@article{SitzSchwarzKurthsetal.2002,
  author    = {Sitz, Andre and Schwarz, Udo and Kurths, J{\"u}rgen and Voss, Henning U.},
  title     = {Estimation of parameters and unobserved components for nonlinear systems from noisy time series},
  year      = {2002},
  abstract  = {We study the problem of simultaneous estimation of parameters and unobserved states from noisy data of nonlinear time-continuous systems, including the case of additive stochastic forcing. We propose a solution by adapting the recently developed statistical method of unscented Kalman filtering to this problem. Due to its recursive and derivative-free structure, this method minimizes the cost function in a computationally efficient and robust way. It is found that parameters as well as unobserved components can be estimated with high accuracy, including confidence bands, from heavily noise-corrupted data.},
  language  = {en}
}
@article{KopitzkiWarnkeSaparinetal.2002,
  author    = {Kopitzki, K. and Warnke, P. C. and Saparin, Peter and Kurths, J{\"u}rgen and Timmer, Jens},
  title     = {Comment on "Kullback-Leibler and renormalized entropies: Applications to electroencephalograms of epilepsy patients"},
  year      = {2002},
  language  = {en}
}
@article{ZhangHuHuetal.2002,
  author    = {Zhang, H. and Hu, B. and Hu, G. and Ouyang, Q. and Kurths, J{\"u}rgen},
  title     = {Turbulence control by developing a spiral wave with a periodic signal injection in the complex Ginzburg-Laundau equation},
  year      = {2002},
  language  = {en}
}
@article{ZhouKurths2002,
  author    = {Zhou, Changsong and Kurths, J{\"u}rgen},
  title     = {Noise-induced phase synchronization and synchronization transitions in chaotic oscillators},
  year      = {2002},
  language  = {en}
}
@article{TokudaKurthsRosa2002,
  author    = {Tokuda, I. and Kurths, J{\"u}rgen and Rosa, Epaminondas},
  title     = {Learning phase synchronization from nonsynchronized chaotic regimes},
  year      = {2002},
  language  = {en}
}
@article{KuznetsovKurths2002,
  author    = {Kuznetsov, A. S. and Kurths, J{\"u}rgen},
  title     = {Stable heteroclinic cycles for ensembles of chaotic oscillators},
  year      = {2002},
  language  = {en}
}
@article{ZhouKurthsKissetal.2002,
  author    = {Zhou, Changsong and Kurths, J{\"u}rgen and Kiss, Istvan Z. and Hudson, J. L.},
  title     = {Noise-enhanced phase synchronization of chaotic oscillators},
  year      = {2002},
  language  = {en}
}
@article{OsipovPikovskijKurths2002,
  author    = {Osipov, Grigory V. and Pikovskij, Arkadij and Kurths, J{\"u}rgen},
  title     = {Phase Synchronization of Chaotic Rotators},
  year      = {2002},
  abstract  = {We demonstrate the existence of phase synchronization of two chaotic rotators. Contrary to phase synchronization of chaotic oscillators, here the Lyapunov exponents corresponding to both phases remain positive even in the synchronous regime. Such frequency locked dynamics with different ratios of frequencies are studied for driven continuous-time rotators and for discrete circle maps. We show that this transition to phase synchronization occurs via a crisis transition to a band-structured attractor.},
  language  = {en}
}
@article{RosenblumPikovskijKurthsetal.2002,
  author    = {Rosenblum, Michael and Pikovskij, Arkadij and Kurths, J{\"u}rgen and Osipov, Grigory V. and Kiss, Istvan Z. and Hudson, J. L.},
  title     = {Locking-based frequency measurement and synchronization of chaotic oscillators with complex dynamics},
  year      = {2002},
  language  = {en}
}
@article{BoccalettiKurthsOsipov2002,
  author    = {Boccaletti, Stefano and Kurths, J{\"u}rgen and Osipov, Grigory V.},
  title     = {The synchronization of chaotic systems},
  year      = {2002},
  language  = {en}
}
@article{OsipovKurths2002,
  author    = {Osipov, Grigory V. and Kurths, J{\"u}rgen},
  title     = {Regular and chaotic phase synchronization of coupled circle maps},
  year      = {2002},
  language  = {en}
}
@article{MarwanWesselMeyerfeldtetal.2002,
  author    = {Marwan, Norbert and Wessel, Niels and Meyerfeldt, Udo and Schirdewan, Alexander and Kurths, J{\"u}rgen},
  title     = {Recurrence-plot-based measures of complexity and its application to heart-rate-variability data},
  year      = {2002},
  abstract  = {The knowledge of transitions between regular, laminar or chaotic behavior is essential to understand the underlying mechanisms behind complex systems. While several linear approaches are often insufficient to describe such processes, there are several nonlinear methods which however require rather long time observations. To overcome these difficulties, we propose measures of complexity based on vertical structures in recurrence plots and apply them to the logistic map as well as to heart rate variability data. For the logistic map these measures enable us not only to detect transitions between chaotic and periodic states, but also to identify laminar states, i.e. chaos-chaos transitions. The traditional recurrence quantification analysis fails to detect the latter transitions. Applying our new measures to the heart rate variability data, we are able to detect and quantify the laminar phases before a life-threatening cardiac arrhythmia occurs thereby facilitating a prediction of such an event. Our findings could be of importance for the therapy of malignant cardiac arrhythmias.},
  language  = {en}
}
@article{EngbertScheffczykKrampeetal.2002,
  author    = {Engbert, Ralf and Scheffczyk, Christian and Krampe, Ralf-Thomas and Kurths, J{\"u}rgen and Kliegl, Reinhold},
  title     = {Symbolic dynamics of bimanual production of polyrhythms},
  isbn      = {3-540- 63481-9},
  year      = {2002},
  abstract  = {We analyse time series from a study on bimanual rhythmic movements in which the speed of performance (the external control parameter) was experimentally manipulated. Using symbolic transformations as a visualization technique we observe qualitative changes in the dynamics of the timing patterns. Such phase transitions are quantitatively described by measures of complexity. Using these results we develop an advanced symbolic coding which enables us to detect important dynamical structures. Furthermore, our analysis raises new questions concerning the modelling of the underlying human cognitive-motor system.},
  language  = {en}
}
@article{RaabKurths2001,
  author    = {Raab, Corinna and Kurths, J{\"u}rgen},
  title     = {Estimation of Large-Scale Dimension Densities},
  year      = {2001},
  abstract  = {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.},
  language  = {en}
}
@article{PalusKurthsSchwarzetal.2001,
  author    = {Palus, Milan and Kurths, J{\"u}rgen and Schwarz, Udo and Novotn{\´a}, Dagmar and Charv{\´a}tov{\´a}, Ivanka},
  title     = {Is the solar activity cycle synchronized with the solar inertial motion?},
  year      = {2001},
  abstract  = {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.},
  language  = {en}
}
@article{ZaikinMuraliKurths2001,
  author    = {Zaikin, Alexei A. and Murali, K. and Kurths, J{\"u}rgen},
  title     = {Simple electronic circuit model for doubly stochastic resonance},
  year      = {2001},
  abstract  = {We have recently reported the phenomenon of doubly stochastic resonance [Phys. Rev. Lett. 85, 227 (2000)], a synthesis of noise-induced transition and stochastic resonance. The essential feature of this phenomenon is that multiplicative noise induces a bimodality and additive noise causes stochastic resonance behavior in the induced structure. In the present paper we outline possible applications of this effect and design a simple lattice of electronic circuits for the experimental realization of doubly stochastic resonance.},
  language  = {en}
}
@article{RomanoThielSchwarzetal.2001,
  author    = {Romano, Maria Carmen and Thiel, Marco and Schwarz, Udo and Kurths, J{\"u}rgen and Lange, Holger and Hauhs, M.},
  title     = {Conceptual model of runoff from a forested catchment},
  year      = {2001},
  abstract  = {We investigate the relationship between precipitation and runoff data from a small forested catchment in the Harz mountains (Germany). For this purpose, we develop a conceptual model including memory effects to predict the runoff signal using the precipitation data as input. An enhanced variant of the model also includes air temperature as input variable. We show in terms of correlation functions that this model describes main dynamical properties of the runoff, especially the delay between rain event and runoff response as the annual persistence in the runoff data.},
  language  = {en}
}
@article{ZaikinKurths2001,
  author    = {Zaikin, Alexei A. and Kurths, J{\"u}rgen},
  title     = {Additive noise in noise-induced nonequilibrium transitions},
  issn      = {1054-1500},
  year      = {2001},
  language  = {en}
}
@article{SitzSchwarzKurthsetal.2001,
  author    = {Sitz, Andre and Schwarz, Udo and Kurths, J{\"u}rgen and Maus, Doris and Wiese, Michael and Warnecke, G{\"u}nter},
  title     = {Signatures of acoustic emission signals generated during high speed cutting},
  year      = {2001},
  abstract  = {Acoustic emission signals generated during high speed cutting of steel are investigated. The data are represen ted in time-folded form. Several methods from linear and nonlinear data analysis based on time- and frequency- domain are applied to the data and reveal signatures of the observed acoustic emission signal. These investiga tions are necessary for modeling the cutting process by means of differential equations.},
  language  = {en}
}
@article{ThielRomanoSchwarzetal.2001,
  author    = {Thiel, Marco and Romano, Maria Carmen and Schwarz, Udo and Kurths, J{\"u}rgen and Hasinger, G{\"u}nther and Belloni, Tomaso},
  title     = {Nonlinear Time series analysis of the X-ray flux of compact objects},
  issn      = {0004-640x},
  year      = {2001},
  abstract  = {We analyse the X-ray light curves of compact objects using linear and nonlinear time series analysis methods. A Power Density Spectrum (PDS) describes the overall second order properties of the observed data well. To look beyond we propose the nonlinear Q-statistic to detect an asymmetry of the time series. This allows us to find relevant time scales. This method even grants a subclassification of the known states of X-ray sources.},
  language  = {en}
}