Anomalous synchronization of spatially extended chaotic systems in the presence of asymmetric coupling

Communicated by Werner Ebeling and Bernardo Spagnolo This paper describes the e ects of an asymmetric coupling in the synchronization of two spatially extended systems. Namely, we report the consequences induced by the presence of asymmetries in the coupling con guration of a pair of one-dimensional elds obeying Complex Ginzburg Landau equations. While synchronization always occurs for large enough coupling strengths, asymmetries have the e ect of enhancing synchronization and play a crucial role in setting the threshold for the appearance of the synchronized dynamics, as well as in selecting the statistical and dynamical properties of the synchronized motion. We discuss the process of synchronization in the presence of asymmetries by using some analytic expansions valid for a regime of soft spatial temporal chaos (i.e. phase turbulence regime). The in uence of phase singularities that break the validity of the analysis is also discussed

Convective instabilities of synchronization manifolds in spatially extended systems

We study the stability properties of anticipating synchronization in an open chain of unidirectionally coupled identical chaotic oscillators. Despite being absolutely stable, the synchronization manifold is unstable to propagating perturbations. We analyze and characterize such instabilities drawing a qualitative and quantitative comparison with the convective instabilities typical of spatially extended systems

Synchronization of spatially extended chaotic systems with asymmetric coupling

In this paper, we report the consequences induced by the presence of asymmetries in the coupling scheme on the synchronization process of a pair of one-dimensional complex fields obeying Complex Ginzburg Landau equations. While synchronization always occurs for large enough coupling strengths, asymmetries have the effect of modifying synchronization thresholds and play a crucial role in selecting the statistical and dynamical properties of the highly coupled synchronized motion. Possible consequences of such symmetry induced effects in biological and natural systems are discussed

Defect-enhanced anomaly in frequency synchonization of asymmetrically coupled spatially extended systems

We analytically establish and numerically show that anomalous frequency synchronization occurs in a pair of asymmetrically coupled chaotic space extended oscillators. The transition to anomalous behaviors is crucially dependent on asymmetries in the coupling configuration, while the presence of phase defects has the effect of enhancing the anomaly in frequency synchronization with respect to the case of merely time chaotic oscillators

Synchronization of spatially extended chaotic systems in the presence of asymmetric coupling

In a recent paper [Phys. Rev. Lett. 91, 064103 (2003)] we described the effects of asymmetric coupling configurations on the synchronization of spatially extended systems. In this paper, we report the consequences induced by the presence of asymmetries in the coupling scheme on the synchronization process of a pair of one-dimensional fields obeying complex Ginzburg-Landau equations. While synchronization always occurs for large enough coupling strengths, asymmetries have the effect of enhancing synchronization and play a crucial role in setting the threshold for the appearance of the synchronized dynamics, as well as in selecting the statistical and dynamical properties of the synchronized motion. We analyze the process of synchronization in the presence of asymmetries when the dynamics is affected by the presence of phase singularities, and show that defects tend to anchor one system to the other. In addition, asymmetry controls the number of synchronized defects that are present in the dynamics. Possible consequences of such asymmetry induced effects in biological and natural systems are discussed

Chaos suppression through asymmetric coupling

We study pairs of identical coupled chaotic oscillators. In particular, we have used Roessler in the funnel and no funnel regimes , Lorenz, and four-dimensional chaotic Lotka-Volterra models. In all four of these cases, a pair of identical oscillators is asymmetrically coupled. The main result of the numerical simulations is that in all cases, specific values of coupling strength and asymmetry exist that render the two oscillators periodic and synchronized. The values of the coupling strength for which this phenomenon occurs is well below the previously known value for complete synchronization. We have found that this behavior exists for all the chaotic oscillators that we have used in the analysis. We postulate that this behavior is presumably generic to all chaotic oscillators. In order to complete the study, we have tested the robustness of this phenomenon of chaos suppression versus the addition of some Gaussian noise. We found that chaos suppression is robust for the addition of finite noise level. Finally, we propose some extension to this research

Desarrollo tecnológico en ingeniería automotriz

El proceso de investigación y desarrollo tecnológico está directamente relacionado con una adecuada metodología de procesos industriales, que cada vez son más exigentes en competitividad, eficiencia energética y de normativas ambientales. Este libro contempla resultados de un proceso de investigación y desarrollo de nuevas técnicas aplicadas en el campo de la Ingeniería Automotriz desde cuatro aristas: eficiencia energética y contaminación ambiental, planificación del transporte, ingeniería del mantenimiento aplicada al transporte y desagregación tecnológica. Este libro conmemora 20 años de formación universitaria salesiana en el sector de transporte y recoge las experiencias y resultados obtenidos asociados con el desarrollo tecnológico en ingeniería automotriz. Para lograr este objetivo, se ha convocado a la comunidad científica, académica y profesionales de la industria automotriz a participar en la publicación. Cada capítulo fue sometido a revisión, evaluación y aprobación por un comité científico altamente calificado, proveniente de seis países: Colombia, Ecuador, España, Guinea Ecuatorial, México y Venezuela. Este trabajo ha sido posible gracias al gran apoyo de la Universidad Politécnica Salesiana (UPS sede Cuenca), Ecuador y Universidad de Los Andes (ULA)

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016