Viser treff 2021-2040 av 5445

    • The computational complexity of understanding binary classifier decisions 

      Wäldchen, Stephan; Macdonald, Jan; Hauch, Sascha; Kutyniok, Gitta Astrid Hildegard (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-21)
      For a d-ary Boolean function Φ: {0, 1}<sup>d</sup> → {0, 1} and an assignment to its variables x = (x<sub>1</sub>, x<sub>2</sub>, . . . , x<sub>d</sub>) we consider the problem of finding those subsets of the variables that are sufficient to determine the function value with a given probability δ. This is motivated by the task of interpreting predictions of binary classifiers described as Boolean ...
    • Multimodal on-chip nanoscopy and quantitative phase imaging reveals the nanoscale morphology of liver sinusoidal endothelial cells 

      Butola, Ankit; Coucheron, David Andre; Szafranska, Karolina; Ahmad, Azeem; Mao, Hong; Tinguely, Jean-Claude; McCourt, Peter Anthony; Paramasivam, Senthilkumaran; Mehta, Dalip Singh; Agarwal, Krishna; Ahluwalia, Balpreet Singh (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-23)
      Visualization of three-dimensional (3D) morphological changes in the subcellular structures of a biological specimen is a major challenge in life science. Here, we present an integrated chip-based optical nanoscopy combined with quantitative phase microscopy (QPM) to obtain 3D morphology of liver sinusoidal endothelial cells (LSEC). LSEC have unique morphology with small nanopores (50-300 nm in ...
    • First Studies of Mesosphere and Lower Thermosphere Dynamics Using a Multistatic Specular Meteor Radar Network Over Southern Patagonia 

      Conte, J. F.; Chau, Jorge L.; Urco, Juan M.; Latteck, Ralph; Vierinen, Juha; Salvador, Jacobo (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-18)
      This paper presents for the first time results on winds, tides, gradients of horizontal winds, and momentum fluxes at mesosphere and lower thermosphere altitudes over southern Patagonia, one of the most dynamically active regions in the world. For this purpose, measurements provided by SIMONe Argentina are investigated. SIMONe Argentina is a novel multistatic specular meteor radar system ...
    • Explicit values for Ramanujan's theta function φ(q) 

      Berndt, Bruce C.; Rebák, Örs (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-09)
      This paper provides a survey of particular values of Ramanujan's theta function φ(q) = ∑ q^(n^2), n = −∞ ... ∞, when q = e^(−π√n), where n is a positive rational number. First, descriptions of the tools used to evaluate theta functions are given. Second, classical values are briefly discussed. Third, certain values due to Ramanujan and later authors are given. Fourth, the methods that are used to ...
    • Physics-based machine learning for subcellular segmentation in living cells 

      Sekh, Arif Ahmed; Opstad, Ida Sundvor; Godtliebsen, Gustav; Birgisdottir, Åsa Birna; Ahluwalia, Balpreet Singh; Agarwal, Krishna; Prasad, Dilip K. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-15)
      Segmenting subcellular structures in living cells from fluorescence microscope images is a ground truth (GT)-deficient problem. The microscopes’ three-dimensional blurring function, finite optical resolution due to light diffraction, finite pixel resolution and the complex morphological manifestations of the structures all contribute to GT-hardness. Unsupervised segmentation approaches are quite ...
    • Coloring the Voronoi tessellation of lattices 

      Dutour Sikirić, Mathieu; Madore, David A.; Moustrou, Philippe; Vallentin, Frank (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-03)
      In this paper we define the chromatic number of a lattice: It is the least number of colors one needs to color the interiors of the cells of the Voronoi tessellation of a lattice so that no two cells sharing a facet are of the same color. We compute the chromatic number of the root lattices, their duals, and of the Leech lattice, we consider the chromatic number of lattices of Voronoi’s first ...
    • Detection of ground contact times with inertial sensors in elite 100-m sprints under competitive field conditions 

      Blauberger, Patrick; Horsch, Alexander; Lames, Martin (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-04)
      This study describes a method for extracting the stride parameter ground contact time (GCT) from inertial sensor signals in sprinting. Five elite athletes were equipped with inertial measurement units (IMU) on their ankles and performed 34 maximum 50 and 100-m sprints. The GCT of each step was estimated based on features of the recorded IMU signals. Additionally, a photo-electric measurement ...
    • Decadal trend of plankton community change and habitat shoaling in the Arctic gateway recorded by planktonic foraminifera 

      Greco, Mattia; Werner, Kristin; Zamelczyk, Katarzyna; Rasmussen, Tine Lander; Kucera, Michal (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-16)
      The Fram Strait plays a crucial role in regulating the heat and sea-ice dynamics in the Arctic. In response to the ongoing global warming, the marine biota of this Arctic gateway is experiencing significant changes with increasing advection of Atlantic species. The footprint of this ‘Atlantification’ has been identified in isolated observations across the plankton community, but a systematic, ...
    • Finite-sample properties of estimators for first and second order autoregressive processes 

      Sørbye, Sigrunn Holbek; Nicolau, Pedro Guilherme; Rue, Håvard (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-05)
      The class of autoregressive (AR) processes is extensively used to model temporal dependence in observed time series. Such models are easily available and routinely fitted using freely available statistical software like R. A potential problem is that commonly applied estimators for the coefficients of AR processes are severely biased when the time series are short. This paper studies the ...
    • High natural PHA production from acetate in Cobetia sp. MC34 and Cobetia marina DSM 4741T and in silico analyses of the genus specific PhaC2 polymerase variant 

      Christensen, Mikkel; Jablonski, Piotr; Altermark, Bjørn; Irgum, Knut; Hansen, Hilde (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-20)
      Background: Several members of the bacterial Halomonadacea family are natural producers of polyhydroxyalkanoates (PHA), which are promising materials for use as biodegradable bioplastics. Type-strain species of Cobetia are designated PHA positive, and recent studies have demonstrated relatively high PHA production for a few strains within this genus. Industrially relevant PHA producers may therefore ...
    • MSRF-Net: A Multi-Scale Residual Fusion Network for Biomedical Image Segmentation 

      Srivastava, Abhishek; Jha, Debesh; Chanda, Sukalpa; Pal, Umapada; Johansen, Håvard D.; Johansen, Dag; Riegler, Michael; Ali, Sharib; Halvorsen, Pål (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-23)
      Methods based on convolutional neural networks have improved the performance of biomedical image segmentation. However, most of these methods cannot efficiently segment objects of variable sizes and train on small and biased datasets, which are common for biomedical use cases. While methods exist that incorporate multi-scale fusion approaches to address the challenges arising with variable ...
    • Supramolecular coronation of platinum(II) complexes by macrocycles: Structure, relativistic DFT calculations, and biological effects 

      Sojka, Martin; Chyba, Jan; Paul, Shib Shankar; Wawrocka, Karolina; Honigova, Katerina; Cuyacot, Ben Joseph R.; Castro, Abril C.; Vaculovic, Tomas; Marek, Jaromir; Repisky, Michal; Masarik, Michal; Novotny, Jan; Marek, Radek (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-05)
      Platinum-based anticancer drugs are actively developed utilizing lipophilic ligands or drug carriers for the efficient penetration of biomembranes, reduction of side effects, and tumor targeting. We report the development of a supramolecular host–guest system built on cationic platinum(II) compounds bearing ligands anchored in the cavity of the macrocyclic host. The host–guest binding and hydrolysis ...
    • Evaluation of global EMEP MSC-W (rv4.34) WRF (v3.9.1.1) model surface concentrations and wet deposition of reactive N and S with measurements 

      Ge, Yao; Heal, Mathew R; Stevenson, David S.; Wind, Peter; Vieno, Massimo (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-18)
      Atmospheric pollution has many profound effects on human health, ecosystems, and the climate. Of concern are high concentrations and deposition of reactive nitrogen (N<sub>r</sub>) species, especially of reduced N (gaseous NH<sub>3</sub>, particulate NH<sub>4</sub> <sup>+</sup>). Atmospheric chemistry and transport models (ACTMs) are crucial to understanding sources and impacts of N<sub>r</sub> ...
    • Intrinsic Strand-Incision Activity of Human UNG: Implications for Nick Generation in Immunoglobulin Gene Diversification 

      Alexeeva, Marina; Moen, Marivi Nabong; Xu, Xiang Ming; Rasmussen, Anette; Leiros, Ingar; Kirpekar, Finn; Klungland, Arne; Alsøe, Lene; Nilsen, Hilde; Bjelland, Svein (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-22)
      Uracil arises in cellular DNA by cytosine (C) deamination and erroneous replicative incorporation of deoxyuridine monophosphate opposite adenine. The former generates C ! thymine transition mutations if uracil is not removed by uracil-DNA glycosylase (UDG) and replaced by C by the base excision repair (BER) pathway. The primary human UDG is hUNG. During immunoglobulin gene diversification in ...
    • Generalization of Intrinsic Orbitals to Kramers-Paired Quaternion Spinors, Molecular Fragments, and Valence Virtual Spinors 

      Senjean, Bruno; Sen, Souloke; Repisky, Michal; Knizia, Gerald; Visscher, Lucas (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-08)
      Localization of molecular orbitals finds its importance in the representation of chemical bonding (and antibonding) and in the local correlation treatments beyond mean-field approximation. In this paper, we generalize the intrinsic atomic and bonding orbitals [G. Knizia, J. Chem. Theory Comput. 2013, 9, 11, 4834–4843] to relativistic applications using complex and quaternion spinors, as well as to ...
    • Evaluation of the Climate Forecast System Reanalysis data for hydrological model in the Arctic watershed Målselv 

      Bui, Minh Tuan; Lu, Jinmei; Nie, Linmei (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-04-13)
      The high-resolution Climate Forecast System Reanalysis (CFSR) data have recently become an alternative input for hydrological models in data-sparse regions. However, the quality of CFSR data for running hydrological models in the Arctic is not well studied yet. This paper aims to compare the quality of CFSR data with ground-based data for hydrological modeling in an Arctic watershed, Målselv. The ...
    • Implementation of Relativistic Coupled Cluster Theory for Massively Parallel GPU-Accelerated Computing Architectures 

      Pototschnig, Johann V.; Papadopoulos, Anastasios; Lyakh, Dmitry I.; Repisky, Michal; Halbert, Loïc; Gomes, Andre Severo Pereira; Jensen, Hans Jørgen Aa.; Visscher, Lucas (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-09)
      In this paper, we report reimplementation of the core algorithms of relativistic coupled cluster theory aimed at modern heterogeneous high-performance computational infrastructures. The code is designed for parallel execution on many compute nodes with optional GPU coprocessing, accomplished via the new ExaTENSOR back end. The resulting ExaCorr module is primarily intended for calculations of molecules ...
    • Multiobjective optimization of a hybrid wind/solar battery energy system in the Arctic 

      Nguyen, Tuan Thanh; Boström, Tobias Kristoffer (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-04-30)
      This paper presents an optimal design of a hybrid wind turbine/PV/battery energy system for a household application using a multiobjective optimization approach, namely, particle swarm optimization (PSO). The ultimately optimal component selection of the hybrid renewable energy system (HRES) is suggested by comprehensively investigating the effects of various factors on the cost-reliability relation, ...
    • Northeast Arctic Cod and Prey Match-Mismatch in a High-Latitude Spring-Bloom System 

      Vikebø, Frode Bendiksen; Broch, Ole Jacob; Kajiya Endo, Clarissa Akemi; Frøysa, Håvard G; Carroll, JoLynn; Juselius, Jonas; Langangen, Øystein Ole Gahr (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-20)
      By combining an ocean model, a nutrient-phytoplankton-zooplankton-detritus-model and an individual-based model for early life stages of Northeast Arctic cod we systematically investigate food limitations and growth performance for individual cod larvae drifting along the Norwegian coast from spawning grounds toward nursery areas in the Barents Sea. We hypothesize that there is food shortage for ...
    • A discipline without a name? Contrasting three fields dealing with hazards and disaster 

      Staupe-Delgado, Reidar; Abdel-Fattah, Dina; Pursiainen, Christer Henrik (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-29)
      A growing number of research fields have been striving for recognition as an academic discipline. Rather than argue that ‘our field’ should also be recognised as such, we stop to ask two fundamental questions. Our first question concerns whether and how disciplinary concerns would benefit research fields dealing with hazards and disasters. Second, we reflect on the implications of not having a broadly ...