The world of computer networks is constantly evolving towards more efficient algorithms and more effective ways of using hardware resources. One of these evolutions is the eXpress Data Path (XDP). XDP is an interrupt based data path in the Linux kernel. XDP uses JIT-compiled programs in a virtual machine in a device driver context. Through XDP, fast packet processing is possible while still keeping the functionality of the Linux kernel intact. Therefore, this thesis aims to illuminate possible use cases for XDP in 5G simulators, as this real-world application of XDP is of interest. Specifically, use-cases where there is a need for fast packet processing. This thesis evaluates the use-cases using a performance evaluation of XDP and a literary review of 5G simulators, XDP, and technologies relating to XDP. This evaluation indicates that XDP is a candidate for packet processing in 5G simulators, specifically when compared to what performance is possible currently. This thesis argues from the performance evaluation and the literary review that XDP can be used for small programs, preferably data ingestion, in 5G simulators.

Even though there are no regulations on the interior noise level of passenger cars, it is a significant quality aspect both for customers and for car manufacturers. The reduction of many other car noise sources pushed tyre road noise to the forefront.What is more, well known phenomenon of the tyre acoustic cavity resonance (TCR), appearing around 225 Hz, makes the interior noise noticeably worse. Some techniques to mitigate this phenomenon right at the source are discussed in this thesis, however, these has not been adopted by the tyre nor car manufacturers yet.Therefore, there is a desire to minimise at least the transmission of the acoustic or vibration energy from the tyre to the compartment. This is where methods like TPA (Transfer Path Analysis) come into play.In this thesis, two different approaches to TPA are used to investigate transmission of the TCR energy.First, the coherence based road decomposition method is used to determine whether the TCR energy is transmitted by a structure-borne or an air-borne mechanism. The same method serves to identify if the TCR noise comes mainly from the front or the rear suspension.Second, the impedance matrix method was used to determine critical structure-borne transfer paths yielding clear results indicating two critical mounts at the rear suspension which dominate the transfer of vibro-acoustic energy. Subsequent physical modification of the critical mount was tested to verify the results of the transmission study.Moreover, deflection shape analysis of the tyre, rim, front and rear suspension was performed to identify possible amplification effects of the TCR phenomenon.

In the modern urban lifestyle, more and more people are exposed to noise pollution in form of traffic noise. As a response to this, the automotive OEMs (Original Equipment Manufacturer) are put under pressure to reduce the emitted noise from vehicles. To be able to meet the upcoming, stricter regulations, the automotive OEMs seeks new techniques to be able to front load the pass-by noise engineering in the vehicle development process and to identify and understand the different sources that contributes to the exterior noise.Earlier exterior sources ranking using ASQ (Airborn Source Quantification) with an energetic approach during pass-by noise test has yielded very good and reliable results for an ICE (Internal Combustion Engine) vehicle.In this Master Thesis, two exterior source ranking methods have been tested and evaluated for an electric vehicle during in-room pass-by noise test. The two methods were: ASQ and OPA (Operational Path Analysis). In total, five models were built from the two methods and each model was evaluated for, in total, three driving conditions corresponding to the current ISO362-1:2007 and the proposed, revised version.The results show that the ASQ models are not capable to correctly estimate the engine contribution due to its high tonality. Moreover, it was seen that the energetic ASQ model is very sensitive to small changes. Both ASQ models underestimated the tire noise.The OPA model on the other hand managed to estimate the total contribution very well. Both the engine contribution and the tire contributions are well estimated. Nevertheless, OPA as method has several weaknesses and building an OPA model is not a straightforward task. Its weaknesses and the process to reach a final OPA model are discussed in this thesis.It was seen that one of the most crucial steps in an OPA model is to have clean references to get meaningful results. A MIMO-FIR filter was therefore used to filter out engine harmonics from the tire references. Its principles and importance for the end results are also discussed.Included is also an overview of the basic principles in TPA (Transfer Path Analysis), ASQ, OPA and in room pass by noise test as well as a description of the test campaign.

<div>Exploring and surveilling the marine environment away from shore is critical for scientific, economic, and military purposes as we progress through the 21st century. Until recently, these missions far from shore were only possible using manned surface vehicles. Over the past decade, advances in energy density, actuators, electronics, and controls have enabled great improvements in vehicle endurance, yet, no solution is capable of supporting persistent operation especially when considering power hungry scientific surveys. This dissertation summarizes contributions related to the development of an adaptable underwater docking station and associated navigation solutions to allow applications in the wide range of maritime missions. The adaptable docking system is a novel approach to the standard funnel shaped docking station design that enables the dock to be collapsible, portable, and support a wide range of vehicles. It has been optimized and tested extensively in simulation. Field experiments in both pool and open water validate the simulation results. The associated control strategies for approach and terminal homing are also introduced and studied in simulation and field trials. These strategies are computationally efficient and enable operation in a variety of scenarios and conditions. Combined, the adaptable docking system and associated navigation strategies can form a baseline for future extended endurance missions away from manned support.</div>

Multi-Agent coordination and control has been studied for a long time, but has recently gained more interest because of technology improvements allowing smaller, more versatile robots and other types of agents. To facilitate multi-agent experiments between heterogeneous agents, including robots and UAVs, we have created a test-bed with both simulation and hardware capabilities. This thesis discusses the creation of this unique, versatile test-bed for multi-agent experiments, also a unique graph creation algorithm, and some experimental results obtained using the test-bed.

Topographic maps are an invaluable tool for planning routes through unfamiliar terrain. However, accurately planning routes on topographic maps is a time- consuming and error-prone task. One factor is the difficulty of interpreting the map itself, which requires prior knowledge and practice. Another factor is the difficulty of making choices between possible routes that have different trade-offs between length and the terrain they traverse. To alleviate these difficulties, this thesis presents a system to automate the process of finding routes on scanned images of topographic maps. The system allows users to select any two points on a topographic map and identify their specific preferences for their route. This system extracts terrain and contour line data from topographic map images using image processing techniques and then uses the A* Search algorithm to find a route between the specified points. This system can be used as a starting point for hand-drawn routes, as a means of considering alternative routes, or to entirely replace drawing routes by hand. This thesis also presents a user study which shows that this system produces routes in a significantly shorter time than hand-drawn routes, and with a similar level of accuracy.

The Quality of Service (QoS) routing approach is gaining an increasing interest in the Internet community due to the new emerging Internet applications such as real-time multimedia applications. These applications require better levels of quality of services than those supported by best effort networks. Therefore providing such services is crucial to many real time and multimedia applications which have strict quality of service requirements regarding bandwidth and timeliness of delivery. QoS routing is a major component in any QoS architecture and thus has been studied extensively in the literature. Scalability is considered one of the major issues in designing efficient QoS routing algorithms due to the high cost of QoS routing both in terms of computational effort and communication overhead. Localized quality of service routing is a promising approach to overcome the scalability problem of the conventional quality of service routing approach. The localized quality of service approach eliminates the communication overhead because it does not need the global network state information. The main aim of this thesis is to contribute towards the localised routing area by proposing and developing some new models and algorithms. Toward this goal we make the following major contributions. First, a scalable and efficient QoS routing algorithm based on a localised approach to QoS routing has been developed and evaluated. Second, we have developed a path selection technique that can be used with existing localized QoS routing algorithms to enhance their scalability and performance. Third, a scalable and efficient hierarchical QoS routing algorithm based on a localised approach to QoS routing has been developed and evaluated.

Synen på negativ miljöpåverkan har stärkt miljölagstiftning under de senaste decennierna i Sverige och internationellt. Människor vill leva bättre och längre liv med högre livskvalité än någonsin och miljöpåverkan kan vara ett stort hinder. I Sverige är miljöbalken försvaret för att förhindra negativ miljöpåverkan och samtidigt stärka en ekonomiskt tillväxt i förhållande till miljön. Där det lagstiftning inom Sverige som beskriver kumulativa effekter och europeisk lagstiftning kräver beskrivning av dessa effekter. Denna studie analyserar hur olika miljökonsekvensbeskrivningar beskriver och hanterar kumulativa effekter.  Den valda metoden är tematisk innehållsanalys för att analysera tre olika miljökonsekvensbeskrivningar med ett teoretiskt ramverk som består av path dependecy och politisk ekologi. Resultatet visar att samtliga dokument enbart indirekt beskriver kumulativa effekter. Kumulativa effekter beskrivs vanligtvis inte i miljökonsekvensbeskrivningarna emellertid finns det flera bilagor som kan hantera kumulativa effekter även det inte är sannolikt. Resultatet visar på att det saknas stora beskrivning och hantering av de kumulativa effekter och andra prioriteringar ligger först till hands på grund av olika orsaker som framför i resultatet, resultatdiskussion och slutligen i slutsatsen.   Nyckelord: Miljökonsekvensbeskrivning, Miljöbedömning, Kumulativa effekter, Path dependency / The view of negative environmental impact has strengthened environmental legislation in recent decades in Sweden and internationally. People want to live better and longer lives with a better quality of life than ever before, but negative environmental impacts can be a major obstacle. In Sweden, the Environmental Code is the defense to reduce negative environmental impacts and at the same time strengthen economic growth in relation to the environment. The Swedish legislation describes cumulative effects and European legislation requires a description of these effects. This study analyzes how different environmental impact statements describe and manage cumulative effects. The chosen method is thematic content analysis to analyze three different environmental impact statements with a theoretical framework consisting of path dependency and political ecology. The result shows that all documents only indirectly describe cumulative effects. While cumulative effects are often not described in the environmental impact statements, however, they could be addressed in the several appendices. However, this is not very likely. The result shows that there is a lack of description and management of the cumulative effects. Other things are prioritized over cumulative effects because of various reasons as presented in the result, result discussion and finally in the conclusion.

Problematisering: Arbetsformen hybridarbete har efter covid-19-pandemin blivit vanlig. Det råder dock tvetydighet i hur ledarskapet ska utformas för att fungera på bästa sätt i det nya normala. Studier visar vidare att sociala dimensioner påverkas av förändringar i tillit, men även att självledarskap kan öka tilliten mellan ledare och anställda. Självledarskap lämpar sig väl i hybridarbete då en högre grad av eget ansvar efterfrågas av de anställda.  Syfte: Syftet med studien är att skapa förståelse för hur ledare i kunskapsintensiva företag upplever att ledarskapet har förändrats i samband med hybridarbete. Eftersom självledarskap kan motverka exempelvis tillitsproblem, undersöks även självledarskapets betydelse i förändringen.  Metod: Kvalitativ metod har valts i form av sex intervjuer av ledare som leder med självledarskap i hybridarbete. Resultat/slutsats: Resultatet visar att ledarna inte upplever stora förändringar i ledarskapet, däremot har tydlighet och kommunikation blivit viktigare. Självledarskapet har i princip samma betydelse som tidigare men användandet har ökat i hybridarbetet. / Problem statement: Hybrid work has become common after the pandemic. However, there is ambiguity about how leadership in the hybrid workplace should be designed to work best. Furthermore, studies show that social dimensions are affected by changes in trust, but also that self-leadership can increase trust between leaders and employees. Self-leadership is well suited to hybrid work where a higher degree of personal responsibility is demanded from employees.  Purpose: The purpose of this study is to gain an understanding of how leaders in knowledge intensive organizations perceive that leadership has changed in the context of hybrid work. The importance of self-leadership is also investigated.  Method: A qualitative method was chosen, six leaders who lead with self-leadership were interviewed.  Results/conclusion: The leaders do not experience major changes in leadership, but clarity and communication have become more important. Self-leadership has not become more important but its use has increased in hybrid work.

Järnvägen transporterar människor samt gods billigt och miljövänligt. I Sverige identifierar Trafikverket flera alternativa sträckningar när de planerar en ny järnväg. Landskapets karaktär, miljöförhållanden, geologi, tätortsstruktur, befolkningsutveckling, resande och transporter är exempel på kriterier som kan påverka beslutet om var dessa sträckningar ska placeras. Geografiska Informationssystem (GIS) kan standardisera processen för att identifiera flera möjliga korridorer. Syftet med detta examensarbete är att ge rekommendationer på hur GIS, särskilt cost path och känslighetsanalys, kan användas vid planering av nya järnvägskorridorer. Ett testfall i Blekinge län valdes för att illustrera potentialen i dessa metoder. Examensarbetet utvärderar även den nuvarande användningen av GIS inom företagsvärlden genom semistrukturerade intervjuer med medarbetare på Vectura Consulting AB. Cost path och känslighetsanalysen identifierar fem olika korridorer där olika teman (miljö, jordarter, markanvändning, lutning och lika vikt) används och viktas enligt deras betydelse. De resulterande sträckningarna, speciellt sträckningen som baserades på markanvändningstemat, överensstämmer till viss del en planerad korridor från en tidigare förstudie. Intervjuerna indikerade att GIS ses som ett användbart verktyg men att det idag används huvudsakligen för presentation och visualisering av data. Resultaten visar att det finns en önskan om att använda GIS för att utföra analyser. Det kan även användas som ett samgranskningsverktyg för att lätt visualisera alla parters intressen. En nackdel däremot, är att det tar tid att lära sig och förstå samt att det krävs kunskap för att behärska det fullt ut. Trots skillnaderna i hur den planerade korridoren och de GIS-genererade korridorerna skapades, visade resultatet likheter mellan dem. De övergripande resultaten indikerar att GIS, speciellt cost path-analyser är ett användbart verktyg för att välja nya järnvägs korridorer. / Railway systems transport people and goods in an economic and environmentally-friendly way. In Sweden the Transport Administration identifies several possible routes when planning a new railway. Landscape features, environmental conditions, geology, population structure, population trends, travel and transport are examples of criteria that can affect decisions about the location of the routes. Geographical Information Systems (GIS) can standardize the process of identifying several possible corridors. The main aims of this thesis are to recommend on how GIS and particularly cost path and sensitivity analysis can be used to plan new railway tracks. A test case in Blekinge County (southeastern Sweden) was selected to illustrate the potential of these methods. The thesis also assesses the current use of GIS in the industry through semi-structured interviews of employees of Vectura consulting AB. The cost path and sensitivity analyses identified five different corridors. Different selection themes (environment, soil, land-use, slope and equal weight) were used and weighted, according to their importance. The selected routes especially the land-use theme correspond in a part to a corridor identified by a previous study. The interviews indicated that GIS is seen to be a useful tool but that its use at present is primarily for presenting and visualizing data. The results suggest however that there is also a desire to use GIS to perform analyses. It can also be used as an assessment tool to easily visualize the interests of all parties. High training requirements were identified as the principal disadvantages of GIS based analyses. Despite differences in how the planned and the GIS-generated corridors were created, the results of the two methods were similar. Overall, the results indicate that GIS, particularly cost path-analysis can be a useful tool for selecting new railway corridors.