11,219 research outputs found
Towards hardware acceleration of neuroevolution for multimedia processing applications on mobile devices
This paper addresses the problem of accelerating large artificial neural networks (ANN), whose topology and weights can evolve via the use of a genetic algorithm. The proposed digital hardware architecture is capable of processing any evolved network topology, whilst at the same time providing a good trade off between throughput, area and power consumption. The latter is vital for a longer battery life on mobile devices. The architecture uses multiple parallel arithmetic units in each processing element (PE). Memory partitioning and data caching are used to minimise the effects of PE pipeline stalling. A first order minimax polynomial approximation scheme, tuned via a genetic algorithm, is used for the activation function generator. Efficient arithmetic circuitry, which leverages modified Booth recoding, column compressors and carry save adders, is adopted throughout the design
Starburst radio galaxies: general properties, evolutionary histories and triggering
In this paper we discuss the results of a programme of spectral synthesis
modelling of a sample of starburst radio galaxies in the context of scenarios
for the triggering of the activity and the evolution of the host galaxies. The
starburst radio galaxies -- comprising ~15 - 25% of all powerful extragalactic
radio sources -- frequently show disturbed morphologies at optical wavelengths,
and unusual radio structures, although their stellar masses are typical of
radio galaxies as a class. In terms of the characteristic ages of their young
stellar populations (YSP), the objects can be divided into two groups: those
with YSP ages t_ysp < 0.1 Gyr, in which the radio source has been triggered
quasi-simultaneously with the main starburst episode, and those with older YSP
in which the radio source has been triggered or re-triggered a significant
period after the starburst episode. Combining the information on the YSP with
that on the optical morphologies of the host galaxies, we deduce that the
majority of the starburst radio galaxies have been triggered in galaxy mergers
in which at least one of the galaxies is gas rich. However, the triggering (or
re-triggering) of the radio jets can occur immediately before, around, or a
significant period after the final coalescence of the merging nuclei,
reflecting the complex gas infall histories of the merger events. Overall, our
results provide further evidence that powerful radio jet activity can be
triggered via a variety of mechanisms, including different evolutionary stages
of major galaxy mergers; clearly radio-loud AGN activity is not solely
associated with a particular stage of a unique type of gas accretion event.Comment: 16 pages, 3 Figures, accepted for publication in MNRA
Covariation Among Vowel Height Effects on Acoustic Measures
Covariation among vowel height effects on vowel intrinsic fundamental frequency (IF0), voice onset time (VOT), and voiceless interval duration (VID) is analyzed to assess the plausibility of a common physiological mechanism underlying variation in these measures. Phrases spoken by 20 young adults, containing words composed of initial voiceless stops or /s/ and high or low vowels, were produced in habitual and voluntarily increased F0 conditions. High vowels were associated with increased IF0 and longer VIDs. VOT and VID exhibited significant covariation with IF0 only for males at habitua
Resonance production from jet fragmentation
Short lived resonances are sensitive to the medium properties in heavy-ion
collisions. Heavy hadrons have larger probability to be produced within the
quark gluon plasma phase due to their short formation times. Therefore heavy
mass resonances are more likely to be affected by the medium, and the
identification of early produced resonances from jet fragmentation might be a
viable option to study chirality. The high momentum resonances on the away-side
of a triggered di-jet are likely to be the most modified by the partonic or
early hadronic medium. We will discuss first results of triggered
hadron-resonance correlations in Cu+Cu heavy ion collisions.Comment: Hot Quarks Colorado 2008 Proceedings, 4 pages 5 figure
Spectral representation of the effective dielectric constant of graded composites
We generalize the Bergman-Milton spectral representation, originally derived
for a two-component composite, to extract the spectral density function for the
effective dielectric constant of a graded composite. This work has been
motivated by a recent study of the optical absorption spectrum of a graded
metallic film [Applied Physics Letters, 85, 94 (2004)] in which a broad
surface-plasmon absorption band has been shown to be responsible for enhanced
nonlinear optical response as well as an attractive figure of merit. It turns
out that, unlike in the case of homogeneous constituent components, the
characteristic function of a graded composite is a continuous function because
of the continuous variation of the dielectric function within the constituent
components. Analytic generalization to three dimensional graded composites is
discussed, and numerical calculations of multilayered composites are given as a
simple application.Comment: Physical Review E, submitted for publication
Age- and Disease-Dependent HERV-W Envelope Allelic Variation in Brain: Association with Neuroimmune Gene Expression
Background: The glycoprotein, Syncytin-1, is encoded by a human endogenous retrovirus (HERV)-W env gene and is capable of inducing neuroinflammation. The specific allele(s) responsible for Syncytin-1 expression in the brain is uncertain. Herein, HERV-W env diversity together with Syncytin-1 abundance and host immune gene profiles were examined in the nervous system using a multiplatform approach. Results: HERV-W env sequences were encoded by multiple chromosomal encoding loci in primary human neurons compared with less chromosomal diversity in astrocytes and microglia (p,0.05). HERV-W env RNA sequences cloned from brains of patients with systemic or neurologic diseases were principally derived from chromosomal locus 7q21.2. Within the same specimens, HERV-W env transcript levels were correlated with the expression of multiple proinflammatory genes (p,0.05). Deep sequencing of brain transcriptomes disclosed the env transcripts to be the most abundant HERV-W transcripts, showing greater expression in fetal compared with healthy adult brain specimens. Syncytin-1ās expression in healthy brain specimens was derived from multiple encoding loci and linked to distinct immune and developmental gene profiles. Conclusions: Syncytin-1 expression in the brain during disease was associated with neuroinflammation and was principally encoded by a full length provirus. The present studies also highlighted the diversity in HERV gene expression within th
The Effects of Foam Rolling on Hamstring Flexibility, Muscle Soreness and Power
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