Doktorgradsavhandlinger (NT-fak): Nye registreringer
Viser treff 281-300 av 312
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Interactive Visualization on High-Resolution Tiled Display Walls with Network Accessible Compute- and Display-Resources
(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
(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; ... -
U-Pb geochronology of crustal evolution and orogeny Contributions from Caledonide Spitsbergen and the Precambrian West Troms Basement Complex, North Norway
(Doctoral thesis; Doktorgradsavhandling, 2011-09-23) -
Minor element abundances in the corona and solar wind
(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 ... -
Theoretical studies of natural and magnetic circular dichroism
(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 ... -
Theoretical studies of natural and electromagnetically induced birefringences
(Doctoral thesis; Doktorgradsavhandling, 2011-06-01) -
Model based Statistics for Protein Sequence Families
(Doctoral thesis; Doktorgradsavhandling, 2011-07-01) -
Water and heat transfer in cement based materials
(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 ... -
Complexity in plasma and geospace systems
(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 ... -
Late Glacial – Holocene climate variability and sedimentary environments on northern continental shelves Zonal and meridional Atlantic Water advection
(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 ... -
Studies of ionospheric parameters by means of electron plasma lines observed by EISCAT
(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 ... -
Rockslide Mapping in Norway by Means of Interferometric SAR Time Series Analysis
(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 ... -
Non-Gaussian statistical analysis of polarimetric synthetic aperture radar images
(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 ... -
Principle and Practice of Distributing Low and High Resolution Display Content from One Computer to Many Computers in Stand-alone or Display Wall Configurations
(Doctoral thesis; Doktorgradsavhandling, 2011-02-24) -
Characterization of sub-seabed fluid flow and hydrate systems at Nyegga, offshore mid- Norway : integration of seismic imaging and velocity modeling
(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
(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
(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 ... -
The few touch digital diabetes diary : user-involved design of mobile self-help tools for peoplewith diabetes
(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. ... -
Relative sea level, deglaciation and tsunami history deduced from isolation basins
(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 ... -
Behavioral and energetic response of Arctic-breeding seabirds to environmental variability.
(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. ...