order to evaluate the convergence algorithm, it is shown that the sacrifice, here testing time, would be grossly disproportionate compared to the benefit attained, which in this context is any further significant increase in the MORT after stopping the test.   Our algorithm includes a set of tunable parameters. The second part of this work is to improve the algorithm performance and scalability through the following steps: firstly, it is determined whether the parameters do affect the algorithm. Secondly, the most influential parameters are identified and tuned. This process is based on the Design of Experiment (DoE)  approach.   Moreover, the algorithm is required to be robust, which in this context is defined “the algorithm provides valid stop-test decisions across a required range of task sets”. For example, if the system’s number of tasks varies from 10 to 50 tasks and the tasks’ periods change from the range [200 μ s, 400 μ s] to the range [200 μ s, 1000 μ s], the algorithm performance would not be adversely affected. In order to achieve robustness, firstly, the most influential task set parameters on the algorithm performance are identified by the Analysis of Variance (ANOVA)  approach. Secondly, it is examined whether the algorithm is sound over some required ranges of those parameters, and if not, the situations in which the algorithm’s performance significantly degrades are identified. Then, these situations will be used in our future work to stress test the algorithm and to tune it so that it becomes robust across the required ranges.   Finally, the convergence algorithm was shown to be successful while being applied on task sets having similar characteristics. However, we observe some experiments in which the algorithm could not suggest a proper stop-test decision in compliance to the ALARP principle, e.g., it stops sooner than expected. Therefore, we examine whether the algorithm itself can be further improved focusing on the statistical test it uses and if another test would perform better.

This thesis examines the experiences and results regarding the development of the web application Cash-on- Arrival, an online currency exchange service where the customer can order their currency exchange ahead of their travel to save money compared to exchanging their money at the time of arrival to their destination. The thesis mainly focuses on answering the research questions raised concerning how a secure and usable web application can be developed as well as how it can save money for travelers. In order to establish what design and features customers preferred, a market research in the form of a survey and market plan was done in the pre-study phase. Furthermore, the thesis continues with presenting how the implementation of features and solutions were performed. The result of the development is the web application Cash-on-Arrival where focus was on the security and usability of the application. Conclusions drawn were the need for a secure site, with a quick and efficient buying process, to encourage users to utilize the service. The implementation of the currency exchange optimization has not been fully answered.

This study treats behavioral biometric authentication, and its focus is on creating an application that uses hand-arm-movements to identify users. The systemis modelled to achieve a minimal false rejection rate (FRR) and false acceptance rate (FAR). Experiments featuring several test subjects performing hand-arm-movements using our device were performed in order to gauge the FRR and FAR of our system. The FRR and FAR achieved were 35% and 15.8%, respectively. The study concludes that hand-arm-movements may be useful for authentication, but further research is required.