168,295 research outputs found
The measurement of science and technology in China.
This paper introduced the background about the measurement of science and technology in China and selectively introduced the most recent statistic results released by the Institute of Scientific and Technical Information of China.China; Science and technology; Measurement;
Early Turn-taking Prediction with Spiking Neural Networks for Human Robot Collaboration
Turn-taking is essential to the structure of human teamwork. Humans are
typically aware of team members' intention to keep or relinquish their turn
before a turn switch, where the responsibility of working on a shared task is
shifted. Future co-robots are also expected to provide such competence. To that
end, this paper proposes the Cognitive Turn-taking Model (CTTM), which
leverages cognitive models (i.e., Spiking Neural Network) to achieve early
turn-taking prediction. The CTTM framework can process multimodal human
communication cues (both implicit and explicit) and predict human turn-taking
intentions in an early stage. The proposed framework is tested on a simulated
surgical procedure, where a robotic scrub nurse predicts the surgeon's
turn-taking intention. It was found that the proposed CTTM framework
outperforms the state-of-the-art turn-taking prediction algorithms by a large
margin. It also outperforms humans when presented with partial observations of
communication cues (i.e., less than 40% of full actions). This early prediction
capability enables robots to initiate turn-taking actions at an early stage,
which facilitates collaboration and increases overall efficiency.Comment: Submitted to IEEE International Conference on Robotics and Automation
(ICRA) 201
Electron-phonon correlations on spin texture of gapped helical Dirac Fermions
The metallic surface states of a topological insulator support helical Dirac
fermions protected by topology with their spin locked perpendicular to their
momentum. They can acquire mass through magnetic doping or through
hybridization of states on opposite faces of a thin sample. In this case there
can be a component of electron spin oriented perpendicular to the surface
plane. The electron-phonon interaction renormalizes the dynamics of the charge
carriers through their spectral density. It also modifies the gap channel and a
second spectral function enters which, not only determines the out of plane
spin component, but also comes into in-plane properties. While the out of plane
spin component is decreased below the Fermi momentum (), the in plane
component increases. There are also correlation tails extending well beyond
. The angular resolved photo-emission line shapes aquire Holstein side
bands. The effective gap in the density of states is reduced and the optical
conductivity aquires distinct measurable phonon structure even for modest value
of the electron-phonon coupling.Comment: 9pages, 9 figure
Longitudinal and spin/valley Hall optical conductivity in single layer
A monolayer of has a non-centrosymmetric crystal structure, with
spin polarized bands. It is a two valley semiconductor with direct gap falling
in the visible range of the electromagnetic spectrum. Its optical properties
are of particular interest in relation to valleytronics and possible device
applications. We study the longitudinal and the transverse Hall dynamical
conductivity which is decomposed into charge, spin and valley contributions.
Circular polarized light associated with each of the two valleys separately is
considered and results are filtered according to spin polarization. Temperature
can greatly change the spin admixture seen in the frequency window where they
are not closely in balance.Comment: 8 pages, 5 figures, accepted by Phys. Rev.
Black hole hair in generalized scalar-tensor gravity
The most general action for a scalar field coupled to gravity that leads to
second order field equations for both the metric and the scalar --- Horndeski's
theory --- is considered, with the extra assumption that the scalar satisfies
shift symmetry. We show that in such theories the scalar field is forced to
have a nontrivial configuration in black hole spacetimes, unless one carefully
tunes away a linear coupling with the Gauss--Bonnet invariant. Hence, black
holes for generic theories in this class will have hair. This contradicts a
recent no-hair theorem, which seems to have overlooked the presence of this
coupling.Comment: 4+1 pages, PRL versio
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