Browsing Mathematics by Title
Now showing items 111130 of 296

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 ... 
Generation and escape of local waves from the boundary of uncoupled cardiac tissue
(Biophysical Society, 2008)We aim to understand the formation of abnormal waves of activity from myocardial regions with diminished celltocell coupling. En route to this goal, we studied the behavior of a heterogeneous myocyte network in which a ... 
GLACE: the global land–atmosphere coupling experiment. Part I: overview
(American Meteorological Society, 2006)The Global Land–Atmosphere Coupling Experiment (GLACE) is a model intercomparison study focusing on a typically neglected yet critical element of numerical weather and climate modeling: land–atmosphere coupling strength, ... 
GLACE: the global land–atmosphere coupling experiment. Part II: analysis
(American Meteorological Society, 2006)The 12 weather and climate models participating in the Global Land–Atmosphere Coupling Experiment (GLACE) show both a wide variation in the strength of land–atmosphere coupling and some intriguing commonalities. In this ... 
Global changes in extreme daily temperature since 1950
(American Geophysical Union, 2008)Extreme value analysis of observed daily temperature anomalies from a new quasiglobal data set indicates that extreme daily maximum and minimum temperatures (>98.5 or <1.5 percentile) have warmed for most regions since ... 
Glucocorticoid dynamics: insights from mathematical, experimental and clinical studies
(BioScientifica, 2015)A pulsatile pattern of secretion is a characteristic of many hormonal systems, including theglucocorticoidproducinghypothalamic–pituitary–adrenal(HPA)axis. Despite recent evidence supporting its importance for behavioural, ... 
Group theoretic conditions for existence of robust relative homoclinic trajectories
(Cambridge University Press, 2002)We consider robust relative homoclinic trajectories (RHTs) for Gequivariant vector fields. We give some conditions on the group and representation that imply existence of equivariant vector fields with such trajectories. ... 
Halfcentury air temperature change above Antarctica: Observed trends and spatial reconstructions
(American Geophysical Union, 2012)This study provides a comprehensive analysis of observed 50year (1961–2010) seasonal air temperature trends from radiosonde ascents above Antarctica. Comparisons between multiple radiosonde data sets (homogenized in ...