On behalf of Avia Satcom Co., Ltd. we have conducted research in the eld of Computer Vision. Avia Satcom Co., Ltd. is in the stage of developing an Unmanned Aerial Vehicle and is interested in developing an algorithm for video tracking of arbitrary ground objects. The key requirements imposed on the tracker are: (1) being able to track arbitrary targets, (2) track accurately through challenging conditions and (3) performing the tracking in real-time. With these requirements in mind, we have researched what has been done in the eld and proposed an algorithm for video tracking. Video tracking in general is the process of estimating, over time, the location of one or multiple objects in a video captured by an analogue camera. Video Tracking is often divided into Target Representation, Target Detection and Target Tracking. First you create a model of the target. Then you implement techniques for detecting the object using the target model. Lastly, you use dierent techniques to predict the new target location given the current location. After comparing some trackers we chose to implement the Particle Filter. The Particle Filter is a robust tracker which can handle partial occlusion and non-Gaussian distributions. To represent the target we used Haar-like rectangular features and Edge Orientation Histograms features. The features have been shown to be robust and simple to calculate. Moreover, in a combination they have shown to serve well as each other complements, addressing each others shortcomings. We tested our tracker on a set of videos with challenging scenarios. Although the tracker could handle some scenarios if the parameters were tuned correctly, it did not perform satisfactory when dealing with appearance changes. To address the issue we extended our approach and implemented a strong classifier to help aid our observation model. The strong classifier consists of several trained weak classi ers. The strong classifier can classify estimates as either foreground or background and output a value of how con dent it is. Along with the classifier we also de ned a completely new set of features. With the new approach our tracker is significantly more robust and can handle all scenarios well. However, due to some minor error in our adaptive procedure we were not able to learn appearance changes over time, only the initial appearance. Therefore, any larger appearance changes still remain a challenge for the tracker. We do believe this is just a coding error which can be easily fixed. Nevertheless, the tracker still performs satisfactory in tracking arbitrary objects. We did however find that the tracker had difficulties with small objects and was not as robust in maintaining track lock in that case. For future work we would like to investigate the error preventing us from adapting our weak classi ers over time. We would also like to look into a technique for locating extremely small moving objects using Background Subtraction which could act as a good complement to what has already been done.

As the formation of nearly abrupt p-n junctions in aggressively scaled transistors has become a complex task, a novel type of device in which there are no junctions has recently been suggested (J. P. Colinge et al., Nature 2010). The device of interest is referred to as the junctionless transistor, and it has demonstrated excellent functionality, with the advantage of a simpler fabrication process than conventional FETs. Despite the remarkable performances exhibited by the junctionless transistor, this device has to be tested against variability before it may be produced in large scale. Hence, the study of how the fluctuations in the number and in the position of the dopant atoms affects a large number of devices has been developed in this work. Such variability source is referred to as Random Dopant Fluctuations (RDF) and it is among the most critical ones for conventional MOSFETs. Our view is that RDF ought to largely affect the junctionless transistors. Hence, in this work we mainly aim at investigating the impact of RDF in these type of devices. Firstly, we provide a detailed analysis on the performance of an ideal junctionless transistor with a uniform non-random doping concentration, by mean of simulations developed using a TCAD software. Secondly, we investigate the effects of RDF in the junctionless transistor, as the principal aim of our study. Here, we determine how the I-V characteristics are affected by the random dopants and we illustrate fundamental the causes of the variations. A first estimation of the impact of RDF is provided by the illustration of the threshold voltage and beta [1] distributions, and by the computation of the fundamental statistical quantities relating to the two parameters. A further and last estimation is provided by the comparison obtained studying RDF on the inversion mode FET.

This master thesis project is a cooperation between Fortum Distribution AB and The Royal Institute of Technology (KTH). When maintaining and operating a power distribution system, which is the task of Fortum Distribution AB, the aim is to always be able to deliver electric energy to the customers. A 100% reliability is however not a realistic goal since too high reliability would cost too much. The net planners at Fortum have to choose the most cost effective investments. Due to the complexity of the power system, grid analyses are expensive and simplifications have to be made. In this master thesis it is examined if Fortum Distribution AB’s methods for prioritizing between different reliability investments for the rural power distribution system are detailed enough to give the same result as more complex methods. This is done by creating theoretical models of two 11 kV lines out of two different substations in a rural part of Fortum’s grid. The fault management process at Fortum Distribution AB is thoroughly described and implemented in the theoretical models of the two case lines. The time it takes to perform specific tasks in the fault management are listed for future reference. A couple of investments for better reliability are applied to the case lines. The effect on reliability and cost efficiency of different investments allow for the investments to be prioritized after which are better to implement. One of the case lines is in an area where reliability investments have already been performed. This line is chosen because the results from the analysis then can be compared to the real investments. To test and apply the result the other case study is performed on an area that has not yet been renovated. For this case line cost-efficient investments are recommended. The conclusion of the analyses is that the detail level of the analyses made by Fortum Distribution AB most likely are sufficient for today’s grid. However, because of the ongoing project to weather-secure the grid, changing overhead lines for underground cables is the number one priority. The analysis in this thesis could have reflected the effect of extreme weather better, but even so, the result shows such a significantly lower cost-efficiency for investing in cables that it might be favorable for Fortum Distribution AB to review the benefits of changing overhead lines for underground cables. In some cases other investments might be more beneficial. / Denna svenska sammanfattning av examensarbetet riktar sig kanske främst till personer på Fortum eller den som annars har en inblick i arbetet på ett elnätsföretag. Det här examensarbetet är ett samarbete mellan Fortum Distribution AB och KTH.  Målet med examensarbetet är att undersöka om Fortum Distibution AB’s metoder för att prioritera mellan olika investeringar för bättre tillförlitlighet på lokala landsbygdsnät ger samma resultat som mer komplexa metoder. Projektet har genomförts genom att göra teoretiska modeller av två linjer i Fortums nät. Den ena, 102A Lesjöfors, är en linje där omfattande upprustningar redan genomförts. Där görs modellen av hur linjen såg ut innan den byggdes om för att sedan kunna jämföras mot verkligheten. Den andra linjen, 020E Charlottenberg, är en linje som är i behov av renovering. För denna linje kommer rekommendationer baserade på resultatet av denna studie att ges. Indata till modellerna är felintensiteter för ett par olika komponenter och åtgärdstiderna för att återställa funktionen då ett avbrott inträffat. Komponenterna som beaktas är luftledningar, kablar, brytare, frånskiljare och lågspänningskomponenter (vars felintensitet aggregeras till en). Felintensiteterna uppskattas från historiska data över avbrott i området. Ett mål är att använda så lokala avbrottsdata som möjligt för att spegla de lokala variationerna av hur ofta fel inträffar. Åtgärdstiderna har uppskattats genom intervjuer med nätplanerare, driftoperatörer och montörer på Fortum och Infratek. Infratek är ett bolag som bygger och underhåller infrastruktur. Linjen delas upp i olika segment efter var frånskiljarna sitter placerade, och kunderna som bor mellan samma två frånskiljare slås samman till en s.k. lastpunkt. För varje lastpunkt beräknas felintensitet och åtgärdstid för olika typer av felfall, som t.e.x. fel på luftledning. För varje lastpunkt beräknas det total antalet avbrott och den totala tiden då lastpunkten varit utan ström. Dessa multipliceras sedan med antalet kunder vid varje lastpunkt, och det totala antalet kundavbrott och kundavbrottstimmar används sedan för att beräkna SAIFI och SAIDI (se definition i avsnitt 2.1). Ett antal olika investeringsscenarier undersöks för linjen. De olika investeringsalternativen är både vanliga typer av investeringar, så som kablifiering, men även lite nyare investeringar undersöks. Att sänka spänningen på en mindre radiell ledning till 1 kV och att installera en linjebrytare är exempel på sådana investeringar som ännu inte har användts speciellt mycket. Utöver dessa investeringar undersöktes även alternativet att uppgradera de manuella frånskiljarna till automatiska och att lägga till en möjlighet till sekundär matning. Kablifiering var den investering som tidigare har utförts på den verkliga Lesjöforslinjen. En modell gjordes därför även av Lesjöforslinjen som den ser ut idag. På så vis kunde den i verkligheten genomförda investeringen jämföras mot de teoretiska investeringarna. Övriga investeringar beräknades genom att modifiera de befintliga modellerna för linjerna. För investeringarna beräknas nya SAIFI och SAIDI, samt minskningen av kundavbrottsminuter. En LCC-analys görs av kostnader och inkomster från investeringarna under dess livslängd, som antas vara 40 år. I den totala kostnaden ingår investeringskostnad, underhållskostnader, kundavbrottsersättningar för långa avbrott och förändringar på intäktsramen via regleringen. Förändringarna på intäktsramen beror dels av en kvalitetsjustering baserat på hur mycket SAIFI och SAIDI har sänkts, dels på om kapitalbasen ändras genom investeringen. Med de totala kostnaderna och sänkningen av kundavbrottsminuter tas nyckeltalen SEK/kundavbrottsminut och SEK/isolerad km ledning fram. Dessa nyckeltal används av Fortum i investeringsplaneringen. Investeringarna sorteras sedan efter kostnadseffektivitet. Slutsatserna av projektet kan sammanfattas i ett antal punker: Vädersäkring har högsta prioritet inom investeringsplaneringen på Fortum idag. Analyserna i detta examensarbete kunde ha speglat effekten av extremväder starkare. Trots detta är kostnadseffektiviteten för kablifiering så signifikant mycket lägre än för de andra investeringarna att det kan vara värt för Fortum att räkna på vinsterna med att kablifiera för att se om det kanske finns situationer där andra investeringar hade varit lönsammare. I Fortums analyser görs flera förenklingar, bl.a. att kablar är felfria. Beräkningarna i denna rapport har visat att kablar har mycket liten effekt på systemets tillförlitlighet och att denna förenkling nog kan anses vara acceptabel. Detta kan dock komma att förändras. Om kablifieringen av nätet fortsätter kommer en större och större del av det bestå av kabel. Detta gör att kablarnas felintensitet får en allt större procentuell betydelse. Det kan vara värt att fundera på hur detaljerade beräkningar man bör ha på sikt om luftledningsnäten byggs bort. Regleringen har en mycket stor påverkan på hur kostnadseffektiva investeringar blir. Det är därför fördelaktigt att ta med regleringens inverkan i beräkningarna för att kunna avgöra vilken investering som ger bäst resultat. Regleringen av elnätsföretagen har dock, och kan komma att, skifta och det är inte säkert att de regler som gäller idag även gäller nästa reglerperiod. Därför kan det även vara bra att välja investeringar vars lönsamhet inte rasar om en förändring av regleringen skulle ske, med tanke på att livslängden på investeringen beräknas vara 40 år.

In the past few years, silicon mm-wave, especially 60GHz CMOS design has experienced a transition from an obscure topic to a research hot spot. The focus of this thesis is the design of a 60GHz receiver front-end integrated circuit, together with device modeling solutions, using 65nm CMOS technology.   A 60GHz to 5GHz heterodyne receiver topology is initially architected to exploit its possible compatibility with the 5GHz legacy WLAN system. In order to implement this frontend, an EM simulation based device modeling methodology together with the corresponding design flow has been proposed, which is tailored for the specific 65nm CMOS design kits and the available simulation tool. Based on thorough analysis of the process feature, efforts on device modeling for 60GHz operation have been taken. For active device, an EM model, using exiting transistor compact model as core, is developed for the NFET valid in vicinity of 60GHz to account for parasitic elements due to wiring stacks. Solutions for implementing the passive components in the specific circuit blocks have been illustrated. In particular, constructing, optimizing and physically characterizing of spiral inductor operating around 60GHz frequency band has been demonstrated. After the modeling efforts, a single-stage cascode LNA and a single-gate transconductance-pumped mixer are individually designed in the IBM 65nm CMOS process, characterized by EM co-simulation, and then compared with the state-of-the-art. Finally, the LNA and mixer has been integrated, layout and simulated as a complete front-end. The frontend achieves a conversion gain of 11.9dB and an overall SSB noise figure of 8.2dB, with an input return loss of -13.7dB. It consumes 6.11mW power, and its layout occupies a die area of 0.33×0.44mm2.

The analysis of large-scaled 2D finite planar arrays with the Method of Momentsrelying on the RWG basis functions requires a huge amount of memory for saving theequation system and a long computation time for solving the surface current distribu-tion. In this project, the Array Scanning Method - Macro Basis Function (ASM-MBF)method created by Craeye is implemented in an existing MoM’s code in order to verifythe reduction of the equation system keeping a good accuracy. Some improvementshave been implemented in the existing code in order to analyze arrays with rectangularand skew lattices. The time spent in the impedance matrix construction has also beenreduced. A program for solving 2D infinite arrays has been created for obtaining theinfinite surface current distributions necessary for the implementation of the ASM-MBF method. Finally, the definitive program has been tested with arrays of dipoleand bowtie antennas. In both cases, the computation time is reduced without affectingthe accuracy of the input impedance.

The rapid development of wind power technology is reshaping conventional power grids in many countries across the world. As the installed capacity of wind power increases, its impact on power grids is becoming more important. To ensure the reliable operation of a power system which is significantly fed by wind power, the dynamics of the power system must be understood, and the purpose of this study is to develop suitable analytical tools for analysing the dynamic impact of large-scale wind parks on the stability of a power grid, and to investigate the possibility of improving the stabilisation and damping of the grid by smart control strategies for wind turbines.Many of the newer, larger turbines now being produced are variable speed turbines, which use doubly fed induction generators (DFIGs). These are induction generators which have their stator and rotor independently excited. When unconventional generators of this type are used in a power system, the system behaves differently under abnormal dynamic events.  For example, new types of generators cause different modes of oscillation in the power system, not only because of their dynamic characteristics, but also because they load the system differently.Very large power oscillations can occur in a power system as a result of internal disturbances.  Ordinarily these oscillations are slow and, in principle, it is possible to damp them with the help of wind power.  This leads to the idea of using a power system stabiliser (PSS) for a DFIG.  In order to damp oscillations in the system, it is necessary to understand the equipment causing these oscillations, and the methods to optimally damp the oscillations.Voltage stability is another important aspect of the safe operation of a power system. It has been shown that the voltage stability of a power system is affected by induction generators.  The voltage stability must therefore be carefully analysed in order to guard against a power system collapse.By using modal analysis and dynamic simulations, we show that the presence of a wind farm in the vicinity of a power system will improve the angular behaviour of the power system under small disturbances, but may decrease voltage stability under larger disturbances. We compare the performance of wind turbines to that of conventional synchronous generator power plants, and we show that a wind park consisting of DFIGs, which are equipped with PSSs, may be used as a positive contribution to power system damping.

No description available.

Effektförstärkare för radiofrekvensapplikationer utgör fortfarande ett av de största problemen i trådlösa kommunikationssystem. Detta beror på att dessa förstärkare är ickelinjära, har låg energieffektivitet och ger mycket distortioner. Bättre verktyg för att förstå och korrigera dessa beteenden är nödvändiga. Ett sådant verktyg är beteendemodellering. En beteendemodell kan ses som en svart låda med insignal(er) och utsignal(er). In detta fall är dessa signaler samplade basbandssignaler och den svarta lådan är en matematisk relation mellan en insignal och en utsignal. Avhandlingen behandlar några krav för beteendemodellering av nämnda system genom att presentera metoder för utvärdering och förbättring av modellernas prestanda. Detta åstadkoms genom att betrakta ett frekvensviktat felkriterium. Ett högpresterande mätsystem är också nödvändigt för experimenten. Prestandan hos det tillgängliga systemet jämförs med prestandan hos ett allmänt erkänt mätsystem, en s.k. storsignalsnätverksanalysator, genom att betrakta prestandan hos beteendemodellerna som extraheras och valideras med data från respektive mätsystem. Resultatet visar att det existerande mätsystemet har god prestanda. Ett stort problem vid beteendemodellering är att kunna sampla med tillräckligt hög hastighet. Genom att använda Zhu-Franks generaliserade samplingsteorem vid beteendemodellering kan en del av detta problem undvikas. Teoremet medför att man kan sampla med en väsentligt lägre samlingsfrekvens än vad Nyquistteoremet säger. Modeller extraheras och prestandan utvärderas genom att använda kriteriet normalized mean square error (NMSE). För stabil prediktion och korrektion av utsignalen måste robustheten hos de använda modellerna verifieras. En sådan studie som berör robustheten mot variationer i lastimpedansen har genomförts. Prestandan på direkta modeller försämras med 7 dB mätt som adjacent channel error power ratio (ACEPR). Prestanda på inversmodellen, implementerad som digital predistortion, försämras med upp till 13 dB mätt som adjacent channel power ratio (ACPR). / Radio frequency (RF) power amplifiers (PA) are still the most troublesomepart of a wireless system due to their inherent nonlinearity, low powerefficiency and high distortions. Better tools are needed to understand and correct the undesirable behavior. Some of these tools are behavioral models. A behavioral model is often thought of as a black box with some inputs andsome outputs. In the case here these inputs are sampled signals which meansthat the modeling amounts to finding a mathematical relationship betweenthe input signal(s) and the output signal(s). This thesis considers some requirements for behavioral modeling of said systems by presenting methods for general performance evaluation and improvement by considering a frequency weighted error criterion. A high performance measurement system is also needed. The performance of the available system is compared to the performance of a well recognized system, the largesignal network analyzer (LSNA). The results show that the existing measurementsystem can extract behavioral models with the same performance as the LSNA and can give lower performance validation errors. Still the need for higher bandwidths drives the measurement systems to the limits, especially the digital parts. By utilizing the so called Zhu-Frank generalized sampling theorem, behavioral modeling of a PA is done by using data acquired at a sampling rate lower than the Nyquist rate. Models of a PA are extracted and the performance is evaluated using the normalized meansquare error (NMSE) criterion. For prediction and correction of the output signals the stability of the models regarding changes must be investigated. One such study considering controlled variations on the output load of the PA is done and both the predictive and corrective capabilities of the models are evaluated. The predictive capability gets up to 7 dB worse measured as adjacent channel error powerratio (ACEPR) and the corrective, as digital predistortion, gets up to 13 dB worse measured as adjacent channel power ratio (ACPR).

The rapid development of the global economics has made power systems allover the world become large-scale interconnected grids. This increases the capabilityof power grids to transfer power over the long distance to serve the desiredpower demand with the minimum cost of operation. Unfortunately, it alsoenables the propagation of local failures into global networks. In other words,if a blackout happens in a power system, the size and the damage may significantlyincrease. One of the main ways in which blackouts become widespread is cascadingfailures. This type of failure originates after a critical component of the systemhas been removed fromthe service by protective relaying. As a consequence, theload handled by the failed component needs to be redistributed which mightcause an overloading on other components in the system. On the other hand, the high power electronics controllable devices suchas Voltage Source Converters-based High Voltage Direct Current (VSC-HVDC)transmission are recently developed. These electronics devices have the potentialadvantages such as the ability to independently control active and reactivepower, and maintain voltage to be at acceptable level. Therefore, they are consideredto be the promising devices that with an appropriately designed controlstrategy, they can substantially improve the performance and reliability of thepower system. This thesis presents the possibility to consider protection system status inthe control of VSC-HVDC link. A great deal of this research is development ofcoordination between this power electronic device and protection system which normally are considered separately. The derivation of protection system has been selected to determine the operation of VSC-HVDC. The methodology isbased on utilizing the signal created from a logical evaluation of relay and simplificationsof certain parameters. By introducing information from the relays tothe VSC-HVDC link via Central Control Unit (CCU), the modulation of transmitted power is devised in order to reduce the risk of system-wide failures. In turn,this means an avoided blackout.Furthermore, this thesis also includes the preliminary suggestion to selectthe location of VSC-HVDC. The methodology is based on predicting voltage instabilityusing voltage stability indices and related parameterswhich are derivedby using Singular ValueDecomposition method. The solutions indicate an effectivelocation for applying corrective action such as load shedding. This optimallocation is selected to reinforce the control strategy of VSC-HVDC in order toprevent cascading failures in the more encompassing systems. / QC20100615

Aerial and space autonomous systems are safety-critical systems that need to operate safely and reliably for long periods of time. Their applications range from autonomous inspection of complex and sensitive structures, to surveillance and transportation of sensitive payloads. These tasks impose strict operation requirements in order to be successfully accomplished, which the operating agents must ensure at all times while taking advantage of all the available sensing and communication modules, but considering energy constraints and individual autonomy as much as possible.  In this thesis, predictive and vision-based control techniques are explored to coordinate multi-agent systems, with a particular focus to aerial and space robotic applications. A particular focus is set on model predictive control (MPC) and image-based visual servoing (IBVS), and extensions are provided for controlling multi-agent systems using these frameworks. Initially, MPC is explored to distributively navigate a formation of multiple unmanned aerial vehicles (UAVs) in a leader-follower scheme, where minimal communication among agents in the formation is prioritized. Then, MPC is explored with IBVS in a cascaded control fashion to stabilize a UAV using image features, while taking advantage of the optimal control inputs provided by the MPC module given the dynamics of an aerial vehicle. This work serves as motivation and stepping stone to two other extensions. The first is a distributed IBVS framework to coordinate multiple agents using image-features and one distance measurement between any 2 agents in the formation, removing the need for magnetometers or global reference frames. The second is a robust MPC controller for tracking of time-varying trajectories considering additive and bounded noise on the system dynamics and safety of the agent. The thesis concludes with the main ideas provided in the manuscript, and sheds light on the possible future research directions that may spawn from this work. / <p>QC 20220224</p>