1,373 research outputs found
Recommended from our members
Lexical stress constrains English-learning infants' segmentation in a non-native language.
Infants' ability to segment words in fluent speech is affected by their language experience. In this study we investigated the conditions under which infants can segment words in a non-native language. Using the Head-turn Preference Procedure, we found that monolingual English-learning 8-month-olds can segment bisyllabic words in Spanish (trochees and iambs) but not French (iambs). Our results are incompatible with accounts that rely on distributional learning, language rhythm similarity, or target word prosodic shape alone. Instead, we show that monolingual English-learning infants are able to segment words in a non-native language as long as words have stress, as is the case in English. More specifically, we show that even in a rhythmically different non-native language, English-learning infants can find words by detecting stressed syllables and treating them as word onsets or offsets
Is the Theta+ a K pi N bound state?
Following a recent suggestion that the could be a bound
state we perform an investigation under the light of the meson meson and meson
baryon dynamics provided by the chiral Lagrangians and using methods currently
employed to dynamically generate meson and baryon resonances by means of
unitary extensions of chiral perturbation theory. We consider two body and
three body forces and examine the possibility of a bound state below the three
particle pion-kaon-nucleon and above the kaon-nucleon thresholds. Although we
find indeed an attractive interaction in the case of isospin I=0 and
spin-parity , the interaction is too weak to bind the system. If we
arbitrarily add to the physically motivated potential the needed strength to
bind the system and with such strong attraction evaluate the decay width into
, this turns out to be small. A discussion on further work in this
direction is done.Comment: Change of title and few sentences, size of two graphs. References
adde
Filtenna Integration Achieving Ideal Chebyshev Return Losses
This paper demonstrates that it is possible to find an ideal filter response (Chebyshew, Butterworth,..) considering the antenna as the last resonator of a filter under certain circumstances related with the antenna performance and the bandwidth of the filtenna device. If these circumstances are not accomplished, we can achieve excellent performance as well, by means of an iterative process the goal of which is defined by either a filter mask or a classical filter function itself. The methodology is based on the conventional coupling matrix technique for filter design and has been validated by fabricating a microstrip prototype using hairpin resonators and a rectangular patch antenna
A multistate single-connection calibration for microwave microfluidics
©2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.With emerging medical, chemical, and biological applications of microwave-microfluidic devices, many researchers desire a fast and accurate calibration that can be achieved in
a single connection. However, traditional on-wafer or coaxial calibrations require measurements of several different artifacts to the data prior to measuring the microwave-microfluidic device.
Ideally, a single artifact would be able to present different impedance states to correct the vector network analyzer data, minimizing drift and eliminating artifact-to-artifact connection
errors. Here, we developed a multistate single-connection calibration that used a coplanar waveguide loaded with a microfluidic channel. We then used measurements of the uncorrected scattering parameters of the coplanar waveguide with the channel empty, filled with deionized water, and filled with 30 w% (30 grams per liter) of saline to construct an eight-term error
model and switch-term correction. After correction, the residuals between measured scattering parameters and with the literaturebased finite-element simulations were below -40 dB from
100 MHz to 110 GHz. This multistate single-connection calibration is compatible with both wafer-probed and connectorized microwave-microfluidic devices for accurate impedance spectroscopy
and materials characterization without the need for multiple device measurements.Peer ReviewedPostprint (author's final draft
Nonlinear Performance of BAW Filters Including BST Capacitors
This paper evaluates the nonlinear effects occurring in a bulk acoustic wave (BAW) filter which includes barium strontium titanate (BST) capacitors to cancel the electrostatic capacitance of the BAW resonators. To do that we consider the nonlinear effects on the BAW resonators by use of a nonlinear Mason model. This model accounts for the distributed nonlinearities inherent in the materials forming the resonator. The whole filter is then implemented by properly connecting the resonators in a balanced configuration. Additional BST capacitors are included in the filter topology. The nonlinear behavior of the BST capacitors is also accounted in the overall nonlinear assessment. The whole circuit is then used to evaluate its nonlinear behavior. It is found that the nonlinear contribution arising from the ferroelectric nature of the BST capacitors makes it impractical to fulfill the linearity requirements of commercial filters
Searching for tidal tails around Centauri using RR Lyrae Stars
We present a survey for RR Lyrae stars in an area of 50 deg around the
globular cluster Centauri, aimed to detect debris material from the
alleged progenitor galaxy of the cluster. We detected 48 RR Lyrae stars of
which only 11 have been previously reported. Ten among the eleven previously
known stars were found inside the tidal radius of the cluster. The rest were
located outside the tidal radius up to distances of degrees from the
center of the cluster. Several of those stars are located at distances similar
to that of Centauri. We investigated the probability that those stars
may have been stripped off the cluster by studying their properties (mean
periods), calculating the expected halo/thick disk population of RR Lyrae stars
in this part of the sky, analyzing the radial velocity of a sub-sample of the
RR Lyrae stars, and finally, studying the probable orbits of this sub-sample
around the Galaxy. None of these investigations support the scenario that there
is significant tidal debris around Centauri, confirming previous
studies in the region. It is puzzling that tidal debris have been found
elsewhere but not near the cluster itself.Comment: 11 pages, 11 figures, Accepte
Hadronic aspects of exotic baryons
In this talk I look into three different topics, addressing first the
possibility that the is a bound state of , exploiting the
results of this study to find out the contribution of two meson and one baryon
components in the baryon antidecuplet and in the third place I present results
on a new resonant exotic baryonic state which appears as dynamically generated
by the Weinberg Tomozawa interaction.Comment: Talk at the International Workshop PENTAQUARK0
On the determination of quantum numbers and other topics of exotic baryons
In this talk I look into three different topics, addressing first a method to
determine the quantum numbers of the , then exploiting the
possibility that the is a bound state of and in the third
place I present results on a new resonant exotic baryonic state which appears
as dynamically generated by the Weinberg Tomozawa interaction.Comment: 9 pags. Talk in the NSTAR04 Workshop, Grenoble, march 200
- …