120,806 research outputs found
Coded Computation Against Processing Delays for Virtualized Cloud-Based Channel Decoding
The uplink of a cloud radio access network architecture is studied in which
decoding at the cloud takes place via network function virtualization on
commercial off-the-shelf servers. In order to mitigate the impact of straggling
decoders in this platform, a novel coding strategy is proposed, whereby the
cloud re-encodes the received frames via a linear code before distributing them
to the decoding processors. Transmission of a single frame is considered first,
and upper bounds on the resulting frame unavailability probability as a
function of the decoding latency are derived by assuming a binary symmetric
channel for uplink communications. Then, the analysis is extended to account
for random frame arrival times. In this case, the trade-off between average
decoding latency and the frame error rate is studied for two different queuing
policies, whereby the servers carry out per-frame decoding or continuous
decoding, respectively. Numerical examples demonstrate that the bounds are
useful tools for code design and that coding is instrumental in obtaining a
desirable compromise between decoding latency and reliability.Comment: 11 pages and 12 figures, Submitte
Audio-visual Rhetoric: Visualizing the Pattern Language of Film
Audio-visual Rhetoric is a knowledge domain for designers in theory and practice that is valid for all communicative actions through media that aim for persuasion. Within this domain, we introduce a framework for media analysis. We developed an Audio-Visual Pattern (AVP) language for film that is visualized within a notation system. This system shows auditory and visual parameters in order to reveal film’s rhetorical structure. We discuss related theories from pattern language and rhetoric and apply the AVP method to analyze 10 commercials.
Keywords:
Pattern Language, Film Analysis, Rhetoric, Emotion, Persuasion, Design Research</p
Probing weak dipole-dipole interaction using phase-modulated non-linear spectroscopy
Phase-modulated non-linear spectroscopy with higher harmonic demodulation has
recently been suggested to provide information on many-body excitations. In the
present work we theoretically investigate the application of this method to
infer the interaction strength between two particles that interact via weak
dipole-dipole interaction. To this end we use full numerical solution of the
Schr\"odinger equation with time-dependent pulses. For interpretation purpose
we also derive analytical expressions in perturbation theory. We find one can
detect dipole-dipole interaction via peak intensities (in contrast to
line-shifts which typically are used in conventional spectroscopy). We provide
a detailed study on the dependence of these intensities on the parameters of
the laser pulse and the dipole-dipole interaction strength. Interestingly, we
find that there is a phase between the first and second harmonic demodulated
signal, whose value depends on the sign of the dipole-dipole interaction.Comment: 12 pages, 8 figures, Supporting information provided with the source
file
Physics and application of photon number resolving detectors based on superconducting parallel nanowires
The Parallel Nanowire Detector (PND) is a photon number resolving (PNR)
detector which uses spatial multiplexing on a subwavelength scale to provide a
single electrical output proportional to the photon number. The basic structure
of the PND is the parallel connection of several NbN superconducting nanowires
(100 nm-wide, few nm-thick), folded in a meander pattern. PNDs were fabricated
on 3-4 nm thick NbN films grown on MgO (TS=400C) substrates by reactive
magnetron sputtering in an Ar/N2 gas mixture. The device performance was
characterized in terms of speed and sensitivity. PNDs showed a counting rate of
80 MHz and a pulse duration as low as 660ps full width at half maximum (FWHM).
Building the histograms of the photoresponse peak, no multiplication noise
buildup is observable. Electrical and optical equivalent models of the device
were developed in order to study its working principle, define design
guidelines, and develop an algorithm to estimate the photon number statistics
of an unknown light. In particular, the modeling provides novel insight of the
physical limit to the detection efficiency and to the reset time of these
detectors. The PND significantly outperforms existing PNR detectors in terms of
simplicity, sensitivity, speed, and multiplication noise
Echo, not quotation: what conversation analysis reveals about classroom responses to heard poetry
This article applies conversation analysis to classroom talk-in-interaction where pupils respond to poetry they have heard. The phenomenon of repeating in discussion details from the poem, including patterns of delivery, is considered and named echo to distinguish it from quotation in writing. The phenomenon is significant to the pedagogy of literary study given the existing tacit and unexamined assumption that when pupils repeat textual details verbally this has equivalence with quotation in writing. Three episodes drawn from a single sequence of classroom interaction are presented together with a transcript of the stimulus heard poem. Each is accompanied by an interpretive commentary. It appears that echo in classroom discussions of poetry performs actions distinct from quotation in writing, for example that the acts of presenting and analysing textual detail occur simultaneously. The innovation of the research lies in the inclusion of the transcript-rendered poem as a turn in the sequence of interaction: as a verbally oriented method, conversation analysis provides an apt means of rendering response to poetry presented in the oral mode. More broadly, the discussion is consistent with the emergent popularity of conversation analysis as a method for considering classroom interactions with a view to reflecting on subtle aspects of learning
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