8,050 research outputs found
A discriminant rule under transformation
We present a new rule for discriminating among continuous populations which are not multivariate normal. The basic idea is to construct the sample maximum likelihood discriminant rule after transforming the data by a suitable multivariate transformation to normalit
A discriminant rule under transformation.
We present a new rule for discriminating among continuous populations which are not multivariate normal. The basic idea is to construct the sample maximum likelihood discriminant rule after transforming the data by a suitable multivariate transformation to normalityCross-validation; Multivariate Box-Cox Transformation;
An optimal transportation approach for assessing almost stochastic order
When stochastic dominance does not hold, we can improve
agreement to stochastic order by suitably trimming both distributions. In this
work we consider the Wasserstein distance, , to stochastic
order of these trimmed versions. Our characterization for that distance
naturally leads to consider a -based index of disagreement with
stochastic order, . We provide asymptotic
results allowing to test vs , that,
under rejection, would give statistical guarantee of almost stochastic
dominance. We include a simulation study showing a good performance of the
index under the normal model
Dynamics of deceptive interactions in social networks
In this paper we examine the role of lies in human social relations by
implementing some salient characteristics of deceptive interactions into an
opinion formation model, so as to describe the dynamical behaviour of a social
network more realistically. In this model we take into account such basic
properties of social networks as the dynamics of the intensity of interactions,
the influence of public opinion, and the fact that in every human interaction
it might be convenient to deceive or withhold information depending on the
instantaneous situation of each individual in the network. We find that lies
shape the topology of social networks, especially the formation of tightly
linked, small communities with loose connections between them. We also find
that agents with a larger proportion of deceptive interactions are the ones
that connect communities of different opinion, and in this sense they have
substantial centrality in the network. We then discuss the consequences of
these results for the social behaviour of humans and predict the changes that
could arise due to a varying tolerance for lies in society.Comment: 17 pages, 8 figures; Supplementary Information (3 pages, 1 figure
Rhythmic firing patterns in SCN: The role of circuit interactions
The suprachiasmatic nucleus (SCN) is believed to contain the main generator of circadian rhythmicity in mammals. In order to obtain further functional details of this, electrophysiological extracellular measurements in vitro were made. By means of an interspike interval distribution analysis, it is shown that there is a novel kind of neuronal firing pattern: the harmonic pattern. From these observations, we have developed a theoretical model based on possible filtering processes occurring during synaptic transmission. The model suffices to infer that regular ultradian oscillators could be an emergent property of circuit interactions of cells in the suprachiasmatic nucleus
A new dimension to Turing patterns
It is well known that simple reaction-diffusion systems can display very rich
pattern formation behavior. Here we have studied two examples of such systems
in three dimensions. First we investigate the morphology and stability of a
generic Turing system in three dimensions and then the well-known Gray-Scott
model. In the latter case, we added a small number of morphogen sources in the
system in order to study its robustness and the formation of connections
between the sources. Our results raise the question of whether Turing
patterning can produce an inductive signaling mechanism for neuronal growth.Comment: Movies available here at
http://www.lce.hut.fi/research/polymer/turing.shtm
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