We grow epitaxial graphene on 6H-SiC (0001) substrates in Ar background and intercalatehydrogen to reform the carbon bu↵er layer into single and multilayered graphene. We willanalyze the graphene using a combination of techniques including optical microscopy,micro-Raman spectroscopy, Atomic Force Microscopy (AFM), and reflectance mappingand contactless measurements of sheet carrier density and charge carrier mobility. We havestudied in detail, the influence of growth parameters and in-situ surface preparation ofsubstrate on the thickness uniformity and surface morphology of graphene. Additionally,as-grown graphene layers were intercalated with H to obtain quasi-free standing layers ofgraphene with enhanced charge carrier mobility.

As a promising field, the development of smart grid has drawn more and more attention from many countries. A smart meter plays a significant role in a smart grid. It replaces the traditional electricity meter with the ability to frequently transmit instantaneous energy consumptions of the consumer to theenergy provider of the smart grid. From the view of electricity suppliers, it isbeneficial for planning, controlling and billing. However, from consumers’ perspective, the high-resolution energy record may lead to privacy problem, which means the consumers’ behaviour can be revealed by analysing the smart meter readings. In this thesis project, we will focus on the privacy leakage problem of the smart meter. We study the problem of optimal privacy-cost trade-off in a smart grid equipped with an energy provider, an alternative energy source, a smart meter,and an energy control unit. The privacy leakage is modelled as unauthorized detections of the consumer’s behaviours based on the smart meter readings of energy supplies from the energy provider. The control strategy is designed to manage the energy inflows to satisfy the instantaneous energy demands of the consumer and also to optimally trade off the privacy risk and energy cost. To evaluate the privacy risk, we use a Bayesian detection-operational privacy metric. Different scenarios are considered for which we show that their optimization problems can be reduced to linear programmings. Therefore, based on this observation, we propose optimal control strategy design algorithms to solve the optimization problems efficiently. / Inom ett potentiellt område, har utvecklingen av smarta elnät dragit mer och mer uppmärksamhet från många länder. En smart elmätare spelar en signifikant roll i ett smart elnät. Den ersätter den traditionella elmätaren med förmågan att ofta överföra den momentana energiförbrukning som konsumenten mottar av energileverantören av smarta elnät. Från elleverantörens sida, är det fördelaktigt för planering, styrning och fakturering. Men från konsumenternas perspektiv kan den högupplösta energiförbrukningen leda till integritetsproblem, vilket innebär att konsumenternas beteende kan avslöjas genom att analysera de smarta mätaravläsningarna. I detta projekt kommer vi fokusera på integritetsproblemen som dessa mätare ger upphov till. Vi studerar problemet med att balansera integritetsproblemeti ett smart elnät bestående av en energileverantör, en alternativ energikälla, ensmart mätare, och en energistyrenhet. Den personliga integriteten äventyras dåen obehörig kan få tillgång till konsumentens beteende baserat på de smartamätvärdena av energiförbrukningen från energileverantören. Kontrollstrateginär utformad för att hantera energiinflödet för att tillfredsställa de momentanaenergibehov konsumenten har, och även för att optimalt avväga privatlivs riskoch energikostnader. För att utvärdera den personliga integriteten risk, an-vänder vi en Bayesiansk upptäckt dvs. operativ integritets uträkning. Olikascenarier beaktas och deras optimeringsproblem kan reduceras till linjära pro-grammeringar. Baserat på observationen är motsvarande kontrollstrategi meddesignade algoritmer att föredra.

In the reliability analysis community Bayesian Networks have gained increasedinterest and is a eld of research also in the automotive industry company ScaniaCV AB. At Scania, testing of requirements is widely used to ensure functionalityand safety for vehicles. Sometimes testing of a requirement does not exploreall of its possible behaviours and at Scania it is desired to guarantee that allrequired behaviors hold. To estimate the quotient of required behaviours thathold based on testing, a method using Bayesian Networks is proposed in thisthesis to estimate this quotient. It provides a novel framework for modellingrequirements in a hierarchical structure that calculates an estimate of the quotientof required behaviors that hold. Graphs created with the method visualizeswhich requirements that aects the quotient the most.1

Silicon-germanium (SiGe) thermoelectric material is especially suited in power generation operating above 700 °C to 1000 °C to convert heat into electricity. Traditional bulk SiGe alloy thermoelectric materials has the value of dimensionless thermoelectric figure of merit (ZT) at maximum about 0.93 at 900 °C. It corresponds to 8% highest device efficiency to convert heat into electricity for commercial SiGe thermoelectric devices. Recently, many efforts have been made to increase the ZT value of SiGe thermoelectric materials. Among them, nanostructuring of SiGe alloy is an effective mechanism to enhance the ZT value of the thermoelectric material. In this approach, the ZT value increases due to the reduction of thermal conductivity caused by enhanced phonon scattering off the increased density of nanograin boundaries. There are different approaches to make nanostructured SiGe alloy bulk thermoelectric materials. Mechanical alloying of elemental Si and Ge powder is one of them. In this thesis work, different compositions of elemental Si and Ge micro powders have been mechanically alloyed using ball milling technique to produce SiGe alloy nanopowder and then were compacted and sintered by spark plasma sintering (SPS) method. Different characterization techniques have been used to see the effect of compositions, milling parameters and sintering conditions on the properties of the synthesized nanopowders and sintered compact samples.

In the recent power system expansion driven by growing energy demand, more attention is beingput towards integration of large-scale renewable resources. The HVDC transmission system on topof, or in complement to, existing AC power has been considered as a relevant solution for integratingremote energy resources as well as cross-border power trading. This thesis considers an approachwhere more than two HVDC stations are connected in the DC side to form a meshed HVDC grid.In an HVDC grid, the real-time mismatch of power injection can be compensated by the DC voltagecontrolling converter(s). Similar to frequency in the AC grid, the DC voltage deviation is a localindication of power mismatch in an HVDC grid. The capability of a converter to control DC voltageand contribute in power sharing impacts the secure operation of an HVDC grid. The selection ofDC voltage controlling station becomes even more critical when a present DC voltage controllingstation is tripped and the system operator has to assign a new one.This thesis proposes a real-time quantitative evaluation of HVDC converters in an HVDC gridto select the proper DC slack converter. This real-time evaluation considers the strength of theconnecting AC grid as well as the converter's on-line capacity margin as the selection metrics.Strength of the AC grid is evaluated in real-time by estimation of grid Short Circuit Capacity(SCC). Low computational requirement, low operational complication and acceptable accuracy ofestimated parameters have been considered as performance metrics for the selection of a suitablealgorithm. This thesis shows that the Recursive Least Square (RLS) algorithm can be very ecientlyused for the real-time estimation of SCC.The concept of on-line ranking of the converter's capability in controlling DC voltage has beenevaluated through dierent scenarios for the CIGRE B4 DC grid test system. To evaluate theperformance of the concept, a real-time co-simulation platform has been used to mimic the aspectsof the system. This platform includes OPAL-RT to model the power system, ABB's industrialHVDC controllers and corresponding ICT (Information and Communication Technology) systems.The results show that the proper selection of the slack station can improve the AC system responseand DC voltage drops during the disturbances. / En vaxande efterfragan pa elektrisk energi har bland annat medfort okade krav pa integreringav fornyelsebar energi i dagens elkraftsystem. Som komplement till det bentliga vaxelstromsnatetbetraktas HVDC-nat som en attraktiv losning for bade integrering av fornyelsebar energi och forgransoverskridande elhandel. Detta examensarbete studerar ett fall dar er an tva HVDC-stationerar anslutna pa likspanningssidan i ett HVDC-nat. Likt frekvensen i ett vaxelstromsnat arlikspanningen i ett HVDC-nat ett matt pa natets eektobalans. I ett HVDC-nat kan denna obalanskompenseras till exempel genom att styra nagon eller nagra av omriktarstationerna. Valet av vilkenstation som ska styra likspanningen blir an mer kritiskt da en station med den rollen kopplas bortoch systemoperatoren tvingas utse en ny.Detta examensarbete foreslar en kvantitativ realtidsutvardering av omriktare i ett HVDC-nati syfte att valja den station som ska kontrollera likspanningen. Realtidsutvarderingen anvanderkortslutningseekten, dvs. styrkan, hos de anslutna vaxelstromsnaten samt omriktarnaskapacitetsmarginal som urvalsparametrar. Val av lamplig algoritm har gjorts utifran kriteriersasom laga berakningskrav, lag komplexitet och acceptabel noggrannhet av beraknade parametrar.Resultaten visar att den rekursiva minsta kvadratmetoden (eng. RLS) kan vara mycket eektiv foratt i realtid uppskatta kortslutningseekten.Konceptet att ranka omriktarnas formaga att kontrollera likspanningen har utvarderats genomolika scenarier i testsystemet CIGRE B4 som bland annat innehaller HVDC-nat med eraomriktare. For att utvardera konceptets prestanda har en realtidsplattform anvants for attmodellera relevanta delar hos systemet. Denna plattform inkluderar realtidssimulatorn OPAL-RT forkraftsystemet och ABBs industriella styrsystem MACH for HVDC med tillhorande informations- ochkommunikationsutrustning. Resultatet visar att korrekt val av station for reglering av likspanningenkan forbattra vaxelstromssystemets respons saval som minimera HVDC-natets likspanningsfall dastorningar intraar.

En viktig faktor for att fortsatta forbattra traksakerheten ar genom att utveckla ochimplementera avancerade forarstodsfunktioner (ADAS) i fordon. Gemensamma aspekterhos de undersokta ADAS ar deras formagor att detektera och undvika farliga traksituationergenom att nyttja sensordata och fordonstillstand for att kontrollera fordonetsforyttning. Nya testmetoder maste overvagas eftersom nyutvecklade ADAS ar mer komplexaoch sakerhetskritiska. Detta arbete undersoker hur man kan testa nya ADAS fran etthelfordonsperspektiv, genom att bland annat ta hansyn till aspekter sasom lampliga testomgivningaroch trakscenarier, och darefter jamfora resultaten med nuvarande testmetoder.Olika typer av ADAS klassikationer har undersokts och kombinerat med egna komplexitetsoch traksakerhets klassikationer har gjort det mojligt att dra slutsatser och foreslagenerella teststrategier for olika ADAS. / A key factor to further improve road safety is the development and implementation ofAdvanced Driver Assistance Systems (ADAS) in vehicles. Common aspects of the investigatedADAS' are their abilities of detecting and avoiding hazardous trac situations byusing sensor data and vehicle states in order to control the movement. As more complex andsafety critical ADAS are developed, new test methods have to be considered. This thesisinvestigate how to test new ADAS from a complete vehicle level by considering aspects suchas suitable test environments and trac scenarios, and thereafter compare the results withexisting testing methods. Dierent classications of ADAS have been investigated and combinedwith own classications considering complexity and trac safety aspects, have madeit possible to conclude and propose general test strategies for dierent ADAS.

Biosensing is currently a growing research field which is relevant for different applications, for instance in health care. Sensitive and cheap biosensors are required, preferably as simple as possible in their working principle. In this work Si nanopillar structures have been fabricated and used to show the sensing principle by both depositing oxide layers with different thicknesses and by using the biotinstreptavidin model system. Si nanopillars were fabricated by two different surface patterning methods – colloidal lithography and nanoimprint lithography (obtained from a commercial source). For colloidal lithography, a modified drop-coating technique as well as a spin-coating technique is used to make self-assembled silicon dioxide (SiO2) monolayers. It is shown that SiO2 particles with sizes of 0.5 μm and 1.0 μm form even monolayers across areas of ~2 mm2 (sufficient for optical measurements) after optimizing the spin-coating parameters. Particle size reduction is done by using reactive ion etching (RIE) and nanopillars with heights of 1.0 μm to 1.5 μm are etched by inductively coupled plasma RIE (ICP RIE). Spectrally resolved reflectance from the nanopillar arrays, often show distinct reflectance peaks. Depending on the nanopillar geometry, the wavelength position of the reflectance peaks can be sensitive to changes in the refractive index at the nanopillar surface, for example by attached bio-molecules or by a thin dielectric (e.g. silicon-di-oxide) surface layer. In order to simulate the effect of a surface-bio layer on the optical properties of the nanopillar arrays, silicon-di-oxide coated Si nanopillars were investigated experimentally and theoretically. The simulated reflectance spectra, obtained by Lumerical FDTD, show that the spectral shifts of the reflectance peaks grow linearly with the layer thickness. The deposition of the oxide layers is done by plasma-enhanced chemical vapor deposition (PECVD). While this technique is reliable for planar surfaces, pillar structures showed both a much reduced side-wall oxide thickness as well as oxide pile-up on the top of the pillars. However, by thermally driven material reflow it was possible, though not completely, to redistribute the piled-up oxide from the pillar top to the sidewalls. Reflectance from Si nanopillar structures was investigated primarily using UV-vis-NIR spectrophotometer. However, ellipsometry and Fourier transform infrared spectroscopy were also used for comparison. The experimental results of the oxide layer deposition on Si nanopillars show a maximum spectral shift of 4.6 nm per every 10 nm of deposited SiO2. 3 Moreover, the obtained linear behavior of the spectral shift with oxide thickness is similar to the simulated one. In order to use the biotin-streptavidin model system to demonstrate the sensing principle with Si nanopillar structures, a surface functionalization protocol was optimized on the planar SiO2 coated Si surface. As it turns out, both an anhydrous environment and water presence during the surface silanization prior to biotinilation are acceptable and lead to similar results. Further work is necessary for effective surface functionalization of nanopillars. However, preliminary investigations of (test structures) nanopillar arrays surface functionalized by biotinstreptavidin showed spectral shifts. The sensitivity was not sufficient to perform a full assay. Optimization of the nanopillar geometry for high surface sensitivity as well as improvement in the surface functionalization process are required to produce a sensitive biosensor.

The rise of large scale integration has resulted in large number of processing elements/cores on a single ASIC. Thus an efficient interconnect scheme between the different processing elements and interfaces is required. Bus based interconnect poses problems such as non-scalability. This thesis explores the Network-on-Chip (NOC) as a global interconnect scheme on a state of the art ASIC. Different On-chip interconnect techniques proposed by the academia/industry are summarized and Design space exploration of NOC schemes is performed. A Network-on-Chip interconnect, primarily utilized for short messaging service between the processing elements/nodes in the ASIC, is designed for Ericsson ASICs. Practical ASIC design issues such as non-uniform network topology (irregular mesh) and performance immunity of interconnect due to variations in the floorplan are addressed in the NOC design. The proposed Network-on-chip interconnect for Ericsson ASICs is evaluated in terms of varying traffic models, routing algorithms, NOC router FIFO depths and floor plans. The SystemC cycle accurate performance results of NOC are compared with the currently implemented Bus based solution for the Ericsson ASIC.

In this thesis data taken by the EISCAT Svalbard Radar during the International PolarYear have been analyzed. The radar data have been searched for anomalous radarechoes. These radar echoes appear in an altitude range between 200 and 300 km, showa strong enhancement of the backscattered power and are limited in altitude to tensof kilometers. These anomalous radar echoes also show a distinct zero Doppler shiftedpeak in the ion line spectrum. The power prole of the data have been visually inspectedto identify the anomalies. The data have then been analyzed using a Matlab programcalled GUISDAP in order to get basic plasma parameters. It has been found that thereis a high occurrence of these anomalies during particle precipitation and at a certainE-region electron density peak more than 40 % of the data contains these anomalies.

As far as the Printed Circuit Boards (PCB) manufacture industry is concerned, for high production volumes, solder paste is applied on the connection pads through customized stencils. This is a very productive method, yet if the design has to be updated, cost is increasing as the stencil should be changed. For higher exibility, such as in rapid prototyping, jet-printing machines similar to Mycronic MY500 are used. In these equipments, solder paste is jet-printed on the circuit board. The shooting is done by a piston moving on the vertical axis at high speed, hence projecting solder paste onto the connection pads of the PCB. In order to improve the understanding of the jetting process, it is important to collect data on pressure uctuations in the jetting head. To do so, this project is using a strain gauge to sense the strain applied by the piston on the nozzle. The gauge is connected in a Wheatstone bridge, and the differential signal is extracted and amplified a first time with an instrumentation amplifier. The remaining amplification is then performed with the help of an operational amplifier so that the signal matches the Analog to Digital Converter (ADC) levels. Finally, the converted results are transmitted to a personal computer for further analysis.