Now showing items 1521-1540 of 5304

    • Resiliens og Sårbarhet i Norske Smart Byer: Hvordan smart byer påvirker norsk transportsektor 

      Pollen, Stian Wachelin (Master thesis; Mastergradsoppgave, 2022-06-22)
      Sammendrag Denne oppgaven undersøker hvordan konseptet Smart City eller smart by påvirker samfunnssikkerheten i Norge. Smart by er et konsept som har fått stor internasjonal oppmerksomhet de senere årene. Konseptet er utviklet i stor del som et for å møte de klimautfordringene vi står ovenfor. Derfor ønsket jeg med denne oppgaven å undersøke hvordan denne trenden innenfor byutviklingen med fokus ...
    • Non-Opportunistic Data Transfer for IoT and Cyber-Physical Systems with Mostly Sleeping Nodes 

      Hellemo, Isak Østrem (Mastergradsoppgave; Master thesis, 2022-07-12)
      Sensor networks are frequently used to monitor our environment. From monitoring the habitat of seabirds [1], to the structural integrity of bridges [2]. They can also be used to monitor the arctic tundra to help us monitor climate change. The arctic tundra does however place additional requirements on a monitoring system. Low access to energy sources, human intervention, and networks to transfer ...
    • Towards an improved organic carbon budget for the western Barents Sea shelf 

      Pathirana, Irene Dorothea; Knies, Jochen; Felix, Maarten; Mann, Ute (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-03-21)
      There is generally a lack of knowledge on how marine organic carbon accumulation is linked to vertical export and primary productivity patterns in the Arctic Ocean. Despite the fact that annual primary production in the Arctic has increased as a consequence of shrinking sea ice, its effect on flux, preservation, and accumulation of organic carbon is still not well understood. In this study, a ...
    • Reduced Numerical Model for Methane Hydrate Formation under Conditions of Variable Salinity. Time-Stepping Variants and Sensitivity 

      Peszynska, M.; Medina, F.P.; Hong, Wei-Li; Torres, M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-12-24)
      In this paper, we consider a reduced computational model of methane hydrate formation in variable salinity conditions, and give details on the discretization and phase equilibria implementation. We describe three time-stepping variants: Implicit, Semi-implicit, and Sequential, and we compare the accuracy and efficiency of these variants depending on the spatial and temporal discretization parameters. ...
    • A Stimulated Emission Diagnostic Technique for Electron Temperature of the High Power Radio Wave Modified Ionosphere 

      Fu, Haiyang; Jiang, M. L.; Vierinen, Juha; Häggström, Ingemar; Rietveld, Michael T.; Varberg, Erik; Sato, Hiroatsu; Wu, Jiang; Scales, Wayne A.; Jin, Y. Q. (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-09)
      We report observations of stimulated electromagnetic emission (SEE) induced by high power high frequency (HF) radio waves near the third electron gyroharmonic (3urn:x-wiley:00948276:media:grl64672:grl64672-math-0022) at European Incoherent Scatter Radar (EISCAT). It is discovered that stimulated Brillouin scattering (SBS) spectrum behaves similarly as spectral ion lines of the incoherent scatter ...
    • A 30-year probability map for oil spill trajectories in the barents sea to assess potential environmental and socio-economic threats 

      Pavlov, Victor; Martins de Aguiar, Victor Cesar; Hole, Lars Robert; Pongrácz, Eva (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-24)
      Increasing exploration and exploitation activity in the Arctic Ocean has intensified maritime traffic in the Barents Sea. Due to the sparse population and insufficient oil spill response infrastructure on the extensive Barents Sea shoreline, it is necessary to address the possibility of offshore accidents and study hazards to the local environment and its resources. Simulations of surface oil ...
    • Symmetry gaps for higher order ordinary differential equations 

      Kessy, Johnson Allen; The, Dennis (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-07-04)
      The maximal contact symmetry dimensions for scalar ODEs of order ≥ 4 and vector ODEs of order ≥ 3 are well known. Using a Cartan-geometric approach, we determine for these ODEs the next largest realizable (submaximal) symmetry dimension. Moreover, finer curvature-constrained submaximal symmetry dimensions are also classified.
    • Deep Tower Networks for Efficient Temperature Forecasting from Multiple Data Sources 

      Eide, Siri Sofie; Riegler, Michael; Hammer, Hugo Lewi; Bremnes, John Bjørnar (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-04-06)
      Many data related problems involve handling multiple data streams of different types at the same time. These problems are both complex and challenging, and researchers often end up using only one modality or combining them via a late fusion based approach. To tackle this challenge, we develop and investigate the usefulness of a novel deep learning method called tower networks. This method is able ...
    • Efficient quantile tracking using an oracle 

      Hammer, Hugo Lewi; Yazidi, Anis; Riegler, Michael; Rue, Håvard (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-04-14)
      Concept drift is a well-known issue that arises when working with data streams. In this paper, we present a procedure that allows a quantile tracking procedure to cope with concept drift. We suggest using expected quantile loss, a popular loss function in quantile regression, to monitor the quantile tracking error, which, in turn, is used to efficiently adapt to concept drift. The suggested ...
    • Offshore permafrost decay and massive seabed methane escape in water depths >20 m at the South Kara Sea shelf 

      Portnov, Alexey; Mienert, Jurgen; Cherkashov, Georgy; Rekant, Pavel; Semenov, Peter; Serov, Pavel; Vanshtein, Boris; Smith, Andrew James (Journal article; Tidsskriftartikkel; Peer reviewed, 2013-07-14)
      Since the Last Glacial Maximum (~19 ka), coastal inundation from sea-level rise has been thawing thick subsea permafrost across the Arctic. Although subsea permafrost has been mapped on several Arctic continental shelves, permafrost distribution in the South Kara Sea and the extent to which it is acting as an impermeable seal to seabed methane escape remains poorly understood. Here we use >1300 km ...
    • Aligned glaciotectonic rafts on the central Barents Sea seafloor revealing extensive glacitectonic erosion during the last deglaciation 

      Ruther, Denise Christina; Andreassen, Karin; Spagnolo, Matteo (Journal article; Tidsskriftartikkel; Peer reviewed, 2013-12-07)
      Erosion rates on glaciated continental shelves are remarkably high, especially within ice stream troughs. Although glaciotectonic erosion may have considerably contributed to enhanced glacial erosion of these landscapes, entrainment mechanisms of glaciotectonically emplaced megablocks and rafts remain little understood. Here we report a northeast-southwest trending chain of over 1300 glacial rafts, ...
    • Marine CDOM accumulation during a coastal Arctic mesocosm experiment: No response to elevated pCO2 levels 

      Pavlov, Alexey K.; Silyakova, Anna; Granskog, Mats A.; Bellerby, Richard; Engel, Anja; Schulz, Kai G.; Brussaard, Corina P. D. (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-05-22)
      A large-scale multidisciplinary mesocosm experiment in an Arctic fjord (Kongsfjorden, Svalbard; 78°56.2′N) was used to study Arctic marine food webs and biogeochemical elements cycling at natural and elevated future carbon dioxide (CO2) levels. At the start of the experiment, marine-derived chromophoric dissolved organic matter (CDOM) dominated the CDOM pool. Thus, this experiment constituted a ...
    • Modeling the evolution of climate-sensitive Arctic subsea permafrost in regions of extensive gas expulsion at the West Yamal shelf 

      Portnov, Aleksei D; Mienert, Jurgen; Serov, Pavel (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-10-01)
      Thawing subsea permafrost controls methane release from the Russian Arctic shelf having a considerable impact on the climate-sensitive Arctic environment. Expulsions of methane from shallow Russian Arctic shelf areas may continue to rise in response to intense degradation of relict subsea permafrost. Here we show modeling of the permafrost evolution from the Late Pleistocene to present time at the ...
    • Nonlinear Preisach maps: Detecting and characterizing separate remanent magnetic fractions in complex natural samples 

      Church, Nathan Stewart; Fabian, Karl; McEnroe, Suzanne (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-10-27)
      Natural remanent magnetization carriers in rocks can contain mixtures of magnetic minerals that interact in complex ways and are challenging to characterize by current measurement techniques. Here a nonlinear mapping scheme is described that efficiently enhances sensitivity and the resolution power of remanent Preisach maps. Using this scheme a large dynamic range of magnetic moments and coercivities ...
    • The EMSO-ERIC pan-european consortium: Data benefits and lessons learned as the legal entity forms 

      Best, Mairi M.R.; Favali, Paolo; Beranzoli, Laura; Blandin, Jerome; Çağatay, Namik M.; Cannat, Mathilde; Dañobeitia, Juan José; Delory, Eric; de Miranda, Jorge M.A.; Del Rio Fernandez, Joaquin; de Stigter, Henko; Gillooly, Mick; Grant, Fiona; Hall, Per O.J.; Hartman, Susan E.; Hernandez-Brito, Joaquin; Lanteri, Nadine; Mienert, Jurgen; Oaie, Gheorge; Piera, Jaume; Radulescu, Vlad; Rolin, Jean-Francois; Ruhl, Henry A.; Waldmann, Christoph (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-05-01)
      The European Multidisciplinary Seafloor and water-column Observatory (EMSO) European Research Infrastructure Consortium (ERIC) provides power, communications, sensors, and data infrastructure for continuous, high-resolution, (near-)real-time, interactive ocean observations across a multidisciplinary and interdisciplinary range of research areas including biology, geology, chemistry, physics, ...
    • Towards a New Model for Chronic Disease Consultations 

      Randine, Pietro; Cooper, John Graham; Hartvigsen, Gunnar; Årsand, Eirik (Chapter; Bokkapittel, 2022-08-22)
      Medical consultations for chronic diseases form an arena to provide information from health personnel to patients. This information is necessary for patients to understand how to deal with the possible lifelong symptoms and needed self-management activities. The amount of patient-generated health data is increasing. Today’s patients gather an increasing amount of personalised health-related information. ...
    • Plio-Pleistocene evolution of water mass exchange and erosional input at the Atlantic-Arctic gateway 

      Teschner, Claudia; Frank, Martin; Haley, Brian A.; Knies, Jochen (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-04-28)
      Water mass exchange between the Arctic Ocean and the Norwegian-Greenland Seas has played an important role for the Atlantic thermohaline circulation and Northern Hemisphere climate. We reconstruct past water mass mixing and erosional inputs from the radiogenic isotope compositions of neodymium (Nd), lead (Pb), and strontium (Sr) at Ocean Drilling Program site 911 (leg 151) from 906 m water depth on ...
    • Response time correction of slow-response sensor data by deconvolution of the growth-law equation 

      Dølven, Knut Ola; Vierinen, Juha; Grilli, Roberto; Triest, Jack; Ferré, Benedicte (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-11)
      Accurate high-resolution measurements are essential to improve our understanding of environmental processes. Several chemical sensors relying on membrane separation extraction techniques have slow response times due to a dependence on equilibrium partitioning across the membrane separating the measured medium (i.e., a measuring chamber) and the medium of interest (i.e., a solvent). We present a new ...
    • Revised ΔR values for the Barents Sea and its archipelagos as a pre-requisite for accurate and robust marine-based 14C chronologies 

      Pienkowski, Anna; Husum, Katrine; Furze, Mark; Missana, Amandine F.J.; Irvali, Nil; Divine, Dmitry V.; Eilertsen, Vårin Trælvik (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-11)
      The calibration of marine 14C dates requires the incorporation of regionally specific marine reservoir offsets known as ΔR, essential for accurate and meaningful inter-archive comparisons. Revised, regional ΔR (‘ΔRR’) values for the Barents Sea are presented for molluscs and cetaceans for the two latest iterations of the marine calibration curve, based on previously published pre-bomb live-collected ...
    • Physical conditions and frictional properties in the source region of a slow-slip event 

      Arnulf, Adrien F.; Biemiller, James; Lavier, Luc; Wallace, Laura M.; Bassett, Dan; Henrys, Stuart; Pecher, Ingo; Crutchley, Gareth; Plaza-Faverola, Andreia (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-06)
      Recent geodetic studies have shown that slow-slip events can occur on subduction faults, including their shallow (<15 km depth) parts where tsunamis are also generated. Although observations of such events are now widespread, the physical conditions promoting shallow slow-slip events remain poorly understood. Here we use full waveform inversion of controlled-source seismic data from the central ...