5,644 research outputs found
End-to-end visual speech recognition with LSTMS
Traditional visual speech recognition systems consist of two stages, feature extraction and classification. Recently, several deep learning approaches have been presented which automatically extract features from the mouth images and aim to replace the feature extraction stage. However, research on joint learning of features and classification is very limited. In this work, we present an end-to-end visual speech recognition system based on Long-Short Memory (LSTM) networks. To the best of our knowledge, this is the first model which simultaneously learns to extract features directly from the pixels and perform classification and also achieves state-of-the-art performance in visual speech classification. The model consists of two streams which extract features directly from the mouth and difference images, respectively. The temporal dynamics in each stream are modelled by an LSTM and the fusion of the two streams takes place via a Bidirectional LSTM (BLSTM). An absolute improvement of 9.7% over the base line is reported on the OuluVS2 database, and 1.5% on the CUAVE database when compared with other methods which use a similar visual front-end
Communities, Action and Inter--action: A framework for mediated communication exploring service delivery and planning of community care services
This chapter outlines the conceptual framework, methodology and initial interpretations of a pilot study undertaken by a state government agency and coordinated by the Human Services Network (HSNet). The study, conducted in a rural community in NSW, Australia, approaches the communication between the service delivery and consumer as a dialogue. A dialogue between two parties can be positioned to trace and reflect on: (1) the governmental planning model of service delivery and (2) the community that experiences these services as individuals. Such experiential knowledge can be gained from understandings from a range of client stories that reflect the community interaction with service delivery. The design problem focuses on how to increase the bandwidth for such interactions so that all parties can derive meaning. The long term goal is to position the health service network in a role where such mediation between parties can: (1) be explicitly and implicitly linked to action that affects service planning and community delivery, and (2) that the experience of the individual in the community can be incorporated actively into the process of such planning. The chapter concludes with summary of preliminary insights from the project and a brief overview of future developments
Small doubling in groups
Let A be a subset of a group G = (G,.). We will survey the theory of sets A
with the property that |A.A| <= K|A|, where A.A = {a_1 a_2 : a_1, a_2 in A}.
The case G = (Z,+) is the famous Freiman--Ruzsa theorem.Comment: 23 pages, survey article submitted to Proceedings of the Erdos
Centenary conferenc
Search for the QCD critical point in nuclear collisions at the CERN SPS
Pion production in nuclear collisions at the SPS is investigated with the aim
to search, in a restricted domain of the phase diagram, for power-laws in the
behavior of correlations which are compatible with critical QCD. We have
analyzed interactions of nuclei of different size (p+p, C+C, Si+Si, Pb+Pb) at
158 GeV adopting, as appropriate observables, scaled factorial moments in a
search for intermittent fluctuations in transverse dimensions. The analysis is
performed for pairs with invariant mass very close to the two-pion
threshold. In this sector one may capture critical fluctuations of the sigma
component in a hadronic medium, even if the -meson has no well defined
vacuum state. It turns out that for the Pb+Pb system the proposed analysis
technique cannot be applied without entering the invariant mass region with
strong Coulomb correlations. As a result the treatment becomes inconclusive in
this case. Our results for the other systems indicate the presence of power-law
fluctuations in the freeze-out state of Si+Si approaching in size the
prediction of critical QCD.Comment: 31 pages, 11 figure
An environmentally benign antimicrobial nanoparticle based on a silver-infused lignin core
Silver nanoparticles have antibacterial properties, but their use has been a cause for concern because they persist in the environment. Here, we show that lignin nanoparticles infused with silver ions and coated with a cationic polyelectrolyte layer form a biodegradable and green alternative to silver nanoparticles. The polyelectrolyte layer promotes the adhesion of the particles to bacterial cell membranes and, together with silver ions, can kill a broad spectrum of bacteria, including Escherichia coli, Pseudomonas aeruginosa and quaternary-amine-resistant Ralstonia sp. Ion depletion studies have shown that the bioactivity of these nanoparticles is time-limited because of the desorption of silver ions. High-throughput bioactivity screening did not reveal increased toxicity of the particles when compared to an equivalent mass of metallic silver nanoparticles or silver nitrate solution. Our results demonstrate that the application of green chemistry principles may allow the synthesis of nanoparticles with biodegradable cores that have higher antimicrobial activity and smaller environmental impact than metallic silver nanoparticles
Transverse Momentum Fluctuations in Nuclear Collisions at 158 AGeV
Results are presented on event-by-event fluctuations in transverse momentum
of charged particles, produced at forward rapidities in p+p, C+C, Si+Si and
Pb+Pb collisions at 158 AGeV. Three different characteristics are discussed:
the average transverse momentum of the event, the Phi_pT fluctuation measure
and two-particle transverse momentum correlations. In the kinematic region
explored, the dynamical fluctuations are found to be small. However, a
significant system size dependence of Phi_pT is observed, with the largest
value measured in peripheral Pb+Pb interactions. The data are compared with
predictions of several models.Comment: will be submitted to Phys. Rev.
Approaching the Gamow Window with Stored Ions : Direct Measurement of Xe 124 (p,γ) in the ESR Storage Ring
© 2019 American Physical Society. All rights reserved.We report the first measurement of low-energy proton-capture cross sections of Xe124 in a heavy-ion storage ring. Xe12454+ ions of five different beam energies between 5.5 and 8 AMeV were stored to collide with a windowless hydrogen target. The Cs125 reaction products were directly detected. The interaction energies are located on the high energy tail of the Gamow window for hot, explosive scenarios such as supernovae and x-ray binaries. The results serve as an important test of predicted astrophysical reaction rates in this mass range. Good agreement in the prediction of the astrophysically important proton width at low energy is found, with only a 30% difference between measurement and theory. Larger deviations are found above the neutron emission threshold, where also neutron and γ widths significantly impact the cross sections. The newly established experimental method is a very powerful tool to investigate nuclear reactions on rare ion beams at low center-of-mass energies.Peer reviewedFinal Published versio
High p_T Spectra of Identified Particles Produced in Pb+Pb Collisions at 158GeV/nucleon Beam Energy
Transverse momentum spectra of pi^{+/-}, p, pbar, K^{+/-}, K^0_s and Lambda
at midrapidity were measured at high p_T in Pb+Pb collisions at 158GeV/nucleon
beam energy by the NA49 experiment. Particle yield ratios (p/pi, K/pi and
Lambda/K^0_s) show an enhancement of the baryon/meson ratio for p_T>2GeV/c. The
nuclear modification factor R_{CP} is extracted and compared to RHIC
measurements and pQCD calculations.Comment: Quark Matter 2005 parallel section proceeding
NA49 results on hadron production: indications of the onset of deconfinement ?
The NA49 experiment at the CERN SPS measured the energy and system size
dependence of particle production in A+A collisions. A change of the energy
dependence of several hadron production properties at low SPS energies is
observed which suggests a scenario requiring the onset of deconfinement.Comment: XXXV International Symposium on Multiparticle Dynamics 200
Energy dependence of particle ratio fluctuations in central Pb+Pb collisions from ~6.3 to 17.3 GeV
We present measurements of the energy dependence of event-by-event
fluctuations in the K/pi and (p + \bar{p})/pi multiplicity ratios in heavy ion
collisions at the CERN SPS. The particle ratio fluctuations were obtained for
central Pb+Pb collisions at five collision energies, \sqrt{s_{_{NN}}}, between
6.3 and 17.3 GeV. After accounting for the effects of finite-number statistics
and detector resolution, we extract the strength of non-statistical
fluctuations at each energy. For the K/pi ratio, larger fluctuations than
expected for independent particle production are found at all collision
energies. The fluctuations in the (p + \bar{p})/pi ratio are smaller than
expectations from independent particle production, indicating correlated pion
and proton production from resonance decays. For both ratios, the deviation
from purely statistical fluctuations shows an increase towards lower collision
energies. The results are compared to transport model calculations, which fail
to describe the energy dependence of the K/pi ratio fluctuations.Comment: 11 pages, 10 figures, update to published versio
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