A study of resonance tongues near a Chenciner bifurcation using MatcontM

MatcontM is a matlab toolbox for numerical analysis of bifurcations of fixed points and periodic orbits of maps. It computes codim 1 bifurcation curves and supports the computation of normal coefficients including branch switching from codim 2 points to secondary curves. Recently, the initialization and computation of connecting orbits was improved. Moreover, a graphical user interface was added enabling interactive control of all these computations. To further support these computations it allows to compute orbits of the map and its iterates and to represent them in 2D, 3D and numeric windows. We demonstrate the use of the toolbox in a study of Arnol'd tongues near a degenerate Neimark-Sacker (Chenciner) bifurcation. Here we illustrate the recent theory of [Baesens&Mackay,2007] how resonance tongues interact with a quasi-periodic saddle-node bifurcation of invariant curves in maps. Using normal form coefficients we find evidence for one of their cases, but not the other. Actually, we find another unfolding, i.e. a third possibility. We also find a structure that resembles a quasi-periodic cusp bifurcation of invariant curves

Vibration-based structural interrogation and health monitoring based on nonlinear signal analysis

Vibration-based structural interrogation and health monitoring is a field which is concerned with the estimation of the current state of a structure or a component from its vibration response with regards to its ability to perform its intended function appropriately. This study suggests using the concept of signal cross-correlation for the purposes of vibration-based health monitoring. A nonlinear alternative of the cross-correlation, the mutual information between two signals measured on the structure, regarded as an input and an output, is used to develop a damage metric and a damage index. The application of the suggested methodology is shown on a composite beam test set using experimental measurements

Forced response of shrouded blades with a coupled static/dynamic approach

A coupled static-dynamic method is proposed and applied to bladed disks with shrouds, in order to calculate the nonlinear forced response in presence of friction damping in the frequency domain. The novel approach allows to improve the already existing methods, which require a preliminary static analysi

Il libro di Daniele e l'apocalittica ebraica antica

1. Un genere letterario e una visione del mondo. 2. La letteratura apocalittica ebraica. 3. Le radici dell'apocalittica ebraica. 4. Apocalittica, enochismo, qumranesimo. 5. Il libro di Daniele. 6. Le principali apocalissi non canoniche