21,004 research outputs found
Speech intelligibility and prosody production in children with cochlear implants
Objectives—The purpose of the current study was to examine the relation between speech intelligibility and prosody production in children who use cochlear implants. Methods—The Beginner\u27s Intelligibility Test (BIT) and Prosodic Utterance Production (PUP) task were administered to 15 children who use cochlear implants and 10 children with normal hearing. Adult listeners with normal hearing judged the intelligibility of the words in the BIT sentences, identified the PUP sentences as one of four grammatical or emotional moods (i.e., declarative, interrogative, happy, or sad), and rated the PUP sentences according to how well they thought the child conveyed the designated mood. Results—Percent correct scores were higher for intelligibility than for prosody and higher for children with normal hearing than for children with cochlear implants. Declarative sentences were most readily identified and received the highest ratings by adult listeners; interrogative sentences were least readily identified and received the lowest ratings. Correlations between intelligibility and all mood identification and rating scores except declarative were not significant. Discussion—The findings suggest that the development of speech intelligibility progresses ahead of prosody in both children with cochlear implants and children with normal hearing; however, children with normal hearing still perform better than children with cochlear implants on measures of intelligibility and prosody even after accounting for hearing age. Problems with interrogative intonation may be related to more general restrictions on rising intonation, and th
Exact phase diagrams for an Ising model on a two-layer Bethe lattice
Using an iteration technique, we obtain exact expressions for the free energy
and the magnetization of an Ising model on a two - layer Bethe lattice with
intralayer coupling constants J1 and J2 for the first and the second layer,
respectively, and interlayer coupling constant J3 between the two layers; the
Ising spins also couple with external magnetic fields, which are different in
the two layers. We obtain exact phase diagrams for the system.Comment: 24 pages, 2 figures. To be published in Phys. Rev. E 59, Issue 6,
199
Observation of a Degenerate Fermi Gas Trapped by a Bose-Einstein Condensate
We report on the formation of a stable quantum degenerate mixture of
fermionic Li and bosonic Cs in an optical trap by sympathetic
cooling near an interspecies Feshbach resonance. New regimes of the quantum
degenerate mixtures are identified. With moderate attractive interspecies
interactions, we show that a degenerate Fermi gas of Li can be fully confined
in the Cs condensate without external potentials. For stronger attraction where
mean-field collapse is expected, no such instability is observed. In this case,
we suggest the stability is a result of dynamic equilibrium, where the
interspecies three-body loss prevents the collapse. Our picture is supported by
a rate equation model, and the crossover between the thermalization rate and
the observed inelastic loss rate in the regime where the mean-field collapse is
expected to occur.Comment: 6 Pages, 4 Figure
The Asymmetric Avalanche Process
An asymmetric stochastic process describing the avalanche dynamics on a ring
is proposed. A general kinetic equation which incorporates the exclusion and
avalanche processes is considered. The Bethe ansatz method is used to calculate
the generating function for the total distance covered by all particles. It
gives the average velocity of particles which exhibits a phase transition from
an intermittent to continuous flow. We calculated also higher cumulants and the
large deviation function for the particle flow. The latter has the universal
form obtained earlier for the asymmetric exclusion process and conjectured to
be common for all models of the Kardar-Parisi-Zhang universality class .Comment: 33 pages, 3 figures, revised versio
Backhaul-Aware Caching Placement for Wireless Networks
As the capacity demand of mobile applications keeps increasing, the backhaul
network is becoming a bottleneck to support high quality of experience (QoE) in
next-generation wireless networks. Content caching at base stations (BSs) is a
promising approach to alleviate the backhaul burden and reduce user-perceived
latency. In this paper, we consider a wireless caching network where all the
BSs are connected to a central controller via backhaul links. In such a
network, users can obtain the required data from candidate BSs if the data are
pre-cached. Otherwise, the user data need to be first retrieved from the
central controller to local BSs, which introduces extra delay over the
backhaul. In order to reduce the download delay, the caching placement strategy
needs to be optimized. We formulate such a design problem as the minimization
of the average download delay over user requests, subject to the caching
capacity constraint of each BS. Different from existing works, our model takes
BS cooperation in the radio access into consideration and is fully aware of the
propagation delay on the backhaul links. The design problem is a mixed integer
programming problem and is highly complicated, and thus we relax the problem
and propose a low-complexity algorithm. Simulation results will show that the
proposed algorithm can effectively determine the near-optimal caching placement
and provide significant performance gains over conventional caching placement
strategies.Comment: 6 pages, 3 figures, accepted to IEEE Globecom, San Diego, CA, Dec.
201
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