281 research outputs found
Recurrence Plots 25 years later -- gaining confidence in dynamical transitions
Recurrence plot based time series analysis is widely used to study changes
and transitions in the dynamics of a system or temporal deviations from its
overall dynamical regime. However, most studies do not discuss the significance
of the detected variations in the recurrence quantification measures. In this
letter we propose a novel method to add a confidence measure to the recurrence
quantification analysis. We show how this approach can be used to study
significant changes in dynamical systems due to a change in control parameters,
chaos-order as well as chaos-chaos transitions. Finally we study and discuss
climate transitions by analysing a marine proxy record for past sea surface
temperature. This paper is dedicated to the 25th anniversary of the
introduction of recurrence plots
Quantifying Changes in the Spatial Structure of Trabecular Bone
We apply recently introduced measures of complexity for the structural
quantfication of distal tibial bone. For the first time, we are able to
investigate the temporal structural alteration of trabecular bone. Based on
four patients, we show how bone may alter due to temporal immobilisation
Complex networks in climate dynamics - Comparing linear and nonlinear network construction methods
Complex network theory provides a powerful framework to statistically
investigate the topology of local and non-local statistical interrelationships,
i.e. teleconnections, in the climate system. Climate networks constructed from
the same global climatological data set using the linear Pearson correlation
coefficient or the nonlinear mutual information as a measure of dynamical
similarity between regions, are compared systematically on local, mesoscopic
and global topological scales. A high degree of similarity is observed on the
local and mesoscopic topological scales for surface air temperature fields
taken from AOGCM and reanalysis data sets. We find larger differences on the
global scale, particularly in the betweenness centrality field. The global
scale view on climate networks obtained using mutual information offers
promising new perspectives for detecting network structures based on nonlinear
physical processes in the climate system.Comment: 24 pages, 10 figure
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