6,250 research outputs found
Analyticity of a class of degenerate evolution equations on the canonical simplex of arising from Fleming--Viot processes
We study the analyticity of the semigroups generated by a class of degenerate
second order differential operators in the space , where is the
canonical simplex of . The semigroups arise from the theory of
Fleming--Viot processes in population genetics.Comment: 32 page
Dependency-aware unequal erasure protection codes
Classical unequal erasure protection schemes split data to be protected into classes which are encoded independently. The unequal protection scheme presented in this paper is based on an erasure code which encodes all the data together according to the existing dependencies. A simple algorithm generates dynamically the generator matrix of the erasure code according to the packets streams structure, i.e., the dependencies between the packets, and the rate of the code. This proposed erasure code was applied to a packetized MPEG4 stream transmitted over a packet erasure channel and compared with other classical protection schemes in terms of PSNR and MOS. It is shown that the proposed code allows keeping a high video quality-level in a larger packet loss rate range than the other protection schemes
Adjoint bi-continuous semigroups and semigroups on the space of measures
For a given bi-continuous semigroup T on a Banach space X we define its
adjoint on an appropriate closed subspace X^o of the norm dual X'. Under some
abstract conditions this adjoint semigroup is again bi-continuous with respect
to the weak topology (X^o,X). An application is the following: For K a Polish
space we consider operator semigroups on the space C(K) of bounded, continuous
functions (endowed with the compact-open topology) and on the space M(K) of
bounded Baire measures (endowed with the weak*-topology). We show that
bi-continuous semigroups on M(K) are precisely those that are adjoints of a
bi-continuous semigroups on C(K). We also prove that the class of bi-continuous
semigroups on C(K) with respect to the compact-open topology coincides with the
class of equicontinuous semigroups with respect to the strict topology. In
general, if K is not Polish space this is not the case
Are Happy Individuals Less Xenophobic Than Unhappy Individuals? Happiness & Income Versus Xenophobia
The social science literature on xenophobia is immense. Researchers have found that individual levels of xenophobia have a strong correlation with economic indicators, education, and political affiliation. However, do they have any correlation with unconventional indicators like happiness? This paper uses data from the World Value Survey to study the correlation between individual happiness and xenophobia. I find that there is a significant correlation between individual levels of happiness and xenophobia, even when controlling for income around the world
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