5,706 research outputs found
Dynamical aspects of Kinouchi-Copelli model: emergence of avalanches at criticality
We analyze the behavior of bursts of neural activity in the Kinouchi-Copelli
model, originally conceived to explain information processing issues in sensory
systems. We show that, at a critical condition, power-law behavior emerges for
the size and duration of the bursts (avalanches), with exponents experimentally
observed in real biological systems.Comment: Paper accepted for Brazilian Conference on Dynamics, Control and
Applications (oral presentation and poster). 4 pages, 5 figure
Duality and interval analysis over idempotent semirings
In this paper semirings with an idempotent addition are considered. These
algebraic structures are endowed with a partial order. This allows to consider
residuated maps to solve systems of inequalities . The
purpose of this paper is to consider a dual product, denoted , and the
dual residuation of matrices, in order to solve the following inequality . Sufficient conditions ensuring the
existence of a non-linear projector in the solution set are proposed. The
results are extended to semirings of intervals
Editorial
info:eu-repo/semantics/publishedVersio
Particle Creation by a Moving Boundary with Robin Boundary Condition
We consider a massless scalar field in 1+1 dimensions satisfying a Robin
boundary condition (BC) at a non-relativistic moving boundary. We derive a
Bogoliubov transformation between input and output bosonic field operators,
which allows us to calculate the spectral distribution of created particles.
The cases of Dirichlet and Neumann BC may be obtained from our result as
limiting cases. These two limits yield the same spectrum, which turns out to be
an upper bound for the spectra derived for Robin BC. We show that the particle
emission effect can be considerably reduced (with respect to the
Dirichlet/Neumann case) by selecting a particular value for the oscillation
frequency of the boundary position
Effects of in-group bias on face recognition using minimal group procedures
2014 Fall.Includes bibliographical references.The current series of experiments examined the effects of social categorization on face recognition. The use of minimal group procedures was expected to enhance recognition for in-group members compared to out-group members. In Experiment 1, participants were assigned to 1 of 3 conditions: name study--participants studied a list of 16 names associated with their in-group [red or green], numerical estimation--participants were randomly divided into 2 groups [red or green] after estimating the number of dots in a series of 10 images, and the control condition. This was followed by a study phase in which participants were presented with a total of 32 female and male Caucasian faces on red or green backgrounds. A final recognition test was given following a filler task. Experiment 2 had two of the previously used conditions, name study and control. Faces were presented on red and green backgrounds during test--with old faces presented on the same background as seen at study. Experiment 3 presented a subset of stimuli used in Experiment 2 with a longer presentation time (10 seconds). Findings suggest only moderate difference in response bias between experimental and control groups overall in Experiments 2 and 3. Moderate differences in hits, false alarms, and d' were also found in Experiment 3 between experimental conditions. Group membership did not elicit significant effects on measures of accuracy, reaction time, and confidence ratings
Quantum radiation in a plane cavity with moving mirrors
We consider the electromagnetic vacuum field inside a perfect plane cavity
with moving mirrors, in the nonrelativistic approximation. We show that low
frequency photons are generated in pairs that satisfy simple properties
associated to the plane geometry. We calculate the photon generation rates for
each polarization as functions of the mechanical frequency by two independent
methods: on one hand from the analysis of the boundary conditions for moving
mirrors and with the aid of Green functions; and on the other hand by an
effective Hamiltonian approach. The angular and frequency spectra are discrete,
and emission rates for each allowed angular direction are obtained. We discuss
the dependence of the generation rates on the cavity length and show that the
effect is enhanced for short cavity lengths. We also compute the dissipative
force on the moving mirrors and show that it is related to the total radiated
energy as predicted by energy conservation.Comment: 17 pages, 1 figure, published in Physical Review
Topological Properties from Einstein's Equations?
In this work we propose a new procedure for to extract global information of
a space-time. We considered a space-time immersed in a higher dimensional space
and we formulate the equations of Einstein through of the Frobenius conditions
to immersion. Through of an algorithm and the implementation into algebraic
computing system we calculate normal vectors from the immersion to find out the
second fundamental form. We make a application for space-time with spherical
symmetry and static. We solve the equations of Einstein to the vacuum and we
obtain space-times with different topologies.Comment: 7 pages, accepted for publication in Int. J. Mod. Phys.
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