There are limited tools to evaluate a microservice architecture and no common definition of how the architecture should be designed. Moreover, developing systems with microservices introduces additional complexity to the software architecture. That, together with the fact the systems are becoming more complex has led to a desire for architecture evaluation methods. In this thesis a set of quality attributes measured by structural metrics are used to evaluate Scania's IoT Offboard platform. By implementing a metrics evaluation program the quality of the software architecture can be improved. Also, metrics can assist developers and architects while they are becoming more efficient since they better understand how performance is measured, i.e. which quality attributes are the most important and how these are measured. For Scania's IoT Offboard platform the studied quality attributes are listed in decreasing importance: flexibility, reusability and understandability. All the microservices are loosely coupled in the platform, which results in a loosely coupled architecture. This indicates a flexible, reusable and understandable system, in terms of coupling. Furthermore, the architecture is decentralized, i.e. the system is unflexible and difficult to change. The other metrics were lacking a reference scale, hence they will act as a point of reference for future measurements as the architecture evolves. To improve the flexibility, reusability and understandability of the architecture the large microservices should be divided into several smaller microservices. Also aggregators should be utilized more to make the system more flexible.

Hultsfreds kommun håller just nu på att föra över sina accesspunkter till ett nytt system som ska hantera dessa. I samband med detta, har de fått önskemål om att lägga upp ett öppet nätverk som personal och elever kan använda till sina privata enheter istället för att ta från sin surfpott. Här har då en undersökning genomförts på Albäcksskolan, där man har kollat på hur detta påverkar accesspunkterna när fler enheter ansluter sig mot dessa. En spectrumanalys har också genomförts för att optimera vilka kanaler som accesspunkterna ska använda. Det öppna nätet har även strypts till 3Mb/s och denna hastighet har utvärderats om den räcker för att utföra de dagliga sysslorna. Till sist har även en täckningskarta tagits fram för att se om täckningsytan går att förbättra. Det blev en väldigt liten ökning i antal enheter och påverkan på accesspunkterna blev därför inte särskilt stor. Det bedöms i nuläget inte att accesspunkterna påverkas så pass mycket att de behöver stärka upp med fler eller bättre accesspunkter. Spectrumanalysen visar konstanta störningar på tre kanaler i en lokal på skolan, där då dessa kanaler tas bort från accesspunkten. Strypningen på det öppna nätet bedömdes vara tillräckligt för att utföra vardaliga sysslor som mail och surf. Täckningen på Albäcksskolan var bra, men några förbättringar kan göras t.ex ta bort överflödiga och flytta till områden med sämre täckningsyta, samt flytta på några för att optimera täckningen ytterligare. / The municipality of Hultsfred is just about to bring over its access points to a new system that will handle these. In associate with this, they have had the desire to set up an open network that staff and students can use for their private devices instead of taking from their own mobile surf. Here has a survey been done at Albäcksskolan, where i have looked at how this affects access points, when more wireless devices join them. A spectrum analysis have also been done to optimize which channels that the access points use. The open network has been limited to 3Mb/s per user and this speed have been evaluated if it is enough for the daily tasks. A map over the wireless coverage area have been developed to see if this can be improved. There was a very small increase in the number of units and the impact on the access points was therefore not particularly high. It is estimated that the access points are not affected to the point so that they need to strengthen with more or better access points. The spectrum analysis shows constant interference on three channels in one place in the school, and as a solution, these channels will not be used there. The speed limitation on the open network is judged to be sufficient for the daily tasks such as e-mail and surfing the net. The wireless coverage  in Albäcksskolan is good, but some improvements can be made, for example remove some of the access points that are overkill and move them to places that need some extra coverage, as well as move some of the access points to optimize coverage further.

The heavy duty vehicle industry has today no requirement to providea tire pressure monitoring system by law. This has created issues sur-rounding unknown tire pressure and thread depth during active service.There is also no standardization for these kind of systems which meansthat different manufacturers and third party solutions work after theirown principles and it can be hard to know what works for a given vehicletype. National Highway Traffic Safety Administration (NHTSA) put out a new study that determined that underinflated tires of 25% or less are 3 times more likely to be involved in a crash related to tire issues versus vehicles with properly inflated tires. The objective for this thesis is to create an indirect tire monitoring system that can generalize a method that detect both incorrect tire pressure and thread depth for different type of vehicles within a fleet without the need for additional physical sensors or vehicle specific parameters. Drivec Bridge hardware interprets existing sensors from the vehicle. By using supervised machine learning a classifier was created for each axle where the main focus was the front axle which had the most issues.The classifier will classify the vehicles tires condition. The classifier will be implemented in Drivecs cloud service and use data to classify  the tires condition. The resulting classifier of the project is a random forest implemented in Python. The result from the front axle with a dataset consisting of 9767 samples of buses with correct tire condition and 1909 samples of buses with incorrect tire condition it has an accuracy of90.54% (±0.96%). The data sets are created from 34 unique measurements from buses between January and May 2017. The developed solution is called Indirect Tire Monitoring System (ITMS) and is seen as a process. The project group has verified with high accuracy that a vehicle has been classified as bad and then been reclassified as good over a time span of 16 days. At the first day offboard measurements were performed and it showed that the tires of the front axle were underinflated. The classifier indicated that the vehicle had bad classifications until day 14. At this day an offboard measurement was performed and it was concluded that they were no longer underinflated and the classifier indicated this as well. To verify the result the workshop was contacted and verified that the vehicle had changed tires of the front axle at day 14. This has verified that the classifier is able to detect change and stay consistent in the results over a longer time period.

The combat vehicle, CV90 has a semi-active hydraulic suspension system which uses inertial measurements for regulation to improve accessibility. To improve performance further measurements of future terrain can be used to, for example, prepare for impacts. This master's thesis investigates the ability to use existing sensors and new sensors to facilitate these measurements. Two test runs were performed, with very different conditions and outcomes. The results seem to suggest that a sweeping LIDAR was the most accurate and robust solution. However, using a very recent visual odometry algorithm, promising results were achieved using an Infra-red heat camera. Especially given that no efforts were put into adjusting parameters for that particular algorithm.

As the growth and enthusiasm for IoT increases, energy consumption and efficiency is of immense importance in order to develop maintainable and dependable sensor networks. In this thesis, we implement and evaluate a wireless sensor network using Bluetooth Low Energy (BLE) as the communication standard with regards to energy consumption and range capabilities. We found BLE to be a highly viable option for such systems, yielding long battery life for systems where long-range capabilities are not needed.

The purpose of this thesis is to extend an existing autopilot with automatic takeoff and landing algorithms for small fixed wing unmanned aircrafts. The work has been done from a systems engineering perspective and as for solution candidates this thesis has a bias towards solutions utilizing fuzzy logic. The coveted promises of fuzzy logic was primarily the idea to have a design that was easily tunable with very little knowledge beyond flight experience for a particular aircraft. The systems engineering perspective provided a way to structure and reason about the project where the problem has been decoupled from different solutions and the work has been divided in a way that would allow multiple aspects of the project to be pursued simultaneously. Though the fuzzy logic controllers delivered functional solutions the promises related to ease of tuning was not fulfilled in a landing context. This might have been a consequence of the designs attempted but in the end a simpler solution outperformed the implemented fuzzy logic controllers. Takeoff did not present the same issues in tuning but did require some special care to handle the initial low airspeeds in an hand launch.

With the growing number of association rules, it becomes moreand more difficult for users to explore interesting rules due toits nature complexity. Studies base on human perception andintuition show that graphical representation could be a betterillustration of how to handle data by using the capabilities ofthe human visual system to seek information. The 3D matrixbasedapproach visualization system of association rules called3DMVS was implemented in present study. The main visualrepresentation employed the extended matrix-based approachwith rule-to-items mapping to general transaction data set. Anovel method merging rules and assigning weight is proposedto generate new rules to reduce the dimension of theassociation rules, which will help users to find more importantitems in the new rule. Additionally, several interactions suchas sorting, filtering, zoom and rotation, facilitate decisionmakers to explore the rules they are interested in variousaspects. Finally, various evaluation techniques have beenemployed to assess the system from a logical reasoning pointof view.

Temporal data analysis and mining has attracted substantial interest due to theproliferation and ubiquity of time series in many fields. Time series clustering isone of the most popular mining methods, and many time series clustering algorithmsprimarily focus on detecting the clusters in a batch fashion that will use alot of memory space and thus limit the scalability and capability for large timeseries.The BIRCH algorithm has been proven to scale well to large datasets,which is characterized by an incrementally clustering data objects using a singlescan. However the Euclidean distance metric employed in BIRCH has beenproven to not be accurate for time series and will degrade the accuracy performance.To overcome this drawback, this work proposes an extended BIRCH algorithmfor large time series. The BIRCH clustering algorithm is extended bychanging the cluster feature vector to the proposed modified cluster feature, replacingthe original Euclidean distance measure with dynamic time warping andemploying DTW barycenter averaging method as the centroid computation approach,which is more suitable for time-series clustering than any other averagingmethods. To demonstrate the effectiveness of the proposed algorithm, weconducted an extensive evaluation of our algorithm against BIRCH, k-meansand their variants with combinations of competitive distance measures. Experimentalresults show that the extended BIRCH algorithm improves the accuracysignificantly compared to the BIRCH algorithm and its variants, and achievescompetitive and similar accuracy as k-means and its variant, k-DBA. However,unlike k-means and k-DBA, the extended BIRCH algorithm maintains the abilityof incrementally handling continuous incoming data objects, which is thekey to cluster large time-series datasets. Finally the extended BIRCH-based algorithmis applied to solve a subsequence time-series clustering task of a simulationmulti-variate time-series dataset with the help of a sliding window.

The emerging topic, symmetric encryption technique for digital imagesusing chaotic function and DNA bases has recently drawn a lot ofattentions from the research community. The use of voice and visualmaterial as an addition to textual data has become more widespread.Multimedia content, the core of which is the digital image, has becomean earth-shaking element in prospective information transmission. Thismeans that multimedia contents such as audio, video and images haveto be transmitted over communication channels securely using newencryption techniques.Chaos theory is a widely studied topic in non-linear dynamics becauseof features like periodicity, sensitivity to initial conditions and controlparameters. The lower dimensional discrete chaotic functions are simpleand efficient to generate a pseudo-random sequence for encryption.However, DNA cryptography is an additional weapon in thecryptographer’s armoury. Characteristics such as of vast parallelism andlarge storage capacity make it a very promising field. The algorithmsbased on DNA and discrete chaotic functions use the advantages of bothfields to provide image protection in an effective way.Traditional digital cryptosystems like DES, AES and RSA are designedprimarily for textual data, which does not fit the multimedia streambecause of the essential structures of image data such as large size, solidpixel correlation and high redundancy, which incurs significantoverhead. Also, in conventional cryptographic techniques, thedecrypted data is exactly the same as plaintext data.To solve this problem, symmetric encryption aims to provide sufficientsecurity with an important gain in computational complexity anddelays, thereby making the cipher suitable for real time applications.This study uses an encryption approach by adding adjacent rows andcolumns of plain text after converting into DNA bases in order to reducethe encryption overhead. To improve the use of DNA complementary rules in a better and moredynamic way, and to incorporate DNA diffusion prior to the encryptionalgorithm, a complete set of DNA complementary rules is employed inthe encryption and decryption process. The selection of DNA rules foreach block is made depending on the chaotic sequence. The initialconditions and control parameters of the chaotic maps are madedepending on the 256-bits hash value which is generated from a plainimage to avoid chosen plaintext attacks.

In order to keep up with the increasing demand on speed and reliability in modern wireless systems, new standards have to be introduced. By using Multiple Input Multiple Output technology (MIMO) and Orthogonal Frequency Division Multiplexing (OFDM) technologies the performance can be increased dramatically. Forthcoming standards such as WLAN 802.11n, WiMax and 3GPP LTE are all taking advantage of MIMO technology. To perform realistic tests with these standards it is often not enough to run software simulations in for example Matlab. Instead, as many real world parameters as possible need to be included. This can be done using a testbed, like the LiUMIMO, that actually transmits and receives data through the air. The LiUMIMO is designed as a Software Defined Radio (SDR), only the RF front end and the data log are implemented in hardware, while all signal processing will be performed in Matlab.