<p>This thesis is concerned with the use of multiple antenna elements in wireless communication over frequency non-selective radio channels. Both measurement results and theoretical analysis are presented. New transmit strategies are derived and compared to existing transmit strategies, such as beamforming and space-time block coding (STBC). It is found that the best transmission algorithm is largely dependent on the channel characteristics, such as the number of transmit and receive antennas and the existence of a line of sight component. Rayleigh fading multiple input multiple output (MIMO) channels are studied using an eigenvalue analysis and exact expressions for the bit error rates and outage capacities for beamforming and STBC is found. In general are MIMO fading channels correlated and there exists a mutual coupling between antenna elements. These findings are supported by indoor MIMO measurements. It is found that the mutual coupling can, in some scenarios, increase the outage capacity. An adaptive antenna testbed is used to obtain measurement results for the single input multiple output (SIMO) channel. The results are analyzed and design guidelines are obtained for how a beamformer implemented in hardware shall be constructed. The effects of nonlinear transmit amplifiers in array antennas are also analyzed, and it is shown that an array reduces the effective intermodulation distortion (IMD) transmitted by the array antenna by a spatial filtering of the IMD. A novel frequency allocation algorithm is proposed that reduces IMD even further. The use of a low cost antenna with switchable directional properties, the switched parasitic antenna, is studied in a MIMO context and compared to array techniques. It is found that it has comparable performance, at a fraction of the cost for an array antenna.</p>

This thesis is concerned with the use of multiple antenna elements in wireless communication over frequency non-selective radio channels. Both measurement results and theoretical analysis are presented. New transmit strategies are derived and compared to existing transmit strategies, such as beamforming and space-time block coding (STBC). It is found that the best transmission algorithm is largely dependent on the channel characteristics, such as the number of transmit and receive antennas and the existence of a line of sight component. Rayleigh fading multiple input multiple output (MIMO) channels are studied using an eigenvalue analysis and exact expressions for the bit error rates and outage capacities for beamforming and STBC is found. In general are MIMO fading channels correlated and there exists a mutual coupling between antenna elements. These findings are supported by indoor MIMO measurements. It is found that the mutual coupling can, in some scenarios, increase the outage capacity. An adaptive antenna testbed is used to obtain measurement results for the single input multiple output (SIMO) channel. The results are analyzed and design guidelines are obtained for how a beamformer implemented in hardware shall be constructed. The effects of nonlinear transmit amplifiers in array antennas are also analyzed, and it is shown that an array reduces the effective intermodulation distortion (IMD) transmitted by the array antenna by a spatial filtering of the IMD. A novel frequency allocation algorithm is proposed that reduces IMD even further. The use of a low cost antenna with switchable directional properties, the switched parasitic antenna, is studied in a MIMO context and compared to array techniques. It is found that it has comparable performance, at a fraction of the cost for an array antenna.

<p>Användbarhet är en term som används för att bedöma kvaliteten hos ett gränssnitt. God användbarhet är viktig då den ger en ökad produktivitet och andra affärsfördelar i form av färre misstag och bättre kvalitet på slutprodukten. Användbarhet är en viktig designprincip men är en svår egenskap att uppfylla hos applikationer. </p><p>Studien behandlar användbarhet ur olika perspektiv, dels det teoretiska genom litteraturgenomgång, dels det praktiska genom intervjuer och observationer. Syftet var att förklara vad användbarhet är, hur det bedöms och vad man kan göra för att bygga in egenskapen i applikationer man utvecklar. För att exemplifiera och finna verklig förankring har jag valt att observera hur användare interagerar med ett existerande gränssnitt för bibliotek, Horizon. </p><p>Slutsatser kring studien är att Horizon inte används till allt den var tänkt att användas till, vilket i princip är ett dåligt betyg för en applikation. Samtidigt är detta inget större problem då den negativa verkan på verksamheten kan i det här fallet vara en definitionsfråga: är studenternas produktivitet när det gäller att söka och beställa litteratur kritisk? </p><p>När det gäller användbarhet i utvecklingsskedet kan man konstatera att även om intentionerna varit goda så har användbarhetsarbetet kring Horizon inte infriat förväntningarna. Vad som gått fel är varken sensationellt eller ovanligt; det har handlat om avsaknaden av slutanvändarens perspektiv, organisatoriska problem och möjligen också bristande kunskap om användbarhet i en eller annan form. En betydelsefull insikt som inte nämns i litteraturen men som togs upp är att beakta leverantörens marknadsställning när man ska köpa ett system. Trots bristerna, som ofta relaterar till brott mot designkonventioner, upplevs Horizon som ett bra och ändamålsenligt verktyg av sina användare. </p> / <p>Usability denotes the quality of a user interface. Even though usability is an important design principle, efforts to incorporate this quality in applications often fail. In this paper I study usability from a theoretical and a practical perspective. The goal is to explain usability and how to incorporate usability in applications. In order to exemplify, I study usability within the context of the library application Horizon. </p><p>This study shows that Horizon is only partially utilized by its users which in principle is a bad grade for an application. Partial use is however in this case, not a serious problem since the negative effects partial use imply could very well be a matter of definition: is the productivity of students, when it comes to searching and ordering library material, critical for the organization? </p><p>When it comes to usability in the development phases of a project, once again one can conclude that good intentions exist but efforts fail all the same and Horizon is no exception. This time we can attribute failure to the lack of the end users’ perspective, organizational problems and perhaps also unsufficient knowledge of usability in one form or another. An important conclusion, which has not been mentioned in the literature, is the importance of considering the market position of a presumptive vendor when buying a generic system. Despite the flaws (often related to violations of well established design principles) presented in this paper, Horizon is considered a good, effective and efficient application by its users.</p>

Användningen av Linux i inbyggda system fortsätter att öka för varje år. Öppen källkod och nya verktyg för utvecklandet av Linux för inbyggda system har inte bara gjort Linux till ett kostnadseffektivt val, utan även ett tidseffektivt val. Målet med den här undersökningen har varit att åt LVI undersöka en möjlig migration av operativsystem i deras inbäddade system från Windows XP Embedded till ett inbyggt Linuxbaserat operativsystem för ARM-processorer med stöd för OCR-behandling. Linux och öppen källkod till inbyggda system för med sig en hel del fördelar. Några av dessa inkluderar låg kostnad, full kontroll över ditt inbyggda system samt möjligheten att testa och utvärdera mjukvara helt gratis. För att komma fram till ett resultat har vi undersökt vilka alternativ som finns och om det finns stöd för de funktioner som LVI använder sig av. Resultatet av den här undersökningen är en redovisning av de val man står inför och vad som kan lämpa sig bäst för LVI. Vi har främst undersökt Yocto Project och Buildroot i denna undersökning och anser att Yocto Project är ett bra val för LVI. Två enklare applikationer har även skrivits där bildhantering och maskinläsning uppvisas. Applikationerna har utvecklats i C++ med hjälp av OpenCV och Tesseract-ocr.

In this report the feasibility of using a dual-tag setup in an indoor positioning system was investigated. The reason for the dual-tag setup was to be able to estimate both position and orientation. The system was designed using UWB-technology, with an time of flight trilateration algorithm to calculate the position. The orientation was then estimated from the relative position between the two tags. The system was tested both with stationary tags, but also with the tags moving along two paths. These tests were conducted for different separation distance between the tags, namely 20 cm, 30 cm and 40 cm. The result was that the mean position error for stationary tags was less than 8 cm for all separations and the mean orientation error was less than 3$^\circ$ for all separations. For the moving tag tests a decrease of the error in orientation of about 30 \% could be observed for a separation of 30 and 40 cm compared to 20 cm. However this difference is small in absolute values so more tests are needed to draw any conclusion about whether 30 and 40 cm tag separation performs better than 20 cm tag separation. The performance of the system could also be increased further by optimizing the anchor placement as well as the calibration of the antenna delays of the UWB-modules.

In this master thesis some of the most promising existing frameworks and implementations of deep convolutional neural networks on multiprocessor system-on-chips (MPSoCs) are researched and evaluated. The thesis’ starting point was a previousthesis which evaluated possible deep learning models and frameworks for object detection on infra-red images conducted in the spring of 2018. In order to fit an existing deep convolutional neural network (DCNN) on a Multiple-Processor-System on Chip it needs modifications. Most DCNNs are trained on Graphic processing units (GPUs) with a bit width of 32 bit. This is not optimal for a platform with hard memory constraints such as the MPSoC which means it needs to be shortened. The optimal bit width depends on the network structure and requirements in terms of throughput and accuracy although most of the currently available object detection networks drop significantly when reduced below 6 bits width. After reducing the bit width, the network needs to be quantized and pruned for better memory usage. After quantization it can be implemented using one of many existing frameworks. This thesis focuses on Xilinx CHaiDNN and DNNWeaver V2 though it touches a little on revision, HLS4ML and DNNWeaver V1 as well. In conclusion the implementation of two network models on Xilinx Zynq UltraScale+ ZCU102 using CHaiDNN were evaluated. Conversion of existing network were done and quantization tested though not fully working. The results were a two to six times more power efficient implementation in comparison to GPU inference.

Demand of CO2 gas sensors is expected to continue to increase in the foreseeable future, due to an increasing awareness of air pollution and fossil fuel emissions. A truly low cost and accurate NDIR sensor has the potential of greatly benefiting the environment by an increased human awareness due to CO2 measurements. In the objective to reach these goals, a CO2 sensor core on an ASIC needs to be investigated. In this study an ASIC prototype design is tested on an FPGA and evaluated towards logic resource requirements, power analysis and estimated cost impacts towards a full ASIC. The results show that a potential ASIC implementation would have a very small cost impact on a full system design if the use of a preexisting ASIC design is utilized. Using a manufacturing process of 180 nm, the total logic implementation would require between 0.54-0.76 mm2. The cost impact of such a logic area would be around $0.025 USD per chip. The power consumption of the logical part would also be very small when compared to the various analog components of a full system design.

<p>Correlations between the coefficient of variations (COV) of ion current integrals and COV of indicated mean effective pressure (IMEP) are investigated. The investigations are made to see if there is a possibility to use ion sense technique for closed loop combustion control to maximize Exhaust Gas Recirculation (EGR) level with remaining combustion stability. The engine studied in this thesis is a stoichiometric natural gas engine with a three way catalyst working with different EGR levels. One way to increase the efficiency in a stoichiometric natural gas engine is to maximize the EGR level [3]. With a higher EGR level it is possible to open the throttle even further with a result of lower pumping losses. Also temperature losses to chamber walls will be smaller with high EGR levels. A closed loop system controlling the EGR valve against COV of IMEP around 5 % is used for this engine. For COV of flame peak integral in range from 0 to 15-20% of COV of IMEP a linear correlation was found for lambda less than 1.3. For COV of two peaks integral a linear correlation was found for the entire measured range. This correlation may not be used for a robust EGR control system due to a small increase of COV of ion integral and due to a high variance in COV of ion integral. Correlations are discussed for different ion integrals with different air/fuels ratios and EGR levels. A control strategy is also presented.</p>

<p>Functionality in the automotive industry is becoming more complex, withcomplex communication networks between control systems. Information isshared among many control systems and extensive testing ensures high quality.</p><p>Degradations testing, that has the objective to test functionality with some faultpresent, is performed on single control systems, but is not frequently performed on the entire electrical system. There is a wish for testing degradation automatically on the complete electrical system in a so called Hardware-In-the-Loop laboratory.</p><p>A technique is needed to perform these tests on a regular basis.Problems with testing degradation in complex communication systems will bedescribed. Methods and solutions to tackle these problems are suggested, thatfinally end up with two independent test strategies. One strategy is suited to test degradation on new functionality. The other strategy is to investigate effects in the entire electrical system. Both strategies have been implemented in a Hardware-In-the-Loop laboratory and evaluated.</p>

<p>This thesis project has been carried out at Linköpings universitet at the Department of Mechanical Engineering. The emphasis of the project lies in the exploration of automatic selection of components for a propulsion kit. Specifically for this project, propulsion based on electric power and meeting the requirements for use in a Micro Aerial Vehicle (MAV). The key features include a systematic selection method based on user criterias and a model for evaluating propeller performance. These are implemented in a program written as a part of the project. The conclusion is that it is possible to make a program capable of a component selection and that the programs usability is mainly reliant on three factors: model for propeller evaluation, method of selection and the quality of the component database.</p>