Now showing items 84-103 of 435

  • Convergence to local random attractors 

    Ashwin, Peter; Ochs, Gunter (Taylor & Francis, 2003)
    Random attractors allow one to classify qualitative and quantitative aspects of the long-time behaviour of stochastically forced systems viewed as random dynamical systems (RDS) in an analogous way to attractors for ...
  • Coronal Alfvén speed determination : consistency between seismology using AIA/SDO transverse loop oscillations and magnetic extrapolation 

    Verwichte, E.; Van Doorsselaere, T.; Foullon, Claire; White, R.S. (American Astronomical Society / IOP Publishing, 2013)
    Two transversely oscillating coronal loops are investigated in detail during a flare on the 2011 September 6 using data from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory. We compare two ...
  • Correcting the finite-ensemble bias of the ignorance score 

    Siegert, Stefan; Ferro, Christopher A.T.; Stephenson, David B. (Royal Meteorological Society, 2015)
    This study considers the application of the Ignorance Score (also known as the Logarithmic Score) in the context of ensemble verification. In particular, we consider the case where an ensemble forecast is transformed to a ...
  • A counterexample to "positive realness preserving model reduction with ℋ∞ norm error bounds" 

    Guiver, Chris; Opmeer, Mark R. (Institute of Electrical and Electronics Engineers (IEEE), 2011)
    We provide a counterexample to the H∞ error bound for the difference of a positive real transfer function and its positive real balanced truncation stated in “Positive realness preserving model reduction with H∞ norm error ...
  • Countertraveling waves in rotating Rayleigh-Bénard convection. 

    Li, Ligang; Liao, X.; Zhang, Keke (American Physical Society, 2008)
    Linear and nonlinear counter-traveling waves in a fluid-filled annular cylinder with realistic no-slip boundary conditions uniformly heated from below and rotating about a vertical axis are investigated. When the gap of ...
  • Criteria for robustness of heteroclinic cycles in neural microcircuits. 

    Ashwin, Peter; Karabacak, Ozkan; Nowotny, Thomas (BioMed Central / SpringerOpen, 2011)
    We introduce a test for robustness of heteroclinic cycles that appear in neural microcircuits modeled as coupled dynamical cells. Robust heteroclinic cycles (RHCs) can appear as robust attractors in Lotka-Volterra-type ...
  • Critical fronts in initiation of excitation waves 

    Idris, I.; Biktashev, V. N. (American Physical Society, 2007)
    We consider the problem of initiation of propagating waves in a one-dimensional excitable fiber. In the FitzHugh-Nagumo theory, the key role is played by "critical nucleus" and "critical pulse" solutions whose (center-) ...
  • Critical layer and radiative instabilities in shallow-water shear flows 

    Riedinger, X; Gilbert, Andrew D. (Cambridge University Press, 2014-06-23)
    In this study a linear stability analysis of shallow-water flows is undertaken for a representative Froude number $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let ...
  • Cycling chaos: its creation, persistence and loss of stability in a model of nonlinear magnetoconvection 

    Ashwin, Peter; Rucklidge, Alastair M. (Elsevier, 1998)
    We examine a model system where attractors may consist of a heteroclinic cycle between chaotic sets; this `cycling chaos' manifests itself as trajectories that spend increasingly long periods lingering near chaotic invariant ...
  • Cycling chaotic attractors in two models for dynamics with invariant subspaces 

    Ashwin, Peter; Rucklidge, Alastair M.; Sturman, Rob (American Institute of Physics, 2004)
    Nonergodic attractors can robustly appear in symmetric systems as structurally stable cycles between saddle-type invariant sets. These saddles may be chaotic giving rise to "cycling chaos." The robustness of such attractors ...
  • Damped large amplitude transverse oscillations in an EUV solar prominence, triggered by large-scale transient coronal waves 

    Hershaw, J.; Foullon, Claire; Nakariakov, V.M.; Verwichte, E. (EDP Sciences, 2011)
    Aims. We investigate two successive trains of large amplitude transverse oscillations in an arched EUV prominence, observed with SoHO/EIT on the north-east solar limb on 30 July 2005. The oscillatory trains are triggered ...
  • Decelerating defects and non-ergodic critical behaviour in a unidirectionally coupled map lattice 

    Ashwin, Peter; Sturman, Rob (Elsevier, 2003)
    We examine a coupled map lattice (CML) consisting of an infinite chain of logistic maps coupled in one direction by inhibitory coupling. We find that for sufficiently strong coupling strength there are dynamical states ...
  • Decentralised static output feedback stabilisation and synchronisation of networks 

    Prathyush, P. Menon; Edwards, Christopher (Elsevier, 2009-12)
    In this paper global stabilisation of a complex network is attained by applying local decentralised output feedback control to a minimum number of nodes of the network. The stabilisation of the network is treated as a rank ...
  • A decentralized parallelization-in-time approach with parareal 

    Schreiber, Martin; Peddle, Adam; Haut, Terry; Wingate, Beth (Arxiv.org, 2015-06-16)
    With steadily increasing parallelism for high-performance architectures, simulations requiring a good strong scalability are prone to be limited in scalability with standard spatial-decomposition strategies at a certain ...
  • Declining summer snowfall in the Arctic: Causes, impacts and feedbacks 

    Screen, James A.; Simmonds, Ian (Springer Verlag, 2012)
    Recent changes in the Arctic hydrological cycle are explored using in situ observations and an improved atmospheric reanalysis data set, ERA-Interim. We document a pronounced decline in summer snowfall over the Arctic Ocean ...
  • Delayed static output feedback control of a network of double integrator agents 

    Deshpande, Paresh; Prathyush, P. Menon; Edwards, Christopher (Elsevier, 2013-11)
    This paper considers a network of vehicles moving in a two dimensional plane. The overall network, described by a collection of double integrator dynamics, is controlled by a novel distributed static output feedback ...
  • Dengue epidemic early warning system for Brazil 

    Lowe, Rachel; Rodo, X.; Barcellos, Christovam; Carvalho, Marilia Sa; Coelho, Caio A.S.; Bailey, Trevor C.; Jupp, Tim E.; Stephenson, David B.; Coelho, G.E.; Graham, Richard J.; Ramalho, W.M. (UNISDR Scientific and Technical Advisory Group, 2015)
    The problem Brazil has reported more cases of dengue fever than anywhere else in the world this century1. Many cities have tropical and sub-tropical climate conditions that allow the dengue mosquito to thrive during warmer, ...
  • Dependency of global mean precipitation on surface temperature 

    Lambert, F. Hugo; Webb, Mark J. (American Geophysical Union (AGU), 2008)
    We investigate the causes of temperature dependent changes in global precipitation in contemporary General Circulation Models (GCMs) subjected to a doubling of atmospheric CO2 concentration. By analyzing the energy budget ...
  • Designing heteroclinic and excitable networks in phase space using two populations of coupled cells 

    Ashwin, Peter; Postlethwaite, Claire (Springer Verlag, 2015-06-10)
    We give a method for realizing an arbitrary directed graph (with no one-cycles) as a heteroclinic or an excitable dynamic network in the phase space of a system of coupled cells of two types. In each case, the system is ...
  • Designing the dynamics of globally coupled oscillators 

    Orosz, Gábor; Moehlis, Jeff; Ashwin, Peter (Oxford University Press, 2009)
    A method for designing cluster states with prescribed stability is presented for coupled phase oscillator systems with all-to-all coupling. We determine criteria for the coupling function that ensure the existence and ...