488 research outputs found
Coupled map lattices without cluster expansion
No full textWe present an approach to the investigation of the statistical
properties of weakly coupled map lattices
that avoids completely cluster expansion techniques. Although here it
is implemented on a simple case we expect similar strategies to be
applicable in a much larger class of situations
Rare events, escape rates and quasistationarity: some exact formulae.
No full textAbstract. We present a common framework to study decay and exchanges rates in a wide class of dynamical systems. Several applications, ranging form the metric theory of continuons fractions and the Shannon capacity of con-trained systems to the decay rate of metastable states, are given. 1
Random walk in Markovian environment
No full textWe prove a quenched central limit theorem for random
walks with bounded increments in a randomly evolving environment on
. We assume that the transition probabilities of the walk depend not
too strongly on the environment and that the evolution of the environment
is Markovian with strong spatial and temporal mixing properties
A spectral gap for a one-dimensional lattice of coupled piecewise expanding interval maps
No full textAbstract. We study one-dimensional lattices of weakly coupled piecewise expanding interval maps as dynamical systems. Since neither the local maps need to have full branches nor the coupling map needs to be a homeomorphism of the infinite dimensional state space, we cannot use symbolic dynamics or other techniques from statistical mechanics. Instead we prove that the transfer operator of the infinite dimensional system has a spectral gap on suitable Banach spaces generated by measures with marginals that have densities of bounded variation. This implies in particular exponential decay of correlations in time and space.
Uniqueness of the SRB measure for piecewise expanding weakly coupled map lattices in any dimension
No full textAbstract. We prove the existence of a unique SRB measure for a wide range of multidimensional weakly coupled map lattices. These include piecewise expanding maps with diffusive coupling. 1
True Bi-Manual User Interface for Free-Form Surfaces Modeling
No full textThis work is devoted to introduce a new Bi-manual system that provides an handful user interface for free-form surface modelling. The Bi-Manual user interface (Bi-Manual-UI) has been realized exploiting a 6DOF (degree-of-freedom) motion controller.
The system considers the integration of a motion controller with a pen based graphical tablet. The Bi-Manual-UI aims to increase the interaction with users enhancing the creation of complex shapes. A sketching plane is available to users who can control its 3D position by the motion controller. In the meanwhile, users can draw a section curve on the plane, using the pen tablet. Moving the plane into a 3D space, the set of created curves area used to generate interactively the free-form surface. Unlikely standard CAD systems, the developed framework enables to change the sectional curve in real-time leading to the creation of shapes with different sections.
Advantages introduced by this innovative instrument consist in the usage of it as a true geometric modelling tool and not only in order to move and rotate virtual camera
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