uu.seUppsala University Publications
Change search
Refine search result
12 1 - 50 of 68
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Ahl, Philip
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Johansson Norman, Simon
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Projekt inom framkopplat aktivt brusreduceringssystem2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 2. Ahlgren Peters, Adam
    et al.
    Söderholm, Robin
    Wahlmark, Rickard
    Analog gitarrförstärkare: med rörliknande egenskaper2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 3. Andersson, Hjalmar
    et al.
    Zdansky Cottle, Leo
    Claesson, Melker
    Karlsson, Nils
    Stenhammar, Oscar
    Insamling av drift- och produktionsdata från energiteknik vid Ihus anläggning på Vaksala-Eke2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    För att minska den globala uppvärmningen bär utbyggnaden av förnybar energiproduktion en stor vikt i dagens samhälle. Av den anledningen är det av stor betydelse som nya tekniker för energiproduktion testas. För att undersöka huruvida dessa tekniker är effektiva och lönsamma är det viktigt att deras produktionsdata publiceras och görs tillgänglig för allmänheten. Det är anledningen till att det här projektet beställts från Ihus via STUNS energi.

    Projektidén var att samla in högfrekvent uppmätt produktionsdata från en soltracker, ett vindkraftverk och ett batterilager. Dessutom skulle väderdata samlas från en väderstation och solinstrålningsmätare för att sedan offentliggöra datan via STUNS Energiportal.

    För genomförandet av projektet användes en enklare dator för att ta emot information från olika sensorer. För att kommunicera med enheterna användes olika standardiserade kommunikationsprotokoll. Enheterna konfigurerades och kopplades in i datorn. Den insamlade datan bearbetades med en programmerad kod. Programmet sände iväg datan till en molnlagringsplattform för att sedan publicera den.

    Uppkoppling mot soltrackerns växelriktare samt pyranometern lyckades. Den insamlade informationen från de två enheterna publicerades sedan på Energiportalen. Väderstationen producerade data men kommunikation med det ursprungligt tänkta protokollet lyckades inte att upprättas. Genom ett annat protokoll erhölls värden, men inte genom den implementerade koden. Dessutom uppstod problem med batterilagret och vindkraftverket. Ingen information lyckades hämtas från någon av dem.

    I projektets gång har det samlats in mätpunkter var femte sekund för respektive enhet. Utifrån det erhållna resultatet kan de konstateras att vid högfrekvent insamling av väder- och produktionsdata, blir viktig information tydligare för vardera energiproduktionsenhet. Denna information kan gå förlorad vid lågfrekvent datainsamling. Det beror på vädrets hastiga fluktuation. En lågfrekventare datainsamling ger således en sämre uppfattning av hur värdena egentligen ändras med tiden.

  • 4. Andersson, Ludvig
    et al.
    Rasouli, Karwan
    Modeling fuel ion orbits during sawtooth instabilities in fusion plasmas2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    An important part of the fusion research program is to understand and control the large number of plasma instabilities that a fusion plasma can exhibit. One such instability is known as the “sawtooth” instability, which is a perturbation in the plasma electric and magnetic fields that manifests itself as periodic relaxations of the temperature and density in the plasma center.

    The aim of this project was to investigate how the fuel ions in a fusion plasma react to the sawtooth instability.

    We were able to implement a model of the plasma electromagnetic field during a sawtooth relaxation into an existing code that computes the orbits of the fuel ions in the tokamak magnetic field. To this end, it was necessary to modify the orbit code to allow for non-zero electric fields, and for time-varying fields. In order to validate the new additions to the code, we compared simulated results to analytical ones.

    The model of the sawtooth electromagnetic fields required for our simulations was set up within a different student project. However, due to unforeseen complications, only the magnetic (not the electric) field contribution was available to us during our project, but once the electric field is available it is straightforward to include in our code.

    Our simulations did not exhibit any noticeable perturbation to the particle orbit during a sawtooth crash. However, before the electric field contribution is included it is not possible to draw any physics conclusions from these results. Our code could also be used as a foundation for future projects since it is possible (with further implementations to the existing code) to simulate how the spatial profile of the neutron emission is expected to vary during the sawtooth. These simulations can be compared against experimental measurements of the neutron emission profile in order to investigate the accuracy of the sawtooth model under consideration.

  • 5.
    Andersson, Melanie
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Maja, Arvola
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Hedar, Sara
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Sketch Classification with Neural Networks: A Comparative Study of CNN and RNN on the Quick, Draw! data set2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of the study is to apply and compare the performance of two different types of neural networks on the Quick, Draw! dataset and from this determine whether interpreting the sketches as sequences gives a higher accuracy than interpreting them as pixels. The two types of networks constructed were a recurrent neural network (RNN) and a convolutional neural network (CNN). The networks were optimised and the final architectures included five layers. The final evaluation accuracy achieved was 94.2% and 92.3% respectively, leading to the conclusion that the sequential interpretation of the Quick, Draw! dataset is favourable.

  • 6.
    Andreasson, Joel
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Design och konstruktion av distorsionseffekt för gitarrer2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This project has been done as a part of a bachelors degree in engineering at Uppsala university. The project was supervised by Jörgen Olsson at the division of solid state electronics.

    The goal of this project was to develop a distortion effect that can be used with an guitar and a amplifier. The effect was to have controllable distorsion, volume and tone control including bass and treble. The circuit is also supposed to be run using a 9V battery as power supply, which means that the in circuit currents shold be low. When the circuit was finished it was also analyzed through different measurements and simulations.

    The distortion of the circuit was achieved using diodes to get a nonlinear amplification. The goals of the circuit controls was achieved, and although a low circuit current was achieved, it only satisfied the goal of 1 mA when high distorsion was set for the circuit.

    When measuring and simulating the system, some major differences was found. The simulated frequency response characteristics was found to be very different from the measured. This is likely due to the simulation program not being

  • 7. Bagher Nori, Mohammad
    et al.
    Husseini, Majid
    Jafari, Taqi
    Mätning av radioaktivitet med fokus på ytkontamination2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

     This project is a part of the radiological characterization of the Gamma hall and the Radiochemistry laboratory (RKL) at The Svedberg laboratory. Measurements of surface contamination in both premises have been done by taking wipe-test samples from the floors and walls in the two rooms.

    A 3D model of both premises has been designed in MATLAB. The model shows the distribution of the measurement points and their contamination values on the floors and walls in these premises.

    Measurements of the surface contamination were done with two different methods. The results of the measurements do not indicate any contamination in the Gamma hall. In the Radiochemistry laboratory small amount of the contamination has been detected mostly on the floor.

  • 8.
    Bengtsson, Jenny
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Nykvist, Filip
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Ljung, Alvin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Internet of Things: Uppkopplade sensorer med Raspberry Pi2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I detta projekt, som gjorts på uppdrag av IoT Sverige, har en produkt skapats åt derasDemorum för att visa hur Internet of Things fungerar och vad man kan använda dettill. Rapporten beskriver hur arbetet har utformats fram till den färdiga produktensom, utifrån deras önskemål, består av en koldioxid- och en rörelsesensor koppladetill en enkortsdator. Med hjälp av kodade skript skickas den insamlade datan till enserver placerad på ett så kallat moln. I grafer på en hemsida kan man därefter se datan illustrativt och det enda man då behöver är en dator med internetuppkoppling.

  • 9.
    Berendt, Gustaf
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Solceller på Kungliga Slottets i Stockholm tak: En symbolisk vägledning till hållbar utveckling2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A study has been conducted to determine whether it is possible to install solar panels on the roof of the Royal Palace of Stockholm. Simulations have been performed using physical models of the motion of the sun in Stockholm, solar panel angular dependence and atmospheric effects. Moreover, interviews with representatives from involved parties and gathering of market data have been conducted in order to understand what economical, antiquarian, legal, political and technical obstacles may be encountered and what is required for the installation of solar panels.

    Results show that a maximized solar plant on the roof of the Royal Palace of Stockholm, covering a total area of 4470 square meters would generate 500 MWh electricity annually. The electricity could be used to reduce the energy cost of operation leading to a decrease in electricity cost of approximately 675 000 SEK annually. An investment of 8 000 000 SEK is required according to market prices. Results indicate there are solutions to the antiquarian, legal, political and technical obstacles.

  • 10.
    Bergfors, Anund
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Using machine learning to identify the occurrence of changing air masses2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the forecast data post-processing at the Swedish Meteorological and Hydrological Institute (SMHI) a regular Kalman filter is used to debias the two meter air temperature forecast of the physical models by controlling towards air temperature observations. The Kalman filter however diverges when encountering greater nonlinearities in shifting weather patterns, and can only be manually reset when a new air mass has stabilized itself within its operating region. This project aimed to automate this process by means of a machine learning approach. The methodology was at its base supervised learning, by first algorithmically labelling the air mass shift occurrences in the data, followed by training a logistic regression model. Observational data from the latest twenty years of the Uppsala automatic meteorological station was used for the analysis.

    A simple pipeline for loading, labelling, training on and visualizing the data was built. As a work in progress the operating regime was more of a semi-supervised one - which also in the long run could be a necessary and fruitful strategy. Conclusively the logistic regression appeared to be quite able to handle and infer from the dynamics of air temperatures - albeit non-robustly tested - being able to correctly classify 77% of the labelled data.

    This work was presented at Uppsala University in June 1st of 2018, and later in June 20th at SMHI.

  • 11.
    Bjervig, Joel
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Slagbrand, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Thermal Imaging Platform for Drones: Cost-effective localization of forest fires2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A device for identifying forest fires in an early stage has been developed during the course of this project. Attached to a drone, this prototype will provide a live-stream to a web server displaying a blended frame, made of a thermographic image showing thermal radiation and a regular photography with the visible light. The platform consists of a small single-boarded computer, a thermal camera sensor and a regular camera module. All powered by a power bank and fitted into a custom made 3D printed plastic case. At startup the computer automatically executes scripts written in Python, initializing its sensor components and processes the captured images which finally gets transmitted to a live-stream via a web server connection. Everything described above worked well, but originally the intent was for the web interface to provide a map with the current location coordinates of the drone. Since a module for mobile communication with support for GPS was not acquired, any implementation of such kind was impossible. However, several drone models already possess the feature to obtain such coordinates.

  • 12.
    Björck, Olof
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics.
    Creating Interactive Visualizations for Twitter Datasets using D32018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Project Meme Evolution Programme (Project MEP) is a research program directed by Raazesh Sainudiin, Uppsala University, Sweden, that collects and analyzes datasets from Twitter. Twitter can be used to understand how ideas spread in social media. This project aims to produce interactive visualizations for datasets collected in Project MEP. Such interactive visualizations will facilitate exploratory data analysis in Project MEP. Several technologies had to be learned to produce the visualizations, most notably JavaScript, D3, and Scala. Three interactive visualizations were produced; one that allows for exploration of a Twitter user timeline and two that allows for exploration and understanding of a Twitter retweet network. The interactive visualizations are accessible as Scala functions and in a website developed in this project and uploaded to GitHub. The interactive visulizations contain some known bugs but they still allow for useful exploratory data analysis of Project MEP datasets and the project goal is therefore considered met.

  • 13. Bohlin, Johannes
    et al.
    Strandberg, Daniel
    Piven, Yegor
    Solcellspotential för Uppsalahem till år 20252019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna rapport undersöker bostadsbolaget Uppsalahems möjligheter att investera i solceller. Syftet med rapporten är att uppskatta Uppsalahems solcellspotential fram till år 2025 utifrån ett lönsamhetsperspektiv och besvara i vilken utsträckning Uppsalahem kan bidra till målet om 100MW installerad solenergieffekt till år 2030. Taken som utvärderas uppskattas med hjälp av en simulering baserad på LiDAR-data och en solcellsmodell konstrueras utifrån denna data. Solcellsmodellen valideras med andra kända beräkningsmodeller och en investerings lönsamhet uppskattas för olika scenarier baserat på Uppsalahems juridiska och ekonomiska förutsättningar vad gäller försäljning och inköp av el.

    Enligt lönsamhetsberäkningarna uppskattas 16 av 516 solcellssystem vara lönsamma i grundsscenariot som förmodas vara det mest sannolikascenariot att inträffa. Många solcellssystem är väldigt nära på att vara lönsamma i grundsscenariot och beroende på scenariot uppskattas upp till 300 solcellssystem vara lönsamma. Om solcellspotentialen uppskattas utan hänsyn till lönsamhet, estimeras Uppsalahem enligt solcellsmodellen kunna bygga solcellssystem som tillsammans har en installerad effekt på drygt 16MW, vilket är en relativt grov uppskattning med hög osäkerhet.

  • 14.
    Boholm Kylesten, Karl-Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, FREIA.
    Numerical methods for design of the transfer line of the ESSnuSB project: Independent Project in Engineering Physics2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    ESS neutrino Super Beam (ESSnuSB) is a project that aim to create ahigh energy beam of neutrinos and anti-neutrinos to study thephenomenon neutrino oscillation and learn more about symmetryviolations in quantum mechanics. To create the neutrino beam, negativeHydrogen ions must be transported from the ESS linear accelerator at2.5 GeV, to a proton accumulation ring. This is done through a transferline, that shall direct the ion beam while preserve the beam as much aspossible. In thisproject, there was an attempt at finding a design for this transferline. Preferably, the line consists of a long main line of FODO cellsand two matching sections at each end. A simulation of the beam wasdone that gives the progression beta and dispersion functions,statistical measurements of the particle distribution, through a partof the transfer line. A design for the main line was found. For tuningthe quadrupole magnets, an iterative method using the system's responsematrix was used. However, it could not match more than four parametersat the time, while six was required for complete matching. Because ofthis, it is not able to match thedispersion.

  • 15.
    Brynolf, Max
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Sengupta, Rohini
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Magneto-Plasmonic Gold & Nickel Core-Shell Structures2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The presented project explores the optical properties of magnetoplasmonic Au/Ni core-shell structures. The work aims at controlling dimensions and parameters in order to influence and analyze the optical properties of the nanostructures. The softwares utilized for the simulations were COMSOL Multiphysics 5.1 and MATLAB. Experimental results were acquired from labs done at Ångströms laboratory. From the research based study where the gold to nickel ratio was influenced, it was observed that the transmissions for the nanostructures at the differing wavelengths produced transmissions of similar bearings. Modes for certain wavelengths were found in correspondence with the transmissions and could potentially render explanations for influence on the optical properties of the nanostructures. Conclusively, it can be stated that the optical properties of the nanostructures could be influenced and controlled by varying the dimensions and properties of the said structure. Differing dimensions corresponded to noteworthy changes in the cross sections, the transmissions as well as the mode formations.

  • 16.
    Brännström, Elin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Eric, Pettersson
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Kategorisering och kvantifiering av ärenden för att optimera samt lokalisera tidsåtgång för SAP-supportgruppen på ABB Robotics.2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

     I detta projekt har en undersökning relaterad till tidsåtgång för inkommande

    ärenden gjorts inom SAP-supportgruppen på ABB Robotics i Västerås. Syftet med

    studien har varit att skapa ett verktyg i form av en algoritm som estimerar

    tidsåtgången för inkommande ärenden. Genom intervjuer med SAP-supportgruppen

    samt tillgång till en databas med historiska ärenden kunde olika kategoriseringar

    och parametrar sättas upp. Varje ärende ansågs dels ha en återkommande tid som

    inte antogs variera beroende på ärendetyp, men även en varierande del som består

    av det beredningsarbete som SAP-supportgruppen utför. För kvantifiering av

    beredningsarbetet behandlades tre olika metoder.

    Det bästa resultatet erhölls då beredningsarbetet kvantifierades med hänsyn till

    antal beredningsnivåer. Kvantifiering då hänsyn togs till arbete per beredningsnivå

    stämde dåligt överens med de uppskattade tiderna. Denna kvantifiering innehåller

    huruvida mest information och bör vara den som utvecklas vidare. Anledningen till

    det försämrade resultatet anses bero på felaktigheter i modellen samt

    noggrannheten i det historiska underlaget.

    Studien har visat att kvantifiering och kategorisering av ärenden är möjligt men

    problematiskt. Vidare implementation och förändring i modellen av algoritmen

    kommer göra det möjligt att i fortsättningen estimera tid för inkommande ärenden.

  • 17. Dahlgren, David
    et al.
    Mehic, Amela
    Non-Thermal Modeling Of Energy Propagation Carried By Phonons and Magnons2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Heat transport by phonons and magnons in crystals due to a local perturbation in temperature is described by the Boltzmann transport equation. In this project a one phonon one magnon system was studied in a one dimensional rod with reflective boundaries. Using the splitting algorithm the problem was reduced to a transport and collision term. The resulting stabilization time for a initial phonon and magnon distribution and the respective temperatures at equilibrium was calculated. This study shows how energy propagates in crysials and gives further understanding of how the coupling of phonons and magnons affect heat transport.

  • 18. Edin, Martin
    et al.
    Erlanson, Nils
    Mathematical modeling of interactions between colonic crypts.2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 19. Emadi, Milad
    et al.
    Tynelius, Sofia
    Beas Peterson, Patric
    Ljung, Johnny
    Design of an X-ray transfer beamline for the Soft X-ray project at MAX IV2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    At the MAX-IV lab in Lund, there is a current goal to build a new soft X-Ray laser. The beam will be generated from a free-electron laser (FEL), which is an instrument consisting of high-speed electrons. The electrons move through alternating magnetic fields, causing the beam to become monochromatic. After the FEL, the Xrays will enter a beamline consisting of different optical components, such as mirrors, gratings and slits. This project investigated the necessary parameter values of the components, in order for the new X-Ray laser to focus the beam enough. The project consisted of a theoretical part and a simulation part. The use of so-called Kirkpatrick-Baez mirrors enables the beam to be very focused. The best focus achieved was 7.23um*10.87um for ''Pink beamline'' and the intensity at the end was 71.5%, which meant that only 30% of the rays were lost. For the monochromatic beamline, a loss of intensity is inevitable. With a pair of KBmirrors, this beam was focused to be 6.95um*9.80um. The energy spread is ranging from 6.198 eV to 0.3442 eV. The analytical calculations for the spot size matched well with the simulations. The pink beamline which was built in Ray satisfied the criterias of a spot size and intensity loss. The monochromatic beamline did fullfil the criterias of spot size and narrowing the energy spread. A loss of intensity will for this beamline be inevitable. Studying the misalignment effect showed that the components were most sensitive for vertical misalignment. The most sensitive parameters were the curvature of the mirrors.

  • 20.
    Engstrand, Johan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Kavathatzopoulos, Niklas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Nordenholm, Jonathan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Simulation and Construction of a Half-Bridge Class D Audio Amplifier2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Usage of class D audio amplifiers has become increasingly widespread in recent years, mainly due to their high efficiency, which can reach almost 100 %. Class D amplifiers can also be compact, making them suitable for mobile applications. In contrast, the most efficient conventional amplifiers such as class B can reach a maximum efficiency of 78.5 %. The high efficiency of class D amplifiers can be attributed to the switching stage, which in the case of a half-bridge design consists of two amplifying MOSFETs. These MOSFETs are never on at the same time, which minimizes the quiescent current and thereby the power losses. The goal of this project was to design, simulate and construct a half-bridge class D audio amplifier. A working amplifier with 80 % efficiency was built, with power losses occuring mainly in the voltage regulators. Simulations of the amplifier corresponded well with the constructed amplifier apart from issues originating from the aforementioned voltage regulation as well as the triangle wave generator. The goal of the project was achieved and the finished amplifier possessed good sound quality and little unwanted noise. To further improve on the design, better voltage regulation, a full-bridge configuration and a feedback loop could be utilized.

  • 21. Gillgren, Andreas
    Analysis of spatial subdomains in the Generalized Weighted Residual Method: Optimization of the distribution of spatial subdomains in one spatial dimension2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Generalized Weighted Residual Method (GWRM) is a recently developed time- spectral method for parabolic or hyperbolic initial-value partial differential equations. In this paper, spatial subdomains, used in this method, are analyzed. Subdomains are used to enhance efficiency by dividing entire domains into smaller parts that can be independently solved for and then combined to get the final solution.

    An automatic grid mapping algorithm for spatial subdomains, called "Compressive Method", is presented and applied to Burgers' viscous equation. The error of the solution, as compared to the analytic solution, is compared for this compressive Method and the uniform grid case. Results show that accuracy can be gained at a small extra cost, using this compressive Method. Conclusions are that this adaptive algorithm shows great potential for further development. 

  • 22.
    Hajjar, Gabriel
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Design and construction of a photoplotter: Building a device for rapid prototyping of PCBs2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The goal was to build a machine that could rapidly prototype PCBs using a moving light source and photoresist. The project failed, as the UV light did not make it through the lenses used to concentrate it. Better lenses and a laser would allow it to function better.

  • 23.
    Hariharan, Venkataraman
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    THE EFFECT OF EDDY CURRENT ON THE MAGNETIC INDUCTANCE OF SYNCHRONOUS MACHINE WITH LARGE POLES2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The project deals with both experimental and simulation analysis of the synchronous machine. The effect of Eddy currents on the impedance is verified experimentally. A core set-up is designed and analysed for the influence of Eddy current in the system. The set-up is altered to reduce the effect of Eddy current and to validate the effect of it on the magnetic inductance.

  • 24.
    Hedberg, Karolina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Homman, Rebecka
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Konstruktion av EMC-skanner med CoreXY-teknik2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    En god elektromagnetisk kompatibilitet (EMC) är en viktig faktor vid konstruktion av kretskort. EMC syftar på ett systems kompatibilitet med sin omgivning och en god EMC innefattar att ett elektriskt system inte interfererar med sig själv eller närliggande system. Kartläggning av EMC kan göras med en EMC-skanner vilken mäter det elektromagnetiska närfältet kring ett mätobjekt. Målet med det här projektet är att konstruera en EMC-skanner vars rörelsemekanism är baserad på CoreXY-teknik. Långsiktigt är målet att skannern ska kunna användas för att skapa 3D-kartor av EMC:n hos kretskort.

    EMC-skannerns mekaniska konstruktion utgick från en design från den digitala plattformen Thingiverse och bestod av aluminiumprofil och delar utskrivna med 3D-skrivare. För mätningar av det elektriska respektive magnetiska närfältet användes en närfältsprob. Rörelsen hos EMC-skannern styrdes av ett styrkort bestående av en Arduino och en RAMPS 1.4 med tre stegmotordrivare. Projektets arbetsgång bestod i att finna en lämplig design av skannern, skriva ut delar med 3D-skrivare, montera skannern, koppla och programmera komponenter för EMC-skannerns styrning samt att utföra en enklare provmätning. Slutprodukten blev en EMC-skanner med fungerande rörelser i x-, y- och z-led och vars rörelsemekanism i xy-planet baserats på CoreXY-teknik. Provmätningar visade att skannern kan användas för att mäta elektriska och magnetiska närfält från ett plant mätobjekt förutsatt att närfältsproben placeras tillräckligt nära detta. För att effektivt kunna använda EMC-skannern för att utföra mätningar på kretskort krävs vidareutveckling främst av skannerns styrning.   

  • 25.
    Hellmers, Robin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Boström, Viktor
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Konstruktion och reglering av inverterad pendel2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med projektet är att konstruera en inverterad pendel som sedan med hjälp av reglertekniska metoder ska stabiliseras. De linjära regulatorer som prövats är Proportionell, Integrerande och Deriverande (PID) -regulatorn och Linnear Quadratic Gaussian (LQG) -regulatorn som båda är populära och beprövade i industrin. PID-regulatorn är den absolut mest använda regulatorn medan LQG-regulatorn är mer raffinerad och i vissa avseenden en optimal regulator. Regulatorerna programmerades in i mikrokontrollern Arduino Nano som skickar signaler till en motordrivare som styr den stegmotor som ska balansera pendeln. Mycket av arbetet har handlat om att skapa en uppställning som tillåter goda förutsättningar för att pröva regulatorerna. I uppställningen finns delar som utformats i Computor-Aided design (CAD) -verktyget OpenSCAD och skrivits ut på en 3D-skrivare. Den givare vi använt för att mäta pendelns vinkel är en potentiometer infäst i dessa 3D-utskrivna delar. Motorn kunde styras till sin maximala kapacitet och en uppställning har skapats. Dock skulle en starkare motor och en mer robust uppställning möjliggöra en avsevärt bättre reglering. Regulatorerna klarade inte av att stabilisera systemet mer än ett fåtal sekunder, detta bland annat pågrund av tidsbrist till att justera regleringsvariablerna.

  • 26.
    Hultmar, Oscar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Paulsson, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Sundell, Jonathan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Mechanical design and construction of solar panel experiment in stratospheric conditions2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This project will be a part of the LODESTAR experiment. LODESTAR is one of the experiments scheduled to fly on the REXUS/BEXUS 26 high altitude balloon flight. The primary objective of the experiment is to investigate the effects of cosmic radiation on CIGS solar cells. The objective of this project is to build a mechanical design that can fulfill all requirements set by the ESA user manual.

    The mechanical design will first be drawn in mechanical CAD, where the drawing will be constructed from the ESA requirements. Later the design will be simulated in order to choose appropriate materials and a design that can withstand all simulations. Lastly the design will be built according to the drawings and tested according to the simulations.

    The mechanical design withstood all the simulations and verification tests with no visual deformation, except for the simulation and verification of the drop test. Both the drop simulation and verification test resulted in deformation in one of the aluminium plates.

    Since this mechanical design is constructed to be used only once, small deformations is within the margin of error. The deformation resulted by the simulation and verification of the drop test matched with a high precision. This is a good confirmation of the results of the drop test.

    In conclusion, the executed tests gave very promising results. Therefor the design constructed fits all the requirements to travel with solar panels in stratospheric conditions.

  • 27.
    Ibstedt, Julia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Systems and Control.
    Rådahl, Elsa
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Systems and Control.
    Turesson, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Systems and Control.
    vande Voorde, Magdalena
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Systems and Control.
    Application and Further Development of TrueSkill™ Ranking in Sports2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of this study was to explore the ranking model TrueSkill™ developed by Microsoft, applying it on various sports and constructing extensions to the model. Two different inference methods for TrueSkill was constructed using Gibbs sampling and message passing. Additionally, the sequential method using Gibbs sampling was successfully extended into a batch method, in order to eliminate game order dependency and creating a fairer, although computationally heavier, ranking system. All methods were further implemented with extensions for taking home team advantage, score difference and finally a combination of the two into consideration. The methods were applied on football (Premier League), ice hockey (NHL), and tennis (ATP Tour) and evaluated on the accuracy of their predictions before each game. On football, the extensions improved the prediction accuracy from 55.79% to 58.95% for the sequential methods, while the vanilla Gibbs batch method reached the accuracy of 57.37%. Altogether, the extensions improved the performance of the vanilla methods when applied on all data sets. The home team advantage performed better than the score difference on both football and ice hockey, while the combination of the two reached the highest accuracy. The Gibbs batch method had the highest prediction accuracy on the vanilla model for all sports.

    The results of this study imply that TrueSkill could be considered a useful ranking model for other sports as well, especially if tuned and implemented with extensions suitable for the particular sport.

  • 28. Isaac, Andreas
    et al.
    Kakavandy, Shahow
    The earth trembles before cryptocurrencies; but how does a blokchain-based smart money platform perform?2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Swedish central bank has in 2018 launched an investigation into what a digital e-currency in Sweden would look like. Tendermint is being investigated for a potential implementation. Tendermint is a blockchain building environment which has its own consensus-algorithm, and its own solution to the Byzantine general's problem. The most relevant part is the scalability and reliability of Tendermint. To do this we tested out the software by sending transactions between our computers, and recorded its performance in the case of one node and two nodes. After a series of simulations, we then come to the conclusion that indeed Tendermint is a suitable software for a potential e-krona.

  • 29.
    Jonasson, Fredrik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Sparresäter, Björn
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Monte Carlo-simuleringar av germaniumdetektor för gammaspektroskopi2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med projektet är att undersöka en HPGe-detektors egenskaper med hjälp av Monte Carlo-simuleringar i simuleringskoden FLUKA. Resultaten från detta projekt ska sedan användas som underlag för en kartläggning där halten av den radioaktiva isotopen cesium-137 ska mätas på svampprover insamlade från hela landet. En rad simuleringar har gjorts med olika typer av strålningskällor och med variationer på detektorns geometri. Den detektor som ska användas för dessa mätningar är över 30 år gammal vilket kan medföra att vissa egenskaper kan ha förändrats med tiden. Resultaten från simuleringarna visar dock att eventuella förändringar är försumbara. En annan del av detektorns geometri, ett kylningshål i botten av germaniumkristallen, specificeras inte tydligt i produktspecifikationerna från tillverkaren. Även här visar dock simuleringarna att hålets storlek inte har någon större betydelse. Däremot visar simuleringarna, som förväntat, att detektorns effektivitet varierar beroende på strålningens energi och avståndet från strålningskällan.

  • 30.
    Kanestad, Linus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Andersson, Gustaf
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Hällgren, Karl-Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Monitoring Air Quality in Ångström Cleanroom Laboratory2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The air quality in the Ångström cleanroom was to be measured for monitoring and control purposes, with the measurements displayed on a website. To do this several sensors, micro controllers, means of communication, and ways to host the server were investigated. In the end the chosen components were the DHT12 sensor, Arduino Nano micro controllers, 433MHz LoRa modules for communication, and a Raspberry Pi for data aggregation and website hosting. Four edge nodes with sensors were placed in locations of interest and transmitted data to the central node that hosted the website. For the website a development methodology called AJAX was used to handle data, and the HTML canvas element was used to display data. The system as a whole met its requirements.

  • 31.
    Kellner, Oscar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Silverforsen, Kasper
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Application development for collecting and visualizing data from a portable sensor2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Our task was to produce a mobile application that could retrieve and visualize emission data from portable measurement sensors. The purpose of this project is to develop an user interface for the portable sensors since it has not been done before. The project is an opensource project. The project was made for Uppsala Municipality’s smart city project GreenIoT and the sensor we used was produced by UPWIS AB. The final product became a mobile application that was able to find and connect to the sensor via Wi-Fi Direct. The sensor sent measurement data to the phone which was shown on a map. Finally, the data was sent to a cloud. The mobile application was created in the program Android Studido and the programming language was Java. 

  • 32.
    Kindblom, Mikael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Abdeljawad, Raghid
    Agha Mohammadi, Sina
    Construction of a Powder Bed 3D Printer2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This project is part of a bigger project where the goal is to be able to create smaller batches of individually designed pills with a high resolution. This could be done by using a powder bed 3D printer, which our job was to find out. This type of machine prints out a thin pattern of binder through a printer head and then sweeps powder over the pattern, making the powder stick to the binder. This process is repeated until the object is formed. The machine necessary was created from scratch using a guide provided by the Internet.

    The results were unfortunately uncertain. We managed to print with ink and the pattern created had a high level of accuracy but due to time limitations, we never got to print with actual binder in the cartridge.

  • 33.
    Kiselman, Klara
    Atomic Physics division, Department of Physics, Stockholm University.
    Studies of Molecular Carbon Cluster Dianions in DESIREE2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Since the surprising first detection of small carbon cluster dianions by Compton et al 1990, several studies have been made investigating their structure, fragmentation pathways and stability. As other carbon anions have been found in space, it is likely that these dianions exists as well and their ability to react with other molecules is therefore of interest. Previous studies have shown that they may survive on microsecond timescales, but it is still an open question whether they are metastable or thermodynamically stable. Therefore, this study utilizes the cyrogenic storage ring DESIREE to investigate the lifetime and stability of carbon cluster dianions Cn(2-) (n=7-10) in the new domains. Dianions were produced with a cesium ion sputtering source and their spontaneous decay Cn(2-) -> Cn(-) + e- was monitored for almost 100 ms by detection of the singly charged decay products. Also, the extra electron's tunneling probability through the repulsive coloumb barrier for C8(2-) was calculated and the lifetime for different energy states was estimated. Analyzing the DESIREE data, the lifetime of the dianions could be determined to exceed the previous concluded lifetimes of 10 us by a whole order of magnitude. The only way to detect stable ions after that would be if they collided with rest gas and due to good vacuum, this eventual signal is too low. Probably due to varying structures, an alternating pattern was found, dianions with even n decaying slower than their odd neighbours. The fitting of power laws to the data is consistent with that the dianions were produced with a broad internal energy distribution. Calculations for C8(2-) indicated that its electron affinity had to be at least -1eV in order to agree with the experimental results. Continuing the investigations, future studies could, after sufficient time, use DESIREE in an alternative way, allowing detection of possible stable dianions.

  • 34. Land, Lukas
    Adaption of IP-stack for a microcontroller2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    An adjustment of the IP stack to a microcontroller has been attempted.The Ip stack manages IP traffic, which occurs through incomingoutgoing data packets, and these packets are attempted to be storedwith call buffers instead of current implementation. Programming wasdone in C, and a lot of time was spent looking through currently usedcode in order to better understand how it functioned. Data packetswere then sent from a computer to the microcontroller, and by printingout variable locations and sizes, an understaning of how the stackworked and were data were stored, could be reached.The project led to the insight that the project was more difficultthan first estimated, the reason being that much of the software wasbased on the handling of data packets. The project resulted in anincreased understanding of how the adaptation can be implemented, andhow the current stack actually works.

  • 35. Landbris, Maja
    et al.
    Thunqvist, Henrik
    Solcellers funktion, och effektiviteten beroende på dess geometri2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I denna rapport undersöks huruvida olika temperatur och resistans, men framför allt hur geometrier påverkar solcellers effektivitet och varför. Undersökningen har omfattat cylindriska, koniska och elliptiska solceller, och dessa har jämförts med en platt solcell som är optimalt vinklad. Undersökningen har gjorts genom simuleringar på en hemsida [1], där man framför allt tar hänsyn till tre olika parametrar. Den första är vädret, där man har samlat in väderdata under 10 år. Den andra är temperatur, vilken påverkar solcellens effektivitet. Den tredje parametern är platsens longitud och latitud, då det påverkar hur mycket solinstrålning som sker och därmed solcellens effektivitet. En laboration har genomförts för att undersöka solcellers temperaturberoende. Dess effektivitet reducerades markant då temperaturen ökade. Under samma laboration undersöktes även lastmotståndets inverkan på solcellers effektivitet, där det framgick att det har stor betydelse. Simuleringarna visade att en platt solcell genererar mer energi än alla andra alternativen som gåtts igenom, med en tydlig topp mitt på dagen. De andra geometriska formerna för en solcell kan generera energi under längre tid på dagen än en platt solcell och därmed ge en jämnare fördelning. Med tanke på dagens antingen för dyra ellerför dåligt presterande batterier kan andra former på solceller därför vara ett alternativ till platta. För att få en bra förståelse för hur solceller fungerar förklaras teorin bakom dem grundligt i rapporten.

  • 36.
    Langelaar, Johannes
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Signals and Systems Group.
    Strömme Mattsson, Adam
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Signals and Systems Group.
    Natvig, Filip
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Signals and Systems Group.
    Development of real time audio equalizer application using MATLAB App Designer2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This paper outlines the design of a high-precision graphic audio equalizer with digital filters in parallel, along with its implementation in MATLAB App Designer. The equalizer is comprised of 31 bands separated with a one-third octave frequency ratio, and its frequency response is controlled by 63 filters. Furthermore, the application can process audio signals, in real time, recorded by microphone and from audio files. While processing, it displays an FFT plot of the output sound, also in real time, equipped with a knob by which the refreshing pace can be adjusted. The actual frequency response proved to match the desired one accurately, but the matching is computationally demanding for the computer. An even higher accuracy would entail a computational complexity beyond the power of ordinary computers, and was thus concluded to be inappropriate. As a result, the final application manages to provide most laptops with both high precision and proper functionality.

  • 37.
    Laskar, Tasnim
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Determining shallow P-wave velocity and its engineering implication in Adama City, Ethiopia2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A great number of the urban areas in Ethiopia are situated within the Great Rift Valley of Ethiopia, a system consisting of depressions and large faults. As a region with significant seismic activities, it is vital that careful planning is implemented to avoid constructing buildings on flat surfaces as they can amplify ground motion in the case of an earthquake.

     

    This study was conducted in Adama, a city located within the rift system, to map and characterize the subsurface of a construction site with seismic refraction and investigate whether this is an optimal area to construct a building should an earthquake occur. Seismic refraction is based on Snell’s law, specifically the case of the critical angle, which is when the refracted angle is at 90 degrees and a number of the energy from the wave is rebounded back to the surface in accordance with Huygen’s Principle.    

     

    Seismic waves were generated with a sledgehammer and recorded with 24 vertical geophones. The acquired data was then analysed with SeisImager and produced a 2D-tomography of the site with the corresponding velocity layers for a P-wave. Comparing the P-wave velocities to a table of Seismic Velocities of Rocks and Various Materials, one could determine that the subsurface layers consisted of rock soils, sand and silt. These are incredibly loose materials that will amplify ground motion during earthquake crisis and are therefore not optimal or ideal for constructing buildings.

  • 38.
    Lindesvik Warma, Simon
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Elmgren, Felix
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Micrometer Gap Distance Dependence on Temperature Changes in a Large Electrode System2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this project is to verify if the so called capacitance method is a sensitive enough method to measure micrometer distance changes in an electrode system. This is done by heating up an electrode system to 60°C and make capacitance measurements during the procedure. With the inverse relationship between the capacitance and the distance between the surfaces the distance is attained. The incitement to find a sensitive measurement method is that in a particle accelerator the temperature is down to 4K and the components of an electrode system will contract which can lead to a breakdown of the system. The change in temperature gives a theoretical change in "gap distance" that is close to the measured change in gap distance, therefore the method is a reliable enough method to measure micrometer distance changes. A possible reason for the small deviation is that the measured temperature is the temperature of the surface of the electrode system. It would be preferable to measure the total temperature of the electrodes, not just the surfaces because it is the whole electrode that expands and contracts with the temperature. This could be done with an IR-camera.

  • 39. Lindgren, Andreas
    et al.
    Lind, Gustav
    Language Classification Using Neural Networks2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this project a model has been created that with an audio sequence as input can classify the language being spoken to be either english or french. The focus of the project has been to experiment with different ways to process audio files and to design a neural network in order to maximize the performance for the task of language classification. The purpose of the project was to investigate the highest reachable accuracy and to examine what sample length that would be appropriate in order to be useful in voice control application. The signal processing part dealt mainly with how enveloping, Mel frequency ceptral coefficients (MFCC) and Mel frequency spectral coefficients (MFSC) could be used to enhance the accuracy of the model. The neural network design focused on how the width and depth of the network and the use of dropouts could be used to increase the performance. The experiments resulted in a model with a maximum accuracy of 92,30 % that could outperform humans for samples of approximately 1,2 seconds of shorter. A suitable sample length to be usable in other applications was concluded to be in the interval of 0,7 to 1,5 seconds.

  • 40.