General Stability Analysis of Synchronized Dynamics in Coupled Systems

We consider the stability of synchronized states (including equilibrium point, periodic orbit or chaotic attractor) in arbitrarily coupled dynamical systems (maps or ordinary differential equations). We develop a general approach, based on the master stability function and Gershgorin disc theory, to yield constraints on the coupling strengths to ensure the stability of synchronized dynamics. Systems with specific coupling schemes are used as examples to illustrate our general method.Comment: 8 pages, 1 figur

THEORETICAL DESCRIPTION OF THE INFLUENCE OF DISLOCATIONS ON THE LUMINESCENCE OF LIGHT-EMITTING DIODES

Dans l'hypothèse qu'une dislocation isolée décorée par des impuretés peut être considérée comme une inhomogénéité macroscopique, on propose un modèle simple qui décrit l'influence de dislocations non corrélées sur la luminescence de diodes électroluminescentes. L'accord de ce modèle avec les données expérimentales est raisonnable.Under the assumption that a single dislocation decorated by impurities can be considered as a macroscopic inhomogeneity a simple model is proposed which describes the influence of uncorrelated dislocations on the luminescence of LEDs in reasonable agreement with experimental data

Some remarks on the review « Quantitative evaluation of the EBIC contrast of dislocations » by C. Donolato

Contrary views on an appropriate representation of the recombination strength of a dislocation are discussed with the consequence that a new fonction is proposed which describes the recombination strength nearly independent of the lifetime of the bulk.La formulation donnée par divers auteurs, de l'efficacité de recombinaison d'une dislocation est discutée. On propose finalement une nouvelle expression qui est quasiment indépendante de la durée de vie des porteurs du matériau massif

Comment on « EBIC contrast theory of dislocations: intrinsic recombination properties »

It is shown that a recent analysis of the EBIC (electron beam induced current) contrast of a dislocation (J. L. Farvacque and B. Sieber, Revue Phys. Appl. 25 (1990) 353) has some mathematical flaws and yields the erroneous result that the contrast does not become equal to zero if the recombination activity of the defect vanishes

Comment on « EBIC contrast theory of dislocations: intrinsic recombination properties »

It is shown that a recent analysis of the EBIC (electron beam induced current) contrast of a dislocation (J. L. Farvacque and B. Sieber, Revue Phys. Appl. 25 (1990) 353) has some mathematical flaws and yields the erroneous result that the contrast does not become equal to zero if the recombination activity of the defect vanishes.Nous montrons que les faiblesses mathématiques d'une analyse récente du contraste EBIC (electron beam induced current) d'une dislocation (J. L. Farvacque et B. Sieber, Revue Phys. Appl. 25 (1990) 353) conduit au résultat erroné que le contraste n'est pas égal à zéro lorsque l'activité électrique du défaut disparaît

DISCUSSION OF THE CONVERGENCE PROPERTIES OF THE PERTURBATION SERIES USED IN THE CALCULATION OF EBIC- AND CL-CONTRASTS

For the calculation of the contrast of a defect in semiconducting material, the defect is regarded as a bounded region where the minority carrier lifetime τ' is lower than that (τ) outside the defect region. The minority carrier density in the presence of the defect is normally written in terms of a perturbation series. The conditions for using a perturbation series for different kinds of defects are discussed

The Emergence of Communication by Evolving Dynamical Systems

In the context of minimally cognitive behavior, we used multirobotic systems to investigate the emergence of communication and cooperation during the evolution of recurrent neural networks. The networks are systematically analyzed to identify their relevant dynamical properties. Evolution efficiently adapts these properties through small structural changes within the networks when specific environmental conditions are altered, such as the number of interacting robots. The findings signify the importance of reducing the predefined knowledge about resulting behaviors, dynamical properties of control, and the topology of neural networks in order to utilize the strength of the Evolutionary Robotics approach to Artificial Life