63,480 research outputs found
Simulation of Chua's Circuit by Means of Interval Analysis
The Chua's circuit is a paradigm for nonlinear scientific studies. It is
usually simulated by means of numerical methods under IEEE 754-2008 standard.
Although the error propagation problem is well known, little attention has been
given to the relationship between this error and inequalities presented in
Chua's circuit model. Taking the average of round mode towards and
, we showed a qualitative change on the dynamics of Chua's circuit.Comment: 6th International Conference on Nonlinear Science and Complexity -
S\~ao Jos\'e dos Campos, 2016, p. 1-
The Phillips - Barger model for the elastic cross section and the Odderon
Inspired by the recent TOTEM data for the elastic proton -- proton ()
scattering at 8 and 13 TeV, we update previous studies of the
differential cross sections using the Phillips -- Barger (PB) model, which
parametrizes the amplitude in terms of a small number of free parameters. We
demonstrate that this model is able to describe the recent data on a
statistically acceptable way. Additionally, we perform separate fits of the
data for each center - of - mass energy and propose a parametrization for
the energy dependence of the parameters present in the PB model. As a
consequence, we are able to present the PB predictions for the elastic proton -
proton cross section at GeV and TeV, which are compared
with the existing antiproton -- proton () data. We show that the PB
predictions, constrained by the data, are not able to describe the
data. In particular, the PB model predicts a dip in the differential
cross section that is not present in the data. Such result suggests
the contribution of the Odderon exchange at high energies.Comment: 6 pages, 4 tables, 2 figures, results updated, matches published
versio
Visco-elastic regularization and strain softening
In this paper it is intended to verify the capacity of regularization of the numerical
solution of an elasto-plastic problem with linear strain softening. The finite element method
with a displacement approach is used. Drucker-Prager yield criteria is considered. The radial
return method is used for the integration of the elasto-plastic constitutive relations. An elastovisco-
plastic scheme is used to regularize the numerical solution. Two constitutive laws have
been developed and implemented in a FE-program, the first represent the radial return
method applied to Drucker-Prager yield criteria and the second is a time integration
procedure for the Maxwell visco-elastic model. Attention is paid to finite deformations. An
associative plastic flow is considered in the Drucker-Prager elasto-plastic model. The
algorithms are tested in two problems with softening. Figures showing the capability of the
algorithms to regularize the solution are presented
Development of an open-source platform for calculating losses from earthquakes
Risk analysis has a critical role in the reduction of casualties and damages due to earthquakes.
Recognition of this relation has led to a rapid rise in demand for accurate, reliable and flexible risk
assessment numerical tools and software. As a response to this need, the Global Earthquake Model
(GEM) started the development of an open source platform called OpenQuake, for calculating
seismic hazard and risk at different scales. Along with this framework, also several other tools to
support users creating their own models and visualizing their results are currently being
developed, and will be made available as a Modelers Tool Kit (MTK). In this paper, a description
of the architecture of OpenQuake is provided, highlighting the current data model, workflow of
the calculators and the main challenges raised when running this type of calculations in a global
scale. In addition, a case study is presented using the Marmara Region (Turkey) for the calculations, in which the losses for a single event are estimated, as well as probabilistic risk for a
50 years time span
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