4,585 research outputs found
Characterization of a dense aperture array for radio astronomy
EMBRACE@Nancay is a prototype instrument consisting of an array of 4608
densely packed antenna elements creating a fully sampled, unblocked aperture.
This technology is proposed for the Square Kilometre Array and has the
potential of providing an extremely large field of view making it the ideal
survey instrument. We describe the system,calibration procedures, and results
from the prototype.Comment: 17 pages, accepted for publication in A&
Neural Correlates of Auditory Figure-Ground Segregation Based on Temporal Coherence
To make sense of natural acoustic environments, listeners must parse complex mixtures of sounds that vary in frequency, space, and time. Emerging work suggests that, in addition to the well-studied spectral cues for segregation, sensitivity to temporal coherence-the coincidence of sound elements in and across time-is also critical for the perceptual organization of acoustic scenes. Here, we examine pre-attentive, stimulus-driven neural processes underlying auditory figure-ground segregation using stimuli that capture the challenges of listening in complex scenes where segregation cannot be achieved based on spectral cues alone. Signals ("stochastic figure-ground": SFG) comprised a sequence of brief broadband chords containing random pure tone components that vary from 1 chord to another. Occasional tone repetitions across chords are perceived as "figures" popping out of a stochastic "ground." Magnetoencephalography (MEG) measurement in naïve, distracted, human subjects revealed robust evoked responses, commencing from about 150 ms after figure onset that reflect the emergence of the "figure" from the randomly varying "ground." Neural sources underlying this bottom-up driven figure-ground segregation were localized to planum temporale, and the intraparietal sulcus, demonstrating that this area, outside the "classic" auditory system, is also involved in the early stages of auditory scene analysis.
Does an educative approach work? A reflective case study of how two Australian higher education Enabling programs support students and staff uphold a responsible culture of academic integrity
Introduction
Enabling education programs, otherwise known as Foundation Studies or Preparatory programs, provide pathways for students typically under-represented in higher education. Students in Enabling programs often face distinct challenges in their induction to academic culture which can implicate them in cases of misconduct. This case study addresses a gap in the enabling literature reporting on how a culture of academic integrity can be developed for students and staff in these programs through an educative approach.
Case description
This paper outlines how an educative approach to academic integrity is implemented within the Enabling programs of two Australian universities.
Discussion and reflection
This case study reflects upon an approach which makes specific reference to the key elements of ‘support’, ‘approach’ and ‘responsibility’ as highlighted in Bretag and Mahmud’s seminal paper. The paper reports a reduction in misconduct cases at the two institutions suggesting a positive correlation between the interventions and students’ understanding of ethical academic practice. This study reflects upon practitioner experiences with academic integrity investigations to evaluate the effectiveness of this approach.
Conclusions
The authors show that it is possible to ensure academic integrity practices and values are upheld within a supportive learning environment appropriate to a students’ level of study
Decoupling segmental relaxation and ionic conductivity for lithium-ion polymer electrolytes
International audienceThe use of polymer electrolytes instead of liquid organic systems is considered key for enhancing the safety of lithium batteries and may, in addition, enable the transition to high-energy lithium metal anodes. An intrinsic limitation, however, is their rather low ionic conductivity at ambient temperature. Nonetheless, it has been suggested that this might be overcome by decoupling the ion transport and the segmental relaxation of the coordinating polymer. Here, we provide an overview of the different approaches to achieve such decoupling, including a brief recapitulation of the segmental-relaxation dependent ion conduction mechanism, exemplarily focusing on the archetype of polymer electrolytes – polyethylene oxide (PEO). In fact, while the understanding of the underlying mechanisms has greatly improved within recent years, it remains rather challenging to outperform PEO-based electrolyte systems. Nonetheless, it is not impossible, as highlighted by several examples mentioned herein, especially in consideration of the extremely rich polymer chemistry and with respect to the substantial progress already achieved in designing tailored molecules with well-defined nanostructures
Decoupling segmental relaxation and ionic conductivity for lithium-ion polymer electrolytes
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An elasto-visco-plastic model for immortal foams or emulsions
A variety of complex fluids consist in soft, round objects (foams, emulsions,
assemblies of copolymer micelles or of multilamellar vesicles -- also known as
onions). Their dense packing induces a slight deviation from their prefered
circular or spherical shape. As a frustrated assembly of interacting bodies,
such a material evolves from one conformation to another through a succession
of discrete, topological events driven by finite external forces. As a result,
the material exhibits a finite yield threshold. The individual objects usually
evolve spontaneously (colloidal diffusion, object coalescence, molecular
diffusion), and the material properties under low or vanishing stress may alter
with time, a phenomenon known as aging. We neglect such effects to address the
simpler behaviour of (uncommon) immortal fluids: we construct a minimal, fully
tensorial, rheological model, equivalent to the (scalar) Bingham model.
Importantly, the model consistently describes the ability of such soft
materials to deform substantially in the elastic regime (be it compressible or
not) before they undergo (incompressible) plastic creep -- or viscous flow
under even higher stresses.Comment: 69 pages, 29 figure
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