2,466 research outputs found
Spatial audio in small display screen devices
Our work addresses the problem of (visual) clutter in mobile device interfaces. The solution we propose involves the translation of technique-from the graphical to the audio domain-for expliting space in information representation. This article presents an illustrative example in the form of a spatialisedaudio progress bar. In usability tests, participants performed background monitoring tasks significantly more accurately using this spatialised audio (a compared with a conventional visual) progress bar. Moreover, their performance in a simultaneously running, visually demanding foreground task was significantly improved in the eye-free monitoring condition. These results have important implications for the design of multi-tasking interfaces for mobile devices
Radiation-Resistant Solar Cells - A Panel Discussion
Radiation resistant silicon cells for solar energy conversio
Using airborne LiDAR Survey to explore historic-era archaeological landscapes of Montserrat in the eastern Caribbean
This article describes what appears to be the first archaeological application of airborne LiDAR survey to historic-era landscapes in the Caribbean archipelago, on the island of Montserrat. LiDAR is proving invaluable in extending the reach of traditional pedestrian survey into less favorable areas, such as those covered by dense neotropical forest and by ashfall from the past two decades of active eruptions by the Soufrière Hills volcano, and to sites in localities that are inaccessible on account of volcanic dangers. Emphasis is placed on two aspects of the research: first, the importance of ongoing, real-time interaction between the LiDAR analyst and the archaeological team in the field; and second, the advantages of exploiting the full potential of the three-dimensional LiDAR point cloud data for purposes of the visualization of archaeological sites and features
Dramatically Increased Rearrangement and Peripheral Representation of Vβ14 Driven by the 3′Dβ1 Recombination Signal Sequence
AbstractV(D)J recombination is targeted by short recombination signal (RS) sequences that are relatively conserved but exhibit natural sequence variations. To evaluate the potential of RS sequence variations to determine the primary and peripheral TCRβ repertoire, we generated mice containing specific replacement of the endogenous Vβ14 RS with the 3′Dβ1 RS (Vβ14/3′DβRS). These mice exhibited a dramatic increase in Vβ14+ thymocyte numbers at the expense of thymocytes expressing other Vβs. In addition, the percentage of peripheral Vβ14+ αβ T lymphocytes was similarly increased. Strikingly, this altered Vβ repertoire resulted predominantly from a higher relative level of primary Vβ14/3′DβRS rearrangement to DβJβ complexes, despite the ability of the 3′Dβ1 RS to break B12/23 restriction and allow direct rearrangement of Vβ14/3′DβRS to Jβ segments
Model for Spreading of Liquid Monolayers
Manipulating fluids at the nanoscale within networks of channels or chemical
lanes is a crucial challenge in developing small scale devices to be used in
microreactors or chemical sensors. In this context, ultra-thin (i.e.,
monolayer) films, experimentally observed in spreading of nano-droplets or upon
extraction from reservoirs in capillary rise geometries, represent an extreme
limit which is of physical and technological relevance since the dynamics is
governed solely by capillary forces. In this work we use kinetic Monte Carlo
(KMC) simulations to analyze in detail a simple, but realistic model proposed
by Burlatsky \textit{et al.} \cite{Burlatsky_prl96,Oshanin_jml} for the
two-dimensional spreading on homogeneous substrates of a fluid monolayer which
is extracted from a reservoir. Our simulations confirm the previously predicted
time-dependence of the spreading, , with as
the average position of the advancing edge at time , and they reveal a
non-trivial dependence of the prefactor on the strength of
inter-particle attraction and on the fluid density at the reservoir as
well as an -dependent spatial structure of the density profile of the
monolayer. The asymptotic density profile at long time and large spatial scale
is carefully analyzed within the continuum limit. We show that including the
effect of correlations in an effective manner into the standard mean-field
description leads to predictions both for the value of the threshold
interaction above which phase segregation occurs and for the density profiles
in excellent agreement with KMC simulations results.Comment: 21 pages, 9 figures, submitted to Phys. Rev.
FiberGLAST: a scintillating fiber approach to the GLAST mission
FiberGLAST is a scintillating fiber gamma-ray detector designed for the GLAST mission. The system described below provides superior effective area and field of view for modest cost and risk. An overview of the FiberGLAST instrument is presented, as well as a more detailed description of the principle elements of the primary detector volume. The triggering and readout electronics are described, and Monte Carlo Simulations of the instrument performance are presented
Beam test results for the FiberGLAST instrument
The FiberGLAST scintillating fiber telescope is a large-area instrument concept for NASA\u27s GLAST program. The detector is designed for high-energy gamma-ray astronomy, and uses plastic scintillating fibers to combine a photon pair tracking telescope and a calorimeter into a single instrument. A small prototype detector has been tested with high energy photons at the Thomas Jefferson National Accelerator Facility. We report on the result of this beam test, including scintillating fiber performance, photon track reconstruction, angular resolution, and detector efficiency
Charged particle production in the Pb+Pb system at 158 GeV/c per nucleon
Charged particle multiplicities from high multiplicity central interactions
of 158 GeV/nucleon Pb ions with Pb target nuclei have been measured in the
central and far forward projectile spectator regions using emulsion chambers.
Multiplicities are significantly lower than predicted by Monte Carlo
simulations. We examine the shape of the pseudorapidity distribution and its
dependence on centrality in detail.Comment: 17 pages text plus 12 figures in postscript 12/23/99 -- Add TeX
version of sourc
Diffuse supernova neutrinos: oscillation effects, stellar cooling and progenitor mass dependence
We estimate the diffuse supernova neutrino background (DSNB) using the recent
progenitor-dependent, long-term supernova simulations from the Basel group and
including neutrino oscillations at several post-bounce times. Assuming
multi-angle matter suppression of collective effects during the accretion
phase, we find that oscillation effects are dominated by the matter-driven MSW
resonances, while neutrino-neutrino collective effects contribute at the 5-10%
level. The impact of the neutrino mass hierarchy, of the time-dependent
neutrino spectra and of the diverse progenitor star population is 10% or less,
small compared to the uncertainty of at least 25% of the normalization of the
supernova rate. Therefore, assuming that the sign of the neutrino mass
hierarchy will be determined within the next decade, the future detection of
the DSNB will deliver approximate information on the MSW-oscillated neutrino
spectra. With a reliable model for neutrino emission, its detection will be a
powerful instrument to provide complementary information on the star formation
rate and for learning about stellar physics.Comment: 19 pages, including 4 figures and 1 table. Clarifying paragraphs
added; results unchanged. Matches published version in JCA
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