Viser treff 1-20 av 5226

    • Three-dimensional modeling of diffusion-gravity flows in ice-covered lakes 

      Sharifi, Fatemeh Sadat; Hinkelmann, Reinhard; Hattermann, Tore; Kirillin, Georgiy (Journal article; Tidsskriftartikkel; Peer reviewed, 2025-03-03)
      When a solid inclined surface is submerged in a quiescent stratified fluid, the combined effects of buoyancy forces and diffusion generate an upward gravity flow along the slope. Thermally stratified ice-covered lakes remain in a nearly quiescent state and are potentially prone to this effect. We use three-dimensional hydrodynamic modeling to investigate the diffusion-gravity flow and its impact on ...
    • A multi-stage multi-criteria dynamic decision-making framework for fishing route planning and optimization 

      Zhu, Tiantian; Naseri, Masoud; Dhar, Sushmit (Chapter; Bokkapittel, 2024)
      Fishing is a main activity in the Barents Sea. Improving fishing vessel trip planning is a feasible way to improve fishing efficiency, profitability, sustainability and at the same time reducing accidental risk from hazardous weather conditions and reducing environmental impact by reducing fuel consumption. Today, fishing trip planning and route optimization is all up to skippers`s experiences. ...
    • Misconfiguration of Cluster and IoT Systems Recovery: Extended Experiments 

      Elgazazz, Areeg Samir Ahmed; Dagenborg, Håvard Johansen; El Ioini, Nabil (Chapter; Bokkapittel, 2024-08-15)
      Containerized cluster systems and edge devices are vulnerable to security breaches when configuration errors occur. In this paper, we propose more experiments on the self-healing approach for misconfigurations that adopt a Markov Decision Process to determine the optimal recovery action or policy that maximizes performance metrics. The experiments conducted are an improvement on our previous ...
    • REFLECTIONS ON ABSTRACTION IN A WORLD WHERE ATTACHMENT TO PLACE MATTERS 

      Wagner, David; Andersson, Annica; Dewolfe, Sacha; Gerbrandt, Julianne; Huru, Hilja Lisa; Simensen, Anita Movik; Wirkola, Elisabeth (Chapter; Bokkapittel, 2025-01)
      In an earlier reflection, we drew on our experiences, especially in Indigenous contexts, to consider how detachment connects with abstraction (Huru, Andersson & Wagner, 2023). We described abstraction as a process that attaches an idea to an experience—e.g., the realization that a line carved into a bone can represent a real thing, or five such lines, or the symbol 5 referring to the five lines. But ...
    • Fusjon – den endelige energiløsningen for menneskeheten? 

      Csernai, László Pál; Garcia, Odd Erik; Hansen, Jan Petter (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-10-08)
      Siden andre verdenskrig har det pågått et storstilt internasjonalt forskningsprosjekt med mål om å bruke fusjonsprosesser til å lage ren elektrisk energi for menneskeheten fra tilnærmet ubegrensede ressurser. Det pågår nå et storstilt kappløp for å utvikle den første demonstrasjonsreaktoren. Denne artikkelen gir en kortfattet beskrivelse av historien bak og status for kappløpet, og den avsluttes med ...
    • Lithology as a factor for the distribution of metals in stream sediments associated with sediment-hosted Cu deposits: a case study from the Alta-Kvænangen tectonic window, northern Norway 

      Posaric, Laura; Strmic Palinkas, Sabina; Hilmo, Johan; Fiket, Zeljka; Čobić, Andrea; Fajkovic, Hana (Journal article; Tidsskriftartikkel; Peer reviewed, 2025-03-04)
      The Kåfjord area in northern Norway hosts numerous Cu deposits that were subjected to mining activities back in the nineteenth century. Relicts of the historical mining activity are still visible at several abandoned mines and associated mine waste disposal sites that may represent an environmental threat. The area was subjected to mining activities during the nineteenth century and abandoned mines ...
    • What are end-users’ needs and preferences for a comprehensive e-health program for type 2 diabetes? – A qualitative user preference study 

      Rishaug, Tina; Aas, Anne-Marie; Henriksen, André; Hartvigsen, Gunnar; Birkeland, Kåre Inge; Årsand, Eirik (Journal article; Tidsskriftartikkel; Peer reviewed, 2025-03-03)
      Introduction - Type 2 diabetes (T2D) prevalence is rising, which imposes a significant burden on individuals, healthcare systems, and economies worldwide. Lifestyle factors contribute significantly to the escalating incidence of T2D. Consequently, there is an increasing need for interventions that not only target at-risk populations for prevention but also empower individuals with T2D to achieve ...
    • 3D seismic investigation of fluid migration and fluid accumulation related to natural seeps in the Sørvestsnaget Basin, SW Barents Sea 

      Asvald, Marcus Våg (Mastergradsoppgave; Master thesis, 2025-01-27)
      This master thesis examines the intricacies of fluid migration, gas seep areas, and fault dynamics in the southwestern Barents Sea. Acoustic evidence, such as pockmarks and gas flares, indicates active fluid movement within the below seabed sedimentary structures, such as clinoforms and the Upper Regional Unconformity (URU). Challenging lowermost reaches of gas chimneys, obscured by acoustic masking, ...
    • Development of an Environmental Impact Methodology for Arctic Ship- ping: Exploring FMEA and STPA applications considering a Dynamic (varying) Baseline 

      Stirpe, Giacomo; Gudmestad, Ove Tobias (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-09-19)
      Arctic shipping poses environmental risks due to the region's fragile ecosystems and rapid climate changes. Effective risk assessment tools are needed to ensure sustainable expansion and to carry out environmental impact assessments. This paper explores applications of Failure Modes and Effects Analysis (FMEA) and Systems-Theoretic Process Analysis (STPA) coupled with the consequences of a “Dynamic ...
    • Empirical Study and Modelling of Sea-Spray Parameters for Robust Marine Icing Estimation 

      Dhar, Sushmit (Doctoral thesis; Doktorgradsavhandling, 2025-03-20)
      Sea-spray icing poses a significant risk to maritime operations in Arctic and sub-Arctic regions, threatening the stability, safety, and efficiency of vessels and offshore structures. Current icing estimation models are constrained by limited data and are often tailored to specific vessels or structures. A critical challenge lies in accurately estimating spray flux, which is the amount of water ...
    • Life Test and Modelling for Carbon Film Fixed Resistor under Escalated Voltage Stress 

      Yuan, Fuqing; Lu, Jinmei (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-09-23)
      The endurance of the electronic component under an overstress situation is important for the reliability and safety of electronic systems. Failure, and even catastrophic disaster, can occur when voltage overstress last a certain period. This article investigates the thermal and electrical change in resistors under overstressed voltage. The carbon film fixed resistor is taken as an example. Through ...
    • Parameter estimation for the weibull general log-linear model in accelerated life testing 

      Yuan, Fuqing; Lu, Jinmei (Journal article; Tidsskriftartikkel; Peer reviewed, 2025)
      Uncertainty is commonly present in accelerated life test (ALT) data. The combination of a general log-linear model with a statistical distribution model—using the Weibull distribution in this paper—allows for addressing both multiple operational factors and uncertainty within a single model. This paper interprets the Weibull General Log-Linear (WGLL) model from the ALT perspective. Two parameter ...
    • A Novel Device for Accurate Measurement of Spray Frequency and Duration using Capacitive Liquid Sensors in Marine Icing Estimation 

      Dhar, Sushmit; Naseri, Masoud; Zhu, Tiantian; Edvardsen, Kåre (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-06-16)
      Spray duration and frequency are essential parameters to consider when estimating ice accretion on marine structures. The existing expressions for these parameters are derived from limited data, given the challenges in field measurement and the absence of suitable techniques. This paper introduces a novel device utilizing capacitive sensors to accurately measure spray duration and frequency. The ...
    • Comparison of Optimal Reactive Power Dispatch Methods in IEEE 30 Bus System 

      Sachan, Sulabh; Mishra, Sambeet; Øyvang, Thomas; Bordin, Chiara (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-10-19)
      It has been noted that a number of metaheuristics are applied with success to power system optimal reactive power dispatch (ORPD) challenges. These algorithms’ convergence rates are also determined to be low, and the results they provide are deemed to be inadequate. It suggests that there is insufficient investigation and exploitation in the algorithm. Therefore, an appropriate approach is needed ...
    • Addressing Label Shift in Distributed Learning via Entropy Regularization​ 

      Wu, Zhiyuan; Choi, Changkyu; Cevher, Volkan; Ramezani-Kebrya, Ali (Journal article; Tidsskriftartikkel; Peer reviewed, 2025-01-22)
      We address the challenge of minimizing "true risk" in multi-node distributed learning.\footnote{We use the term node to refer to a client, FPGA, APU, CPU, GPU, or worker.} These systems are frequently exposed to both inter-node and intra-node "label shifts", which present a critical obstacle to effectively optimizing model performance while ensuring that data remains confined to each node. To tackle ...
    • Influence of Accelerometer Calibration on the Estimation of Objectively Measured Physical Activity: The Tromsø Study 

      Weitz, Marc Stephan; Morseth, Bente; Hopstock, Laila Arnesdatter; Horsch, Ludwig Alexander (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-01-11)
      Accelerometers are increasingly used to observe human behavior such as physical activity under free-living conditions. An important prerequisite to obtain reliable results is the correct calibration of the sensors. However, accurate calibration is often neglected, leading to potentially biased results. Here, we demonstrate and quantify the effect of accelerometer miscalibration on the estimation of ...
    • Long-range correlations with finite-size effects from a superposition of uncorrelated pulses with power-law distributed durations 

      Korzeniowska, Magdalena A.; Garcia, Odd Erik (Journal article; Tidsskriftartikkel; Peer reviewed, 2025-02-26)
      Long-range correlations manifested as power spectral density scaling 1/<i>f<sup>β</sup></i> for frequency f and a range of exponents <i>β</i> are investigated for a superposition of uncorrelated pulses with distributed durations τ. Closed-form expressions for the frequency power spectral density are derived for a one-sided exponential pulse function and several variants of bounded and unbounded ...
    • New xenophyophores (Foraminifera, Monothalamea) from the eastern Clarion-Clipperton Zone (equatorial Pacific) 

      Gooday, Andrew J.; Holzmann, Maria; Barrenechea Angeles, Inés; Lim, Swee-Cheng; Pawlowski, Jan (Journal article; Tidsskriftartikkel, 2024-03-06)
      Xenophyophores are large, agglutinated foraminifera that dominate the benthic megafauna in some parts of the deep sea. Here, we describe an assemblage of largely fragmentary specimens from the Clarion-Clipperton Zone (CCZ), an area of the eastern abyssal Pacific hosting large, commercially significant deposits of polymetallic nodules. We recognised 18 morphospecies of which eight yielded DNA sequences. ...
    • Cultural activity and impact of extreme weather events revealed by ambient seismic noise and perspective on quick clay failure monitoring in Oslo, Norway 

      Bruland, Charlotte; Dichiarante, Anna Maria; Köhler, Andreas; Oye, Volker; Van Bever, Ivan; Larose, Eric (Journal article; Tidsskriftartikkel; Peer reviewed, 2025-02-01)
      The study of urban seismic noise offers various approaches to monitor cities, from source identification to structural investigations. We demonstrate its potential to monitor cultural activity and quick clay failure in Oslo, Norway using low-cost seismic sensors. We identify train passages, a rock concert, construction blasts, local earthquakes and a meteor. To retrieve seismic velocity variations ...
    • Importance of grain boundary processes for plasticity in the quartz-dominated crust: Implications for flow laws 

      Ghosh, Subhajit; Stunitz, Holger; Raimbourg, Hugues; Précigout, Jacques; Di Carlo, Ida; Heilbronner, Renee; Piani, Laurette (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-06-01)
      When H<sub>2</sub>O is present along grain boundaries, the deformation processes responsible for plasticity in silicate mineral aggregates can deviate from what may be conventionally expected. Although a necessary component of understanding crustal deformation processes, there is no theoretical framework that incorporates grain boundary processes into polycrystalline quartz rheology. To address this ...