TY  - JOUR
A1  - Kurths, Jürgen
A1  - Schwarz, Udo
T1  - Application of techniques of nonlinear dynamics to SS Cyg
N2  - We look for structural properties in the light curve of the dwarf nova SS Cyg by means of techniques from nonlinear dynamics. Applying the popular Grassberger-Procaccia procedure, Cannizzo and Goddings (1988) showed that there is no evidence for a low-dimensional attractor underlying this record. Because there are some hints for order in the light curve, we search for other signatures of deterministic systems. Therefore, we use other methods recently developed in this theory, such as local linear prediction and recurrence maps. Our main findings are: i] the prediction error grows exponentially during outburst phases, but via a power law in the quiescent states, ii] there are some rather regular patterns in this light curve which sometimes recur, but the recurrence is not regular. This leads to the following conclusions: i] The outburst dynamics shows a higher degree of order than the quiescent one. There are some hints for deterministic chaos in the outburst behavior. ii] The light curve is a complex mixture of deterministic and stochastic structures. The analysis presented in this paper shows that methods of nonlinear dynamics can be an efficient tool for the study of complex processes, even if there is no evidence for a low-dimensional attractor.
Y1  - 1993
UR  - http://www.agnld.uni-potsdam.de/~shw/Paper/SS_Cyg_AIP.ps.gz
SN  - 0-7503-0282-8
ER  - 
TY  - JOUR
A1  - Schwarz, udo
A1  - Benz, Arnold O.
A1  - Kurths, Jürgen
A1  - Witt, Annette
T1  - Analysis of solar spike events by means of symbolic dynamics methods
N2  - Using quantities of symbolic dynamics, such as mutual information, Shannon information and algorithmic complexity, we have searched for interrelations of spikes emitted simultaneously at different frequencies during the impulsive phase of a flare event. As the spikes are related to the flare energy release and are interpreted as emissions originating at different sites having different magnetic field strengths, any relation in frequency is interpretated as a relation in space. This approach is appropriate to characterize such spatio-temporal patterns, whereas the popular estimate of fractal dimensions can be applied to low-dimensional systems only. Depending on the energy release and emission processes, two types of fragmentation are possible: a scenario of global organization (spikes are emitted in a succession of similar events by the same system) or a scenario of local organization (many systems triggered by an initial event). Mutual information which is a generalization of correlation indicates a relation in frequency beyond the bandwidth of individual spikes. The scans in the spectrograms with large mutual information also show a low level of Shannon information and algorithmic complexity, indicating that the simultaneous appearance of spikes at other frequencies is not a completely stochastic phenomenon (white noise). It may be caused by a nonlinear deterministic system or by a Markov process. By means of mutual information we find a memory over frequency intervals up to 60 MHz. Shannon information and algorithmic complexity concern the mbox{whole} frequency region, i.e. the global source region. A global organization is also apparent in quasi-periodic changes of the Shannon information and algorithmic complexity in the range of 2 - 8 seconds. The finding is compatible with a scenario of local organization in which the information of one event spreads spatially and triggers further events at different places. The region is not an ensemble of independently flashing sources, each representing a system that cascades in energy after an initial trigger. On the contrary, there is a causal connection between the sources at any time. The analysis of the four spike events suggests that the structure in frequency is not stochastic but a process in which spikes at nearby locations are simultaneously triggered by a common exciter.
Y1  - 1993
UR  - http://www.astro.phys.ethz.ch/papers/benz/schwarz/schwarz/schwarz.html
SN  - 004-6361
ER  - 
TY  - INPR
A1  - Witt, Annette
A1  - Kurths, Jürgen
A1  - Krause, F.
A1  - Fischer, K.
T1  - On the validity of a model for the reversals of the Earth‘s magnetic field
N2  - We have used techniques of nonlinear dynamics to compare a special model for the reversals of the Earth's magnetic field with the observational data. Although this model is rather simple, there is no essential difference to the data by means of well-known characteristics, such as correlation function and probability distribution. Applying methods of symbolic dynamics we have found that the considered model is not able to describe the dynamical properties of the observed process. These significant differences are expressed by algorithmic complexity and Renyi information.
T3  - NLD Preprints - 4 
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13460
ER  - 
TY  - INPR
A1  - Kurths, Jürgen
A1  - Voss, A.
A1  - Witt, Annette
A1  - Saparin, P.
A1  - Kleiner, H. J.
A1  - Wessel, Niels
T1  - Quantitative analysis of heart rate variability
N2  - In the modern industrialized countries every year several hundred thousands of people die due to the sudden cardiac death. The individual risk for this sudden cardiac death cannot be defined precisely by common available, non-invasive diagnostic tools like Holter-monitoring, highly amplified ECG and traditional linear analysis of heart rate variability (HRV). Therefore, we apply some rather unconventional methods of nonlinear dynamics to analyse the HRV. Especially, some complexity measures that are basing on symbolic dynamics as well as a new measure, the renormalized entropy, detect some abnormalities in the HRV of several patients who have been classified in the low risk group by traditional methods. A combination of these complexity measures with the parameters in the frequency domain seems to be a promising way to get a more precise definition of the individual risk. These findings have to be validated by a representative number of patients.
T3  - NLD Preprints - 5 
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13470
ER  - 
TY  - JOUR
A1  - Kurths, Jürgen
A1  - Schwarz, Udo
T1  - Chaos theory and radio emission
N2  - The application of chaos theory has become popular to understand the nature of various features of solar activity because most of them are far from regular. The usual approach, however, that is basing on finding low- dimensional structures of the underlying processes seems to be successful only in a few exceptional cases, such as in rather coherent phenomena as coronal pulsations. It is important to note that most phenomena in solar radio emission are more complex. We present two kinds of techniques from nonlinear dynamics which can be useful to analyse such phenomena: i] Fragmentation processes observed in solar spike events are studied by means of symbolic dynamics methods. Different measures of complexity calculated from such observations reveal that there is some order in this fragmentation. ii] Bursts are a typical transient phenomenon. To study energization processes causing impulsive microwave bursts, the wavelet analysis is applied. It exhibits structural differences of the pre- and post-impulsive phase in cases where the power spectra of both are not distinct.
Y1  - 1994
UR  - http://www.agnld.uni-potsdam.de/~shw/Paper/Review.ps.gz
ER  - 
TY  - JOUR
A1  - Kurths, Jürgen
A1  - Schwarz, Udo
A1  - Parlitz, Ulrich
A1  - Sonett, Charles P.
T1  - Testing for nonlinearity in radiocarbon data
N2  - The radiocarbon record that has been extended from 7199 BC to 1891 AD is of fundamental importance to understand century-scale variations of solar activity. We have, therefore, studied how to extract information from dynamic reconstructions of this observational record. Using some rather unusual methods of nonlinear dynamics, we have found that the data are significantly different from linear colored noise and that there is some evidence of nonlinear behavior. The method of recurrence plots exhibits that the grand minima of solar activity are quite different in their recurrence. Most remarkably, it suggests that the recent epoch seems to be similar to the Medieval maximum.
Y1  - 1994
UR  - http://www.agnld.uni-potsdam.de/~shw/Paper/n.ps.gz
SN  - 1023-5809
ER  - 
TY  - INPR
A1  - Kurths, Jürgen
A1  - Pikovskij, Arkadij
A1  - Scheffczyk, Christian
T1  - Roughening interfaces in deterministic dynamics
N2  - Two deterministic processes leading to roughening interfaces are considered. It is shown that the dynamics of linear perturbations of turbulent regimes in coupled map lattices is governed by a discrete version of the Kardar-Parisi-Zhang equation. The asymptotic scaling behavior of the perturbation field is investigated in the case of large lattices. Secondly, the dynamics of an order-disorder interface is modelled with a simple two-dimensional coupled map lattice, possesing a turbulent and a laminar state. It is demonstrated, that in some range of parameters the spreading of the turbulent state is accompanied by kinetic roughening of the interface.
T3  - NLD Preprints - 3 
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13447
ER  - 
TY  - INPR
A1  - Thiessenhusen, Kai-Uwe
A1  - Esposito, Larry W.
A1  - Kurths, Jürgen
A1  - Spahn, Frank
T1  - Detection of hidden resonances in Saturn's B-ring
N2  - The Voyager 2 Photopolarimeter experiment has yielded the highest resolved data of Saturn's rings, exhibiting a wide variety of features. The B-ring region between 105000 km and 110000 km distance from Saturn has been investigated. It has a high matter density and contains no significance features visible by eye. Analysis with statistical methods has let us to the detection of two significant events. These features are correlated with the inner 3:2 resonances of the F-ring shepherd satellites Pandora and Prometheus, and may be evidence of large ring paricles caught in the corotation resonances.
T3  - NLD Preprints - 13 
KW  - Planetary Rings
Y1  - 1995
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13618
ER  - 
TY  - JOUR
A1  - Kurths, Jürgen
A1  - Schwarz, Udo
A1  - Witt, Annette
T1  - Non-linear data analysis in solar radio astronomy
N2  - We have discussed some tools from nonlinear dynamics which may help to analyze transient phenomena, such as solar bursts. The structure function known from turbulence theory is an appropriate method to find out some scaling behavior of fluctuations in time. More generally, the wavelet analysis, which is some generalization of the power spectrum, exhibits information on the location as well as the size of hidden characteristic features. Applying both techniques to microwave bursts, we have found some scaling properties that refer to the existence of hierarchic time structures. This is in good accordance with the electric circuit model for describing the flare-particle energization process.
Y1  - 1995
UR  - http://www.agnld.uni-potsdam.de/~shw/Paper/lnp.ps.gz
ER  - 
TY  - BOOK
A1  - Feudel, Ulrike
A1  - Kurths, Jürgen
A1  - Neiman, Alexander
T1  - The cumulant approach for investigating the noise influence on mode-locking bifurcations
T3  - Preprint NLD
Y1  - 1995
VL  - 16
PB  - Univ.
CY  - Potsdam
ER  - 
TY  - BOOK
A1  - Rosenblum, Michael
A1  - Kurths, Jürgen
T1  - A model of neural control of heart rate
T3  - Preprint NLD
Y1  - 1995
VL  - 12
PB  - Univ.
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Scheffczyk, Christian
A1  - Engbert, Ralf
A1  - Kurths, Jürgen
A1  - Krampe, Ralf-Thomas
A1  - Kliegl, Reinhold
T1  - Nonlinear Phenomena in Polyrhythmic Hand Movements
N2  - In this paper we apply symbolic transformations as a visualisation technique for analysing rhythm production. It is shown that qualitative information can be extracted from the experimental data. This approach may provide new insights into the organisation of temporal order by the brain on different levels of description. A simple phenomenological model for the explanation of the observed phenomena is proposed.
Y1  - 1995
SN  - 981-02-2689-6
ER  - 
TY  - INPR
A1  - Pikovskij, Arkadij
A1  - Zaks, Michael A.
A1  - Feudel, Ulrike
A1  - Kurths, Jürgen
T1  - Singular continuous spectra in dissipative dynamics
N2  - We demonstrate the occurrence of regimes with singular continuous (fractal) Fourier spectra in autonomous dissipative dynamical systems. The particular example in an ODE system at the accumulation points of bifurcation sequences associated to the creation of complicated homoclinic orbits. Two different machanisms responsible for the appearance of such spectra are proposed. In the first case when the geometry of the attractor is symbolically represented by the Thue-Morse sequence, both the continuous-time process and its descrete Poincaré map have singular power spectra. The other mechanism owes to the logarithmic divergence of the first return times near the saddle point; here the Poincaré map possesses the discrete spectrum, while the continuous-time process displays the singular one. A method is presented for computing the multifractal characteristics of the singular continuous spectra with the help of the usual Fourier analysis technique.
T3  - NLD Preprints - 15 
Y1  - 1995
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13787
ER  - 
TY  - INPR
A1  - Voss, Henning
A1  - Kurths, Jürgen
A1  - Schwarz, Udo
T1  - Reconstruction of grand minima of solar activity from Delta 14 C data : linear and nonlinear signal analysis
N2  - Using a special technique of data analysis, we have found out 34 grand minima of solar activity obtained from a 7,700 years long Δ14C record. The method used rests on a proper filtering of the Δ14C record and the extrapolation of verifiable results for the later history back in time. Additionally, we use a method of nonlinear dynamics, the recurrence rate, to back up the results. Our findings are not contradictory to the record of solar maxima resp. minima by Eddy [5], but constitute a considerable extension. Hence, it has become possible to look closer at the validity of models. This way, we have tested several models for solar activity, esp. the model of Barnes et al. [1]. There are hints for that the grand minima might solely be driven by the 209 year period found in the Δ14C record.
T3  - NLD Preprints - 28 
Y1  - 1996
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14083
ER  - 
TY  - JOUR
A1  - Voss, Henning U.
A1  - Kurths, Jürgen
A1  - Schwarz, Udo
T1  - Reconstruction of grand minima of solar activity from radiocarbon data : linear and nonlinear signal analysis
N2  - Using a special technique of data analysis, we have found out 34 grand minima of solar activity in a 7,700 years long C14 record. The method used rests on a proper filtering of the C14 record and the extrapolation of verifiable results for the later history back in time. Additionally, we have applied a method of nonlinear dynamics, the recurrence rate, to back up the results. Our findings are not contradictory to the record of grand minima by Eddy, but constitute a considerable extension. Hence, it has become possible to look closer at the validity of models. This way, we have tested esp. the model of Barnes et al. There are hints for that the grand minima might solely be driven by the 209--year period found in the C14 record.
Y1  - 1996
UR  - http://www.agnld.uni-potsdam.de/~shw/Paper/vks.ps.gz
ER  - 
TY  - JOUR
A1  - Scheffczyk, Christian
A1  - Engbert, Ralf
A1  - Krampe, Ralf-Thomas
A1  - Kurths, Jürgen
A1  - Rosenblum, Michael
A1  - Zaikin, Alexei A.
T1  - Nonlinear Modelling of Polyrhythmic Hand Movements
Y1  - 1996
ER  - 
TY  - BOOK
A1  - Voss, Henning U.
A1  - Kurths, Jürgen
A1  - Schwarz, Udo
T1  - Reconstruction of grand minima of solar activity from radiocarbon data : linear and nonlinear signal analysis
T3  - Preprint NLD
Y1  - 1996
VL  - 28
PB  - Univ.
CY  - Potsdam
ER  - 
TY  - INPR
A1  - Witt, Annette
A1  - Neiman, Alexander
A1  - Kurths, Jürgen
T1  - Characterizing the dynamics of stochastic bistable systems by measures of complexity
N2  - The dynamics of noisy bistable systems is analyzed by means of Lyapunov exponents and measures of complexity. We consider both the classical Kramers problem with additive white noise and the case when the barrier fluctuates due to additional external colored noise. In case of additive noise we calculate the Lyapunov exponents and all measures of complexity analytically as functions of the noise intensity resp. the mean escape time. For the problem of fluctuating barrier the usual description of the dynamics with the mean escape time is not sufficient. The application of the concept of measures of complexity allows to describe the structures of motion in more detail. Most complexity measures sign the value of correlation time at which the phenomenon of resonant activation occurs with an extremum.
T3  - NLD Preprints - 36 
Y1  - 1997
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14556
ER  - 
TY  - BOOK
A1  - Witt, Annette
A1  - Neiman, Alexander
A1  - Kurths, Jürgen
T1  - Characterizing the dynamics of stochastic bistable systems by measures of complexity
T3  - Preprint NLD
Y1  - 1997
SN  - 1432-2935
VL  - 36
PB  - Univ. Potsdam
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Voss, Henning U.
A1  - Kurths, Jürgen
T1  - Reconstruction of nonlinear time delay models from data by the use of optimal transformations
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Witt, Annette
A1  - Neiman, Alexander
A1  - Kurths, Jürgen
T1  - Charakterizing the dynamics of stochastic bistable systems by measures of complexity
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Spahn, Frank
A1  - Katzorke, Ines
A1  - Petzschmann, Olaf
A1  - Schwarz, Udo
A1  - Kurths, Jürgen
T1  - Cluster instabiliy of granular assemblies
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Spahn, Frank
A1  - Schwarz, Udo
A1  - Kurths, Jürgen
T1  - Clustering of granular assemblies with temperature dependent restitution under Keplerian differential rotation
Y1  - 1997
ER  - 
TY  - BOOK
A1  - Rosenblum, Michael
A1  - Schäfer, Carsten
A1  - Abel, Hans-Henning
A1  - Kurths, Jürgen
T1  - Interrelationship of Parasympathetic Innervation of the Sinoatrial Node and the Atrioventricular Node of Human Heart
Y1  - 1997
SN  - 1120-1797
ER  - 
TY  - JOUR
A1  - Zaikin, Alexei A.
A1  - Rosenblum, Michael
A1  - Landa, Polina S.
A1  - Kurths, Jürgen
T1  - Control of noise-induced oscillations of a pendulum with a rondomly vibrating suspension axis
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Wessel, Niels
A1  - Kleiner, H. J.
A1  - Voss, Andreas
A1  - Kurths, Jürgen
A1  - Dietz, R.
T1  - Nonlinear dynamics in cardiovasscular diseases
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Scheffczyk, Christian
A1  - Krampe, Ralf-Thomas
A1  - Engbert, Ralf
A1  - Rosenblum, Michael
A1  - Kurths, Jürgen
A1  - Kliegl, Reinhold
T1  - Tempo-induced transitions in polyrhythmic hand movements
N2  - We investigate the cognitive control in polyrhythmic hand movements as a model paradigm for bimanual coordination. Using a symbolic coding of the recorded time series, we demonstrate the existence of qualitative transitions induced by experimental manipulation of the tempo. A nonlinear model with delayed feedback control is proposed, which accounts for these dynamical transitions in terms of bifurcations resulting from variation of the external control parameter. Furthermore, it is shown that transitions can also be observed due to fluctuations in the timing control level. We conclude that the complexity of coordinated bimanual movements results from interactions between nonlinear control mechanisms with delayed feedback and stochastic timing components.
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Zaikin, Alexei A.
A1  - Rosenblum, Michael
A1  - Scheffczyk, Christian
A1  - Engbert, Ralf
A1  - Krampe, Ralf-Thomas
A1  - Kurths, Jürgen
T1  - Modeling qualitative changes in bimanual movements
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Feudel, Ulrike
A1  - Jansen, Wolfgang
A1  - Kurths, Jürgen
A1  - Schwarz, Udo
A1  - Voss, Henning U.
T1  - Solar variability : simple models and proxy data
Y1  - 1997
SN  - 4-274-90187-4
ER  - 
TY  - JOUR
A1  - Gowin, W.
A1  - Kurths, Jürgen
A1  - Saparin, Peter
A1  - Felsenberg, D.
T1  - Measures of complexity and processing of vertebral CT-images
Y1  - 1997
SN  - 0-7803-4262-3
ER  - 
TY  - INPR
A1  - Engbert, Ralf
A1  - Scheffczyk, Christian
A1  - Krampe, Ralf-Thomas
A1  - Rosenblum, Mikhael
A1  - Kurths, Jürgen
A1  - Kliegl, Reinhold
T1  - Tempo-induced transitions in polyrhythmic hand movements
N2  - We investigate the cognitive control in polyrhythmic hand movements as a model paradigm for bimanual coordination. Using a symbolic coding of the recorded time series, we demonstrate the existence of qualitative transitions induced by experimental manipulation of the tempo. A nonlinear model with delayed feedback control is proposed, which accounts for these dynamical transitions in terms of bifurcations resulting from variation of the external control parameter. Furthermore, it is shown that transitions can also be observed due to fluctuations in the timing control level. We conclude that the complexity of coordinated bimanual movements results from interactions between nonlinear control mechanisms with delayed feedback and stochastic timing components.
T3  - NLD Preprints - 41 
Y1  - 1997
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14380
ER  - 
TY  - JOUR
A1  - Schiek, Michael
A1  - Scheffczyk, Christian
A1  - Engbert, Ralf
A1  - Kurths, Jürgen
A1  - Krampe, Ralf-Thomas
A1  - Kliegl, Reinhold
A1  - Drepper, Friedhelm R.
T1  - Symbolic dynamics of physiological synchronisation : examples from bimanual movements and cardiorespiratory interaction
N2  - Key words: Nonlinear time series analysis, symbolic dynamics, phase transitions, physiological data, biological synchronization, production of polyrhythms, cardiorespiratory interaction, variation of control parameter
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Rosenblum, Michael
A1  - Pikovskij, Arkadij
A1  - Kurths, Jürgen
T1  - From Phase to Lag Synchronization in Coupled Chaotic Oscillators
N2  - We study synchronization transitions in a system of two coupled self-sustained chaotic oscillators. We demonstrate that with the increase of coupling strength the system first undergoes the transition to phase synchronization. With a further increase of coupling, a new synchronous regime is observed, where the states of two oscillators are nearly identical, but one system lags in time to the other. We describe thisregime as a state with correlated amplitudes and a constant phase shift. These transitions are traced in the Lyapunov spectrum.
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Pikovskij, Arkadij
A1  - Kurths, Jürgen
T1  - Coherence Resonance in a Noise-Driven Excitable System
N2  - We study the dynamics of the excitable Fitz Hugh-Nagumo system under external noisy driving. Noise activates the system producing a sequence of pulses. The coherence of these noise-induced oscillations is shown to be maximal for a certain noise amplitude. This new effect of coherence resonance is explained by different noise dependencies of the activation and the excursion times. A simple one-dimensional model based on the Langevin dynamics is proposed for the quantitative description of this phenomenon.
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Ruzick, Oliver
A1  - Scheffczyk, Christian
A1  - Pikovskij, Arkadij
A1  - Kurths, Jürgen
T1  - Dynamics of chaos-order interface in coupled map lattices
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Rosenblum, Michael
A1  - Pikovskij, Arkadij
A1  - Kurths, Jürgen
T1  - Phase synchronization in noisy and chaotic oscillators
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Zaks, Michael A.
A1  - Pikovskij, Arkadij
A1  - Kurths, Jürgen
T1  - On the correlation dimension of the spectral measure for the Thue-Morse sequence
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Rosenblum, Michael
A1  - Pikovskij, Arkadij
A1  - Kurths, Jürgen
T1  - Phase synchronization in driven and coupled chaotic oscillators
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Rosenblum, Michael
A1  - Pikovskij, Arkadij
A1  - Kurths, Jürgen
T1  - Effect of phase synchronization in driven chaotic oscillators
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Pikovskij, Arkadij
A1  - Kurths, Jürgen
T1  - Coherence resonance in a noise-driven excitable system
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Zaks, Michael A.
A1  - Rosenblum, Michael
A1  - Pikovskij, Arkadij
A1  - Osipov, Grigory V.
A1  - Kurths, Jürgen
T1  - Phase synchronization of chaotic oscillations in terms of periodic orbits
Y1  - 1997
SN  - 1054-1500
ER  - 
TY  - JOUR
A1  - Pikovskij, Arkadij
A1  - Rosenblum, Michael
A1  - Osipov, Grigory V.
A1  - Kurths, Jürgen
T1  - Phase synchronization effects in a lattice of nonidentical Rössler oscillators
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Rosenblum, Michael
A1  - Osipov, Grigory V.
A1  - Pikovskij, Arkadij
A1  - Kurths, Jürgen
T1  - Phase synchronization of chaotic oscillators by external driving
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Osipov, Grigory V.
A1  - Rosenblum, Michael
A1  - Pikovskij, Arkadij
A1  - Zaks, Michael A.
A1  - Kurths, Jürgen
T1  - Attractor-repeller collision and eyelet intermittency at the transition to phase synchronization
N2  - The chaotically driven circle map is considered as the simplest model ofphase synchronization of a chaotic continuous-time oscillator by external periodic force. The phase dynamics is analyzed via phase-locking regions of the periodic cycles embedded in the strange attractor. It is shown that full synchronization, where all the periodic cycles are phase locked, disappears via the attractor-repeller collision. Beyond the transition an intermittent regime with exponentially rare phase slips, resulting from the trajectory's hits on an eyelet, is observed.
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Kliem, Bernhard
A1  - Schwarz, Udo
A1  - Kurths, Jürgen
A1  - Dennis, Brian
A1  - Schwartz, Richard
A1  - Aschwanden, Markus J.
T1  - Wavelet analysis of solar flare hard X-ray
Y1  - 1998
SN  - 0004-637x
ER  - 
TY  - JOUR
A1  - Zaikin, Alexei A.
A1  - Rosenblum, Michael
A1  - Landa, Polina S.
A1  - Kurths, Jürgen
T1  - On-off itermittency phenomena in a pendulum with a randomly vibrating suspension axis
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Engbert, Ralf
A1  - Hainzl, Sebastian
A1  - Zöller, Gert
A1  - Kurths, Jürgen
T1  - Testing for unstable periodic orbits to characterize spatiotemporal dynamics
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Schwarz, Udo
A1  - Kurths, Jürgen
A1  - Spahn, Frank
A1  - Petzschmann, Olaf
T1  - Reply on the comment of "Clustering of granular assemblies with temperature dependent restitution and under differential rotation"
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Kurths, Jürgen
A1  - Kliem, Bernhard
A1  - Schwarz, Udo
A1  - Krüger, Albrecht
A1  - Urpo, S.
T1  - Multiresolution analysis of solar mm-wave bursts
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Kim, G. G.
A1  - Kurths, Jürgen
A1  - Kim, S.
A1  - Cao, L. Y.
T1  - Detecting determinism in human posture control data
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Rosenblum, Michael
A1  - Kurths, Jürgen
A1  - Schäfer, Carsten
A1  - Abel, Hans-Henning
T1  - Heartbeat synchronized with ventilation
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Hnatkova, Katarina
A1  - Vessel, N.
A1  - Voss, Andreas
A1  - Kurths, Jürgen
A1  - Sander, A.
A1  - Schirdewan, Alexander
A1  - Camm, A. J.
A1  - Malik, Marek
T1  - Multiparametric analysis of heart rate variability used for risk stratification among survivors of acute myocardial infarction
Y1  - 1998
SN  - 0895-2795
ER  - 
TY  - JOUR
A1  - Witt, Annette
A1  - Feudel, Fred
A1  - Gebogi, C.
A1  - Kurths, Jürgen
A1  - Braun, Robert
T1  - Tracer dynamics in a flow of driven vortices
JF  - Preprint NLD
Y1  - 1998
SN  - 1432-2935
VL  - 51
PB  - Univ.
CY  - Potsdam
ER  - 
TY  - BOOK
A1  - Kurths, Jürgen
A1  - Mayer-Kress, Gottfried
ED  - Kantz, Holger
T1  - Nonlinear analysis of physiological data
Y1  - 1998
SN  - 3-540-63481-9
PB  - Springer
CY  - Berlin, New York
ER  - 
TY  - JOUR
A1  - Voss, Henning U.
A1  - Kurths, Jürgen
T1  - Test for nonlinear dynamical behavior in symbol sequences
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Tass, Peter
A1  - Rosenblum, Michael
A1  - Weule, J.
A1  - Kurths, Jürgen
A1  - Pikovskij, Arkadij
A1  - Volkmann, J.
A1  - Schnitzler, A.
A1  - Freund, H.-J.
T1  - Detection of n:m phase locking from noisy data : application to magnetoencephalography
N2  - We use the concept of phase synchronization for the analysis of noisy nonstationary bivariate data. Phase synchronization is understood in a statistical sense as an existence of preferred values of the phase difference, and two techniques are proposed for a reliable detection of synchronous epochs. These methods are applied to magnetoencephalograms and records of muscle activity of a Parkinsonian patient. We reveal that
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Rosenblum, Michael
A1  - Kurths, Jürgen
A1  - Pikovskij, Arkadij
A1  - Schafer, C.
A1  - Tass, Peter
A1  - Abel, Hans-Henning
T1  - Synchronization in Noisy Systems and Cardiorespiratory Interaction
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Zaks, Michael A.
A1  - Pikovskij, Arkadij
A1  - Kurths, Jürgen
T1  - Symbolic dynamics behind the singular continuous power spectra of continuous flows
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Witt, Annette
A1  - Kurths, Jürgen
A1  - Pikovskij, Arkadij
T1  - Testing stationarity in time series
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Hainzl, Sebastian
A1  - Zöller, Gert
A1  - Kurths, Jürgen
T1  - Self-organized criticality model for earthquakes : Quiescence, foreshocks and aftershocks
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Lai, Ying Cheng
A1  - Grebogi, Celso
A1  - Kurths, Jürgen
T1  - Modeling of deterministic chaotic systems
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Park, Eun Hyoung
A1  - Zaks, Michael A.
A1  - Kurths, Jürgen
T1  - Phase synchronization in the forced lorenz system
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Hainzl, Sebastian
A1  - Zöller, Gert
A1  - Kurths, Jürgen
T1  - Similar power laws for foreshock and aftershock sequences in a spring block model for earthquakes
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Voss, Henning U.
A1  - Kurths, Jürgen
T1  - Reconstruction of nonlinear time-delayed feedback models from optical data
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Ziehmann, Christine
A1  - Smith, L.
A1  - Kurths, Jürgen
T1  - The bootstrap and lyapunov exponents in deterministic chaos
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Zaikin, Alexei A.
A1  - Kurths, Jürgen
T1  - Modeling Cognitive Control in Simple Movements
Y1  - 1999
SN  - 1-563-96863-0
ER  - 
TY  - JOUR
A1  - Kolodner, P.
A1  - Abel, Markus
A1  - Kurths, Jürgen
A1  - Voss, Henning U.
T1  - Amplitude equations from spatiotemporal binary-fluid convection data
Y1  - 1999
UR  - http://www.stat.physik.uni-potsdam.de/~markus/papers/PRL83-3422.pdf
ER  - 
TY  - JOUR
A1  - Schwache, A.
A1  - Kurths, Jürgen
A1  - Mitschke, F.
A1  - Voss, Henning U.
T1  - Equations of motion from chaotic data : a driven optical fiber ring resonator
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Braun, Robert
A1  - Feudel, Fred
A1  - Gebogi, C.
A1  - Kurths, Jürgen
A1  - Witt, Annette
T1  - Tracer dynamics in a flow of driven vortices
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Rosenblum, Michael
A1  - Abel, Hans-Henning
A1  - Kurths, Jürgen
A1  - Schäfer, Carsten
T1  - Synchronization in the human cardiorespiratory system
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Park, Eun Hyoung
A1  - Rosenblum, Michael
A1  - Kurths, Jürgen
A1  - Zaks, Michael A.
T1  - Alternating locking ratios in imperfect phase synchronization
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Heuer, Axel
A1  - Schultheiss, J.
A1  - Hodgson, N.
A1  - Kurths, Jürgen
A1  - Menzel, Ralf
A1  - Raab, Volker
T1  - Transverse effects in phase conjugate laser mirrors based on stimulated brillouin scattering
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Schwarz, Udo
A1  - Spahn, Frank
A1  - Grebogi, Celso
A1  - Kurths, Jürgen
A1  - Petzschmann, Olaf
T1  - Length scales of clustering in granular gases
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Pikovskij, Arkadij
A1  - Rosenblum, Michael
A1  - Zaks, Michael A.
A1  - Kurths, Jürgen
T1  - Phase synchronization of regular and chaotic oscillators
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Zaks, Michael A.
A1  - Pikovskij, Arkadij
A1  - Kurths, Jürgen
T1  - On the generalized dimensions for the fourier spectrum of the thue-morse sequence
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Marwan, Norbert
A1  - Trauth, Martin H.
A1  - Schwarz, Udo
A1  - Kurths, Jürgen
A1  - Strecker, Manfred
T1  - Climate dynamics of varved pleistocene lake sediments in nw Argentina
Y1  - 1999
SN  - 1029-7006
ER  - 
TY  - JOUR
A1  - Beim Graben, Peter
A1  - Saddy, Douglas
A1  - Schlesewsky, Matthias
A1  - Kurths, Jürgen
T1  - Symbolic dynamics of event-related brain potentials
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Timmer, Jens
A1  - Schwarz, Udo
A1  - Voss, Henning U.
A1  - Wardinski, Ingo
A1  - Belloni, Tomaso
A1  - Hasinger, Günther
A1  - VanDerKlis, Michael
A1  - Kurths, Jürgen
T1  - Linear and Nonlinear Time Series Analysis of the Black Hole Candidate Cygnus X-1
N2  - We analyze the variability in the x-ray lightcurves of the black hole candidate Cygnus X-1 by linear and nonlinear time series analysis methods. While a linear model describes the overall second order properties of the observed data well, surrogate data analysis reveals a significant deviation from linearity. We discuss the relation between shot noise models usually applied to analyze these data and linear stochastic autoregressive models. We debate statistical and interpretational issues of surrogate data testing for the present context. Finally, we suggest a combination of tools from linear and nonlinear time series analysis methods as a procedure to test the predictions of astrophysical models on observed data.
Y1  - 2000
UR  - http://pre.aps.org/
ER  - 
TY  - JOUR
A1  - Wessel, Niels
A1  - Voss, Andreas
A1  - Kurths, Jürgen
A1  - Schirdewan, Alexander
A1  - Hnatkova, Katarina
A1  - Malik, Marek
T1  - Evaluation of renormalised entropy for risk stratification using heart rate variability data
N2  - Standard time and frequency parameters of heart rate variability (HRV) describe only linear and periodic behaviour, whereas more complex relationships cannot be recognised. A method that may be capable of assessing more complex properties is the non-linear measure of 'renormalised entropy.' A new concept of the method, RE(AR), has been developed, based on a non-linear renormalisation of autoregressive spectral distributions. To test the hypothesis that renormalised entropy may improve the result of high-risk stratification after myocardial infarction, it is applied to a clinical pilot study (41 subjects) and to prospective data of the St George's Hospital post- infarction database (572 patients). The study shows that the new RE(AR) method is more reproducible and more stable in time than a previously introduced method (p<0.001). Moreover, the results of the study confirm the hypothesis that on average, the survivors have negative values of RE(AR) (-0.11+/-0.18), whereas the non-survivors have positive values (0.03+/-0.22, p<0.01). Further, the study shows that the combination of an HRV triangular index and RE(AR) leads to a better prediction of sudden arrhythmic death than standard measurements of HRV. In summary, the new RE(AR) method is an independent measure in HRV analysis that may be suitable for risk stratification in patients after myocardial infarction.
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Zaikin, Alexei A.
A1  - Kurths, Jürgen
A1  - Schimansky-Geier, Lutz
T1  - Doubly stochastic resonance
N2  - We report the effect of doubly stochastic resonance which appears in nonlinear extended systems if the influence of noise is twofold: A multiplicative noise induces bimodality of the mean field of the coupled network and an independent additive noise governs the dynamic behavior in response to small periodic driving. For optimally selected values of the additive noise intensity stochastic resonance is observed, which is manifested by a maximal coherence between the dynamics of the mean field and the periodic input. Numerical simulations of the signal-to-noise ratio and theoretical results from an effective two state model are in good quantitative agreement.
Y1  - 2000
UR  - http://link.aps.org/abstract/PRL/v85/p227
ER  - 
TY  - JOUR
A1  - Zaikin, Alexei A.
A1  - Kurths, Jürgen
T1  - Additive noise and noise-induced nonequilibrium phase transitions
Y1  - 2000
SN  - 1-563-96826-6
ER  - 
TY  - JOUR
A1  - Wessel, Niels
A1  - Ziehmann, Christine
A1  - Kurths, Jürgen
A1  - Meyerfeldt, Udo
A1  - Schirdewan, Alexander
A1  - Voss, Andreas
T1  - Short-term forecasting of life-threatening cardiac arrhythmias based on symbolic dynamics and finite-time growth rates
N2  - Ventricular tachycardia or fibrillation (VT-VF) as fatal cardiac arrhythmias are the main factors triggering sudden cardiac death. The objective of this study is to find early signs of sustained VT-VF in patients with an implanted cardioverter-defibrillator (ICD). These devices are able to safeguard patients by returning their hearts to a normal rhythm via strong defibrillatory shocks; additionally, they store the 1000 beat-to-beat intervals immediately before the onset of a life-threatening arrhythmia. We study these 1000 beat-to-beat intervals of 17 chronic heart failure ICD patients before the onset of a life-threatening arrhythmia and at a control time, i.e., without a VT-VF event. To characterize these rather short data sets, we calculate heart rate variability parameters from the time and frequency domain, from symbolic dynamics as well as the finite-time growth rates. We find that neither the time nor the frequency domain parameters show significant differences between the VT-VF and the control time series. However, two parameters from symbolic dynamics as well as the finite-time growth rates discriminate significantly both groups. These findings could be of importance in algorithms for next generation ICD's to improve the diagnostics and therapy of VT-VF.
Y1  - 2000
ER  - 
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  - 
TY  - INPR
A1  - Guasti, Giovanna
A1  - Engbert, Ralf
A1  - Krampe, Ralf T.
A1  - Kurths, Jürgen
T1  - Phase transitions, complexity, and stationarity in the production of polyrhythms
N2  - Contents: 1 Introduction 2 Experiment 3 Data 4 Symbolic dynamics 4.1 Symbolic dynamics as a tool for data analysis 4.2 2-symbols coding 4.3 3-symbols coding 5 Measures of complexity 5.1 Word statistics 5.2 Shannon entropy 6 Testing for stationarity 6.1 Stationarity 6.2 Time series of cycle durations 6.3 Chi-square test 7 Control parameters in the production of rhythms 8 Analysis of relative phases 9 Discussion 10 Outlook
T3  - NLD Preprints - 57 
Y1  - 2000
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-14933
ER  - 
TY  - JOUR
A1  - Pikovskij, Arkadij
A1  - Rosenblum, Michael
A1  - Kurths, Jürgen
T1  - Phase synchronization in regular and chaotic systems
Y1  - 2000
SN  - 0218-1274
ER  - 
TY  - JOUR
A1  - Popovych, Orest
A1  - Maistrenko, Yu
A1  - Mosekilde, Erik
A1  - Pikovskij, Arkadij
A1  - Kurths, Jürgen
T1  - Transcritical loss of synchronization in coupled chaotic systems
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Marwan, Norbert
A1  - Schwarz, Udo
A1  - Kurths, Jürgen
A1  - Strecker, Manfred
T1  - ENSO Impact on landslide generation in northwestern Argentina
N2  - Climatic changes are of major importance in landslide generation in the Argentine Andes. Increased humidity as a potential influential factor was inferred from the temporal clustering of landslide deposits during a period of significantly wetter climate, 30,000 years ago. A change in seasonality was tested by comparing past (inferred from annual-layered lake deposits, 30,000 years old) and modern (present-day observations) precipitation changes. Quantitative analysis of cross recurrence plots were developed to compare the influence of the El Nino/Southern Oscillation (ENSO) on present and past rainfall variations. This analysis has shown the stronger influence of NE trades in the location of landslide deposits in the intra-andean basin and valleys, what caused a higher contrast between summer and winter rainfall and an increasing of precipitation in La Nina years. This is believed to reduce thresholds for landslide generation in the arid to semiarid intra-andean basins and valleys.
Y1  - 2000
SN  - 1029-7006
ER  - 
TY  - JOUR
A1  - Wessel, Niels
A1  - Marwan, Norbert
A1  - Meyerfeldt, Udo
A1  - Schirdewan, Alexander
A1  - Kurths, Jürgen
T1  - Recurrence quantification analysis to characterise the heart rate variability before the onset of ventricular tachycardia
N2  - Ventricular tachycardia or fibrillation (VT) as fatal cardiac arrhythmias are the main factors triggering sudden cardiac death. The objective of this recurrence quantification analysis approach is to find early signs of sustained VT in patients with an implanted cardioverter-defibrillator (ICD). These devices are able to safeguard patients by returning their hearts to a normal rhythm via strong defibrillatory shocks; additionally, they are able to store at least 1000 beat-to-beat intervals immediately before the onset of a life-threatening arrhythmia. We study the
Y1  - 2001
UR  - http://link.springer.de/link/service/series/0558/bibs/2199/21990295.htm
ER  - 
TY  - JOUR
A1  - Raab, Corinna
A1  - Kurths, Jürgen
T1  - Estimation of Large-Scale Dimension Densities
N2  - We propose a technique to calculate large-scale dimension densities in both higher-dimensional spatio-temporal systems and low-dimensional systems from only a few data points, where known methods usually have an unsatisfactory scaling behavior. This is mainly due to boundary and finite size effects. With our rather simple method we normalize boundary effects and get a significant correction of the dimension estimate. This straightforward approach is basing on rather general assumptions. So even weak coherent structures obtained from small spatial couplings can be detected with this method, what is impossible by using the Lyapunov-dimension density. We demonstrate the efficiency of our technique for coupled logistic maps, coupled tent maps, the Lorenz-attractor and the Roessler-attractor.
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Palus, Milan
A1  - Kurths, Jürgen
A1  - Schwarz, Udo
A1  - Novotná, Dagmar
A1  - Charvátová, Ivanka
T1  - Is the solar activity cycle synchronized with the solar inertial motion?
N2  - The 300 year record of the yearly sunspot numbers and numerically generated trajectory of the solar inertial motion (SIM) were subjects of a synchronization analysis. Phase synchronization of the sunspot cycle and a fast component of the SIM have been found and confirmed with statistical significance in three epochs (1727-1757, 1802-1832 and 1863-1922) of the entire 1700-1997 record. This result can be considered as a quantitative support for the hypothesis that there is a weak interaction of gravity and solar activity.
Y1  - 2001
UR  - http://ejournals.wspc.com.sg/ijbc/10/1011/S0218127400001766.html
ER  - 
TY  - JOUR
A1  - Marwan, Norbert
A1  - Nowaczyk, Norbert R.
A1  - Kurths, Jürgen
A1  - Thiel, Marco
T1  - Cross recurrence plot based rescaling of geological time series
N2  - The rescaling of geological data series to a geological reference time series is of major interest in many investigations. For example, geophysical borehole data should be correlated to a given data series whose time scale is known in order to achieve an age-depth function or the sedimentation rate for the borehole data. Usually this synchronization is performed visually and by hand. Instead of using this wiggle matching by eye, we present the application of cross recurrence plots for such tasks. Using this method, the synchronization and rescaling of geological data to a given time scale is much easier and faster than by hand.
Y1  - 2001
SN  - 1029-7006
ER  -