25,014 research outputs found
Continuous Opinions and Discrete Actions in Opinion Dynamics Problems
A model where agents show discrete behavior regarding their actions, but have
continuous opinions that are updated by interacting with other agents is
presented. This new updating rule is applied to both the voter and Sznajd
models for interaction between neighbors and its consequences are discussed.
The appearance of extremists is naturally observed and it seems to be a
characteristic of this model.Comment: 10 pages, 4 figures, minor changes for improved clarit
Note on improvement precision of recursive function simulation in floating point standard
An improvement on precision of recursive function simulation in IEEE floating
point standard is presented. It is shown that the average of rounding towards
negative infinite and rounding towards positive infinite yields a better result
than the usual standard rounding to the nearest in the simulation of recursive
functions. In general, the method improves one digit of precision and it has
also been useful to avoid divergence from a correct stationary regime in the
logistic map. Numerical studies are presented to illustrate the method.Comment: DINCON 2017 - Conferencia Brasileira de Dinamica, Controle e
Aplicacoes - Sao Jose do Rio Preto - Brazil. 8 page
Finite temperature corrections and embedded strings in noncommutative geometry and the standard model with neutrino mixing
The recent extension of the standard model to include massive neutrinos in
the framework of noncommutative geometry and the spectral action principle
involves new scalar fields and their interactions with the usual complex scalar
doublet. After ensuring that they bring no unphysical consequences, we address
the question of how these fields affect the physics predicted in Weinberg-Salam
theory, particularly in the context of the Electroweak phase transition.
Applying the Dolan-Jackiw procedure, we calculate the finite temperature
corrections, and find that the phase transition is first order. The new scalar
interactions significantly improve the stability of the Electroweak Z string,
through the ``bag'' phenomenon described by Watkins and Vachaspati. (Recently
cosmic strings have climbed back into interest due to new evidence). Sourced by
static embedded strings, an internal space analogy of Cartan's torsion is
drawn, and a possible Higgs-force-like `gravitational' effect of this
non-propagating torsion on the fermion masses is described. We also check that
the field generating the Majorana mass for the is non-zero in the
physical vacuum.Comment: 42 page
Remarks on the neuropterofauna (Insecta, Neuroptera) from the Brazilian Cretaceous, with keys for the identification of the known taxa
This paper reviews all previous knowledge about neuropterans from the Santana Formation (Lower Cretaceous, northeastern Brazil) involving a decade of research in this group. The neuropterofauna from Santana Formation is one of the most complete and diverse known, formed by 50 species distributed in 28 genera, representing 11 families: Ascalaphidae, Myrmeleontidae, Psychopsidae, Chrysopidae, Berothidae, Sisyridae, Nemopteridae, Roeslerianidae, Babinskaiidae, Paleoleontidae and Makarkiniidae. All the know n material is from the laminated limestone, tip of the Crato Member, lowest unit of the Santana Formation, Lower Cretaceous, Ceará State, northeastern Brazil. This research have the objective to furnish the keys for the identification of all known Brazilian fossil neuropterans and 16 Figures containing the drafts of all Brazilian neuropterans holotypes
Social Effects in Science: Modelling Agents for a Better Scientific Practice
Science is a fundamental human activity and we trust its results because it
has several error-correcting mechanisms. Its is subject to experimental tests
that are replicated by independent parts. Given the huge amount of information
available, scientists have to rely on the reports of others. This makes it
possible for social effects to influence the scientific community. Here, an
Opinion Dynamics agent model is proposed to describe this situation. The
influence of Nature through experiments is described as an external field that
acts on the experimental agents. We will see that the retirement of old
scientists can be fundamental in the acceptance of a new theory. We will also
investigate the interplay between social influence and observations. This will
allow us to gain insight in the problem of when social effects can have
negligible effects in the conclusions of a scientific community and when we
should worry about them.Comment: 14 pages, 5 figure
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