TY  - JOUR
A1  - Landa, Polina S.
A1  - Zaikin, Alexei A.
A1  - Ushakov, V. G.
A1  - Kurths, Jürgen
T1  - Influence of additive noise on transitions in nonlinear systems
N2  - The effect of additive noise on transitions in nonlinear systems far from equilibrium is studied. It is shown that additive noise in itself can induce a hidden phase transition, which is similar to the transition induced by multiplicative noise in a nonlinear oscillator [P. Landa and A. Zaikin, Phys. Rev. E 54, 3535 (1996)]. Investigation of different nonlinear models that demonstrate phase transitions induced by multiplicative noise shows that the influence of additive noise upon such phase transitions can be crucial: additive noise can either blur such a transition or stabilize noise-induced oscillations.
Y1  - 2000
UR  - http://link.aps.org/abstract/PRE/v61/p4809
ER  - 
TY  - JOUR
A1  - Landa, Polina S.
A1  - Zaikin, Alexei A
A1  - Kurths, Jürgen
T1  - On noise-induced transitions in nonlinear oscillators
Y1  - 2000
SN  - 3-540- 41074-0
ER  - 
TY  - JOUR
A1  - Wessel, Niels
A1  - Schumann, Agnes
A1  - Wessel, Niels
A1  - Schumann, Agnes
A1  - Schirdewan, Alexander
A1  - Voss, Andreas
A1  - Kurths, Jürgen
T1  - Entropy measures in heart rate variability data
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Wessel, Niels
A1  - Voss, Andreas
A1  - Malberg, Hagen
A1  - Ziehmann, Christine
A1  - Voss, Henning U.
A1  - Schirdewan, Alexander
A1  - Meyerfeldt, Udo
A1  - Kurths, Jürgen
T1  - Nonlinear analysis of complex phenomena in cardiological data
N2  - The main intention of this contribution is to discuss different nonlinear approaches to heart rate and blood pressure variability analysis for a better understanding of the cardiovascular regulation. We investigate measures of complexity which are based on symbolic dynamics, renormalised entropy and the finite time growth rates. The dual sequence method to estimate the baroreflex sensitivity and the maximal correlation method to estimate the nonlinear coupling between time series are employed for analysing bivariate data. The latter appears to be a suitable method to estimate the strength of the nonlinear coupling and the coupling direction. Heart rate and blood pressure data from clinical pilot studies and from very large clinical studies are analysed. We demonstrate that parameters from nonlinear dynamics are useful for risk stratification after myocardial infarction, for the prediction of life-threatening cardiac events even in short time series, and for modelling the relationship between heart rate and blood pressure regulation. These findings could be of importance for clinical diagnostics, in algorithms for risk stratification, and for therapeutic and preventive tools of next generation implantable cardioverter defibrillators.
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Hainzl, Sebastian
A1  - Zöller, Gert
A1  - Kurths, Jürgen
A1  - Zschau, Jochen
T1  - Seismic quiescence as an indicator for large earthquakes in a system of self-organized criticality
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Anishchenko, Vadim S.
A1  - Kopeikin, A. S.
A1  - Kurths, Jürgen
T1  - Studying hyperbolicity in chaotic systems
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Ziehmann, Christine
A1  - Smith, Leonard A.
A1  - Kurths, Jürgen
T1  - Localized Lyapunov exponents and the prediction of predictability
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Boccaletti, Stefano
A1  - Valladares, D. L.
A1  - Kurths, Jürgen
T1  - Synchronization of chaotic structurally nonequivalent systems
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Hainzl, Sebastian
A1  - Zöller, Gert
A1  - Kurths, Jürgen
T1  - Self-organization of spatio-temporal earthquake clusters
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Zaks, Michael A.
A1  - Park, Eun Hyoung
A1  - Kurths, Jürgen
T1  - On phase synchronization by periodic force in chaotic oscillators with saddle equilibria
Y1  - 2000
ER  -