• Studies of ionospheric parameters by means of electron plasma lines observed by EISCAT 

      Guio, Patrick (Doctoral thesis; Doktorgradsavhandling, 1998-12-18)
      This work presents a study of the electron plasma lines observed by the incoherent scatter radar EISCAT. The work is focusing on two parts. On one hand, the design of a plasma line experiment for the EISCAT system with an improved spatial resolution. On the other hand, the comparison of the plasma line data collected with the EISCAT radar with an improved model for the intensity and the Doppler ...
    • Wave damping and momentum transfer. Manifestation of momentum transfer in case of ocean surface waves being damped by an elastic film or a viscous layer 

      Foss, Marianne (Doctoral thesis; Doktorgradsavhandling, 2001-02-28)
      Virkninga av å ha et bølgedempende overflatemateriale i ei havoverflate er studert, med særlig vekt på betydninga av strålingstrykket (-stresset) eller bølgetrykket fra et innfallende, udempet bølgefelt. Det er et teoretisk studium av den dynamiske prosess som foregår når udempede overflatebølger propagerer inn i et område med bølgedempende overflatesjikt, i lys av det bølgetrykk bølgene øver på ...
    • Interferometric and high time-resolution observations of naturally enhanced ion-acoustic echoes at the EISCAT Svalbard radar: Software radar and incoherent scattering 

      Grydeland, Tom (Doctoral thesis; Doktorgradsavhandling, 2003-06-24)
      We know that the visible Aurora Borealis is structured on many different scales, down to a few tens of metres. By using the EISCAT radars on Svalbard as an interferometer, we have found structures in the radio echoes from the auroral ionosphere on a scale approaching that of the visible aurora, and simultaneously with it, but at far greater ranges. In this thesis we discuss how these radar observations ...
    • Low-frequency noise characterization of silicon-germanium resistors and devices 

      Johansen, Jarle Andre (Doctoral thesis; Doktorgradsavhandling, 2004-06-03)
      The main topic of this thesis is experimental low-frequency electrical noise characterization of semiconductor devices. In particular, we concentrate on applications of the silicon-germanium alloy (SiGe). Low-frequency electrical noise is a sensitive measure of defects and non-idealities in semiconductor devices, which directly or indirectly impact device performance and reliability. Thus, it ...
    • Angles as tool for grasping space. Teaching of angles based on students’ experiences with physical activities and body movement 

      Fyhn, Anne Birgitte (Doctoral thesis; Doktorgradsavhandling, 2007-06-13)
      The thesis enlightens how the choice of context as well as the approach to mathematics is important in introducing the concepts of angles. The analyses indicate that students should not be introduced to measuring angles before they are able to sort out angles according to their sizes. Angles can be introduced by use of the students’ bodies in a climbing context, where the word angle refers to ...
    • Optical properties of snow and sea ice field measurements, parameterization schemes and validation 

      Pedersen, Christina Alsvik (Doctoral thesis; Doktorgradsavhandling, 2007-12)
      Optiske Egenskaper av Snø og Sjøis: Felt målinger, Modellbeskrivelse og Validering av Modeller I dag hersker det liten tvil om at de raske temperatur endringene vi er vitne til er menneskeskapte. Temperaturen øker dobbelt så hurtig i Arktis i forhold til i resten av verden, med den konsekvensen at sjøisen i Arktis smelter med akselererende hastighet. Klimamodeller kan beskrive fortidens, nåtidens ...
    • Quality of service aware binding in open systems 

      Hanssen, Øyvind (Doctoral thesis; Doktorgradsavhandling, 2008-02-07)
      This thesis addresses negotiation of bindings in QoS aware open systems and in particular how to characterize possible contracts, requirements and capabilities of heterogeneous environments. Our approach is (1) to use trading of policies as the principle for negotiation and (2) the use of declared or rule-based conformance for QoS statements to be used in negotiation and (3) a middleware binding ...
    • Higher-order SCF response functions in a quasi-energy formulation 

      Thorvaldsen, Andreas J. (Doctoral thesis; Doktorgradsavhandling, 2008-09-30)
      This thesis is concerned with computer modelling of molecules interacting with electromagnetic radiation (light, radio waves, etc.), static electric and magnetic fields (in the laboratory), as well as approximate treatments of the motions of the molecules' atomic nuclei (vibration). Compared to interactions between electrons or between electron and nucleus, these interactions are small, and well ...
    • Bonding in low-coordinate complexes : what, if anything, is special? 

      Tangen, Espen (Doctoral thesis; Doktorgradsavhandling, 2008-10-14)
      To contribute to the fundamental picture of the electronic structure of low-coordinate transition metal complexes, we have carried out a series of DFT studies on mono-imido and nitrosyl complexes for different metal ions (Mn<sup>II/III</sup>, Fe<sup>II/III/IV</sup>, Co<sup>II/III</sup>) and different systems of basal ligands. These studies reveal striking similarities of the electronic structure ...
    • Time-frequency characterization of harmonizable random processes 

      Hindberg, Heidi (Doctoral thesis; Doktorgradsavhandling, 2009)
      In this thesis we study how to characterize nonstationary harmonizable random processes simultaneously in time and frequency. Unlike stationary random processes, harmonizable processes can have a frequency content that changes with time. Rather than working directly with the process itself, we analyze the second-order moment functions of the process and characterize the process from these moments. ...
    • Changing circumstances : implications for trophic dynamics and species conservation in the Fennoscandian tundra 

      Henden, John-André (Doctoral thesis; Doktorgradsavhandling, 2009-03-16)
      A special case of population fluctuation is multi-annual population cycles. While such population cycles exist in several ecosystems, they are more prominent in northern (e.g.tundra) ecosystems, especially among key stone herbivore species. These herbivores providean important ecosystem function in the sense of pulsed flows of resources (i.e. for predators) and disturbances (i.e. for vegetation) ...
    • Spatial and temporal analysis of fluid venting systems on the Norvegian-Svalbard margin 

      Hustoft, Steinar (Doctoral thesis; Doktorgradsavhandling, 2009-04-03)
    • POP-cocktails : hangover threats for seabirds? The response of three seabird species to exposure to persistent organic pollutants in the Barents Sea 

      Sagerup, Kjetil (Doctoral thesis; Doktorgradsavhandling, 2009-06-11)
      The overall aim of the thesis was to study immunological effects of pollutants in Barents Sea. The Glaucous gull (Larus hyperboreus), black-legged kittiwake (Rissa tridactyla) and Atlantic puffin (Fratercula arctica) were studied. The apex predatory glaucous gull have high levels of persistent organic pollutants (POPs), while the fish eating black-legged kittiwake and Atlantic puffin are located ...
    • Behavioral and energetic response of Arctic-breeding seabirds to environmental variability. 

      Welcker, Jorg (Doctoral thesis; Doktorgradsavhandling, 2009-06-16)
      Knowledge about the extent to which organisms inhabitating the Arctic are able to adjust to environmental variability is essential in order to predict the impact of future climate change. In this context, the flexibility og two Acrtic-breeding seabirds, the little Auk (Alle alle) and the kittiwake (Rissa tridactyla), in foraging behavior and energy expenditure in response to environmental variability. ...
    • Particle precipitation : effects on selected ionospheric phenomena 

      Lunde, June (Doctoral thesis; Doktorgradsavhandling, 2009-11-26)
      The motivation behind this thesis has been to study particle precipitation from the Sun into the Earth’s upper atmosphere and its effects on selected ionospheric phenomena. Particles from the solar wind can enter the Earth's magnetosphere through magnetic merging, either at the sub-solar point, or at higher latitudes, depending on the configuration of the interplanetary magnetic field. This interaction ...
    • The few touch digital diabetes diary : user-involved design of mobile self-help tools for peoplewith diabetes 

      Årsand, Eirik (Doctoral thesis; Doktorgradsavhandling, 2009-12-10)
      Paradoxically, the technological revolution that has created a vast health problem due to a drastic change in lifestyle also holds great potential for individuals to take better care of their own health. The first consequence is not addressed in this dissertation, but the second represents the focus of the work presented, namely utilizing ICT to support self-management of individual health challenges. ...
    • Statistical Analysis of Multilook Polarimetric Radar Images with the Mellin Transform 

      Anfinsen, Stian Normann (Doctoral thesis; Doktorgradsavhandling, 2010-05-19)
      This thesis presents methods for statistical analysis of the probability distributions used to model multilook polarimetric radar images. The methods are based on a matrix-variate version of Mellin's integral transform. The proposed theoretical framework is referred to as Mellin kind statistics. It is an extension of a theory recently developed for single polarisation amplitude and intensity data ...
    • Relative sea level, deglaciation and tsunami history deduced from isolation basins 

      Romundset, Anders (Doctoral thesis; Doktorgradsavhandling, 2010-10-15)
      NORSK SAMANDRAG: <br>Denne avhandlinga tek for seg endringane i relativt havnivå – strandforskyvinga – dei siste vel 11.500 åra på kysten av Finnmark og i midtre Hardanger. Ei stor mengd kjerneprøver frå avsettingane i innsjøar som ein gong låg under havnivået, er henta inn og analysert. Grenser mellom sediment som vart avsett i salt- eller ferskvatn er bestemt ved å analysere både kiselalgar ...
    • Signal processing techniques for the enhancement of marine seismic data 

      Sanchis, Charlotte Juliette (Doctoral thesis; Doktorgradsavhandling, 2010-11-12)
      This thesis presents several signal processing techniques applied to the enhancement of marine seismic data. Marine seismic exploration provides an image of the Earth's subsurface from reflected seismic waves. Because the recorded signals are contaminated by various sources of noise, minimizing their effects with new attenuation techniques is necessary. A statistical analysis of background noise ...
    • Characterization of sub-seabed fluid flow and hydrate systems at Nyegga, offshore mid- Norway : integration of seismic imaging and velocity modeling 

      Plaza-Faverola, Andreia Aletia (Doctoral thesis; Doktorgradsavhandling, 2010-11-12)
      What causes the escape of natural gases to the seafloor and how significant this escape has been along the mid-Norwegian continental margin? These are questions that guided the doctoral thesis. The thesis is part of a research project supported by the European Commission and the Norwegian Research Council, which aims at quantifying geological processes that control fluid flow and gas hydrate formation ...