120,248 research outputs found
Neutrino Flavor Ratio on Earth and at Astrophysical Sources
We present the reconstruction of neutrino flavor ratios at astrophysical
sources. For distinguishing the pion source and the muon-damped source to the
3 level, the neutrino flux ratios,
and
, need to be measured in accuracies better
than 10%.Comment: 3 pages, 8 figures. Talk presented by T.C. Liu in ERICE 2009, Sicily
Media fusion and future TV: Examining multi-screen TV convergence in Singapore
This study examines Singapore's national media blueprint and industry stakeholders' coping strategies in response to multi-screen TV development. The findings show Singapore muti-screen TV development is still at a nascent stage after launching Media Fushion and FutureTV plans in mid 2009. The policymakers play a key role to follow national media blueprint to unify the inter-industry and cross-country collaboration. TV operators and telcos are found to remediate themselves by harnessing the power of internet and mobile technologies for content innovation and distribution. To tackle the complicated convergent issues in multi-screen TV industry, this study proposes to separately regulate the technology-neutral platforms and diverse audiovisual content. It also recommends a pro-innovative policy with the light-touch licensing scheme and loose content regulation to facilitate the development of the next TV. --three-screen TV,multi-screen TV,convergence,media fusion,IPTV,mobile TV,cross-platform,TV technologies,TV market,TV policy
In situ transmission electron microscopy study on the epitaxial growth of CoSi2 on Si(111) at temperatures below 150 °C
We report an in situ transmission electron microscopy study on the epitaxial growth of CoSi2 on Si(111) from a 10-nm-thick amorphous mixture of Co and Si in the ratio 1:2 which was formed by codeposition of Co and Si near room temperature. Nuclei of CoSi2 are observed in the as-deposited film. These nuclei are epitaxial and extend through the whole film thickness. Upon annealing, these columnar epitaxial CoSi2 grains grow laterally at temperatures as low as 50 °C. The kinetics of this lateral epitaxial growth was studied at temperatures between 50 and 150 °C. The activation energy of the growth process is 0.8±0.1 eV
Nonuniversal Effects in the Homogeneous Bose Gas
Effective field theory predicts that the leading nonuniversal effects in the
homogeneous Bose gas arise from the effective range for S-wave scattering and
from an effective three-body contact interaction. We calculate the leading
nonuniversal contributions to the energy density and condensate fraction and
compare the predictions with results from diffusion Monte Carlo calculations by
Giorgini, Boronat, and Casulleras. We give a crude determination of the
strength of the three-body contact interaction for various model potentials.
Accurate determinations could be obtained from diffusion Monte Carlo
calculations of the energy density with higher statistics.Comment: 24 pages, RevTex, 5 ps figures, included with epsf.te
On the Tidal Dissipation of Obliquity
We investigate tidal dissipation of obliquity in hot Jupiters. Assuming an
initial random orientation of obliquity and parameters relevant to the observed
population, the obliquity of hot Jupiters does not evolve to purely aligned
systems. In fact, the obliquity evolves to either prograde, retrograde or
90^{o} orbits where the torque due to tidal perturbations vanishes. This
distribution is incompatible with observations which show that hot jupiters
around cool stars are generally aligned. This calls into question the viability
of tidal dissipation as the mechanism for obliquity alignment of hot Jupiters
around cool stars.Comment: 6 pages, 4 figures, accepted at ApJ
Characterization of robotics parallel algorithms and mapping onto a reconfigurable SIMD machine
The kinematics, dynamics, Jacobian, and their corresponding inverse computations are six essential problems in the control of robot manipulators. Efficient parallel algorithms for these computations are discussed and analyzed. Their characteristics are identified and a scheme on the mapping of these algorithms to a reconfigurable parallel architecture is presented. Based on the characteristics including type of parallelism, degree of parallelism, uniformity of the operations, fundamental operations, data dependencies, and communication requirement, it is shown that most of the algorithms for robotic computations possess highly regular properties and some common structures, especially the linear recursive structure. Moreover, they are well-suited to be implemented on a single-instruction-stream multiple-data-stream (SIMD) computer with reconfigurable interconnection network. The model of a reconfigurable dual network SIMD machine with internal direct feedback is introduced. A systematic procedure internal direct feedback is introduced. A systematic procedure to map these computations to the proposed machine is presented. A new scheduling problem for SIMD machines is investigated and a heuristic algorithm, called neighborhood scheduling, that reorders the processing sequence of subtasks to reduce the communication time is described. Mapping results of a benchmark algorithm are illustrated and discussed
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