3,355 research outputs found
Loss-Avoidance and Forward Induction in Experimental Coordination Games
We report experiments on how players select among multiple Pareto-ranked
equilibria in a coordination game. Subjects initially choose inefficient equilibria.
Charging a fee to play (which makes initial equilibria money-losing) creates coordination
on better equilibria. When fees are optional, improved coordination is
consistent with forward induction. But coordination improves even when subjects
must pay the fee (forward induction does not apply). Subjects appear to use a
"loss-avoidance" selection principle: they expect others to avoid strategies that
always result in losses. Loss-avoidance implies that "mental accounting" of outcomes
can affect choices in games
Overview of Constrained PARAFAC Models
In this paper, we present an overview of constrained PARAFAC models where the
constraints model linear dependencies among columns of the factor matrices of
the tensor decomposition, or alternatively, the pattern of interactions between
different modes of the tensor which are captured by the equivalent core tensor.
Some tensor prerequisites with a particular emphasis on mode combination using
Kronecker products of canonical vectors that makes easier matricization
operations, are first introduced. This Kronecker product based approach is also
formulated in terms of the index notation, which provides an original and
concise formalism for both matricizing tensors and writing tensor models. Then,
after a brief reminder of PARAFAC and Tucker models, two families of
constrained tensor models, the co-called PARALIND/CONFAC and PARATUCK models,
are described in a unified framework, for order tensors. New tensor
models, called nested Tucker models and block PARALIND/CONFAC models, are also
introduced. A link between PARATUCK models and constrained PARAFAC models is
then established. Finally, new uniqueness properties of PARATUCK models are
deduced from sufficient conditions for essential uniqueness of their associated
constrained PARAFAC models
Self-excited vibrations in turning: cutting moment analysis
This work aims at analysing the moment effects at the tool tip point and at
the central axis, in the framework of a turning process. A testing device in
turning, including a six-component dynamometer, is used to measure the complete
torsor of the cutting actions in the case of self-excited vibrations. Many
results are obtained regarding the mechanical actions torsor. A confrontation
of the moment components at the tool tip and at the central axis is carried
out. It clearly appears that analysing moments at the central axis avoids the
disturbances induced by the transport of the moment of the mechanical actions
resultant at the tool tip point. For instance, the order relation between the
components of the forces is single. Furthermore, the order relation between the
moments components expressed at the tool tip point is also single and the same
one. But at the central axis, two different order relations regarding moments
are conceivable. A modification in the rolling moment localization in the (y,
z) tool plan is associated to these two order relations. Thus, the moments
components at the central axis are particularly sensitive at the disturbances
of machining, here the self-excited vibrations.Comment: 8 page
Transition from the annealed to the quenched asymptotics for a random walk on random obstacles
In this work we study a natural transition mechanism describing the passage
from a quenched (almost sure) regime to an annealed (in average) one, for a
symmetric simple random walk on random obstacles on sites having an identical
and independent law. The transition mechanism we study was first proposed in
the context of sums of identical independent random exponents by Ben Arous,
Bogachev and Molchanov in [Probab. Theory Related Fields 132 (2005) 579--612].
Let be the survival probability at time of the random walk,
starting from site , and let be some increasing function of time. We
show that the empirical average of over a box of side has
different asymptotic behaviors depending on . T here are constants
such that if , with
, a law of large numbers is satisfied and the empirical
survival probability decreases like the annealed one; if , with , also a central limit theorem is
satisfied. If , the averaged survival probability decreases like
the quenched survival probability. If and we obtain an intermediate regime. Furthermore, when the dimension
it is possible to describe the fluctuations of the averaged survival
probability when with : it is
shown that they are infinitely divisible laws with a L\'{e}vy spectral function
which explodes when as stable laws of characteristic exponent
. These results show that the quenched and annealed survival
probabilities correspond to a low- and high-temperature behavior of a
mean-field type phase transition mechanism.Comment: Published at http://dx.doi.org/10.1214/009117905000000404 in the
Annals of Probability (http://www.imstat.org/aop/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Absolutely continuous spectrum for the isotropic Maxwell operator with coefficients that are periodic in some directions and decay in others
The purpose of this paper is to prove that the spectrum of an isotropic
Maxwell operator with electric permittivity and magnetic permeability that are
periodic along certain directions and tending to a constant super-exponentially
fast in the remaining directions is purely absolutely continuous. The basic
technical tools is a new ``operatorial'' identity relating the Maxwell operator
to a vector-valued Schrodinger operator. The analysis of the spectrum of that
operator is then handled using ideas developed by the same authors in a
previous paper
Rapport hydrologique et géologique sur l'équipement du massif du Mahury en vue de l'alimentation en eau de l'agglomération de Cayenne
An approach to anomalous diffusion in the n-dimensional space generated by a self-similar Laplacian
We analyze a quasi-continuous linear chain with self-similar distribution of
harmonic interparticle springs as recently introduced for one dimension
(Michelitsch et al., Phys. Rev. E 80, 011135 (2009)). We define a continuum
limit for one dimension and generalize it to dimensions of the
physical space. Application of Hamilton's (variational) principle defines then
a self-similar and as consequence non-local Laplacian operator for the
-dimensional space where we proof its ellipticity and its accordance (up to
a strictly positive prefactor) with the fractional Laplacian
. By employing this Laplacian we establish a
Fokker Planck diffusion equation: We show that this Laplacian generates
spatially isotropic L\'evi stable distributions which correspond to L\'evi
flights in -dimensions. In the limit of large scaled times the obtained distributions exhibit an algebraic decay independent from the initial distribution
and spacepoint. This universal scaling depends only on the ratio of
the dimension of the physical space and the L\'evi parameter .Comment: Submitted manuscrip
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