1,767 research outputs found
A Mean-field Approach for an Intercarrier Interference Canceller for OFDM
The similarity of the mathematical description of random-field spin systems
to orthogonal frequency-division multiplexing (OFDM) scheme for wireless
communication is exploited in an intercarrier-interference (ICI) canceller used
in the demodulation of OFDM. The translational symmetry in the Fourier domain
generically concentrates the major contribution of ICI from each subcarrier in
the subcarrier's neighborhood. This observation in conjunction with mean field
approach leads to a development of an ICI canceller whose necessary cost of
computation scales linearly with respect to the number of subcarriers. It is
also shown that the dynamics of the mean-field canceller are well captured by a
discrete map of a single macroscopic variable, without taking the spatial and
time correlations of estimated variables into account.Comment: 7pages, 3figure
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Writing the Land: Language and Territory in Modern Hebrew Literature
Marking a new holy community: God’s neighbors and the ascendancy of a new religious hegemony in Israel
Meni Ya'ish's 2012 film God's Neighbors marks a significant cultural moment in the legitimation of Jewish religiosity in Israel and records an important moment in the country's metamorphosis in recent years, marking a change from a secular, liberal society to a more fundamentalist religious one. The film demonstrates this change in three interrelated ways. First, by combining Jewish religiosity with a powerful and aggressive Israeli Mizrahi masculine identity, the film re-legitimizes Jewish religiosity, presents it as attractive and sexy, and declares it as the new Israeli hegemony. Second, by abstaining from killing members of a rival Arab gang, the film symbolically minimizes the conflict between Jews and Arabs and advances the importance of mythical Jewish time over Zionist historical time. Finally, by ending happily with a union between Avi and his girl Miri, the film provides a neat closure that offers an alluringly simple hasidic-like tale to Jewish life in Israel today. As such, the film marks the decline of Israeli Statism and the rise of alternative redemptive narratives in Israel that are primarily religious
Beeping a Maximal Independent Set
We consider the problem of computing a maximal independent set (MIS) in an
extremely harsh broadcast model that relies only on carrier sensing. The model
consists of an anonymous broadcast network in which nodes have no knowledge
about the topology of the network or even an upper bound on its size.
Furthermore, it is assumed that an adversary chooses at which time slot each
node wakes up. At each time slot a node can either beep, that is, emit a
signal, or be silent. At a particular time slot, beeping nodes receive no
feedback, while silent nodes can only differentiate between none of its
neighbors beeping, or at least one of its neighbors beeping.
We start by proving a lower bound that shows that in this model, it is not
possible to locally converge to an MIS in sub-polynomial time. We then study
four different relaxations of the model which allow us to circumvent the lower
bound and find an MIS in polylogarithmic time. First, we show that if a
polynomial upper bound on the network size is known, it is possible to find an
MIS in O(log^3 n) time. Second, if we assume sleeping nodes are awoken by
neighboring beeps, then we can also find an MIS in O(log^3 n) time. Third, if
in addition to this wakeup assumption we allow sender-side collision detection,
that is, beeping nodes can distinguish whether at least one neighboring node is
beeping concurrently or not, we can find an MIS in O(log^2 n) time. Finally, if
instead we endow nodes with synchronous clocks, it is also possible to find an
MIS in O(log^2 n) time.Comment: arXiv admin note: substantial text overlap with arXiv:1108.192
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From Black to White: Changing Images of Mizrahim in Israeli Cinema
The article examines the evolution of Mizrahi images in Israeli cinema in the past fifty years and, unlike most studies about Mizrahim in Israel, focuses on their positive portrayal. The article demonstrates the constructive ways Jewish immigrants from the Islamic world were incorporated into Israeli culture by positing three interrelated arguments. The first is that early films incorporated Mizrahim into the fledgling Israeli nation by legitimizing them as Jews. The second is that, once legitimized, Mizrahim were made part of the national Jewish family through marriage. The third is that after becoming part of the [national] family Mizrahi men were then put in positions of control and, with the decline of Ashkenazi masculinity, eventually became more genuine or authentic representatives of Israeliness
A two-dimensional representation of four-dimensional gravitational waves
The Einstein equation in D dimensions, if restricted to the class of
space-times possessing n = D - 2 commuting hypersurface-orthogonal Killing
vectors, can be equivalently written as metric-dilaton gravity in 2 dimensions
with n scalar fields. For n = 2, this results reduces to the known reduction of
certain 4-dimensional metrics which include gravitational waves. Here, we give
such a representation which leads to a new proof of the Birkhoff theorem for
plane-symmetric space--times, and which leads to an explanation, in which sense
two (spin zero-) scalar fields in 2 dimensions may incorporate the (spin two-)
gravitational waves in 4 dimensions. (This result should not be mixed up with
well--known analogous statements where, however, the 4-dimensional space-time
is supposed to be spherically symmetric, and then, of course, the equivalent
2-dimensional picture cannot mimic any gravitational waves.) Finally, remarks
on hidden symmetries in 2 dimensions are made.Comment: 12 pages, LaTeX, no figures, Int. J. Mod. Phys. D in prin
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