Viser treff 653-672 av 942

    • A Possible Explanation of Interhemispheric Asymmetry of Equatorial Plasma Bubbles in Airglow Images 

      Hickey, Dustin A.; Sau, Sukanta; Narayanan, Viswanathan Lakshmi; Gurubaran, S. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-28)
      Equatorial plasma bubbles resulting from equatorial spread urn:x-wiley:jgra:media:jgra55597:jgra55597-math-0002 are well known to be aligned along the Earth's geomagnetic fields. During the geomagnetic storm on 17 March 2015, all‐sky airglow observations from Tirunelveli (8.7°N, 77.8°E, 1.7°N dip latitude) showed an apparent interhemispheric asymmetry in the tilt of the equatorial plasma bubbles. ...
    • Power law spectra and intermittent fluctuations due to uncorrelated Lorentzian pulses 

      Garcia, Odd Erik; Theodorsen, Audun (Peer reviewed; Journal article; Tidsskriftsartikkel, 2017-02)
      A stochastic model for intermittent fluctuations due to a super-position of uncorrelated Lorentzian pulses is presented. For a constant pulse duration, this is shown to result in an exponential power spectral density for the stationary process. A random distribution of pulse durations modifies the frequency spectrum, and several examples are shown to result in power law spectra. The distribution of ...
    • Power-law scaling of uncorrelated plasma bursts 

      Theodorsen, Audun; Garcia, Odd Erik; Rypdal, Martin wibe (Conference object; Konferansebidrag, 2019-07)
    • Preconditioning of Summer Melt Ponds From Winter Sea Ice Surface Temperature 

      Thielke, Linda; Fuchs, Niels; Spreen, Gunnar; Tremblay, Bruno; Birnbaum, Gerit; Huntemann, Marcus; Hutter, Nils; Itkin, Polona; Jutila, Arttu; Webster, Melinda A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-22)
      Comparing helicopter-borne surface temperature maps in winter and optical orthomosaics in summer from the year-long Multidisciplinary drifting Observatory for the Study of Arctic Climate expedition, we find a strong geometric correlation between warm anomalies in winter and melt pond location the following summer. Warm anomalies are associated with thinner snow and ice, that is, surface depression ...
    • Predicting Energy Demand in Semi-Remote Arctic Locations 

      Foldvik Eikeland, Odin; Bianchi, Filippo Maria; Chiesa, Matteo; Apostoleris, Harry; Hansen, Morten; Chiou, Yu-Cheng (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-03)
      Forecasting energy demand within a distribution network is essential for developing strategies to manage and optimize available energy resources and the associated infrastructure. In this study, we consider remote communities in the Arctic located at the end of the radial distribution network without alternative energy supply. Therefore, it is crucial to develop an accurate forecasting model to ...
    • Predicting Regions of Local Recurrence in Glioblastomas Using Voxel-Based Radiomic Features of Multiparametric Postoperative MRI 

      Cepeda, Santiago; Luppino, Luigi Tommaso; Pérez-Núñez, Angel; Solheim, Ole Skeidsvoll; García-García, Sergio; Velasco-Casares, María; Karlberg, Anna Maria; Eikenes, Live; Sarabia, Rosario; Arrese, Ignacio; Zamora, Tomás; Gonzalez, Pedro; Jiménez-Roldán, Luis; Kuttner, Samuel (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-22)
      The globally accepted surgical strategy in glioblastomas is removing the enhancing tumor. However, the peritumoral region harbors infiltration areas responsible for future tumor recurrence. This study aimed to evaluate a predictive model that identifies areas of future recurrence using a voxel-based radiomics analysis of magnetic resonance imaging (MRI) data. This multi-institutional study included ...
    • Predicting the suitability of lateritic soil type for low cost sustainable housing with image recognition and machine learning techniques 

      Olukan, Tuza Adeyemi; Chiou, Yu-Cheng; Chiu, Cheng-Hsiang; Lai, Chia-Yun; Santos Hernandez, Sergio; Chiesa, Matteo (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-10)
      From a sustainability point of view, laterites-compressed earth bricks (LCEB) are a promising substitute for building structures in place of the conventional concrete masonry units. On the other hand, techniques for identifying and classifying laterites soil for compressed earth bricks (CEB) production are still relying on direct human expertise or ‘experts’. Human experts exploit direct visual ...
    • Preliminary Assessment of Remote Wind Sites 

      Bilal, Muhammad; Araya, Guillermo; Birkelund, Yngve (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08)
      Wind energy is becoming a reliable and affordable source of clean energy and is rapidly expanding to remote places around the world. A crucial input for wind farming prospect is the assessment of potential wind sites. Sites, especially remotely located, often do not have a wind resource map and thus lack credible historical records of wind resources. Measurement campaigns to map these sites are ...
    • Probabilistic forecasts of wind power generation in regions with complex topography using deep learning methods: An Arctic case 

      Foldvik Eikeland, Odin; Hovem, Finn Dag; Olsen, Tom Eirik; Chiesa, Matteo; Bianchi, Filippo Maria (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-05-27)
      The energy market relies on forecasting capabilities of both demand and power generation that need to be kept in dynamic balance. Nowadays, contracts and auctions of renewable energy in a liberalized electricity market heavily rely on forecasting future power generation. The highly intermittent nature of renewable energy sources increases the uncertainty about future power generation. Since point ...
    • A probabilistic framework for source localization in anisotropic composite using transfer learning based multi-fidelity physics informed neural network (mfPINN) 

      Kalimullah, Nur M.-M.; Shelke, Amit; Habib, Anowarul (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-17)
      The practical application of data-driven frameworks like deep neural network in acoustic emission (AE) source localization is impeded due to the collection of significant clean data from the field. The utility of the such framework is governed by data collected from the site and/or laboratory experiment. The noise, experimental cost and time consuming in the collection of data further worsen the ...
    • Probability distribution functions for intermittent scrape-off layer plasma fluctuations 

      Theodorsen, Audun; Garcia, Odd Erik (Journal article; Peer reviewed; Tidsskriftartikkel, 2018-01-24)
      A stochastic model for intermittent fluctuations in the scrape-off layer of magnetically confined plasmas has been constructed based on a super-position of uncorrelated pulses arriving according to a Poisson process. In the most common applications of the model, the pulse amplitudes are assumed exponentially distributed, supported by conditional averaging of large-amplitude fluctuations in experimental ...
    • Probing power laws in multifrequency AFM 

      Santos Hernandez, Sergio; Gadelrab, Karim; Olukan, Tuza Adeyemi; Font, Josep; Barcons, Victor; Chiesa, Matteo (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-17)
      Quantification of conservative forces in multifrequency atomic force microscopy requires solving the general equations of the theory expressed in terms of the virials of interaction. Power law expressions are commonly utilized when dealing with electrostatic, ferroelectric, magnetic, or long range (van der Waals) forces. Here, we discuss long range forces modeled in terms of power laws (n), where ...
    • A procedure to correct the effects of a relative delay between the quadrature components of radar signals at base band. 

      Westman, A.; Grydeland, Tom; Belyey, Vasyl; La Hoz, Cesar (Journal article; Peer reviewed; Tidsskriftartikkel, 2005-01-31)
      The real and imaginary parts of baseband signals are obtained from a real narrow–band signal by quadrature mixing, i.e. by mixing with cosine and sine signals at the narrow band’s selected center frequency. We address the consequences of a delay between the outputs of the quadrature mixer, which arise when digital samples of the quadrature baseband signals are not synchronised, i.e. when ...
    • Productive detours – Atlantic water inflow and acoustic backscatter in the major troughs along the Svalbard shelf 

      Menze, Sebastian; Ingvaldsen, Randi Brunvær; Nikolopoulos, Anna; Hattermann, Tore; Albretsen, Jon; Gjøsæter, Harald (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-30)
      Atlantic Water (AW) flowing along the western and northern Svalbard shelf-break extends the Atlantic domain into the Arctic and is the region’s major source of heat, nutrients and advected plankton. We investigated the inflow and recirculation of AW into four major troughs that cut into the Svalbard shelf, the Isfjorden, Kongsfjorden, Hinlopen and Kvitøya Troughs, and related the circulation patterns ...
    • Pronounced Suppression and X-Pattern Merging of Equatorial Ionization Anomalies After the 2022 Tonga Volcano Eruption 

      Aa, Ercha; Zhang, Shun-Rong; Wang, Wenbing; Erickson, Philip J.; Qian, Liying; Eastes, Richard W.; Harding, Brian; Immel, Thomas; Karan, Deepak; Daniell, Robert E.; Coster, Anthea J.; Goncharenko, Larisa P.; Vierinen, Juha; Cai, Xuguang; Spicher, Andres (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-05-27)
      Following the 2022 Tonga Volcano eruption, dramatic suppression and deformation of the equatorial ionization anomaly (EIA) crests occurred in the American sector ∼14,000 km away from the epicenter. The EIA crests variations and associated ionosphere-thermosphere disturbances were investigated using Global Navigation Satellite System total electron content data, Global-scale Observations of the ...
    • Properties and dynamics of mesoscale eddies in Fram Strait from a comparison between two high-resolution ocean-sea ice models 

      Wekerle, Claudia; Hattermann, Tore; Wang, Qiang; Crews, Laura; von Appen, Wilken-Jon; Danilov, Sergey (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-23)
      Fram Strait, the deepest gateway to the Arctic Ocean, is strongly influenced by eddy dynamics. Here we analyse the output from two eddy-resolving models (ROMS – Regional Ocean Modeling System; FESOM – Finite-Element Sea-ice Ocean Model) with around 1 km mesh resolution in Fram Strait, with a focus on their representation of eddy properties and dynamics. A comparison with mooring observations shows ...
    • A Protocol for Single-Molecule Translation Imaging in Xenopus Retinal Ganglion Cells 

      Ströhl, Florian; Lin, Julie Qiaojin; Tartwijk, Francesca W. van; Wong, Hovy Ho Wai; Holt, Christine E.; Kaminski, Clemens F. (Chapter; Bokkapittel, 2020-04-29)
      Single-molecule translation imaging (SMTI) is a straightforward technique for the direct quantification of local protein synthesis. The protein of interest is fused to a fast-folding and fast-bleaching fluorescent protein, allowing one to monitor the appearance of individual fluorescence events after photobleaching of pre-existing proteins in the cell under investigation. The translation of individual ...
    • ProtoVAE: A Trustworthy Self-Explainable Prototypical Variational Model 

      Gautam, Srishti; Boubekki, Ahcene; Hansen, Stine; Salahuddin, Suaiba Amina; Jenssen, Robert; Hohne, Marina Marie-Claire; Kampffmeyer, Michael (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-10-15)
      The need for interpretable models has fostered the development of self-explainable classifiers. Prior approaches are either based on multi-stage optimization schemes, impacting the predictive performance of the model, or produce explanations that are not transparent, trustworthy or do not capture the diversity of the data. To address these shortcomings, we propose ProtoVAE, a variational autoencoder-based ...
    • Pulsating aurora and cosmic noise absorption associated with growth-phase arcs 

      McKay, Derek; Partamies, Noora; Vierinen, Juha (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-18)
      The initial stage of a magnetospheric substorm is the growth phase, which typically lasts 1–2 h. During the growth phase, an equatorward moving, east–west extended, optical auroral arc is observed. This is called a growth-phase arc. This work aims to characterize the optical emission and riometer absorption signatures associated with growth-phase arcs of isolated substorms. This is done using ...
    • The pulsation modes of the pre-white dwarf PG 1159-035 

      Costa, J. E. S.; Solheim, Jan Erik; Kepler, S. O.; Winget, D. E.; O’Brien, M. S.; Kawaler, S. D.; Costa, A. F. M.; Giovannini, O.; Kanaan, A.; Mukadam, A. S.; Mullally, F.; Nitta, A.; Provenc, J. L.; Shipman, H.; Wood, M. A.; Ahrens, T. J.; Grauer, A.; Kilic, M.; Bradley, P. A.; Sekiguchi, K.; Crowe, R.; Jiang, X. J.; Sullivan, D.; Sullivan, T.; Rosen, R.; Clemens, J. C.; Janulis, R.; O’Donoghue, D.; Ogloza, W.; Baran, A.; Silvotti, R.; Marinoni, S.; Vauclair, G.; Dolez, N.; Chevreton, M.; Dreizler, S.; Schuh, S.; Deetjen, J.; Nagel, T.; Gonzalez Perez, J. M.; Ulla, A.; Barstow, Martin; Burleigh, M.; Good, S.; Metcalfe, T.S.; Kim, S.-L.; Lee, H.; Sergeev, A.; Akan, M.C.; Çakırlı, Ö.; Paparo, M.; Viraghalmy, G.; Ashoka, B. N.; Handler, G.; Hürkal, Özlem; Johannessen, F.; Kleinman, S. J.; Kalytis, R.; Krzesinski, J.; Klumpe, E.; Larrison, J.; Lawrence, T.; Meištas, E.; Martinez, P.; Nather, R. E.; Fu, J.-N.; Pakštienė, E.; Rosen, R.; Romero-Colmenero, E.; Riddle, R.; Seetha, S.; Silvestri, N. M.; Vučković, M.; Warner, B.; Zola, S.; Althaus, L. G.; Córsico, A. H.; Montgomery, M. H. (Journal article; Tidsskriftartikkel; Peer reviewed, 2008)
      Context. PG 1159-035, a pre-white dwarf with Teff ≃ 140 000 K, is the prototype of both two classes: the PG 1159 spectroscopic class and the DOV pulsating class. Previous studies of PG 1159-035 photometric data obtained with the Whole Earth Telescope (WET) showed a rich frequency spectrum allowing the identification of 122 pulsation modes. Analyzing the periods of pulsation, it is possible to ...