Blar i tittel Mastergradsoppgaver i teknologi - anvendt fysikk

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    • Laser Based Altimetry for Unmanned Aerial Vehicle Hovering Over a Snow Surface 

      Haugen, Hallvard (Master thesis; Mastergradsoppgave, 2017-06-02)
      A microwave radar for non-invasive snow stratigraphy measurements has been developed. Results were promising, but it failed to detect light powder snow in the air-snowpack interface. The aim of this thesis is to find and verify a system for estimating altitude on centimeter scale over a snow surface, independent of snow conditions. Also, relative pitch and roll angle estimation between the UAV and ...

    • Machine Learning for Classifying Marine Vegetation from Hyperspectral Drone Data in the Norwegian coast 

      Grue, Silje B.S. (Master thesis; Mastergradsoppgave, 2022-05-30)
      Along the Norwegian coasts the presence of blue forests are the key marine habitats. Due to increased anthropogenic activity and climate change, the health and extent of the blue forests is threatened. However, no low-cost, reliable system for monitoring blue forests exists in Norway at this time. This thesis studied machine learning methods to classify marine vegetation from hyperspectral data ...

    • Mean shift spectral clustering using kernel entropy component analysis 

      Agersborg, Jørgen Andreas (Master thesis; Mastergradsoppgave, 2012-06-01)
      Clustering is an unsupervised pattern recognition technique for finding natural groups in data, whether it is a grouping of web pages found by a search engine or segmenting satellite images into different types of ground cover. There exists a variety of different ways to perform clustering ranging from heuristics rules designed for a specific dataset to general procedures which can be applied to all ...

    • Mikrobølgeradiometri anvendt til deteksjon av temperaturgradienter i brystvevsfantom 

      Klemetsen, Øystein (Master thesis; Mastergradsoppgave, 2006-06-01)
      En passiv, ikke-invasiv og ufarlig metode for detektering av brystkreft er motivasjonen for denne oppgaven. Basisen for mikrobølgeteori og radiometrisk teori er presentert. Videre presenteres grunnlaget for å kunne foreta passive målinger på brystvevsmodeller, målemetoder og forbedringsmuligheter innen mikrobølge radiometri. Vi studerer ulike forbedringsmuligheter ved å se på systemet ved Institutt ...

    • MIR-based in-situ measurement of Silicon crystal-melt interface 

      Jensen, Mathias N. (Master thesis; Mastergradsoppgave, 2020-06-29)
      The project explores the a proposed MIR-based measurement system for measuring the deflection of the interface between the crystal and melt during production of mono-crystalline Silicon in the Czochralski process. The absorption spectrum is modeled and the specific absorption for a select set of wavelengths is estimated for temperatures approching 1687K. It was estimated that the intrinsic absorption ...

    • Modeling probability density functions of non-negative random variables using novel series expansions based on mellin kind statistics 

      Brenn, Torgeir (Master thesis; Mastergradsoppgave, 2017-05-31)
      Mellin kind (MK) statistics is the framework which arises if the Fourier transform is replaced with the Mellin transform when computing the characteristic function from the probability density function. We may then proceed to retrieve logarithmic moments and cumulants, which have important applications in the analysis of heavy-tailed distribution models for non-negative random variables. In this ...

    • Monostatisk antennearray for UWB radar 

      Andersen, Rolf (Master thesis; Mastergradsoppgave, 2009-06)
      Ultrabredbåndet (ultrawideband - UWB) radar brukt til deteksjon av bryst-kreft viser oppløftende resultater på grunn av dens gode romlige oppløsning og dype penetreringsdybde. Bakgrunnen for å bruke UWB-radar til dette formålet er kontrasten mellom de dielektriske egenskapene til friskt brystvev og en kreftsvulst. Noe som vil føre til relativt mye reflektert energi fra kreftsvulsten. En av utfordringene ...

    • Motion induced electromagnetic fields in the ocean: Exploratory data analysis and signal processing 

      Eide, Andreas (Master thesis; Mastergradsoppgave, 2007-12-17)
      We will in this thesis analyse data from antennas located at the seafloor measuring the vertical component of the natural electric field. The internal source to electromagnetic fields in the ocean is saltwater crossing the geomagnetic field, and the main contributor to the motion induced vertical electric field is the water velocity in the East-West direction weighted by the North component of the ...

    • Numerical and experimental investigation of absorbing polymer films suitable for boundary photoacoustic imaging 

      Salmi, Marte Helene Skogdahl (Master thesis; Mastergradsoppgave, 2020-07-13)
      One of the main challenges in conventional photoacoustic methods, is that thin biological samples typically have low optical absorption in the visible region. Therefore, it is often necessary to stain or label the sample with a color which provide sufficient absorption for the laser wavelength used in the scanning system. Unfortunately, the labeling often introduce unwanted properties to the biological ...

    • Numerisk modellering av absorberende randbetingelser for ultralydbølger i væsker og elastiske materialer 

      Grønmo, Tor Arne (Master thesis; Mastergradsoppgave, 2015-06-01)
      Simuleringer av utbredelse av ultralydbølger i elastiske polymerer og i væsker ble utført med et kommersielt simuleringsverktøy, COMSOL Multiphysics, basert på endelig element metode. Simuleringer ble utført i en- og to-dimensjoner. Undersøkelser ble utført for å finne ut ved hvilke oppløsninger av tid og rom ga stabile simuleringer. For en to-dimensjonal modell basert på en elastisk ...

    • Oil Spill Analysis Using Hybrid-Polarization Synthetic Aperture Radar 

      Høifødt, Audun Leonard (Master thesis; Mastergradsoppgave, 2016-06-01)
      The goal for this thesis is to test various Hybrid-Polarization (HP) Synthetic Aperture Radar (SAR) parameters using actual HP data, and to evaluate the validity of these parameters with respect to oil slick detection. As part of the evaluation, the impact of the system noise and incidence angle on the SAR images is discussed. It is shown that the Signal-to-Noise Ratio (SNR) of the sensor has a ...

    • On the improvement and acceleration of eigenvalue decomposition in spectral methods using GPUs 

      Johansen, Thomas A. Haugland (Master thesis; Mastergradsoppgave, 2016-12-08)
      The key objectives in this thesis are; the study of GPU-accelerated eigenvalue decomposition in an effort to uncover both benefits and pitfalls, and then to investigate and facilitate a future GPU implementation of the symmetric QR algorithm with permutations. With the current trend of having ever larger datasets both in terms of features and observations, we propose that GPU computation can help ...

    • Optical Trapping, Levitation and Tracking of Microparticles Using Waveguides 

      Helle, Øystein Ivar (Master thesis; Mastergradsoppgave, 2014-06-02)
      Microparticles are trapped by optical forces created by the evanescent field present on the surface of an optical waveguide. An optical waveguide loop with an intentional gap is used to propel and stably hold the trapped particles. The particles are trapped in the gap of the loop by counter-diverging fields. Simulations indicate that particles trapped in the gap on a strip waveguide will be levitated. ...

    • Optisk resonans i mikrokuler av glass med høy brytningsindeks 

      Husabø, Bjarne Janson (Master thesis; Mastergradsoppgave, 2009-06-15)
      I denne oppgaven har vi sett på effekten av lys som kobles fra en bølgeleder inn i optiske mikrokuler av høyindeksglass. Vi har studert Q-faktorer, og funnet at disse er lavere for kuler omgitt av vann enn tørre kuler, men at forskjellen er mindre enn mellom individuelle kuler. Vi har observert høyere ordens resonanser i kuler med større diameter. Vi har også forsøkt å utnytte resonans til å flytte ...

    • Optiske bølgeledere av silisium-rik nitrid for manipulering av mikro- og nanopartikler 

      Nermo, Thomas (Master thesis; Mastergradsoppgave, 2007-06-01)
      Målet med denne oppgaven er å karakterisere bølgeledere av silisium-rik nitrid, SiRN, med hensyn på koblingstap, propagasjonstap, tall på modi og feltfordeling. Det skal gjøres forsøk på å redusere tapet mest mulig ved å prøve ut forskjellige måter å koble inn lys og forbedre kuttingen av bølgelederene. Det skal også gjøres forsøk på å finne tykkelse og brytningsindeks på bølgelederene ved hjelp av ...

    • Particle tracking in 3D 

      Brox, Petter (Master thesis; Mastergradsoppgave, 2013-06)
      The evanescent field of an optical waveguide can be used to trap and propel microscopic particles. A 1µm particle is trapped on a strip waveguide and propelled forward until it reaches a 10µm gap at the centre of a loop, created by splitting the waveguide into two branches. According to simulations, the particle will be elevated 3µm in the gap and be stably trapped in the middle of the gap. The goal ...

    • Physical and statistical based decomposition of Polarimetric Synthetic Aperture Radar images of Arctic Sea ice 

      Arienzo, Alberto (Master thesis; Mastergradsoppgave, 2015-06-01)
      The studies about the climatic changes have always more underlined the importance of the climatic balance of the Arctic regions. For this reason the need of monitoring the Arctic becomes always more urgent. To measure the sea ice thickness, the sea ice cover, the motion of the glaciers and to discriminate the various kind of ice are only several of the challenges about the Arctic monitoring. But the ...

    • Reconstruction of the full-polarimetric covariance matrix from compact-polarimetric synthetic aperture radar data with convolutional neural networks 

      Bollo Del Rio, Umberto (Master thesis; Mastergradsoppgave, 2017-09-05)
      The focus of this thesis is to find an alternative way to reconstruct a pseudo quadrature polarimetric (quad-pol) covariance matrix from compact polarimetric (compact-pol) data. In the latest years, the compact polarimetry SAR mode was developed and used more and more widely. It provides a good compromise between area covered and information content per pixel [13]. The literature has focused ...

    • Segmentation and Unsupervised Adversarial Domain Adaptation Between Medical Imaging Modalities 

      Strauman, Andreas Storvik (Master thesis; Mastergradsoppgave, 2019-07-13)
      Segmenting and labelling tumors in multimodal medical imaging are often vital parts of diagnostics and can in many cases be very labor intensive for clinicians. The effort in advancing time-saving methods in the medical health sector might be of great help for busy clinicians and can maybe even save lives. Furthermore, creating methods that generically, accurately and successfully process unlabelled ...

    • Semi-supervised Classification using Kernel Entropy Component Analysis and the LASSO. 

      Myhre, Jonas Nordhaug (Master thesis; Mastergradsoppgave, 2011-12-15)
      In this thesis we present a new semi-supervised classification technique based on the Kernel Entropy Component Analysis (KECA) transformation and the least absolute shrinkage selection operator (LASSO). The latter is a constrained version of the least squares classifier. Traditional supervised classification techniques only use a limited set of labeled data to train the classifier, thus leaving ...