Now showing items 21-40 of 232

    • 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 ...
    • 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 ...
    • 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 ...
    • Seafloor depth estimation by means of interferometric synthetic aperture sonar 

      Sæbø, Torstein Olsmo (Doctoral thesis; Doktorgradsavhandling, 2010-11-19)
      The topic of this thesis is relative depth estimation using interferometric sidelooking sonar. We give a thorough description of the geometry of interferometric sonar and of time delay estimation techniques. We present a novel solution for the depth estimate using sidelooking sonar, and review the cross-correlation function, the cross-uncertainty function and the phase-differencing technique. We ...
    • Non-Gaussian statistical analysis of polarimetric synthetic aperture radar images 

      Doulgeris, Anthony Paul (Doctoral thesis; Doktorgradsavhandling, 2011-02-18)
      This thesis describes general methods to analyse polarimetric synthetic aperture radar images, with the primary application of unsupervised image segmentation. The fundamental physics of electromagnetic scattering from distributed targets leads to the image phenomenon called speckle. Speckle is shown to be potentially non-Gaussian and several statistical distributions are investigated. Non-Gaussianity ...
    • Rockslide Mapping in Norway by Means of Interferometric SAR Time Series Analysis 

      Lauknes, Tom Rune (Doctoral thesis; Doktorgradsavhandling, 2011-03-18)
      Rockslides have a high socioeconomic and environmental importance in many coun- tries. Norway is particularly susceptible to large rockslides due to its many fjords and steep mountains. One of the most dangerous hazards related to rock slope failures are tsunamis that can lead to large loss of life. It is therefore very important to systemati- cally identify potential unstable rock slopes. In this ...
    • Late Glacial – Holocene climate variability and sedimentary environments on northern continental shelves Zonal and meridional Atlantic Water advection 

      Sørensen, Steffen Aagaard (Doctoral thesis; Doktorgradsavhandling, 2011-03-22)
      The overall objective for this PhD-study was to further advance the understanding of the oceanographic variability and development in the Nordic Seas during the Late Glacial and the Holocene and towards the present. The focus is specifically on the poleward Atlantic Water advection along the continental margins of Norway, into the SW Barents Sea and along the West Spitsbergen slope. Four high ...
    • Complexity in plasma and geospace systems 

      Živkovic, Tatjana (Doctoral thesis; Doktorgradsavhandling, 2011-05-10)
      The subject of this thesis is self-organization, chaos and stochastic dynamics in laboratory plasmas, the magnetosphere, and in the Earth's climate system. For each of these systems we pose the question whether the global dynamics can be described by a set of a few variables governed by the same small number of deterministic equations. This problem is not trivial, because low-dimensional ...
    • Theoretical studies of natural and electromagnetically induced birefringences 

      Shcherbin, Dmitry (Doctoral thesis; Doktorgradsavhandling, 2011-06-01)
    • Water and heat transfer in cement based materials 

      Nguyen, Hung Thanh (Doctoral thesis; Doktorgradsavhandling, 2011-06-17)
      For the mass transfer case (the absorption of moisture-water into concrete), the water content in concrete has a significant impact on its mechanical properties. Moisture transport in porous media, for example, plays an important role in the degradation of building materials such as mortars and concrete. LWE ignores the complex pore structure and network, typically found in cement materials. Many ...
    • Theoretical studies of natural and magnetic circular dichroism 

      Solheim, Harald (Doctoral thesis; Doktorgradsavhandling, 2011-06-23)
      This dissertation presents theoretical studies mainly of natural and magnetic circular dichroism spectra. For magnetic circular dichroism, the importance of electron correlation effects, here included at the density-functional functional level of theory, and solvent effects are discussed, both being shown to have significant impact on the final spectra. In addition, a unified approach for calculating ...
    • Model based Statistics for Protein Sequence Families 

      Ahmed, Said Hassan (Doctoral thesis; Doktorgradsavhandling, 2011-07-01)
    • Interactive Visualization on High-Resolution Tiled Display Walls with Network Accessible Compute- and Display-Resources 

      Hagen, Tor-Magne Stien (Doctoral thesis; Doktorgradsavhandling, 2011-09-26)
      The vast volume of scientific data produced today requires tools that can enable scientists to explore large amounts of data to extract meaningful information. One such tool is interactive visualization. The amount of data that can be simultaneously visualized on a computer display is proportional to the display’s resolution. While computer systems in general have seen a remarkable increase in ...
    • Practical Fault-Tolerance for Mobile Agents 

      Jacobsen, Kjetil (Doctoral thesis; Doktorgradsavhandling, 2011-10-18)
      The amount of computational resources available on the Internet is increasing. Effectively using these resources for distributed computations is challenging. An infrastructure called computational grids provides tools for structuring and deploying large-scale distributed computations on the Internet. One of the key problems in computational grids is managing the available computational resources; ...
    • Minor element abundances in the corona and solar wind 

      Byhring, Hanne Sigrun (Doctoral thesis; Doktorgradsavhandling, 2011-10-21)
      Using a time-dependent numerical model that spans the chromosphere, corona and solar wind, abundance variations resulting from gravitational settling in the chromosphere and corona have been studied. \noindent Gravitational settling in the chromosphere may lead to a depletion in the abundances of minor elements in the solar wind relative to the photosphere. The observed overabundance (relative ...
    • Automatic Inspection of Cod (Gadus Morhua L.) Fillets by Hyperspectral Imaging 

      Sivertsen, Agnar Holten (Doctoral thesis; Doktorgradsavhandling, 2011-11-11)
      The manual trimming and inspection of cod fillets by candling, is considered the bottleneck of cod fillet processing. The operation is both labour intensive and expensive, reported to account for as much as 50 % of the cost with cod fillet production. Due to the high labour costs in Norway, it is of great interest for the industry to optimize this process. In this work a hyperspectral imaging ...
    • The Dayside Open/Closed Field line Boundary -Ground-based optical determination and examination 

      Johnsen, Magnar Gullikstad (Doctoral thesis; Doktorgradsavhandling, 2011-12-20)
      The Open/Closed eld line Boundary (OCB) is the most important boundary in the magnetospheric system. On the dayside, the equatorward edge of the 6300 Å[OI] cusp aurora can be used as a proxy for the OCB. This work, which is a dissertation for the degree of philosophiæ Doctor consists of three scienti c papers focusing on the latitude of the optical cusp OCB and one paper focusing on polar cap patch ...
    • Cogset : A High-Performance MapReduce Engine 

      Viken Valvåg, Steffen (Doctoral thesis; Doktorgradsavhandling, 2012-01-30)
      MapReduce has become a widely employed programming model for large-scale data-intensive computations. Traditional MapReduce engines employ dynamic routing of data as a core mechanism for fault tolerance and load balancing. An alternative mechanism is static routing, which reduces the need to store temporary copies of intermediate data, but requires a tighter coupling between the components for ...