2,132 research outputs found
ARTIFICIAL INTELLIGENCE RATERS: NEURAL NETWORKS FOR RATING PICTORIAL EXPRESSION
Previous studies on classification of fine art show that features of paintings can be captured and categorized using machine learning approaches. This progress can also benefit art psychology by facilitating data collection on artworks without the need to recruit experts as raters. In this study a machine learning approach is used to predict the ratings of RizbA, a Rating instrument for two-dimensional pictorial works. Based on a pre-trained model, the algorithm was fine-tuned via transfer learning on 886 pictorial works by contemporary professional artists and non-professionals. As quality criterion, artificial intelligence raters (ART) are compared with generic raters (GR) created from the real human expert raters, using error rate and mean squared error (MSE). ART ratings have been found to have the same error range as randomly chosen human ratings. Therefore, they can be seen as equivalent to real human expert raters for almost all items in RizbA. Further training with more data will close the gap to the human raters on all items
Correlation effects in the density of states of annealed GaMnAs
We report on an experimental study of low temperature tunnelling in hybrid
NbTiN/GaMnAs structures. The conductance measurements display a root mean
square V dependence, consistent with the opening of a correlation gap in the
density of states of GaMnAs. Our experiment shows that low temperature
annealing is a direct empirical tool that modifies the correlation gap and thus
the electron-electron interaction. Consistent with previous results on
boron-doped silicon we find, as a function of voltage, a transition across the
phase boundary delimiting the direct and exchange correlation regime.Comment: Replaced with revised version. To appear in Phys. Rev.
Secure Vehicular Communication Systems: Implementation, Performance, and Research Challenges
Vehicular Communication (VC) systems are on the verge of practical
deployment. Nonetheless, their security and privacy protection is one of the
problems that have been addressed only recently. In order to show the
feasibility of secure VC, certain implementations are required. In [1] we
discuss the design of a VC security system that has emerged as a result of the
European SeVeCom project. In this second paper, we discuss various issues
related to the implementation and deployment aspects of secure VC systems.
Moreover, we provide an outlook on open security research issues that will
arise as VC systems develop from today's simple prototypes to full-fledged
systems
The Gerasimov-Drell-Hearn Sum Rule and the Spin Structure of the Nucleon
The Gerasimov-Drell-Hearn sum rule is one of several dispersive sum rules
that connect the Compton scattering amplitudes to the inclusive photoproduction
cross sections of the target under investigation. Being based on such universal
principles as causality, unitarity, and gauge invariance, these sum rules
provide a unique testing ground to study the internal degrees of freedom that
hold the system together. The present article reviews these sum rules for the
spin-dependent cross sections of the nucleon by presenting an overview of
recent experiments and theoretical approaches. The generalization from real to
virtual photons provides a microscope of variable resolution: At small
virtuality of the photon, the data sample information about the long range
phenomena, which are described by effective degrees of freedom (Goldstone
bosons and collective resonances), whereas the primary degrees of freedom
(quarks and gluons) become visible at the larger virtualities. Through a rich
body of new data and several theoretical developments, a unified picture of
virtual Compton scattering emerges, which ranges from coherent to incoherent
processes, and from the generalized spin polarizabilities on the low-energy
side to higher twist effects in deep inelastic lepton scattering.Comment: 32 pages, 19 figures, review articl
Loss of AP-3 function affects spontaneous and evoked release at hippocampal mossy fiber synapses
Synaptic vesicle (SV) exocytosis mediating neurotransmitter release occurs
spontaneously at low intraterminal calcium concentrations and is stimulated by
a rise in intracellular calcium. Exocytosis is compensated for by the
reformation of vesicles at plasma membrane and endosomes. Although the adaptor
complex AP-3 was proposed to be involved in the formation of SVs from
endosomes, whether its function has an indirect effect on exocytosis remains
unknown. Using mocha mice, which are deficient in functional AP-3, we identify
an AP-3-dependent tetanus neurotoxin-resistant asynchronous release that can be
evoked at hippocampal mossy fiber (MF) synapses. Presynaptic targeting of the
tetanus neurotoxin-resistant vesicle soluble N-ethylmaleimide-sensitive factor
attachment protein receptor (SNARE) tetanus neurotoxin-insensitive
vesicle-associated membrane protein (TI-VAMP) is lost in mocha hippocampal MF
terminals, whereas the localization of synaptobrevin 2 is unaffected. In
addition, quantal release in mocha cultures is more frequent and more sensitive
to sucrose. We conclude that lack of AP-3 results in more constitutive
secretion and loss of an asynchronous evoked release component, suggesting an
important function of AP-3 in regulating SV exocytosis at MF terminals
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