Browsing Mathematics by Title
Now showing items 105124 of 297

Evolution of spiral and scroll waves of excitation in a mathematical model of ischaemic border zone
(Public Library of Science, 2011)Abnormal electrical activity from the boundaries of ischemic cardiac tissue is recognized as one of the major causes in generation of ischemiareperfusion arrhythmias. Here we present theoretical analysis of the waves of ... 
Evolution of taxis responses in virtual bacteria: nonadaptive dynamics.
(Public Library of Science, 2008)Bacteria are able to sense and respond to a variety of external stimuli, with responses that vary from stimuli to stimuli and from species to species. The bestunderstood is chemotaxis in the model organism Escherichia ... 
Evolution of the L1 halo family in the radial solar sail circular restricted threebody problem
(Springer Verlag, 2014)We present a detailed investigation of the dramatic changes that occur in the L1 halo family when radiation pressure is introduced into the Sun–Earth circular restricted threebody problem (CRTBP). This photogravitational ... 
The evolution of writhe in kinkunstable flux ropes and erupting filaments
(IOP Publishing, 2014)The helical kink instability of a twisted magnetic flux tube has been suggested as a trigger mechanism for solar filament eruptions and coronal mass ejections (CMEs). In order to investigate if estimations of the preemptive ... 
Evolution under Fluctuating Environments Explains Observed Robustness in Metabolic Networks
(Public Library of Science, 2010)A high level of robustness against gene deletion is observed in many organisms. However, it is still not clear which biochemical features underline this robustness and how these are acquired during evolution. One hypothesis, ... 
Evolving Bayesian Emulators for Structured Chaotic Time Series, with application to large climate models
(Society for Industrial and Applied Mathematics and American Statistical Association, 2014)We develop Bayesian dynamic linear model Gaussian processes for emulation of time series output for computer models that may exhibit chaotic behavior, but where this behavior retains some underlying structure. The statistical ... 
An exact solution for arbitrarily rotating gaseous polytropes with index unity
(Oxford University Press for Royal Astronomical Society, 2015)Many gaseous planets and stars are rapidly rotating and can be approximately described by a polytropic equation of state with index unity.We present the first exact analytic solution, under the assumption of the oblate ... 
Excitability in ramped systems: the compostbomb instability
(Royal Society, 2011)The paper studies a novel excitability type where a large excitable response appears when a system’s parameter is varied gradually, or ramped, above some critical rate. This occurs even though there is a (unique) stable ... 
Explicit integral Galois module structure of weakly ramified extensions of local fields
(American Mathematical Society, 2015)Let L/K be a finite Galois extension of complete local fields with finite residue fields and let G=Gal(L/K). Let G_1 and G_2 be the first and second ramification groups. Thus L/K is tamely ramified when G_1 is trivial and ... 
Explicit representation of subgrid heterogeneity in a GCM land surface scheme
(American Meteorological Society, 2003)A land surface scheme that may be run with or without a tiled representation of subgrid heterogeneity and includes an implicit atmospheric coupling scheme is described. Simulated average surface air temperatures and diurnal ... 
Exploratory ensemble designs for environmental models using kextended Latin Hypercubes
(Wiley, 2015)In this paper we present a novel, flexible, and multipurpose class of designs for initial exploration of the parameter spaces of computer models, such as those used to study many features of the environment. The idea ... 
Exploring links between Arctic amplification and midlatitude weather
(American Geophysical Union, 2013)This study examines observed changes (1979–2011) in atmospheric planetarywave amplitude over northern midlatitudes, which have been proposed as a possible mechanism linking Arctic amplification and midlatitude weather ... 
Exponential integrators for a Markov chain model of the fast sodium channel of cardiomyocytes.
(Institute of Electrical and Electronics Engineers (IEEE), 2015)The modern Markov chain models of ionic channels in excitable membranes are numerically stiff. The popular numerical methods for these models require very small time steps to ensure stability. Our objective is to formulate ... 
Extremal Dependence Indices: improved verification measures for deterministic forecasts of rare binary events
(American Meteorological Society, 2011)Verifying forecasts of rare events is challenging, in part because traditional performance measures degenerate to trivial values as events become rarer. The extreme dependency score was proposed recently as a nondegenerating ... 
Extreme Sensitivity to Detuning for Globally Coupled Phase Oscillators
(American Physical Society, 2006)We discuss the sensitivity of a population of coupled oscillators to differences in their natural frequencies, i.e., to detuning. We argue that for three or more oscillators, one can get great sensitivity even if the ... 
Fast simulation of phasechange processes in chalcogenide alloys using a Gillespietype cellular automata approach
(American Institute of Physics, 2008)A stochastic cellular automata simulator capable of spatiotemporal modeling of the crystallization and amorphization behavior of phasechange materials during the complex annealing cycles used in optical and electrical ... 
Finding periodic orbits in statedependent delay differential equations as roots of algebraic equations
(2012)In this paper we prove that periodic boundaryvalue problems (BVPs) for delay differential equations are locally equivalent to finitedimensional algebraic systems of equations. We rely only on regularity assumptions that ... 
Fixedpoint free pairs of homomorphisms and nonabelian HopfGalois structure
(University at Albany, 2012)Given finite groups Γ and G of order n, regular embeddings from Γ to the holomorph of G yield HopfGalois structures on a Galois extension LK of fields with Galois group Γ. Here we consider regular embeddings that arise ... 
A framework for mimetic discretization of the rotating shallowwater equations on arbitrary polygonal grids
(Society for Industrial and Applied Mathematics, 2012)Accurate simulation of atmospheric flow in weather and climate prediction models requires the discretization of the governing equations to have a number of desirable properties. Although these properties can be achieved ... 
Front propagation in a phase field model with phasedependent heat absorption
(Elsevier, 2006)We present a model for the spatiotemporal behaviour of films exposed to radiative heating, where the film can change reversibly between amorphous (glassy) and crystalline states. Such phase change materials are used ...