Viser treff 1570-1589 av 4757

    • Four-component relativistic density functional theory with the polarisable continuum model: application to EPR parameters and paramagnetic NMR shifts 

      Di Remigio, Roberto; Repisky, Michal; Komorovsky, Stanislav; Hrobárik, Peter; Frediani, Luca; Ruud, Kenneth (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-01-01)
      The description of chemical phenomena in solution is as challenging as it is im- portant for the accurate calculation of molecular properties. Here, we present the implementation of the polarizable continuum model (PCM) in the four-component Dirac–Kohn–Sham density functional theory framework, o ↵ ering a cost-e ↵ ective way to concurrently model solvent and relativistic e ↵ ects. The ...
    • Four-Component Relativistic Density-Functional Theory Calculations of Nuclear Spin-Rotation Constants: Relativistic Effects in p-Block Hydrides 

      Komorovsky, Stanislav; Repisky, Michal; Malkin, Elena; Demissie, Taye Beyene; Ruud, Kenneth (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-01)
      We present an implementation of the nuclear spin–rotation (SR) constants based on the relativistic four-component Dirac–Coulomb Hamiltonian. This formalism has been implemented in the framework of the Hartree–Fock and Kohn–Sham theory, allowing assessment of both pure and hybrid exchange–correlation functionals. In the density-functional theory (DFT) implementation of the response equations, a ...
    • Four-component relativistic time-dependent density-functional theory using a stable noncollinear DFT ansatz applicable to both closed- and open-shell systems 

      Komorovsky, Stanislav; Cherry, Peter J.; Repisky, Michal (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-11-14)
      We present a formulation of relativistic linear response time-dependent density functional theory for the calculation of electronic excitation energies in the framework of the four-component Dirac-Coulomb Hamiltonian. This approach is based on the noncollinear <i>ansatz</i> originally developed by Scalmani and Frisch [J. Chem. Theory Comput. 8, 2193 (2012)] and improves upon the past treatment of ...
    • Fra fyrstikkmønster til matematiske symboler. En casestudie av tre elevers arbeid med to forskjellige geometriske mønster 

      Antonsen, Vanja Renée (Master thesis; Mastergradsoppgave, 2017-05-29)
      Dette er en masteroppgave i matematikkdidaktikk som fremstiller elever i arbeid med geometriske mønster. På bakgrunn av stor interesse i fagområdet algebra og elevers forståelse for det matematiske symbolspråket vil jeg se på problemstillingen: Hvordan kan arbeid med geometriske mønster bidra til elevenes forståelse av det matematiske symbolspråket? Hensikten med studien er å undersøke hvordan ...
    • Fractional Gaussian noise: Prior specification and model comparison 

      Sørbye, Sigrunn Holbek; Rue, Håvard (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-07)
      Fractional Gaussian noise (fGn) is a stationary stochastic process used to model anti-persistent or persistent dependency structures in observed time series. Properties of the autocovariance function of fGn are characterised by the Hurst exponent (<i>H)</i>, which in Bayesian contexts typically has been assigned a uniform prior on the unit interval. This paper argues why a uniform prior is ...
    • Fracture characterization in Upper Permian carbonates in Spitsbergen: A workflow from digital outcrop to geo-model 

      Larssen, Kristine; Senger, Kim; Grundvåg, Sten-Andreas (Journal article; Tidsskriftartikkel, 2020-09-08)
      Carbonates represent major hydrocarbon reservoirs, but often exhibit highly heterogeneous reservoir properties. Outcrop analogues provide important insights into how parameters such as porosity, permeability and natural fractures vary. As such, outcrops can bridge the scale gap between spatially extensive but poor-resolution seismic data and 1D high-resolution well data. However, traditional geological ...
    • Fracture-controlled fluid transport supports microbial methane-oxidizing communities at Vestnesa Ridge 

      Yao, Haoyi; Hong, Wei-Li; Panieri, Giuliana; Sauer, Simone; Torres, Marta E.; Lehmann, Moritz F.; Gründger, Friederike; Niemann, Helge (Journal article; Peer reviewed, 2019-05-29)
      We report a rare observation of a mini-fracture in near-surface sediments (30 cm below the seafloor) visualized using a rotational scanning X-ray of a core recovered from the Lomvi pockmark, Vestnesa Ridge, west of Svalbard (1200 m water depth). Porewater geochemistry and lipid biomarker signatures revealed clear differences in the geochemical and biogeochemical regimes of this core compared with ...
    • Fractured carbonates in the Mediumfjellet thrust-stack in the Tertiary fold-and-thrust belt of Spitsbergen 

      Larsen, Tine (Master thesis; Mastergradsoppgave, 2009-01-15)
      This thesis describes a study that was carried out in the Tertiary fold-and-thrust belt of Svalbard, in the mountain range of Mediumfjellet summer 2007 and 2008. The focuses were on: i) further describing the larger structures of the Mediumfjellet, ii) analyze the fracture distribution in the limestone beds associated with the major structures in the area. Available data sets are based on photo ...
    • Frag: A distributed approach to display wall gaming 

      Grammeltvedt, Åsmund (Master thesis; Mastergradsoppgave, 2006-06-01)
      Computer games with distributed functionality, such as most modern multiplayer games, provide a rich environment in which one can experiment with high performance distribution of computational and graphical resources. Their extremely high requirements for processing power and consistent visual output create a platform with unique demands. Current tiled display walls provide, as a consequence of ...
    • Fragment-Based Drug Discovery 

      Lund, Bjarte Aarmo (Journal article; Tidsskriftartikkel, 2015-06-13)
    • Frailty in Survival Analysis of Widowhood Mortality 

      Ytterstad, Elinor (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-10-02)
      Heterogeneity between individuals has attracted attention in the literature of survival analysis for several decades. Widowed individuals also differ; some are more frail than others and thereby have a higher risk of dying. The traditional hazard rate in a survival model is a measure of population risk and does not provide direct information on the unobservable individual risk. A frailty model is ...
    • A frame based approach to computing symmetries with non-trivial isotropy groups 

      McNutt, David Duncan; Coley, A.A.; Van Den Hoogen, Den (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-24)
      A frame approach to determining the most general solution admitting a desired symmetry group has previously been examined in Riemannian and teleparallel geometries with some success. In teleparallel geometries, one must determine the general form of the frame and spin connection to generate a general solution admitting the desired symmetry group. Current approaches often rely on the use of the ...
    • A Framework for AI-enabled Proactive mHealth with Automated Decision-making for a User’s Context 

      Sulaiman, Muhammad; Håkansson, Anne; Karlsen, Randi (Journal article; Tidsskriftartikkel; Peer reviewed, 2022)
      Health promotion is to enable people to take control over their health. Digital health with mHealth empowers users to establish proactive health, ubiquitously. The users shall have increased control over their health to improve their life by being proactive. To develop proactive health with the principles of prediction, prevention, and ubiquitous health, artificial intelligence with mHealth can ...
    • A framework for building scalable web applications for high-resolution cluster-based display walls 

      Tang, Jason (Master thesis; Mastergradsoppgave, 2015-10-06)
      As technology advances, researchers in the natural sciences collect ever-increasing amounts of data. While computer science research often focuses on effective ways to perform computations on large data sets, the visualization of large data sets can be just as important for achieving new insights. Just as cluster computing enables scalable computation on large data sets, so can cluster-based display ...
    • Framework for development of rule based sensor services in the Argos middleware platform 

      Jakobsen, Tom Arild (Master thesis; Mastergradsoppgave, 2008-01-07)
      Argos is a middleware platform developed at the University of Tromsø. It provides tailored, flexible and extensible middleware support. In this thesis we suggest a new approach to creating user services for Argos by using a rule engine to setup the program flow for components in Argos. The users are provided with a graphical tool where they can set up rules that can trigger an action. The input, ...
    • The Framework for Ice Sheet-Ocean Coupling (FISOC) V1.1 

      Gladstone, Rupert; Galton-Fenzi, Benjamin K.; Gwyther, David; Zhou, Qin; Hattermann, Tore; Zhao, Chen; Jong, Lenneke; Xia, Yuwei; Guo, Xiaoran; Petrakopoulos, Konstantinos; Zwinger, Thomas; Shapero, Daniel; Moore, John C. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-11)
      A number of important questions concern processes at the margins of ice sheets where multiple components of the Earth system, most crucially ice sheets and oceans, interact. Such processes include thermodynamic interaction at the ice–ocean interface, the impact of meltwater on ice shelf cavity circulation, the impact of basal melting of ice shelves on grounded ice dynamics and ocean controls on ...
    • A Framework for Mellin Kind Series Expansion Methods 

      Brenn, Torgeir; Anfinsen, Stian Normann (Journal article; Tidsskriftartikkel, 2017-07-31)
      Mellin kind statistics (MKS) is the framework which arises if the Fourier transform is replaced with the Mellin transform when computing the characteristic function from the probability density function. We may then proceed to retrieve logarithmic moments and cumulants, that have important applications in the analysis of heavy-tailed distribution models for nonnegative random variables. In this paper ...
    • Framework of Transactive Energy Market Strategies for Lucrative Peer-to-Peer Energy Transactions 

      Loganathan, Arun S.; Ramachandran, Vijayapriya; Perumal, Angalaeswari Sendraya; Dhanasekaran, Seshathiri; Lakshmaiya, Natrayan; Paramasivam, Prabhu (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-20)
      Leading to the enhancement of smart grid implementation, the peer-to-peer (P2P) energy transaction concept has grown dramatically in recent years allowing the end-users to successfully exchange their excess generation and demand in a more profitable way. This paper presents local energy market (LEM) architecture with various market strategies for P2P energy trading among a set of end-users ...
    • Free-Base Corrole Anion 

      Tarai, Arup; Mallick, Jyotiprakash; Conradie, Jeanet; Kar, Sanjib; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-30)
      Free-base corroles have long been known to be acidic, readily undergoing deprotonation by mild bases and in polar solvents. The conjugate base, however, has not been structurally characterized until now. Presented here is a first crystal structure of a freebase corrole anion, derived from tris(p-cyanophenyl)corrole, as the tetrabuylammonium salt. The low-temperature (100 K) structure reveals ...
    • Free-standing tantalum pentoxide waveguides for gas sensing in the mid-infrared 

      Vlk, Marek; Datta, Anurup; Alberti, Sebastian; Murugan, Ganapathy Senthil; Aksnes, Astrid; Jagerska, Jana (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-23)
      Typical applications of integrated photonics in the mid-infrared (MIR) are different from near-infrared (telecom) range and, in many instances, they involve chemical sensing through MIR spectroscopy. Such applications necessitate tailored designs of optical waveguides. Both cross-sectional designs and processing methods of MIR waveguides have been a subject of extensive research, where material ...