8,676 research outputs found
Soft Power Runs into Popular Geopolitics: Western Media Frames Democratic Taiwan
How does the Western media frame Taiwan? Analysing a large set of Western newspaper reports over the past two decades, this article provides the first systematic assessment of global coverage of Taiwan. Seeking to explain why Taiwan has been framed in the way it has, the article reports the views of journalists and editors and puts forward a framework based on popular geopolitics. The article concludes with a discussion of why media framing matters, and the implications for Taiwanâs public diplomacy and âsoft powerâ efforts
An Invisible Quantum Tripwire
We present here a quantum tripwire, which is a quantum optical interrogation
technique capable of detecting an intrusion with very low probability of the
tripwire being revealed to the intruder. Our scheme combines interaction-free
measurement with the quantum Zeno effect in order to interrogate the presence
of the intruder without interaction. The tripwire exploits a curious nonlinear
behaviour of the quantum Zeno effect we discovered, which occurs in a lossy
system. We also employ a statistical hypothesis testing protocol, allowing us
to calculate a confidence level of interaction-free measurement after a given
number of trials. As a result, our quantum intruder alert system is robust
against photon loss and dephasing under realistic atmospheric conditions and
its design minimizes the probabilities of false positives and false negatives
as well as the probability of becoming visible to the intruder.Comment: Improved based on reviewers comments; 5 figure
Differences in hearing acuity among ânormal-hearingâ young adults modulate the neural basis for speech comprehension
AbstractIn this paper, we investigate how subtle differences in hearing acuity affect the neural systems supporting speech processing in young adults. Auditory sentence comprehension requires perceiving a complex acoustic signal and performing linguistic operations to extract the correct meaning. We used functional MRI to monitor human brain activity while adults aged 18â41 years listened to spoken sentences. The sentences varied in their level of syntactic processing demands, containing either a subject-relative or object-relative center-embedded clause. All participants self-reported normal hearing, confirmed by audiometric testing, with some variation within a clinically normal range. We found that participants showed activity related to sentence processing in a left-lateralized frontotemporal network. Although accuracy was generally high, participants still made some errors, which were associated with increased activity in bilateral cingulo-opercular and frontoparietal attention networks. A whole-brain regression analysis revealed that activity in a right anterior middle frontal gyrus (aMFG) component of the frontoparietal attention network was related to individual differences in hearing acuity, such that listeners with poorer hearing showed greater recruitment of this region when successfully understanding a sentence. The activity in right aMFGs for listeners with poor hearing did not differ as a function of sentence type, suggesting a general mechanism that is independent of linguistic processing demands. Our results suggest that even modest variations in hearing ability impact the systems supporting auditory speech comprehension, and that auditory sentence comprehension entails the coordination of a left perisylvian network that is sensitive to linguistic variation with an executive attention network that responds to acoustic challenge.</jats:p
Limits to atom-vapor-based room-temperature photon-number-resolving detection
We study the atom-vapor-based photon-number-resolving detection from first principles, including quantum-mechanical treatment of the electromagnetic field. We study a photon detector model that combines coherently controlled absorption of light and resonance fluorescence to achieve photon counting at room temperature. In particular we identify the fundamental limits to this particular scheme of photon detection. We show that there exists a time-energy uncertainty between the incident pulse strength and the time period of the incident pulse. We verify the role of a large ensemble of atoms to boost the efficiency of such a detector
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Distributed battery dispatch for uncertainty mitigation in renewable microgrids
Logarithmic singularities and quantum oscillations in magnetically doped topological insulators
We report magnetotransport measurements on magnetically doped
(Bi,Sb)Te films grown by molecular beam epitaxy. In Hallbar devices,
logarithmic dependence on temperature and bias voltage are obseved in both the
longitudinal and anomalous Hall resistance. The interplay of disorder and
electron-electron interactions is found to explain quantitatively the observed
logarithmic singularities and is a dominant scattering mechanism in these
samples. Submicron scale devices exhibit intriguing quantum oscillations at
high magnetic fields with dependence on bias voltage. The observed quantum
oscillations can be attributed to bulk and surface transport.Comment: 10 pages, 13 figure
Towards photostatistics from photon-number discriminating detectors
We study the properties of a photodetector that has a number-resolving
capability. In the absence of dark counts, due to its finite quantum
efficiency, photodetection with such a detector can only eliminate the
possibility that the incident field corresponds to a number of photons less
than the detected photon number. We show that such a {\em non-photon}
number-discriminating detector, however, provides a useful tool in the
reconstruction of the photon number distribution of the incident field even in
the presence of dark counts.Comment: 7 pages, 4 figure
Excitation functions for (p,x) reactions of niobium in the energy range of E = 40-90 MeV
A stack of thin Nb foils was irradiated with the 100 MeV proton beam at Los
Alamos National Laboratory's Isotope Production Facility, to investigate the
Nb(p,4n)Mo nuclear reaction as a monitor for intermediate energy
proton experiments and to benchmark state-of-the-art reaction model codes. A
set of 38 measured cross sections for Nb(p,x) and
Cu(p,x) reactions between 40-90 MeV, as well as 5 independent
measurements of isomer branching ratios, are reported. These are useful in
medical and basic science radionuclide productions at intermediate energies.
The Cu(p,x)Co, Cu(p,x)Zn, and
Cu(p,x)Zn reactions were used to determine proton
fluence, and all activities were quantified using HPGe spectrometry. Variance
minimization techniques were employed to reduce systematic uncertainties in
proton energy and fluence, improving the reliability of these measurements. The
measured cross sections are shown to be in excellent agreement with literature
values, and have been measured with improved precision compared with previous
measurements. This work also reports the first measurement of the
Nb(p,x)Rb reaction, and of the independent cross
sections for Cu(p,x)Mn and
Nb(p,x)Y in the 40-90 MeV region. The effects of
Si(p,x)Na contamination, arising from silicone
adhesive in the Kapton tape used to encapsulate the aluminum monitor foils, is
also discussed as a cautionary note to future stacked-target cross section
measurements. \emph{A priori} predictions of the reaction modeling codes CoH,
EMPIRE, and TALYS are compared with experimentally measured values and used to
explore the differences between codes for the Nb(p,x) and
Cu(p,x) reactions.Comment: 34 pages, submitted to NIM-
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