734 research outputs found
Signaling over arbitrarily permuted parallel channels
The problem of transmission of information over arbitrarily permuted parallel channels is studied here. The transmitter does not know over which channel a certain code-sequence will actually be transmitted, however the receiver knows how the sequences are permuted. The permutation is arbitrary but constant during the (simultaneous) transmission of the code-sequences via the parallel channels. It is shown first that the sum of the capacities of each channel is achievable for such a communication system in the special case where the capacity achieving input distributions of all channels are identical. More important is that this sum-capacity can also be achieved using a single channel code for all channels combined with a sequential decoding method. The construction of a rate-matching code based on maximum distance separable (MDS) codes turns out to be crucial. Finally, the case where the parallel channels have different capacity-achieving input distributions is investigated. Also for this case the capacity is determined. Again, this capacity is achievable with a sequential decoding procedure
Impact of external migration on changes in the Swedish religious landscape
For most of its history, Sweden has been a country dominated by the Lutheran Church, having the status of the official state religion. Starting in mid-to-late 20th century, mass immigration to Europe had a considerable impact on the confessional structure of Sweden’s population. The growing number of refugees from the Balkan Peninsula, the Middle East, and Africa has turned Sweden into a multi-religious state. Sweden has become one of the leaders among the EU countries as far as the growth rates of adherents of Islam are concerned. Immigrants are exposed to adaptation difficulties causing their social, cultural and geographical isolation and making relatively isolated migrant communities emerge. This study aims at finding correlation between the changes in the confessional structure of Swedish population (as a result of the growing number of non-Christians) and the geographical structure of migrant flows into the country. This novel study addresses the mosaic structure of the Swedish religious landscape taking into account the cyclical dynamics of replacement of Protestantism by Islam. The methods we created make it possible to identify further trends in the Sweden’s religious landscape. This study adds to results of the complex sociological and demographic studies of the confessional structure of the Swedish population
Fluctuations of g-factors in metal nanoparticles: Effects of electron-electron interaction and spin-orbit scattering
We investigate the combined effect of spin-orbit scattering and
electron-electron interactions on the probability distribution of -factors
of metal nanoparticles. Using random matrix theory, we find that even a
relatively small interaction strength %(ratio of exchange constant and mean
level %spacing \spacing ) significantly increases -factor
fluctuations for not-too-strong spin-orbit scattering (ratio of spin-orbit rate
and single-electron level spacing 1/\tau_{\rm so} \spacing \lesssim 1), and
leads to the possibility to observe -factors larger than two.Comment: RevTex, 2 figures inserte
Singularities of the renormalization group flow for random elastic manifolds
We consider the singularities of the zero temperature renormalization group
flow for random elastic manifolds. When starting from small scales, this flow
goes through two particular points and , where the average value
of the random squared potential turnes negative ($l^{*}$) and where
the fourth derivative of the potential correlator becomes infinite at the
origin ($l_{c}$). The latter point sets the scale where simple perturbation
theory breaks down as a consequence of the competition between many metastable
states. We show that under physically well defined circumstances $l_{c} to negative values does not
take place.Comment: RevTeX, 3 page
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